技术领域Technical Field
本申请涉及视频编解码领域，并且更具体地，涉及图像预测方法、编码树节点划分方法及其装置。The present application relates to the field of video coding and decoding, and more specifically, to an image prediction method, a coding tree node partitioning method and a device thereof.
背景技术Background technique
数字视频能力可并入到多种多样的装置中，包含数字电视、数字直播系统、无线广播系统、个人数字助理(personal digital assistant，PDA)、膝上型或桌上型计算机、平板计算机、电子图书阅读器、数码相机、数字记录装置、数字媒体播放器、视频游戏装置、视频游戏控制台、蜂窝式或卫星无线电电话(所谓的“智能电话”)、视频电话会议装置、视频流式传输装置及其类似者。数字视频装置实施视频压缩技术，例如，在由MPEG-2、MPEG-4、ITU-TH.263、ITU-T H.264/MPEG-4第10部分高级视频编码(advanced video coding，AVC)定义的标准、视频编码标准H.265/高效视频编码(high efficiency video coding，HEVC)标准以及此类标准的扩展中所描述的视频压缩技术。视频装置可通过实施此类视频压缩技术来更有效率地发射、接收、编码、解码和/或存储数字视频信息。Digital video capabilities may be incorporated into a wide variety of devices, including digital televisions, digital live broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, electronic book readers, digital cameras, digital recording devices, digital media players, video game devices, video game consoles, cellular or satellite radio telephones (so-called "smart phones"), video teleconferencing devices, video streaming devices, and the like. Digital video devices implement video compression techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264/MPEG-4 Part 10 Advanced Video Coding (AVC), Video Coding Standard H.265/High Efficiency Video Coding (HEVC) standards, and extensions of such standards. Video devices may transmit, receive, encode, decode, and/or store digital video information more efficiently by implementing such video compression techniques.
视频压缩技术执行空间(图像内)预测和/或时间(图像间)预测以减少或去除视频序列中固有的冗余。对于基于块的视频编码，视频条带(即，视频帧或视频帧的一部分)可分割成若干图像块，所述图像块也可被称作树块、编码单元(coding unit，CU)和/或编码节点。使用关于同一图像中的相邻块中的参考样本的空间预测来编码图像的待帧内编码(I)条带中的图像块。图像的待帧间编码(P或B)条带中的图像块可使用相对于同一图像中的相邻块中的参考样本的空间预测或相对于其它参考图像中的参考样本的时间预测。图像可被称作帧，且参考图像可被称作参考帧。Video compression techniques perform spatial (intra-image) prediction and/or temporal (inter-image) prediction to reduce or remove redundancy inherent in video sequences. For block-based video coding, a video slice (i.e., a video frame or a portion of a video frame) may be partitioned into several image blocks, which may also be referred to as tree blocks, coding units (CUs), and/or coding nodes. Image blocks in an intra-coded (I) slice of an image are encoded using spatial predictions with respect to reference samples in neighboring blocks in the same image. Image blocks in an inter-coded (P or B) slice of an image may use spatial predictions with respect to reference samples in neighboring blocks in the same image or temporal predictions with respect to reference samples in other reference images. Images may be referred to as frames, and reference images may be referred to as reference frames.
在熵编码和熵解码处理中，需要根据上下文信息(例如，语法元素对应节点周围已重建区域内的编码信息)，确定语法元素对应的每一个位元的上下文模型，这一过程通常也可以称为上下文建模。然而，如果上下文建模方法不当，会降低视频编解码效率。In entropy coding and decoding, it is necessary to determine the context model of each bit corresponding to the syntax element based on context information (for example, the coding information in the reconstructed area around the corresponding node of the syntax element). This process is also generally called context modeling. However, if the context modeling method is inappropriate, the efficiency of video encoding and decoding will be reduced.
发明内容Summary of the invention
本申请提供图像预测方法、编码树节点划分方法及其装置，能够提高视频编解码效率。The present application provides an image prediction method, a coding tree node division method and a device thereof, which can improve the efficiency of video encoding and decoding.
第一方面，提供了一种图像预测方法，该方法包括：确定当前编码单元的类型，所述当前编码单元的类型为亮度色度编码单元、亮度编码单元或色度编码单元；根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定所述当前编码单元的预测模式，其中，所述当前编码单元中的图像块与所述相邻图像块为空间相邻的图像块，所述相邻图像块包括相邻的亮度块和/或相邻的色度块；根据所述当前编码单元的预测模式，对所述当前编码单元中的图像块进行预测。In a first aspect, an image prediction method is provided, the method comprising: determining a type of a current coding unit, the type of the current coding unit being a luminance-chrominance coding unit, a luminance coding unit or a chrominance coding unit; determining a prediction mode of the current coding unit according to the type of the current coding unit and/or a prediction mode of an adjacent image block, wherein the image block in the current coding unit and the adjacent image block are spatially adjacent image blocks, and the adjacent image blocks include adjacent luminance blocks and/or adjacent chrominance blocks; and predicting the image block in the current coding unit according to the prediction mode of the current coding unit.
在本申请中，根据当前编码单元的类型，选取与当前编码单元的类型相匹配的相邻图像块的预测模式，进行上下文建模，确定当前编码单元的预测模式，并根据所述预测模式，对所述当前编码单元中的图像块进行预测，因此，能够提高视频编解码效率。In the present application, according to the type of the current coding unit, the prediction mode of the adjacent image block that matches the type of the current coding unit is selected, context modeling is performed, the prediction mode of the current coding unit is determined, and according to the prediction mode, the image block in the current coding unit is predicted, thereby improving the video encoding and decoding efficiency.
结合第一方面，在第一方面的某些实现方式中，所述根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定当前编码单元的预测模式，包括：根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定所述当前编码单元的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码单元的预测模式。In combination with the first aspect, in certain implementations of the first aspect, determining the prediction mode of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block includes: determining the context model number corresponding to the syntax element of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block; and determining the prediction mode of the current coding unit according to the context model number.
结合第一方面，在第一方面的某些实现方式中，所述根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定所述当前编码单元的语法元素对应的上下文模型编号，包括：在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，根据左侧相邻的亮度块的预测模式确定condL，根据上侧相邻的亮度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；或在所述当前编码单元为色度编码单元的情况下，根据左侧相邻的色度块的预测模式确定condL，根据上侧相邻的色度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；其中，所述condL与所述condA为二值变量。In combination with the first aspect, in certain implementations of the first aspect, determining the context model number corresponding to the syntax element of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block includes: when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, determining condL according to the prediction mode of the luminance block adjacent to the left, and determining condA according to the prediction mode of the luminance block adjacent to the upper side; determining the context model number according to the condL and the condA; or when the current coding unit is a chrominance coding unit, determining condL according to the prediction mode of the chrominance block adjacent to the left, and determining condA according to the prediction mode of the chrominance block adjacent to the upper side; determining the context model number according to the condL and the condA; wherein the condL and the condA are binary variables.
在本申请中，在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，根据相邻的亮度块的预测模式，确定当前编码单元的语法元素对应的上下文模型，在所述当前编码单元为色度编码单元的情况下，根据相邻的色度块的预测模式，确定当前编码单元的语法元素对应的上下文模型，可以保证上下文建模选取的相邻图像块的预测模式，与当前编码单元的类型相匹配，从而可以降低编码比特数，提高压缩效率，因此，能够提高熵编码和熵解码的效率。In the present application, when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, the context model corresponding to the syntax element of the current coding unit is determined according to the prediction mode of the adjacent luminance block. When the current coding unit is a chrominance coding unit, the context model corresponding to the syntax element of the current coding unit is determined according to the prediction mode of the adjacent chrominance block. This can ensure that the prediction mode of the adjacent image blocks selected by the context modeling matches the type of the current coding unit, thereby reducing the number of coding bits and improving the compression efficiency. Therefore, the efficiency of entropy coding and entropy decoding can be improved.
结合第一方面，在第一方面的某些实现方式中，所述确定所述上下文模型编号，包括根据以下公式确定所述上下文模型编号：In combination with the first aspect, in some implementations of the first aspect, determining the context model number includes determining the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，所述condL表示所述左侧相邻的亮度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的亮度块的预测模式是否为帧内块拷贝预测，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，所述condL表示所述左侧相邻的色度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的色度块的预测模式是否为帧内块拷贝预测，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the number of the context group; when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, the condL indicates whether the prediction mode of the left adjacent luminance block is an intra-block copy prediction, the condA indicates whether the prediction mode of the upper adjacent luminance block is an intra-block copy prediction, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, the condL indicates whether the prediction mode of the left adjacent chrominance block is an intra-block copy prediction, the condA indicates whether the prediction mode of the upper adjacent chrominance block is an intra-block copy prediction, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第一方面，在第一方面的某些实现方式中，所述根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定所述当前编码单元的语法元素对应的上下文模型编号包括：在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，根据左侧相邻的亮度块的预测模式确定condL，根据上侧相邻的亮度块的预测模式确定condA；或根据所述condL和所述condA，确定所述上下文模型编号；在所述当前编码单元为色度编码单元的情况下，根据预设的condL和预设的condA，确定所述上下文模型编号；其中，所述condL与所述condA为二值变量。In combination with the first aspect, in certain implementations of the first aspect, determining the context model number corresponding to the syntax element of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block includes: when the current coding unit is a luminance and chrominance coding unit or a luminance coding unit, determining condL according to the prediction mode of the luminance block adjacent to the left, and determining condA according to the prediction mode of the luminance block adjacent to the top; or determining the context model number according to the condL and the condA; when the current coding unit is a chrominance coding unit, determining the context model number according to a preset condL and a preset condA; wherein the condL and the condA are binary variables.
在本申请中，在所述当前编码单元为色度编码单元的情况下，所述condL与所述condA为预设值，此时，当前编码单元的语法元素对应的上下文模型与相邻图像块无关，因此，可以降低熵编码和熵解码的复杂度，能够提高视频编解码效率。In the present application, when the current coding unit is a chroma coding unit, the condL and the condA are preset values. At this time, the context model corresponding to the syntax element of the current coding unit is independent of the adjacent image blocks. Therefore, the complexity of entropy coding and entropy decoding can be reduced, and the video encoding and decoding efficiency can be improved.
结合第一方面，在第一方面的某些实现方式中，所述确定所述上下文模型编号，包括根据以下公式确定所述上下文模型编号：In combination with the first aspect, in some implementations of the first aspect, determining the context model number includes determining the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，所述condL表示所述左侧相邻的亮度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的亮度块的预测模式是否为帧内块拷贝预测，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，所述condL为预设值，所述condA为预设值，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the context group number; when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, the condL indicates whether the prediction mode of the left adjacent luminance block is an intra-block copy prediction, the condA indicates whether the prediction mode of the upper adjacent luminance block is an intra-block copy prediction, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, the condL is a preset value, the condA is a preset value, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第一方面，在第一方面的某些实现方式中，所述语法元素为pred_mode_ibc_flag，所述语法元素用于标识所述当前编码单元是否使用帧内块拷贝预测，所述condL用于指示左侧相邻的图像块的预测模式是否为帧内块拷贝预测，所述condA用于指示上侧相邻的图像块的预测模式是否为帧内块拷贝预测。In combination with the first aspect, in certain implementations of the first aspect, the syntax element is pred_mode_ibc_flag, the syntax element is used to identify whether the current coding unit uses intra block copy prediction, the condL is used to indicate whether the prediction mode of the left adjacent image block is intra block copy prediction, and the condA is used to indicate whether the prediction mode of the upper adjacent image block is intra block copy prediction.
第二方面，提供了一种编码树节点划分方法，该方法包括：确定当前编码树节点的类型，所述当前编码树节点的类型为亮度色度编码树节点、亮度编码树节点或色度编码树节点；根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定当前编码树节点的划分方式，其中，所述当前编码树节点中的图像块与所述相邻图像块为空间相邻的图像块，所述编码信息包括相邻图像块的四叉树深度和/或相邻图像块的宽和高，所述相邻图像块包括相邻的亮度块和/或相邻的色度块；根据所述编码树节点的划分方式，对所述当前编码树节点进行划分。In a second aspect, a coding tree node division method is provided, the method comprising: determining the type of a current coding tree node, the type of the current coding tree node being a luminance-chrominance coding tree node, a luminance coding tree node or a chrominance coding tree node; determining a division method of the current coding tree node according to the type of the current coding tree node and/or the encoding information of adjacent image blocks, wherein the image blocks in the current coding tree node and the adjacent image blocks are spatially adjacent image blocks, the encoding information includes the quadtree depth of the adjacent image blocks and/or the width and height of the adjacent image blocks, and the adjacent image blocks include adjacent luminance blocks and/or adjacent chrominance blocks; dividing the current coding tree node according to the division method of the coding tree node.
在本申请中，根据当前编码单元的类型，选取与当前编码单元的类型相匹配的相邻图像块的编码信息，进行上下文建模，确定当前编码单元的划分方式，并根据所述划分方式，对所述当前编码树节点进行划分，因此，能够提高视频编解码效率。In the present application, according to the type of the current coding unit, the encoding information of the adjacent image blocks that matches the type of the current coding unit is selected, context modeling is performed, the division method of the current coding unit is determined, and the current coding tree nodes are divided according to the division method, thereby improving the video encoding and decoding efficiency.
结合第二方面，在第二方面的某些实现方式中，所述根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定当前编码树节点的划分方式，包括：根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定所述当前编码树节点的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码树节点的划分方式。In combination with the second aspect, in certain implementations of the second aspect, determining the division method of the current coding tree node according to the type of the current coding tree node and/or the encoding information of the adjacent image blocks includes: determining the context model number corresponding to the syntax element of the current coding tree node according to the type of the current coding tree node and/or the encoding information of the adjacent image blocks; determining the division method of the current coding tree node according to the context model number.
结合第二方面，在第二方面的某些实现方式中，所述根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定所述当前编码树节点的语法元素对应的上下文模型编号，包括：在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，根据所述相邻的亮度块的四叉树深度和当前编码树节点的四叉树深度，确定所述上下文模型编号；或在所述当前编码树节点为色度编码树节点的情况下，根据所述当前编码树节点的四叉树深度，确定所述上下文模型编号。In combination with the second aspect, in certain implementations of the second aspect, determining the context model number corresponding to the syntax element of the current coding tree node according to the type of the current coding tree node and/or the encoding information of the adjacent image blocks includes: when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, determining the context model number according to the quadtree depth of the adjacent luminance block and the quadtree depth of the current coding tree node; or when the current coding tree node is a chrominance coding tree node, determining the context model number according to the quadtree depth of the current coding tree node.
在本申请中，在所述当前编码树节点为色度编码树节点的情况下，所述condL与所述condA为预设值，此时，当前编码单元的语法元素对应的上下文模型与相邻图像块的四叉树深度无关，因此，可以降低熵编码和熵解码的复杂度，能够提高视频编解码效率。In the present application, when the current coding tree node is a chroma coding tree node, the condL and the condA are preset values. At this time, the context model corresponding to the syntax element of the current coding unit is independent of the quadtree depth of the adjacent image block. Therefore, the complexity of entropy coding and entropy decoding can be reduced, and the video encoding and decoding efficiency can be improved.
结合第二方面，在第二方面的某些实现方式中，所述确定所述上下文模型编号，包括根据以下公式确定所述上下文模型编号：In conjunction with the second aspect, in some implementations of the second aspect, determining the context model number includes determining the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，所述condL表示所述左侧相邻的亮度块的四叉树深度是否大于所述当前编码树节点的四叉树深度，所述condA表示所述上侧相邻的亮度块的四叉树深度是否大于所述当前编码树节点的四叉树深度，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，所述condL为预设值，所述condA为预设值，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the context group number; when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, the condL indicates whether the quadtree depth of the left adjacent luminance block is greater than the quadtree depth of the current coding tree node, the condA indicates whether the quadtree depth of the upper adjacent luminance block is greater than the quadtree depth of the current coding tree node, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, the condL is a preset value, the condA is a preset value, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第二方面，在第二方面的某些实现方式中，所述语法元素为split_qt_flag，用于标识当前编码树节点是否使用四叉树划分。In combination with the second aspect, in some implementations of the second aspect, the syntax element is split_qt_flag, which is used to identify whether the current coding tree node uses quadtree partitioning.
结合第二方面，在第二方面的某些实现方式中，所述根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定所述当前编码树节点的语法元素对应的上下文模型编号，包括：在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，根据所述相邻的亮度块的宽和高、及所述当前编码树节点划分方式的可用性，确定所述上下文模型编号；或在所述当前编码树节点为色度编码单元的情况下，根据所述当前编码树节点划分方式的可用性，确定所述上下文模型编号。In combination with the second aspect, in certain implementations of the second aspect, determining the context model number corresponding to the syntax element of the current coding tree node according to the type of the current coding tree node and/or the encoding information of the adjacent image blocks includes: when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, determining the context model number according to the width and height of the adjacent luminance blocks and the availability of the division method of the current coding tree node; or when the current coding tree node is a chrominance coding unit, determining the context model number according to the availability of the division method of the current coding tree node.
在本申请中，在所述当前编码树节点为色度编码树节点的情况下，所述condL与所述condA为预设值，此时，当前编码单元的语法元素对应的上下文模型与相邻图像块的宽和高无关，因此，可以降低熵编码和熵解码的复杂度，能够提高视频编解码效率。In the present application, when the current coding tree node is a chroma coding tree node, the condL and the condA are preset values. At this time, the context model corresponding to the syntax element of the current coding unit is independent of the width and height of the adjacent image blocks. Therefore, the complexity of entropy coding and entropy decoding can be reduced, and the video encoding and decoding efficiency can be improved.
结合第二方面，在第二方面的某些实现方式中，所述确定所述上下文模型编号，包括根据以下公式确定所述上下文模型编号：In conjunction with the second aspect, in some implementations of the second aspect, determining the context model number includes determining the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，condL表示所述左侧相邻的亮度块的宽和高是否大于所述当前编码树节点的宽和高，condA表示所述上侧相邻的亮度块的宽和高是否大于所述当前编码树节点的宽和高，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，condL为预测值或由所述当前编码树节点确定，condA为预设值，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the number of the context group; when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, condL indicates whether the width and height of the left adjacent luminance block are greater than the width and height of the current coding tree node, condA indicates whether the width and height of the upper adjacent luminance block are greater than the width and height of the current coding tree node, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, condL is a predicted value or determined by the current coding tree node, condA is a preset value, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第二方面，在第二方面的某些实现方式中，所述语法元素为split_cu_flag，用于标识当前编码树节点是否划分。In combination with the second aspect, in some implementations of the second aspect, the syntax element is split_cu_flag, which is used to identify whether the current coding tree node is split.
第三方面，提供了一种图像预测方法，该方法包括：在当前编码单元为色度编码单元的情况下，根据如下公式确定所述当前编码单元的语法元素对应的上下文模型编号：In a third aspect, an image prediction method is provided, the method comprising: when a current coding unit is a chroma coding unit, determining a context model number corresponding to a syntax element of the current coding unit according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得；所述condL表示所述左侧相邻的色度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的色度块的预测模式是否为帧内块拷贝预测；或者，所述condL和所述condA均为预设值；根据所述上下文模型编号，确定所述当前编码单元的预测模式；根据所述当前编码单元的预测模式，对所述当前编码单元中的图像块进行预测。Among them, ctxInc is the context model number, ctxSetIdx is the context group number, availableL indicates whether the left adjacent chroma block is available, and availableA indicates whether the upper adjacent chroma block is available; the condL indicates whether the prediction mode of the left adjacent chroma block is intra-frame block copy prediction, and the condA indicates whether the prediction mode of the upper adjacent chroma block is intra-frame block copy prediction; or, both condL and condA are preset values; according to the context model number, the prediction mode of the current coding unit is determined; according to the prediction mode of the current coding unit, the image block in the current coding unit is predicted.
第四方面，提供了一种编码树节点划分方法，该方法包括：在当前编码树节点为色度编码树节点的情况下，根据如下公式确定所述当前编码树节点的语法元素对应的上下文模型编号：In a fourth aspect, a coding tree node division method is provided, the method comprising: when a current coding tree node is a chroma coding tree node, determining a context model number corresponding to a syntax element of the current coding tree node according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得；所述condL和所述condA均为预设值；或者，所述condL由所述当前编码树节点确定，所述condA为预设值；根据所述上下文模型编号，确定所述当前编码树节点的划分方式；根据所述编码树节点的划分方式，对所述当前编码树节点进行划分。Among them, ctxInc is the context model number, ctxSetIdx is the context group number, availableL indicates whether the left adjacent chroma block is available, and availableA indicates whether the upper adjacent chroma block is available; the condL and the condA are both preset values; or, the condL is determined by the current coding tree node, and the condA is a preset value; according to the context model number, the division method of the current coding tree node is determined; according to the division method of the coding tree node, the current coding tree node is divided.
第五方面，提供了一种图像预测装置，包括：确定模块，用于确定当前编码单元的类型，所述当前编码单元的类型为亮度色度编码单元、亮度编码单元或色度编码单元；处理模块，用于根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定当前编码单元的预测模式，其中，所述当前编码单元中的图像块与所述相邻图像块为空间相邻的图像块，所述相邻图像块包括相邻的亮度块和/或相邻的色度块；预测模块，用于根据所述当前编码单元的预测模式，对所述当前编码单元中的图像块进行预测。In a fifth aspect, an image prediction device is provided, comprising: a determination module, used to determine the type of a current coding unit, wherein the type of the current coding unit is a luminance-chrominance coding unit, a luminance coding unit or a chrominance coding unit; a processing module, used to determine the prediction mode of the current coding unit according to the type of the current coding unit and/or the prediction mode of an adjacent image block, wherein the image block in the current coding unit and the adjacent image block are spatially adjacent image blocks, and the adjacent image blocks include adjacent luminance blocks and/or adjacent chrominance blocks; a prediction module, used to predict the image block in the current coding unit according to the prediction mode of the current coding unit.
本申请中的图像预测装置，根据当前编码单元的类型，选取与当前编码单元的类型相匹配的相邻图像块的预测模式，进行上下文建模，确定当前编码单元的预测模式，并根据所述预测模式，对所述当前编码单元中的图像块进行预测，因此，能够提高视频编解码效率。The image prediction device in the present application selects a prediction mode of an adjacent image block that matches the type of the current coding unit according to the type of the current coding unit, performs context modeling, determines the prediction mode of the current coding unit, and predicts the image block in the current coding unit according to the prediction mode, thereby improving the video encoding and decoding efficiency.
结合第五方面，在第五方面的某些实现方式中，所述处理模块具体用于：根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定所述当前编码单元的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码单元的预测模式。In combination with the fifth aspect, in certain implementations of the fifth aspect, the processing module is specifically used to: determine the context model number corresponding to the syntax element of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block; determine the prediction mode of the current coding unit according to the context model number.
结合第五方面，在第五方面的某些实现方式中，所述处理模块具体用于：在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，根据左侧相邻的亮度块的预测模式确定condL，根据上侧相邻的亮度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；或在所述当前编码单元为色度编码单元的情况下，根据左侧相邻的色度块的预测模式确定condL，根据上侧相邻的色度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；其中，所述condL与所述condA为二值变量。In combination with the fifth aspect, in certain implementations of the fifth aspect, the processing module is specifically used to: when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, determine condL according to the prediction mode of the luminance block adjacent to the left, and determine condA according to the prediction mode of the luminance block adjacent to the upper side; determine the context model number according to the condL and the condA; or when the current coding unit is a chrominance coding unit, determine condL according to the prediction mode of the chrominance block adjacent to the left, and determine condA according to the prediction mode of the chrominance block adjacent to the upper side; determine the context model number according to the condL and the condA; wherein the condL and the condA are binary variables.
结合第五方面，在第五方面的某些实现方式中，所述处理模块具体用于根据以下公式确定所述上下文模型编号：In conjunction with the fifth aspect, in some implementations of the fifth aspect, the processing module is specifically configured to determine the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，所述condL表示所述左侧相邻的亮度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的亮度块的预测模式是否为帧内块拷贝预测，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，所述condL表示所述左侧相邻的色度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的色度块的预测模式是否为帧内块拷贝预测，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the number of the context group; when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, the condL indicates whether the prediction mode of the left adjacent luminance block is an intra-block copy prediction, the condA indicates whether the prediction mode of the upper adjacent luminance block is an intra-block copy prediction, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, the condL indicates whether the prediction mode of the left adjacent chrominance block is an intra-block copy prediction, the condA indicates whether the prediction mode of the upper adjacent chrominance block is an intra-block copy prediction, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第五方面，在第五方面的某些实现方式中，所述处理模块具体用于：在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，根据左侧相邻的亮度块的预测模式确定condL，根据上侧相邻的亮度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；或在所述当前编码单元为色度编码单元的情况下，根据预设的condL和预设的condA，确定所述上下文模型编号；其中，所述condL与所述condA为二值变量。In combination with the fifth aspect, in certain implementations of the fifth aspect, the processing module is specifically used to: when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, determine condL according to the prediction mode of the luminance block adjacent to the left, and determine condA according to the prediction mode of the luminance block adjacent to the top; determine the context model number according to the condL and the condA; or when the current coding unit is a chrominance coding unit, determine the context model number according to a preset condL and a preset condA; wherein the condL and the condA are binary variables.
结合第五方面，在第五方面的某些实现方式中，所述处理模块具体用于根据以下公式确定所述上下文模型编号：In conjunction with the fifth aspect, in some implementations of the fifth aspect, the processing module is specifically configured to determine the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，所述condL表示所述左侧相邻的亮度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的亮度块的预测模式是否为帧内块拷贝预测，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，所述condL为预设值，所述condA为预设值，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the context group number; when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, the condL indicates whether the prediction mode of the left adjacent luminance block is an intra-block copy prediction, the condA indicates whether the prediction mode of the upper adjacent luminance block is an intra-block copy prediction, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, the condL is a preset value, the condA is a preset value, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第五方面，在第五方面的某些实现方式中，所述语法元素为pred_mode_ibc_flag，所述语法元素用于标识所述当前编码单元是否使用帧内块拷贝预测，所述condL用于指示左侧相邻的图像块的预测模式是否为帧内块拷贝预测，所述condA用于指示上侧相邻的图像块的预测模式是否为帧内块拷贝预测。In combination with the fifth aspect, in certain implementations of the fifth aspect, the syntax element is pred_mode_ibc_flag, the syntax element is used to identify whether the current coding unit uses intra block copy prediction, the condL is used to indicate whether the prediction mode of the left adjacent image block is intra block copy prediction, and the condA is used to indicate whether the prediction mode of the upper adjacent image block is intra block copy prediction.
第六方面，提供了一种编码树节点划分装置，包括：确定模块，用于确定当前编码树节点的类型，所述当前编码树节点的类型为亮度色度编码树节点、亮度编码树节点或色度编码树节点；处理模块，用于根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定当前编码树节点的划分方式，其中，所述当前编码树节点中的图像块与所述相邻图像块为空间相邻的图像块，所述编码信息包括相邻图像块的四叉树深度和/或相邻图像块的宽和高，所述相邻图像块包括相邻的亮度块和/或相邻的色度块；划分模块，用于根据所述编码树节点的划分方式，对所述当前编码树节点进行划分。In a sixth aspect, a coding tree node division device is provided, comprising: a determination module, used to determine the type of a current coding tree node, the type of the current coding tree node being a luminance-chrominance coding tree node, a luminance coding tree node or a chrominance coding tree node; a processing module, used to determine a division method of the current coding tree node according to the type of the current coding tree node and/or the encoding information of adjacent image blocks, wherein the image blocks in the current coding tree node and the adjacent image blocks are spatially adjacent image blocks, the encoding information includes the quadtree depth of the adjacent image blocks and/or the width and height of the adjacent image blocks, and the adjacent image blocks include adjacent luminance blocks and/or adjacent chrominance blocks; a division module, used to divide the current coding tree node according to the division method of the coding tree node.
本申请中的编码树节点划分装置，根据当前编码单元的类型，选取与当前编码单元的类型相匹配的相邻图像块的编码信息，进行上下文建模，确定当前编码单元的划分方式，并根据所述划分方式，对所述当前编码树节点进行划分，因此，能够提高视频编解码效率。The coding tree node division device in the present application selects the coding information of the adjacent image blocks that match the type of the current coding unit according to the type of the current coding unit, performs context modeling, determines the division method of the current coding unit, and divides the current coding tree node according to the division method, thereby improving the video encoding and decoding efficiency.
结合第六方面，在第六方面的某些实现方式中，所述处理模块具体用于：根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定所述当前编码树节点的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码树节点的划分方式。In combination with the sixth aspect, in certain implementations of the sixth aspect, the processing module is specifically used to: determine the context model number corresponding to the syntax element of the current coding tree node according to the type of the current coding tree node and/or the coding information of the adjacent image block; determine the division method of the current coding tree node according to the context model number.
结合第六方面，在第六方面的某些实现方式中，所述处理模块具体用于：在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，根据所述相邻的亮度块的四叉树深度和当前编码树节点的四叉树深度，确定所述上下文模型编号；或在所述当前编码树节点为色度编码树节点的情况下，根据所述当前编码树节点的四叉树深度，确定所述上下文模型编号。In combination with the sixth aspect, in certain implementations of the sixth aspect, the processing module is specifically used to: when the current coding tree node is a luminance or chrominance coding tree node or a luminance coding tree node, determine the context model number according to the quadtree depth of the adjacent luminance block and the quadtree depth of the current coding tree node; or when the current coding tree node is a chrominance coding tree node, determine the context model number according to the quadtree depth of the current coding tree node.
结合第六方面，在第六方面的某些实现方式中，所述处理模块具体用于根据以下公式确定所述上下文模型编号：In combination with the sixth aspect, in some implementations of the sixth aspect, the processing module is specifically used to determine the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，所述condL表示所述左侧相邻的亮度块的四叉树深度是否大于所述当前编码树节点的四叉树深度，所述condA表示所述上侧相邻的亮度块的四叉树深度是否大于所述当前编码树节点的四叉树深度，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，所述condL为预设值，所述condA为预设值，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the context group number; when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, the condL indicates whether the quadtree depth of the left adjacent luminance block is greater than the quadtree depth of the current coding tree node, the condA indicates whether the quadtree depth of the upper adjacent luminance block is greater than the quadtree depth of the current coding tree node, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, the condL is a preset value, the condA is a preset value, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第六方面，在第六方面的某些实现方式中，所述语法元素为split_qt_flag，用于标识当前编码树节点是否使用四叉树划分。In combination with the sixth aspect, in certain implementations of the sixth aspect, the syntax element is split_qt_flag, which is used to identify whether the current coding tree node uses quadtree partitioning.
结合第六方面，在第六方面的某些实现方式中，所述处理模块具体用于：在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，根据所述相邻的亮度块的宽和高、及所述当前编码树节点划分方式的可用性，确定所述上下文模型编号；或在所述当前编码树节点为色度编码单元的情况下，根据所述当前编码树节点划分方式的可用性，确定所述上下文模型编号。In combination with the sixth aspect, in certain implementations of the sixth aspect, the processing module is specifically used to: when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, determine the context model number according to the width and height of the adjacent luminance block and the availability of the current coding tree node division method; or when the current coding tree node is a chrominance coding unit, determine the context model number according to the availability of the current coding tree node division method.
结合第六方面，在第六方面的某些实现方式中，所述处理模块具体用于根据以下公式确定所述上下文模型编号：In combination with the sixth aspect, in some implementations of the sixth aspect, the processing module is specifically used to determine the context model number according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号；在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，condL表示所述左侧相邻的亮度块的宽和高是否大于所述当前编码树节点的宽和高，condA表示所述上侧相邻的亮度块的宽和高是否大于所述当前编码树节点的宽和高，availableL表示所述左侧相邻的亮度块是否可得，availableA表示所述上侧相邻的亮度块是否可得；或在所述当前编码单元为色度编码单元的情况下，condL为预测值或由所述当前编码树节点确定，condA为预设值，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得。Among them, ctxInc is the context model number, ctxSetIdx is the number of the context group; when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, condL indicates whether the width and height of the left adjacent luminance block are greater than the width and height of the current coding tree node, condA indicates whether the width and height of the upper adjacent luminance block are greater than the width and height of the current coding tree node, availableL indicates whether the left adjacent luminance block is available, and availableA indicates whether the upper adjacent luminance block is available; or when the current coding unit is a chrominance coding unit, condL is a predicted value or determined by the current coding tree node, condA is a preset value, availableL indicates whether the left adjacent chrominance block is available, and availableA indicates whether the upper adjacent chrominance block is available.
结合第六方面，在第六方面的某些实现方式中，所述语法元素为split_cu_flag，用于标识当前编码树节点是否划分。In combination with the sixth aspect, in some implementations of the sixth aspect, the syntax element is split_cu_flag, which is used to identify whether the current coding tree node is split.
第七方面，提供了一种图像预测装置，包括：处理模块，用于在当前编码单元为色度编码单元的情况下，根据如下公式确定所述当前编码单元的语法元素对应的上下文模型编号：In a seventh aspect, an image prediction device is provided, including: a processing module, configured to determine, when a current coding unit is a chroma coding unit, a context model number corresponding to a syntax element of the current coding unit according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得；所述condL表示所述左侧相邻的色度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的色度块的预测模式是否为帧内块拷贝预测；或者，所述condL和所述condA均为预设值；所述处理模块，用于根据所述上下文模型编号，确定所述当前编码单元的预测模式；所述预测模块，用于根据所述当前编码单元的预测模式，对所述当前编码单元中的图像块进行预测。Among them, ctxInc is the context model number, ctxSetIdx is the context group number, availableL indicates whether the left adjacent chroma block is available, and availableA indicates whether the upper adjacent chroma block is available; the condL indicates whether the prediction mode of the left adjacent chroma block is intra-frame block copy prediction, and the condA indicates whether the prediction mode of the upper adjacent chroma block is intra-frame block copy prediction; or, the condL and the condA are both preset values; the processing module is used to determine the prediction mode of the current coding unit according to the context model number; the prediction module is used to predict the image block in the current coding unit according to the prediction mode of the current coding unit.
第八方面，提供了一种编码树节点划分装置，包括：处理模块，用于在当前编码树节点为色度编码树节点的情况下，根据如下公式确定所述当前编码树节点的语法元素对应的上下文模型编号：In an eighth aspect, a coding tree node division device is provided, comprising: a processing module, configured to determine, when a current coding tree node is a chroma coding tree node, a context model number corresponding to a syntax element of the current coding tree node according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得；所述condL和所述condA均为预设值；或者，所述condL由所述当前编码树节点确定，所述condA为预设值；所述处理模块，用于根据所述上下文模型编号，确定所述当前编码树节点的划分方式；划分模块，用于根据所述编码树节点的划分方式，对所述当前编码树节点进行划分。Among them, ctxInc is the context model number, ctxSetIdx is the context group number, availableL indicates whether the left adjacent chroma block is available, and availableA indicates whether the upper adjacent chroma block is available; the condL and the condA are both preset values; or, the condL is determined by the current coding tree node, and the condA is a preset value; the processing module is used to determine the division method of the current coding tree node according to the context model number; the division module is used to divide the current coding tree node according to the division method of the coding tree node.
第九方面，本申请实施例提供一种用于解码视频数据的设备，所述设备包括：In a ninth aspect, an embodiment of the present application provides a device for decoding video data, the device comprising:
存储器，用于存储码流形式的视频数据；A memory, used for storing video data in the form of code stream;
视频解码器，用于实施第一方面或第二方面或第三方面或第四方面中的任意一种方法的部分或全部步骤。A video decoder, used to implement part or all of the steps of any one of the methods in the first aspect, the second aspect, the third aspect, or the fourth aspect.
第十方面，本申请实施例提供一种用于解码视频数据的设备，所述设备包括：In a tenth aspect, an embodiment of the present application provides a device for decoding video data, the device comprising:
存储器，用于存储码流形式的视频数据；A memory, used for storing video data in the form of code stream;
视频解码器，用于实施第一方面或第二方面或第三方面或第四方面中的任意一种方法的部分或全部步骤。A video decoder, used to implement part or all of the steps of any one of the methods in the first aspect, the second aspect, the third aspect, or the fourth aspect.
第十一方面，本申请实施例提供一种编码视频数据的设备，包括：相互耦合的非易失性存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第一方面或第二方面或第三方面或第四方面中的任意一种方法的部分或全部步骤。In the eleventh aspect, an embodiment of the present application provides a device for encoding video data, comprising: a non-volatile memory and a processor coupled to each other, wherein the processor calls a program code stored in the memory to execute part or all of the steps of any one of the methods in the first aspect, the second aspect, the third aspect, or the fourth aspect.
可选地，上述存储器为非易失性存储器。Optionally, the above-mentioned memory is a non-volatile memory.
可选地，上述存储器与处理器互相耦合在一起。Optionally, the memory and the processor are coupled to each other.
第十二方面，本申请实施例提供一种解码视频数据的设备，包括：相互耦合的非易失性存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第一方面或第二方面或第三方面或第四方面中的任意一种方法的部分或全部步骤。In the twelfth aspect, an embodiment of the present application provides a device for decoding video data, comprising: a non-volatile memory and a processor coupled to each other, wherein the processor calls a program code stored in the memory to execute part or all of the steps of any one of the methods in the first aspect, the second aspect, the third aspect, or the fourth aspect.
可选地，上述存储器为非易失性存储器。Optionally, the above-mentioned memory is a non-volatile memory.
可选地，上述存储器与处理器互相耦合在一起。Optionally, the memory and the processor are coupled to each other.
第十三方面，本申请实施例提供一种计算机可读存储介质，所述计算机可读存储介质存储了程序代码，其中，所述程序代码包括用于执行第一方面或第二方面或第三方面或第四方面中的任意一种方法的部分或全部步骤的指令。In the thirteenth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a program code, wherein the program code includes instructions for executing part or all of the steps of any one of the methods in the first aspect, the second aspect, the third aspect, or the fourth aspect.
第十四方面，本申请实施例提供一种计算机程序产品，当所述计算机程序产品在计算机上运行时，使得所述计算机执行第一方面或第二方面或第三方面或第四方面中的任意一种方法的部分或全部步骤。In the fourteenth aspect, an embodiment of the present application provides a computer program product, which, when executed on a computer, enables the computer to execute part or all of the steps of any one of the methods in the first aspect, the second aspect, the third aspect, or the fourth aspect.
应当理解的是，本申请的第二至十四方面与本申请的第一方面的技术方案一致，各方面及对应的可行实施方式所取得的有益效果相似，不再赘述。It should be understood that the second to fourteenth aspects of the present application are consistent with the technical solutions of the first aspect of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here.
可以看到，在本申请中，根据当前编码单元的类型，选取与当前编码单元的类型相匹配的相邻图像块的预测模式，进行上下文建模，确定当前编码单元的预测模式，并根据所述预测模式，对所述当前编码单元中的图像块进行预测，因此，能够提高视频编解码效率。It can be seen that in the present application, according to the type of the current coding unit, the prediction mode of the adjacent image block that matches the type of the current coding unit is selected, context modeling is performed, the prediction mode of the current coding unit is determined, and according to the prediction mode, the image block in the current coding unit is predicted, thereby improving the video encoding and decoding efficiency.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1是用于实现本申请实施例的视频编码系统实例的示意性框图。FIG. 1 is a schematic block diagram of an example of a video encoding system for implementing an embodiment of the present application.
图2是用于实现本申请实施例的视频编码器实例的示意性结构框图。FIG. 2 is a schematic structural block diagram of an example of a video encoder for implementing an embodiment of the present application.
图3是用于实现本申请实施例的视频解码器实例的示意性结构框图。FIG. 3 is a schematic structural block diagram of an example of a video decoder for implementing an embodiment of the present application.
图4是用于实现本申请实施例的视频译码系统实例的示意性结构框图。FIG. 4 is a schematic structural block diagram of an example of a video decoding system for implementing an embodiment of the present application.
图5是用于实现本申请实施例的视频译码设备实例的示意性结构框图。FIG. 5 is a schematic structural block diagram of an example of a video decoding device for implementing an embodiment of the present application.
图6是用于实现本申请实施例的编码装置或者解码装置实例的示意性框图。FIG6 is a schematic block diagram of an example of an encoding device or a decoding device for implementing an embodiment of the present application.
图7是用于实现本申请实施例的视频通信系统的示意性框图。FIG. 7 is a schematic block diagram of a video communication system for implementing an embodiment of the present application.
图8是本申请实施例的图像预测方法的示意性流程图。FIG8 is a schematic flowchart of an image prediction method according to an embodiment of the present application.
图9是本申请实施例的编码树节点划分方法的示意性流程图。FIG9 is a schematic flowchart of a coding tree node partitioning method according to an embodiment of the present application.
图10是本申请实施例的一个图像预测装置的示意性框图。FIG. 10 is a schematic block diagram of an image prediction device according to an embodiment of the present application.
图11是本申请实施例的一个编码树节点划分装置的示意性框图。FIG11 is a schematic block diagram of a coding tree node division device according to an embodiment of the present application.
图12是本申请实施例的另一个图像预测装置的示意性框图。FIG. 12 is a schematic block diagram of another image prediction device according to an embodiment of the present application.
图13是本申请实施例的另一个编码树节点划分装置的示意性框图。FIG13 is a schematic block diagram of another coding tree node division device according to an embodiment of the present application.
图14是本申请实施例的图像编码/解码装置的示意性框图。FIG. 14 is a schematic block diagram of an image encoding/decoding device according to an embodiment of the present application.
具体实施方式Detailed ways
下面将结合附图，对本申请中的技术方案进行描述。The technical solution in this application will be described below in conjunction with the accompanying drawings.
在以下描述中，将会参考形成本申请一部分并以说明之方式示出本申请实施例的具体方面或可使用本申请实施例的具体方面的附图。应理解，本申请实施例还可以在在其它方面中使用，并且可以包括附图中未描绘的结构或逻辑变化。因此，以下详细描述不应以限制性的意义来理解，本申请的范围应由所附权利要求书界定。In the following description, reference will be made to the drawings that form a part of the present application and illustrate specific aspects of the embodiments of the present application or specific aspects of the embodiments of the present application that can be used by way of illustration. It should be understood that the embodiments of the present application can also be used in other aspects and may include structural or logical changes not depicted in the drawings. Therefore, the following detailed description should not be understood in a restrictive sense, and the scope of the present application should be defined by the appended claims.
例如，应理解，结合所描述方法的揭示内容可以同样适用于执行所述方法的对应设备或系统，反之亦然。For example, it should be understood that the disclosure in conjunction with a described method may also be applicable to a corresponding device or system that performs the method, and vice versa.
再如，如果描述一个或多个具体方法步骤，则对应的设备可以包含如功能单元等一个或多个单元，来执行所描述的一个或多个方法步骤(例如，一个单元执行一个或多个步骤，或多个单元，其中每个都执行多个步骤中的一个或多个)，即使附图中未明确描述或说明这种一个或多个单元。For another example, if one or more specific method steps are described, the corresponding device may include one or more units, such as functional units, to perform the described one or more method steps (for example, one unit performs one or more steps, or multiple units, each of which performs one or more of the multiple steps), even if such one or more units are not explicitly described or illustrated in the drawings.
此外，如果基于如功能单元等一个或多个单元描述具体装置，则对应的方法可以包含一个步骤来执行一个或多个单元的功能(例如，一个步骤执行一个或多个单元的功能，或多个步骤，其中每个执行多个单元中一个或多个单元的功能)，即使附图中未明确描述或说明这种一个或多个步骤。进一步，应理解的是，除非另外明确提出，本文中所描述的各示例性实施例和/或方面的特征可以相互组合。In addition, if a specific device is described based on one or more units such as functional units, the corresponding method may include a step to perform the function of one or more units (e.g., one step performs the function of one or more units, or multiple steps, each of which performs the function of one or more units in multiple units), even if such one or more steps are not explicitly described or illustrated in the drawings. Further, it should be understood that unless otherwise explicitly stated, the features of the various exemplary embodiments and/or aspects described herein can be combined with each other.
本申请实施例所涉及的技术方案可以应用于H.266标准以及未来的视频编码标准中。本申请的实施方式部分使用的术语仅用于对本申请的具体实施例进行解释，而非旨在限定本申请。下面先对本申请实施例可能涉及的一些概念进行简单介绍。The technical solutions involved in the embodiments of the present application can be applied to the H.266 standard and future video coding standards. The terms used in the implementation method of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. The following is a brief introduction to some concepts that may be involved in the embodiments of the present application.
视频编码通常是指处理形成视频或视频序列的图片序列。在视频编码领域，术语“图片(picture)”、“帧(frame)”或“图像(image)”可以用作同义词。本文中使用的视频编码表示视频编码或视频解码。视频编码在源侧执行，通常包括处理(例如，通过压缩)原始视频图片以减少表示该视频图片所需的数据量，从而更高效地存储和/或传输。视频解码在目的地侧执行，通常包括相对于编码器作逆处理，以重构视频图片。实施例涉及的视频图片“编码”应理解为涉及视频序列的“编码”或“解码”。编码部分和解码部分的组合也称为编解码(编码和解码)。Video coding generally refers to processing a sequence of pictures that form a video or video sequence. In the field of video coding, the terms "picture", "frame" or "image" can be used as synonyms. Video coding used in this article means video encoding or video decoding. Video encoding is performed on the source side and generally includes processing (for example, by compression) the original video picture to reduce the amount of data required to represent the video picture, thereby more efficiently storing and/or transmitting. Video decoding is performed on the destination side and generally includes inverse processing relative to the encoder to reconstruct the video picture. The "encoding" of the video pictures involved in the embodiments should be understood as involving the "encoding" or "decoding" of the video sequence. The combination of the encoding part and the decoding part is also referred to as codec (encoding and decoding).
视频序列包括一系列图像(picture)，图像被进一步划分为切片(slice)，切片再被划分为块(block)。视频编码以块为单位进行编码处理，在一些新的视频编码标准中，块的概念被进一步扩展。比如，在H.264标准中有宏块(macroblock，MB)，宏块可进一步划分成多个可用于预测编码的预测块(partition)。在高性能视频编码(high efficiency videocoding，HEVC)标准中，采用编码单元(coding unit，CU)，预测单元(prediction unit，PU)和变换单元(transform unit，TU)等基本概念，从功能上划分了多种块单元，并采用全新的基于树结构进行描述。比如CU可以按照四叉树进行划分为更小的CU，而更小的CU还可以继续划分，从而形成一种四叉树结构，CU是对编码图像进行划分和编码的基本单元。对于PU和TU也有类似的树结构，PU可以对应预测块，是预测编码的基本单元。对CU按照划分模式进一步划分成多个PU。TU可以对应变换块，是对预测残差进行变换的基本单元。然而，无论CU，PU还是TU，本质上都属于块(或称图像块)的概念。A video sequence includes a series of pictures, which are further divided into slices, and slices are further divided into blocks. Video coding is performed in blocks. In some new video coding standards, the concept of blocks is further expanded. For example, in the H.264 standard, there are macroblocks (MB), which can be further divided into multiple prediction blocks (partitions) that can be used for predictive coding. In the high-performance video coding (HEVC) standard, basic concepts such as coding units (CU), prediction units (PU) and transform units (TU) are used to functionally divide various block units and describe them using a new tree-based structure. For example, CU can be divided into smaller CUs according to a quadtree, and smaller CUs can be further divided to form a quadtree structure. CU is the basic unit for dividing and encoding coded images. There are similar tree structures for PU and TU. PU can correspond to prediction blocks and is the basic unit of predictive coding. CU is further divided into multiple PUs according to the division mode. TU may correspond to a transform block, which is a basic unit for transforming a prediction residual. However, no matter CU, PU or TU, they all belong to the concept of a block (or image block) in essence.
例如，在HEVC中，通过使用表示为编码树的四叉树结构将CTU拆分为多个CU。在CU层级处作出是否使用图片间(时间)或图片内(空间)预测对图片区域进行编码的决策。每个CU可以根据PU拆分类型进一步拆分为一个、两个或四个PU。一个PU内应用相同的预测过程，并在PU基础上将相关信息传输到解码器。在通过基于PU拆分类型应用预测过程获取残差块之后，可以根据类似于用于CU的编码树的其它四叉树结构将CU分割成变换单元(transformunit，TU)。在视频压缩技术最新的发展中，使用四叉树和二叉树(quad-tree and binarytree，QTBT)分割帧来分割编码块。在QTBT块结构中，CU可以为正方形或矩形形状。For example, in HEVC, a CTU is split into multiple CUs using a quadtree structure represented as a coding tree. A decision is made at the CU level whether to use inter-picture (temporal) or intra-picture (spatial) prediction to encode a picture area. Each CU can be further split into one, two, or four PUs according to the PU split type. The same prediction process is applied within a PU, and the relevant information is transmitted to the decoder on a PU basis. After obtaining the residual block by applying the prediction process based on the PU split type, the CU can be divided into transform units (TUs) according to other quadtree structures similar to the coding tree for the CU. In the latest developments in video compression technology, quad-tree and binarytree (QTBT) are used to split frames to split coding blocks. In the QTBT block structure, the CU can be square or rectangular in shape.
本文中，为了便于描述和理解，可将当前编码图像中待编码的图像块称为当前图像块，例如在编码中，指当前正在编码的块；在解码中，指当前正在解码的块。将参考图像中用于对当前图像块进行预测的已解码的图像块称为参考块，即参考块是为当前图像块提供参考信号的块，其中，参考信号表示图像块内的像素值。可将参考图像中为当前图像块提供预测信号的块为预测块，其中，预测信号表示预测块内的像素值或者采样值或者采样信号。例如，在遍历多个参考块以后，找到了最佳参考块，此最佳参考块将为当前图像块提供预测，此块称为预测块。In this article, for the convenience of description and understanding, the image block to be encoded in the current encoded image may be referred to as the current image block. For example, in encoding, it refers to the block currently being encoded; in decoding, it refers to the block currently being decoded. The decoded image block in the reference image used to predict the current image block is referred to as a reference block, that is, the reference block is a block that provides a reference signal for the current image block, wherein the reference signal represents the pixel value in the image block. The block in the reference image that provides a prediction signal for the current image block may be referred to as a prediction block, wherein the prediction signal represents the pixel value or sampling value or sampling signal in the prediction block. For example, after traversing multiple reference blocks, the best reference block is found. This best reference block will provide a prediction for the current image block, and this block is referred to as a prediction block.
无损视频编码情况下，可以重构原始视频图片，即经重构视频图片具有与原始视频图片相同的质量(假设存储或传输期间没有传输损耗或其它数据丢失)。在有损视频编码情况下，通过例如量化执行进一步压缩，来减少表示视频图片所需的数据量，而解码器侧无法完全重构视频图片，即经重构视频图片的质量相比原始视频图片的质量较低或较差。In the case of lossless video coding, the original video picture can be reconstructed, that is, the reconstructed video picture has the same quality as the original video picture (assuming no transmission loss or other data loss during storage or transmission). In the case of lossy video coding, further compression is performed by, for example, quantization to reduce the amount of data required to represent the video picture, but the decoder side cannot fully reconstruct the video picture, that is, the quality of the reconstructed video picture is lower or worse than the quality of the original video picture.
H.261的几个视频编码标准属于“有损混合型视频编解码”(即，将样本域中的空间和时间预测与变换域中用于应用量化的2D变换编码结合)。视频序列的每个图片通常分割成不重叠的块集合，通常在块层级上进行编码。换句话说，编码器侧通常在块(视频块)层级处理亦即编码视频，例如，通过空间(图片内)预测和时间(图片间)预测来产生预测块，从当前图像块(当前处理或待处理的块)减去预测块以获取残差块，在变换域变换残差块并量化残差块，以减少待传输(压缩)的数据量，而解码器侧将相对于编码器的逆处理部分应用于经编码或经压缩块，以重构用于表示的当前图像块。另外，编码器复制解码器处理循环，使得编码器和解码器生成相同的预测(例如帧内预测和帧间预测)和/或重构，用于处理亦即编码后续块。Several video coding standards of H.261 belong to the category of "lossy hybrid video codecs" (i.e., combining spatial and temporal prediction in the sample domain with 2D transform coding in the transform domain for applying quantization). Each picture of a video sequence is usually divided into a set of non-overlapping blocks, which are usually encoded at the block level. In other words, the encoder side usually processes, i.e., encodes the video at the block (video block) level, for example, by generating a prediction block through spatial (intra-picture) prediction and temporal (inter-picture) prediction, subtracting the prediction block from the current image block (currently processed or to be processed block) to obtain a residual block, transforming the residual block in the transform domain and quantizing the residual block to reduce the amount of data to be transmitted (compressed), while the decoder side applies the inverse processing part relative to the encoder to the coded or compressed block to reconstruct the current image block for representation. In addition, the encoder replicates the decoder processing cycle, so that the encoder and decoder generate the same prediction (e.g., intra-frame prediction and inter-frame prediction) and/or reconstruction for processing, i.e., encoding subsequent blocks.
下面描述本申请实施例所应用的系统架构。参见图1，图1示例性地给出了本申请实施例所应用的视频编码及解码系统10的示意性框图。如图1所示，视频编码及解码系统10可包括源设备12和目的地设备14，源设备12产生经编码视频数据，因此，源设备12可被称为视频编码装置。目的地设备14可对由源设备12所产生的经编码的视频数据进行解码，因此，目的地设备14可被称为视频解码装置。源设备12、目的地设备14或两个的各种实施方案可包含一个或多个处理器以及耦合到所述一个或多个处理器的存储器。所述存储器可包含但不限于只读存储器(read-only memory，ROM)、随机存取存储器(random access memory，RAM)、可擦写可编程只读存储器(erasable programmable read-only memory，EPROM)、快闪存储器或可用于以可由计算机存取的指令或数据结构的形式存储所要的程序代码的任何其它媒体，如本文所描述。源设备12和目的地设备14可以包括各种装置，包含桌上型计算机、移动计算装置、笔记型(例如，膝上型)计算机、平板计算机、机顶盒、例如所谓的“智能”电话等电话手持机、电视机、相机、显示装置、数字媒体播放器、视频游戏控制台、车载计算机、无线通信设备或其类似者。The system architecture used in the embodiment of the present application is described below. Referring to FIG. 1, FIG. 1 exemplarily shows a schematic block diagram of a video encoding and decoding system 10 used in the embodiment of the present application. As shown in FIG. 1, the video encoding and decoding system 10 may include a source device 12 and a destination device 14, the source device 12 generates encoded video data, and therefore, the source device 12 may be referred to as a video encoding device. The destination device 14 may decode the encoded video data generated by the source device 12, and therefore, the destination device 14 may be referred to as a video decoding device. Various embodiments of the source device 12, the destination device 14, or both may include one or more processors and a memory coupled to the one or more processors. The memory may include, but is not limited to, a read-only memory (ROM), a random access memory (RAM), an erasable programmable read-only memory (EPROM), a flash memory, or any other medium that can be used to store the desired program code in the form of instructions or data structures accessible by a computer, as described herein. Source device 12 and destination device 14 may include a variety of devices, including desktop computers, mobile computing devices, notebook (e.g., laptop) computers, tablet computers, set-top boxes, telephone handsets such as so-called "smart" phones, televisions, cameras, display devices, digital media players, video game consoles, in-vehicle computers, wireless communication devices, or the like.
虽然图1将源设备12和目的地设备14绘示为单独的设备，但设备实施例也可以同时包括源设备12和目的地设备14或同时包括两者的功能，即源设备12或对应的功能以及目的地设备14或对应的功能。在此类实施例中，可以使用相同硬件和/或软件，或使用单独的硬件和/或软件，或其任何组合来实施源设备12或对应的功能性以及目的地设备14或对应的功能性。Although FIG1 illustrates the source device 12 and the destination device 14 as separate devices, the device embodiment may also include both the source device 12 and the destination device 14 or the functions of both, that is, the source device 12 or the corresponding functions and the destination device 14 or the corresponding functions. In such embodiments, the source device 12 or the corresponding functionality and the destination device 14 or the corresponding functionality may be implemented using the same hardware and/or software, or using separate hardware and/or software, or any combination thereof.
源设备12和目的地设备14之间可通过链路13进行通信连接，目的地设备14可经由链路13从源设备12接收经编码视频数据。链路13可包括能够将经编码视频数据从源设备12移动到目的地设备14的一个或多个媒体或装置。在一个实例中，链路13可包括使得源设备12能够实时将经编码视频数据直接发射到目的地设备14的一个或多个通信媒体。在此实例中，源设备12可根据通信标准(例如无线通信协议)来调制经编码视频数据，且可将经调制的视频数据发射到目的地设备14。所述一个或多个通信媒体可包含无线和/或有线通信媒体，例如射频(RF)频谱或一个或多个物理传输线。所述一个或多个通信媒体可形成基于分组的网络的一部分，基于分组的网络例如为局域网、广域网或全球网络(例如，因特网)。所述一个或多个通信媒体可包含路由器、交换器、基站或促进从源设备12到目的地设备14的通信的其它设备。The source device 12 and the destination device 14 may be communicatively connected via a link 13, and the destination device 14 may receive the encoded video data from the source device 12 via the link 13. The link 13 may include one or more media or devices capable of moving the encoded video data from the source device 12 to the destination device 14. In one example, the link 13 may include one or more communication media that enable the source device 12 to transmit the encoded video data directly to the destination device 14 in real time. In this example, the source device 12 may modulate the encoded video data according to a communication standard (e.g., a wireless communication protocol), and may transmit the modulated video data to the destination device 14. The one or more communication media may include wireless and/or wired communication media, such as a radio frequency (RF) spectrum or one or more physical transmission lines. The one or more communication media may form part of a packet-based network, such as a local area network, a wide area network, or a global network (e.g., the Internet). The one or more communication media may include routers, switches, base stations, or other devices that facilitate communication from the source device 12 to the destination device 14.
源设备12包括编码器20，另外可选地，源设备12还可以包括图片源16、图片预处理器18、以及通信接口22。具体实现形态中，所述编码器20、图片源16、图片预处理器18、以及通信接口22可能是源设备12中的硬件部件，也可能是源设备12中的软件程序。分别描述如下：The source device 12 includes an encoder 20. Optionally, the source device 12 may also include a picture source 16, a picture preprocessor 18, and a communication interface 22. In a specific implementation, the encoder 20, the picture source 16, the picture preprocessor 18, and the communication interface 22 may be hardware components in the source device 12, or may be software programs in the source device 12. They are described as follows:
图片源16，可以包括或可以为任何类别的图片捕获设备，用于例如捕获现实世界图片，和/或任何类别的图片或评论(对于屏幕内容编码，屏幕上的一些文字也认为是待编码的图片或图像的一部分)生成设备，例如，用于生成计算机动画图片的计算机图形处理器，或用于获取和/或提供现实世界图片、计算机动画图片(例如，屏幕内容、虚拟现实(virtual reality，VR)图片)的任何类别设备，和/或其任何组合(例如，实景(augmentedreality，AR)图片)。图片源16可以为用于捕获图片的相机或者用于存储图片的存储器，图片源16还可以包括存储先前捕获或产生的图片和/或获取或接收图片的任何类别的(内部或外部)接口。当图片源16为相机时，图片源16可例如为本地的或集成在源设备中的集成相机；当图片源16为存储器时，图片源16可为本地的或例如集成在源设备中的集成存储器。当所述图片源16包括接口时，接口可例如为从外部视频源接收图片的外部接口，外部视频源例如为外部图片捕获设备，比如相机、外部存储器或外部图片生成设备，外部图片生成设备例如为外部计算机图形处理器、计算机或服务器。接口可以为根据任何专有或标准化接口协议的任何类别的接口，例如有线或无线接口、光接口。The picture source 16 may include or may be any type of picture capture device, for example, for capturing real-world pictures, and/or any type of pictures or comments (for screen content encoding, some text on the screen is also considered to be part of the picture or image to be encoded) generation device, for example, a computer graphics processor for generating computer animation pictures, or any type of device for acquiring and/or providing real-world pictures, computer animation pictures (e.g., screen content, virtual reality (VR) pictures), and/or any combination thereof (e.g., augmented reality (AR) pictures). The picture source 16 may be a camera for capturing pictures or a memory for storing pictures, and the picture source 16 may also include any type of (internal or external) interface for storing previously captured or generated pictures and/or acquiring or receiving pictures. When the picture source 16 is a camera, the picture source 16 may be, for example, a local or integrated camera integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be, for example, a local or integrated memory integrated in the source device. When the picture source 16 includes an interface, the interface may be, for example, an external interface for receiving pictures from an external video source, such as an external picture capture device, such as a camera, an external memory, or an external picture generating device, such as an external computer graphics processor, a computer, or a server. The interface may be any type of interface according to any proprietary or standardized interface protocol, such as a wired or wireless interface, an optical interface.
其中，图片可以视为像素点(picture element)的二维阵列或矩阵。阵列中的像素点也可以称为采样点。阵列或图片在水平和垂直方向(或轴线)上的采样点数目定义图片的尺寸和/或分辨率。为了表示颜色，通常采用三个颜色分量，即图片可以表示为或包含三个采样阵列。例如在RBG格式或颜色空间中，图片包括对应的红色、绿色及蓝色采样阵列。但是，在视频编码中，每个像素通常以亮度/色度格式或颜色空间表示，例如对于YUV格式的图片，包括Y指示的亮度分量(有时也可以用L指示)以及U和V指示的两个色度分量。亮度(luma)分量Y表示亮度或灰度水平强度(例如，在灰度等级图片中两者相同)，而两个色度(chroma)分量U和V表示色度或颜色信息分量。相应地，YUV格式的图片包括亮度采样值(Y)的亮度采样阵列，和色度值(U和V)的两个色度采样阵列。RGB格式的图片可以转换或变换为YUV格式，反之亦然，该过程也称为色彩变换或转换。如果图片是黑白的，该图片可以只包括亮度采样阵列。本申请实施例中，由图片源16传输至图片处理器的图片也可称为原始图片数据17。Among them, the picture can be regarded as a two-dimensional array or matrix of pixels (picture element). The pixels in the array can also be called sampling points. The number of sampling points in the array or picture in the horizontal and vertical directions (or axes) defines the size and/or resolution of the picture. In order to represent the color, three color components are usually used, that is, the picture can be represented as or include three sampling arrays. For example, in the RBG format or color space, the picture includes corresponding red, green and blue sampling arrays. However, in video coding, each pixel is usually represented in a brightness/chroma format or color space, such as for a picture in the YUV format, including a brightness component indicated by Y (sometimes also indicated by L) and two chroma components indicated by U and V. The brightness (luma) component Y represents the brightness or grayscale level intensity (for example, the two are the same in a grayscale picture), and the two chroma (chroma) components U and V represent the chroma or color information components. Accordingly, the picture in the YUV format includes a brightness sampling array of brightness sampling values (Y), and two chroma sampling arrays of chroma values (U and V). An image in RGB format may be converted or transformed into YUV format, and vice versa, which process is also referred to as color conversion or transformation. If the image is black and white, the image may only include a brightness sampling array. In the embodiment of the present application, the image transmitted from the image source 16 to the image processor may also be referred to as raw image data 17.
图片预处理器18，用于接收原始图片数据17并对原始图片数据17执行预处理，以获取经预处理的图片19或经预处理的图片数据19。例如，图片预处理器18执行的预处理可以包括整修、色彩格式转换(例如，从RGB格式转换为YUV格式)、调色或去噪。The image preprocessor 18 is used to receive the original image data 17 and perform preprocessing on the original image data 17 to obtain a preprocessed image 19 or preprocessed image data 19. For example, the preprocessing performed by the image preprocessor 18 may include refurbishment, color format conversion (e.g., from RGB format to YUV format), color adjustment, or denoising.
编码器20(或称视频编码器20)，用于接收经预处理的图片数据19，采用相关预测模式(如本文各个实施例中的预测模式)对经预处理的图片数据19进行处理，从而提供经编码图片数据21(下文将进一步基于图2或图4或图5描述编码器20的结构细节)。在一些实施例中，编码器20可以用于执行后文所描述的各个实施例，以实现本申请所描述的图像预测方法在编码侧的应用。The encoder 20 (or video encoder 20) is used to receive the preprocessed picture data 19, and process the preprocessed picture data 19 using a relevant prediction mode (such as the prediction mode in various embodiments of this document), thereby providing encoded picture data 21 (the structural details of the encoder 20 will be further described below based on FIG. 2 or FIG. 4 or FIG. 5). In some embodiments, the encoder 20 can be used to execute various embodiments described below to implement the application of the image prediction method described in this application on the encoding side.
通信接口22，可用于接收经编码图片数据21，并可通过链路13将经编码图片数据21传输至目的地设备14或任何其它设备(如存储器)，以用于存储或直接重构，所述其它设备可为任何用于解码或存储的设备。通信接口22可例如用于将经编码图片数据21封装成合适的格式，例如数据包，以在链路13上传输。The communication interface 22 can be used to receive the encoded picture data 21 and transmit the encoded picture data 21 to the destination device 14 or any other device (such as a memory) through the link 13 for storage or direct reconstruction. The other device can be any device for decoding or storage. The communication interface 22 can, for example, be used to encapsulate the encoded picture data 21 into a suitable format, such as a data packet, for transmission on the link 13.
目的地设备14包括解码器30，另外可选地，目的地设备14还可以包括通信接口28、图片后处理器32和显示设备34。分别描述如下：The destination device 14 includes a decoder 30. Optionally, the destination device 14 may also include a communication interface 28, a picture post-processor 32, and a display device 34. They are described as follows:
通信接口28，可用于从源设备12或任何其它源接收经编码图片数据21，所述任何其它源例如为存储设备，存储设备例如为经编码图片数据存储设备。通信接口28可以用于藉由源设备12和目的地设备14之间的链路13或藉由任何类别的网络传输或接收经编码图片数据21，链路13例如为直接有线或无线连接，任何类别的网络例如为有线或无线网络或其任何组合，或任何类别的私网和公网，或其任何组合。通信接口28可以例如用于解封装通信接口22所传输的数据包以获取经编码图片数据21。The communication interface 28 can be used to receive the encoded picture data 21 from the source device 12 or any other source, such as a storage device, such as an encoded picture data storage device. The communication interface 28 can be used to transmit or receive the encoded picture data 21 via the link 13 between the source device 12 and the destination device 14 or via any type of network, such as a direct wired or wireless connection, any type of network, such as a wired or wireless network or any combination thereof, or any type of private network and public network, or any combination thereof. The communication interface 28 can be used, for example, to decapsulate the data packet transmitted by the communication interface 22 to obtain the encoded picture data 21.
通信接口28和通信接口22都可以配置为单向通信接口或者双向通信接口，以及可以用于例如发送和接收消息来建立连接、确认和交换任何其它与通信链路和/或例如经编码图片数据传输的数据传输有关的信息。Both communication interface 28 and communication interface 22 may be configured as unidirectional communication interfaces or bidirectional communication interfaces and may be used, for example, to send and receive messages to establish connections, confirm and exchange any other information related to communication links and/or data transmissions such as encoded picture data transmissions.
解码器30(或称为解码器30)，用于接收经编码图片数据21并提供经解码图片数据31或经解码图片31(下文将进一步基于图3或图4或图5描述解码器30的结构细节)。在一些实施例中，解码器30可以用于执行后文所描述的各个实施例，以实现本申请所描述的图像预测方法在解码侧的应用。The decoder 30 (or decoder 30) is used to receive the encoded picture data 21 and provide decoded picture data 31 or decoded picture 31 (the structural details of the decoder 30 will be further described below based on FIG. 3 or FIG. 4 or FIG. 5). In some embodiments, the decoder 30 can be used to execute the various embodiments described below to implement the application of the image prediction method described in the present application on the decoding side.
图片后处理器32，用于对经解码图片数据31(也称为经重构图片数据)执行后处理，以获得经后处理图片数据33。图片后处理器32执行的后处理可以包括：色彩格式转换(例如，从YUV格式转换为RGB格式)、调色、整修或重采样，或任何其它处理，还可用于将将经后处理图片数据33传输至显示设备34。The picture post-processor 32 is used to perform post-processing on the decoded picture data 31 (also called reconstructed picture data) to obtain post-processed picture data 33. The post-processing performed by the picture post-processor 32 may include: color format conversion (for example, from YUV format to RGB format), color adjustment, repair or resampling, or any other processing, and can also be used to transmit the post-processed picture data 33 to the display device 34.
显示设备34，用于接收经后处理图片数据33以向例如用户或观看者显示图片。显示设备34可以为或可以包括任何类别的用于呈现经重构图片的显示器，例如，集成的或外部的显示器或监视器。例如，显示器可以包括液晶显示器(liquid crystal display，LCD)、有机发光二极管(organic light emitting diode，OLED)显示器、等离子显示器、投影仪、微LED显示器、硅基液晶(liquid crystal on silicon，LCoS)、数字光处理器(digitallight processor，DLP)或任何类别的其它显示器。A display device 34 is provided for receiving the post-processed picture data 33 to display the picture to, for example, a user or viewer. The display device 34 may be or may include any type of display for presenting the reconstructed picture, such as an integrated or external display or monitor. For example, the display may include a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a plasma display, a projector, a micro-LED display, a liquid crystal on silicon (LCoS), a digital light processor (DLP), or any other type of display.
虽然，图1中将源设备12和目的地设备14绘示为单独的设备，但设备实施例也可以同时包括源设备12和目的地设备14或同时包括两者的功能性，即源设备12或对应的功能性以及目的地设备14或对应的功能性。在此类实施例中，可以使用相同硬件和/或软件，或使用单独的硬件和/或软件，或其任何组合来实施源设备12或对应的功能性以及目的地设备14或对应的功能性。Although the source device 12 and the destination device 14 are illustrated as separate devices in FIG1 , device embodiments may also include both the source device 12 and the destination device 14 or the functionality of both, that is, the source device 12 or the corresponding functionality and the destination device 14 or the corresponding functionality. In such embodiments, the source device 12 or the corresponding functionality and the destination device 14 or the corresponding functionality may be implemented using the same hardware and/or software, or using separate hardware and/or software, or any combination thereof.
本领域技术人员基于描述明显可知，不同单元的功能性或图1所示的源设备12和/或目的地设备14的功能性的存在和(准确)划分可能根据实际设备和应用有所不同。源设备12和目的地设备14可以包括各种设备中的任一个，包含任何类别的手持或静止设备，例如，笔记本或膝上型计算机、移动电话、智能手机、平板或平板计算机、摄像机、台式计算机、机顶盒、电视机、相机、车载设备、显示设备、数字媒体播放器、视频游戏控制台、视频流式传输设备(例如内容服务服务器或内容分发服务器)、广播接收器设备、广播发射器设备等，并可以不使用或使用任何类别的操作系统。It is obvious to those skilled in the art based on the description that the functionality of different units or the existence and (accurate) division of the functionality of the source device 12 and/or the destination device 14 shown in Figure 1 may vary according to actual devices and applications. The source device 12 and the destination device 14 may include any of a variety of devices, including any type of handheld or stationary device, such as a notebook or laptop computer, a mobile phone, a smart phone, a tablet or tablet computer, a camera, a desktop computer, a set-top box, a television, a camera, a car device, a display device, a digital media player, a video game console, a video streaming device (such as a content service server or a content distribution server), a broadcast receiver device, a broadcast transmitter device, etc., and may not use or use any type of operating system.
编码器20和解码器30都可以实施为各种合适电路中的任一个，例如，一个或多个微处理器、数字信号处理器(digital signal processor，DSP)、专用集成电路(application-specific integrated circuit，ASIC)、现场可编程门阵列(field-programmable gate array，FPGA)、离散逻辑、硬件或其任何组合。如果部分地以软件实施所述技术，则设备可将软件的指令存储于合适的非暂时性计算机可读存储介质中，且可使用一个或多个处理器以硬件执行指令从而执行本申请的技术。前述内容(包含硬件、软件、硬件与软件的组合等)中的任一者可视为一个或多个处理器。The encoder 20 and the decoder 30 may be implemented as any of a variety of suitable circuits, such as one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), discrete logic, hardware, or any combination thereof. If the technology is partially implemented in software, the device may store the instructions of the software in a suitable non-transitory computer-readable storage medium, and may use one or more processors to execute the instructions in hardware to perform the technology of the present application. Any of the foregoing (including hardware, software, a combination of hardware and software, etc.) may be considered to be one or more processors.
在一些情况下，图1中所示视频编码及解码系统10仅为示例，本申请的技术可以适用于不必包含编码和解码设备之间的任何数据通信的视频编码设置(例如，视频编码或视频解码)。在其它实例中，数据可从本地存储器检索、在网络上流式传输等。视频编码设备可以对数据进行编码并且将数据存储到存储器，和/或视频解码设备可以从存储器检索数据并且对数据进行解码。在一些实例中，由并不彼此通信而是仅编码数据到存储器和/或从存储器检索数据且解码数据的设备执行编码和解码。In some cases, the video encoding and decoding system 10 shown in FIG. 1 is only an example, and the technology of the present application can be applied to video encoding settings (e.g., video encoding or video decoding) that do not necessarily include any data communication between encoding and decoding devices. In other examples, data can be retrieved from local storage, streamed over a network, etc. A video encoding device can encode data and store the data in a memory, and/or a video decoding device can retrieve data from a memory and decode the data. In some examples, encoding and decoding are performed by devices that do not communicate with each other but only encode data to a memory and/or retrieve data from a memory and decode data.
参见图2，图2示出用于实现本申请实施例的编码器20的实例的示意性/概念性框图。在图2的实例中，编码器20包括残差计算单元204、变换处理单元206、量化单元208、逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器单元220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260和熵编码单元270。预测处理单元260可以包含帧间预测单元244、帧内预测单元254和模式选择单元262。帧间预测单元244可以包含运动估计单元和运动补偿单元(未图示)。图2所示的编码器20也可以称为混合型视频编码器或根据混合型视频编解码器的视频编码器。Referring to FIG. 2 , FIG. 2 shows a schematic/conceptual block diagram of an example of an encoder 20 for implementing an embodiment of the present application. In the example of FIG. 2 , the encoder 20 includes a residual calculation unit 204, a transform processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transform processing unit 212, a reconstruction unit 214, a buffer 216, a loop filter unit 220, a decoded picture buffer (decoded picture buffer, DPB) 230, a prediction processing unit 260, and an entropy coding unit 270. The prediction processing unit 260 may include an inter-frame prediction unit 244, an intra-frame prediction unit 254, and a mode selection unit 262. The inter-frame prediction unit 244 may include a motion estimation unit and a motion compensation unit (not shown). The encoder 20 shown in FIG. 2 may also be referred to as a hybrid video encoder or a video encoder according to a hybrid video codec.
例如，残差计算单元204、变换处理单元206、量化单元208、预测处理单元260和熵编码单元270形成编码器20的前向信号路径，而例如逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260形成编码器的后向信号路径，其中编码器的后向信号路径对应于解码器的信号路径(参见图3中的解码器30)。For example, the residual calculation unit 204, the transform processing unit 206, the quantization unit 208, the prediction processing unit 260 and the entropy coding unit 270 form a forward signal path of the encoder 20, while for example, the inverse quantization unit 210, the inverse transform processing unit 212, the reconstruction unit 214, the buffer 216, the loop filter 220, the decoded picture buffer (DPB) 230, and the prediction processing unit 260 form a backward signal path of the encoder, wherein the backward signal path of the encoder corresponds to the signal path of the decoder (see the decoder 30 in Figure 3).
编码器20通过例如输入202，接收图片201或图片201的图像块203，例如，形成视频或视频序列的图片序列中的图片。图像块203也可以称为当前图片块或待编码图片块，图片201可以称为当前图片或待编码图片(尤其是在视频编码中将当前图片与其它图片区分开时，其它图片例如同一视频序列亦即也包括当前图片的视频序列中的先前经编码和/或经解码图片)。The encoder 20 receives a picture 201 or an image block 203 of the picture 201, e.g., a picture in a sequence of pictures forming a video or a video sequence, via, e.g., an input 202. The image block 203 may also be referred to as a current picture block or a picture block to be encoded, and the picture 201 may be referred to as a current picture or a picture to be encoded (particularly when the current picture is distinguished from other pictures in video coding, e.g., previously encoded and/or decoded pictures in the same video sequence, i.e., a video sequence that also includes the current picture).
编码器20的实施例可以包括分割单元(图2中未示出)，用于将图片201分割成多个例如图像块203的块，通常分割成多个不重叠的块。分割单元可以用于对视频序列中所有图片使用相同的块大小以及定义块大小的对应栅格，或用于在图片或子集或图片群组之间更改块大小，并将每个图片分割成对应的块。An embodiment of the encoder 20 may include a segmentation unit (not shown in FIG. 2 ) for segmenting the picture 201 into a plurality of blocks, typically non-overlapping blocks, such as image blocks 203. The segmentation unit may be used to use the same block size for all pictures in the video sequence and define a corresponding grid of block sizes, or to change the block size between pictures or subsets or groups of pictures and segment each picture into corresponding blocks.
在一个实例中，编码器20的预测处理单元260可以用于执行上述分割技术的任何组合。In one example, prediction processing unit 260 of encoder 20 may be used to perform any combination of the above-described segmentation techniques.
如图片201，图像块203也是或可以视为具有采样值的采样点的二维阵列或矩阵，虽然其尺寸比图片201小。换句话说，图像块203可以包括，例如，一个采样阵列(例如黑白图片201情况下的亮度阵列)或三个采样阵列(例如，彩色图片情况下的一个亮度阵列和两个色度阵列)或依据所应用的色彩格式的任何其它数目和/或类别的阵列。图像块203的水平和垂直方向(或轴线)上采样点的数目定义图像块203的尺寸。Like the picture 201, the image block 203 is also or can be regarded as a two-dimensional array or matrix of sampling points with sample values, although its size is smaller than that of the picture 201. In other words, the image block 203 may include, for example, one sampling array (e.g., a luminance array in the case of the black and white picture 201) or three sampling arrays (e.g., one luminance array and two chrominance arrays in the case of a color picture) or any other number and/or type of arrays depending on the color format applied. The number of sampling points in the horizontal and vertical directions (or axes) of the image block 203 defines the size of the image block 203.
如图2所示的编码器20用于逐块编码图片201，例如，对每个图像块203执行编码和预测。The encoder 20 shown in FIG. 2 is used to encode a picture 201 block by block, for example, performing encoding and prediction on each image block 203 .
残差计算单元204用于基于图片图像块203和预测块265(下文提供预测块265的其它细节)计算残差块205，例如，通过逐样本(逐像素)将图片图像块203的样本值减去预测块265的样本值，以在样本域中获取残差块205。The residual calculation unit 204 is used to calculate the residual block 205 based on the picture image block 203 and the prediction block 265 (other details of the prediction block 265 are provided below), for example, by subtracting the sample value of the prediction block 265 from the sample value of the picture image block 203 sample by sample (pixel by pixel) to obtain the residual block 205 in the sample domain.
变换处理单元206用于在残差块205的样本值上应用例如离散余弦变换(discretecosine transform，DCT)或离散正弦变换(discrete sine transform，DST)的变换，以在变换域中获取变换系数207。变换系数207也可以称为变换残差系数，并在变换域中表示残差块205。The transform processing unit 206 is used to apply a transform such as discrete cosine transform (DCT) or discrete sine transform (DST) on the sample values of the residual block 205 to obtain a transform coefficient 207 in the transform domain. The transform coefficient 207 may also be referred to as a transform residual coefficient and represents the residual block 205 in the transform domain.
变换处理单元206可以用于应用DCT/DST的整数近似值，例如为HEVC/H.265指定的变换。与正交DCT变换相比，这种整数近似值通常由某一因子按比例缩放。为了维持经正变换和逆变换处理的残差块的范数，应用额外比例缩放因子作为变换过程的一部分。比例缩放因子通常是基于某些约束条件选择的，例如，比例缩放因子是用于移位运算的2的幂、变换系数的位深度、准确性和实施成本之间的权衡等。例如，在解码器30侧通过例如逆变换处理单元212为逆变换(以及在编码器20侧通过例如逆变换处理单元212为对应逆变换)指定具体比例缩放因子，以及相应地，可以在编码器20侧通过变换处理单元206为正变换指定对应比例缩放因子。The transform processing unit 206 can be used to apply an integer approximation of the DCT/DST, such as the transform specified for HEVC/H.265. Compared to the orthogonal DCT transform, such integer approximation is usually scaled by a certain factor. In order to maintain the norm of the residual block processed by the forward transform and the inverse transform, an additional scaling factor is applied as part of the transform process. The scaling factor is usually selected based on certain constraints, such as the scaling factor is a power of 2 for the shift operation, the bit depth of the transform coefficients, the trade-off between accuracy and implementation cost, etc. For example, a specific scaling factor is specified for the inverse transform on the decoder 30 side by, for example, the inverse transform processing unit 212 (and for the corresponding inverse transform on the encoder 20 side by, for example, the inverse transform processing unit 212), and accordingly, a corresponding scaling factor can be specified for the forward transform on the encoder 20 side by the transform processing unit 206.
量化单元208用于例如通过应用标量量化或向量量化来量化变换系数207，以获取经量化变换系数209。经量化变换系数209也可以称为经量化残差系数209。量化过程可以减少与部分或全部变换系数207有关的位深度。例如，可在量化期间将n位变换系数向下舍入到m位变换系数，其中n大于m。可通过调整量化参数(quantization parameter，QP)修改量化程度。例如，对于标量量化，可以应用不同的标度来实现较细或较粗的量化。较小量化步长对应较细量化，而较大量化步长对应较粗量化。可以通过量化参数(quantizationparameter，QP)指示合适的量化步长。例如，量化参数可以为合适的量化步长的预定义集合的索引。例如，较小的量化参数可以对应精细量化(较小量化步长)，较大量化参数可以对应粗糙量化(较大量化步长)，反之亦然。量化可以包含除以量化步长以及例如通过逆量化210执行的对应的量化或逆量化，或者可以包含乘以量化步长。根据例如HEVC的一些标准的实施例可以使用量化参数来确定量化步长。一般而言，可以基于量化参数使用包含除法的等式的定点近似来计算量化步长。可以引入额外比例缩放因子来进行量化和反量化，以恢复可能由于在用于量化步长和量化参数的等式的定点近似中使用的标度而修改的残差块的范数。在一个实例实施方式中，可以合并逆变换和反量化的标度。或者，可以使用自定义量化表并在例如比特流中将其从编码器通过信号发送到解码器。量化是有损操作，其中量化步长越大，损耗越大。The quantization unit 208 is used to quantize the transform coefficients 207, for example, by applying scalar quantization or vector quantization, to obtain quantized transform coefficients 209. The quantized transform coefficients 209 may also be referred to as quantized residual coefficients 209. The quantization process may reduce the bit depth associated with some or all of the transform coefficients 207. For example, an n-bit transform coefficient may be rounded down to an m-bit transform coefficient during quantization, where n is greater than m. The degree of quantization may be modified by adjusting a quantization parameter (QP). For example, for scalar quantization, different scales may be applied to achieve finer or coarser quantization. A smaller quantization step size corresponds to finer quantization, while a larger quantization step size corresponds to coarser quantization. A suitable quantization step size may be indicated by a quantization parameter (QP). For example, the quantization parameter may be an index to a predefined set of suitable quantization step sizes. For example, a smaller quantization parameter may correspond to fine quantization (a smaller quantization step size), a larger quantization parameter may correspond to coarse quantization (a larger quantization step size), and vice versa. Quantization may include division by a quantization step size and corresponding quantization or inverse quantization, for example, performed by inverse quantization 210, or may include multiplication by a quantization step size. Embodiments according to some standards such as HEVC may use a quantization parameter to determine the quantization step size. In general, the quantization step size may be calculated based on the quantization parameter using a fixed-point approximation of an equation containing division. Additional scaling factors may be introduced for quantization and inverse quantization to recover the norm of the residual block that may be modified due to the scale used in the fixed-point approximation of the equation for the quantization step size and the quantization parameter. In an example embodiment, the scales of the inverse transform and inverse quantization may be merged. Alternatively, a custom quantization table may be used and sent from an encoder to a decoder through a signal, for example in a bitstream. Quantization is a lossy operation, where the larger the quantization step size, the greater the loss.
逆量化单元210用于在经量化系数上应用量化单元208的逆量化，以获取经反量化系数211，例如，基于或使用与量化单元208相同的量化步长，应用量化单元208应用的量化方案的逆量化方案。经反量化系数211也可以称为经反量化残差系数211，对应于变换系数207，虽然由于量化造成的损耗通常与变换系数不相同。The inverse quantization unit 210 is used to apply the inverse quantization of the quantization unit 208 on the quantized coefficients to obtain inverse quantized coefficients 211, for example, applying an inverse quantization scheme of the quantization scheme applied by the quantization unit 208 based on or using the same quantization step size as the quantization unit 208. The inverse quantized coefficients 211 may also be referred to as inverse quantized residual coefficients 211, corresponding to the transform coefficients 207, although the loss due to quantization is generally different from that of the transform coefficients.
逆变换处理单元212用于应用变换处理单元206应用的变换的逆变换，例如，逆离散余弦变换(discrete cosine transform，DCT)或逆离散正弦变换(discrete sinetransform，DST)，以在样本域中获取逆变换块213。逆变换块213也可以称为逆变换经反量化块213或逆变换残差块213。The inverse transform processing unit 212 is used to apply the inverse transform of the transform applied by the transform processing unit 206, such as an inverse discrete cosine transform (DCT) or an inverse discrete sine transform (DST), to obtain an inverse transform block 213 in the sample domain. The inverse transform block 213 may also be referred to as an inverse transform dequantized block 213 or an inverse transform residual block 213.
重构单元214(例如，求和器214)用于将逆变换块213(即经重构残差块213)添加至预测块265，以在样本域中获取经重构块215，例如，将经重构残差块213的样本值与预测块265的样本值相加。The reconstruction unit 214 (e.g., the summer 214) is used to add the inverse transform block 213 (i.e., the reconstructed residual block 213) to the prediction block 265 to obtain the reconstructed block 215 in the sample domain, for example, by adding the sample values of the reconstructed residual block 213 to the sample values of the prediction block 265.
可选地，例如线缓冲器216的缓冲器单元216(或简称“缓冲器”216)用于缓冲或存储经重构块215和对应的样本值，用于例如帧内预测。在其它的实施例中，编码器可以用于使用存储在缓冲器单元216中的未经滤波的经重构块和/或对应的样本值来进行任何类别的估计和/或预测，例如帧内预测。Optionally, a buffer unit 216 (or simply "buffer" 216), such as a line buffer 216, is used to buffer or store the reconstructed blocks 215 and corresponding sample values for, for example, intra-frame prediction. In other embodiments, the encoder can be used to use the unfiltered reconstructed blocks and/or corresponding sample values stored in the buffer unit 216 for any type of estimation and/or prediction, such as intra-frame prediction.
例如，编码器20的实施例可以经配置以使得缓冲器单元216不只用于存储用于帧内预测254的经重构块215，也用于环路滤波器单元220(在图2中未示出)，和/或，例如使得缓冲器单元216和经解码图片缓冲器单元230形成一个缓冲器。其它实施例可以用于将经滤波块221和/或来自经解码图片缓冲器230的块或样本(图2中均未示出)用作帧内预测254的输入或基础。For example, embodiments of the encoder 20 may be configured such that the buffer unit 216 is used not only to store the reconstructed blocks 215 for the intra-frame prediction 254, but also for the loop filter unit 220 (not shown in FIG. 2 ), and/or, for example, such that the buffer unit 216 and the decoded picture buffer unit 230 form one buffer. Other embodiments may be used to use the filtered blocks 221 and/or blocks or samples from the decoded picture buffer 230 (neither shown in FIG. 2 ) as input or basis for the intra-frame prediction 254.
环路滤波器单元220(或简称环路滤波器220)用于对经重构块215进行滤波以获取经滤波块221，从而顺利进行像素转变或提高视频质量。环路滤波器单元220旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset，SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元220在图2中示出为环内滤波器，但在其它配置中，环路滤波器单元220可实施为环后滤波器。经滤波块221也可以称为经滤波的经重构块221。经解码图片缓冲器230可以在环路滤波器单元220对经重构编码块执行滤波操作之后存储经重构编码块。The loop filter unit 220 (or simply loop filter 220) is used to filter the reconstructed block 215 to obtain the filtered block 221, so as to smoothly perform pixel conversion or improve video quality. The loop filter unit 220 is intended to represent one or more loop filters, such as a deblocking filter, a sample adaptive offset (sample-adaptive offset, SAO) filter or other filters, such as a bilateral filter, an adaptive loop filter (adaptive loop filter, ALF), or a sharpening or smoothing filter, or a collaborative filter. Although the loop filter unit 220 is shown as an in-loop filter in FIG. 2, in other configurations, the loop filter unit 220 can be implemented as a post-loop filter. The filtered block 221 can also be referred to as a filtered reconstructed block 221. The decoded picture buffer 230 can store the reconstructed coding block after the loop filter unit 220 performs a filtering operation on the reconstructed coding block.
编码器20(对应地，环路滤波器单元220)的实施例可以用于输出环路滤波器参数(例如，样本自适应偏移信息)，例如，直接输出或由熵编码单元270或任何其它熵编码单元熵编码后输出，例如使得解码器30可以接收并应用相同的环路滤波器参数用于解码。Embodiments of the encoder 20 (correspondingly, the loop filter unit 220) can be used to output loop filter parameters (e.g., sample adaptive offset information), for example, directly or after entropy encoding by the entropy encoding unit 270 or any other entropy encoding unit, such that the decoder 30 can receive and apply the same loop filter parameters for decoding.
经解码图片缓冲器(decoded picture buffer，DPB)230可以为存储参考图片数据供编码器20编码视频数据之用的参考图片存储器。DPB 230可由多种存储器设备中的任一个形成，例如动态随机存储器(dynamic random access memory，DRAM)(包含同步DRAM(synchronous DRAM，SDRAM)、磁阻式RAM(magnetoresistive RAM，MRAM)、电阻式RAM(resistive RAM，RRAM))或其它类型的存储器设备。可以由同一存储器设备或单独的存储器设备提供DPB 230和缓冲器216。在某一实例中，经解码图片缓冲器(decoded picturebuffer，DPB)230用于存储经滤波块221。经解码图片缓冲器230可以进一步用于存储同一当前图片或例如先前经重构图片的不同图片的其它先前的经滤波块，例如先前经重构和经滤波块221，以及可以提供完整的先前经重构亦即经解码图片(和对应参考块和样本)和/或部分经重构当前图片(和对应参考块和样本)，例如用于帧间预测。在某一实例中，如果经重构块215无需环内滤波而得以重构，则经解码图片缓冲器(decoded picture buffer，DPB)230用于存储经重构块215。The decoded picture buffer (DPB) 230 may be a reference picture memory for storing reference picture data for use by the encoder 20 in encoding video data. The DPB 230 may be formed by any of a variety of memory devices, such as a dynamic random access memory (DRAM) (including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM)) or other types of memory devices. The DPB 230 and the buffer 216 may be provided by the same memory device or separate memory devices. In one example, the decoded picture buffer (DPB) 230 is used to store the filtered block 221. The decoded picture buffer 230 may further be used to store other previously filtered blocks of the same current picture or a different picture, such as a previously reconstructed picture, such as the previously reconstructed and filtered block 221, and may provide a complete previously reconstructed, i.e., decoded picture (and corresponding reference blocks and samples) and/or a portion of the reconstructed current picture (and corresponding reference blocks and samples), such as for inter-frame prediction. In one example, if the reconstructed block 215 is reconstructed without in-loop filtering, the decoded picture buffer (DPB) 230 is used to store the reconstructed block 215.
预测处理单元260，也称为块预测处理单元260，用于接收或获取图像块203(当前图片201的当前图像块203)和经重构图片数据，例如来自缓冲器216的同一(当前)图片的参考样本和/或来自经解码图片缓冲器230的一个或多个先前经解码图片的参考图片数据231，以及用于处理这类数据进行预测，即提供可以为经帧间预测块245或经帧内预测块255的预测块265。The prediction processing unit 260, also referred to as the block prediction processing unit 260, is used to receive or obtain an image block 203 (a current image block 203 of a current picture 201) and reconstructed picture data, such as reference samples of the same (current) picture from a buffer 216 and/or reference picture data 231 of one or more previously decoded pictures from a decoded picture buffer 230, and to process such data for prediction, i.e., to provide a prediction block 265 which may be an inter-prediction block 245 or an intra-prediction block 255.
模式选择单元262可以用于选择预测模式(例如帧内或帧间预测模式)和/或对应的用作预测块265的预测块245或255，以计算残差块205和重构经重构块215。The mode selection unit 262 may be used to select a prediction mode (eg, intra or inter prediction mode) and/or a corresponding prediction block 245 or 255 for use as a prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215 .
模式选择单元262的实施例可以用于选择预测模式(例如，从预测处理单元260所支持的那些预测模式中选择)，所述预测模式提供最佳匹配或者说最小残差(最小残差意味着传输或存储中更好的压缩)，或提供最小信令开销(最小信令开销意味着传输或存储中更好的压缩)，或同时考虑或平衡以上两者。模式选择单元262可以用于基于码率失真优化(rate distortion optimization，RDO)确定预测模式，即选择提供最小码率失真优化的预测模式，或选择相关码率失真至少满足预测模式选择标准的预测模式。Embodiments of the mode selection unit 262 may be used to select a prediction mode (e.g., from those prediction modes supported by the prediction processing unit 260) that provides the best match or minimum residual (minimum residual means better compression in transmission or storage), or provides minimum signaling overhead (minimum signaling overhead means better compression in transmission or storage), or considers or balances both. The mode selection unit 262 may be used to determine the prediction mode based on rate distortion optimization (RDO), i.e., select a prediction mode that provides minimum rate distortion optimization, or select a prediction mode whose associated rate distortion at least satisfies the prediction mode selection criteria.
下文将详细解释编码器20的实例(例如，通过预测处理单元260)执行的预测处理和(例如，通过模式选择单元262)执行的模式选择。The prediction processing performed by an example of encoder 20 (eg, by prediction processing unit 260) and the mode selection performed (eg, by mode selection unit 262) will be explained in detail below.
如上文所述，编码器20用于从(预先确定的)预测模式集合中确定或选择最好或最优的预测模式。预测模式集合可以包括例如帧内预测模式和/或帧间预测模式。As described above, the encoder 20 is used to determine or select the best or optimal prediction mode from a (predetermined) prediction mode set. The prediction mode set may include, for example, an intra-frame prediction mode and/or an inter-frame prediction mode.
帧内预测模式集合可以包括35种不同的帧内预测模式，例如，如DC(或均值)模式和平面模式的非方向性模式，或如H.265中定义的方向性模式，或者可以包括67种不同的帧内预测模式，例如，如DC(或均值)模式和平面模式的非方向性模式，或如正在发展中的H.266中定义的方向性模式。The intra-frame prediction mode set may include 35 different intra-frame prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in H.265, or may include 67 different intra-frame prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in H.266 under development.
在可能的实现中，帧间预测模式集合取决于可用参考图片(即，例如前述存储在DBP230中的至少部分经解码图片)和其它帧间预测参数，例如取决于是否使用整个参考图片或只使用参考图片的一部分，例如围绕当前图像块的区域的搜索窗区域，来搜索最佳匹配参考块，和/或例如取决于是否应用如半像素和/或四分之一像素内插的像素内插，帧间预测模式集合例如可包括先进运动矢量(advanced motion vector prediction，AMVP)模式和融合(merge)模式。具体实施中，帧间预测模式集合可包括本申请实施例改进的基于控制点的AMVP模式，以及，改进的基于控制点的merge模式。在一个实例中，帧内预测单元254可以用于执行下文描述的帧间预测技术的任意组合。In a possible implementation, the inter-frame prediction mode set depends on the available reference picture (i.e., at least part of the decoded picture stored in DBP230 as described above) and other inter-frame prediction parameters, such as whether to use the entire reference picture or only a part of the reference picture, such as a search window area around the area of the current image block, to search for the best matching reference block, and/or for example, whether to apply pixel interpolation such as half-pixel and/or quarter-pixel interpolation. The inter-frame prediction mode set may include, for example, an advanced motion vector prediction (AMVP) mode and a merge mode. In a specific implementation, the inter-frame prediction mode set may include an improved control point-based AMVP mode according to an embodiment of the present application, as well as an improved control point-based merge mode. In one example, the intra-frame prediction unit 254 may be used to perform any combination of the inter-frame prediction techniques described below.
除了以上预测模式，本申请实施例也可以应用跳过模式和/或直接模式。In addition to the above prediction modes, embodiments of the present application may also apply skip mode and/or direct mode.
预测处理单元260可以进一步用于将图像块203分割成较小的块分区或子块，例如，通过迭代使用四叉树(quad-tree，QT)分割、二进制树(binary-tree，BT)分割或三叉树(triple-tree，TT)分割，或其任何组合，以及用于例如为块分区或子块中的每一个执行预测，其中模式选择包括选择分割的图像块203的树结构和选择应用于块分区或子块中的每一个的预测模式。The prediction processing unit 260 can be further used to partition the image block 203 into smaller block partitions or sub-blocks, for example, by iteratively using quad-tree (QT) partitioning, binary-tree (BT) partitioning or triple-tree (TT) partitioning, or any combination thereof, and for performing prediction for each of the block partitions or sub-blocks, for example, wherein the mode selection includes selecting a tree structure of the partitioned image block 203 and selecting a prediction mode to be applied to each of the block partitions or sub-blocks.
帧间预测单元244可以包含运动估计(motion estimation，ME)单元(图2中未示出)和运动补偿(motion compensation，MC)单元(图2中未示出)。运动估计单元用于接收或获取图片图像块203(当前图片201的当前图片图像块203)和经解码图片231，或至少一个或多个先前经重构块，例如，一个或多个其它/不同先前经解码图片231的经重构块，来进行运动估计。例如，视频序列可以包括当前图片和先前经解码图片31，或换句话说，当前图片和先前经解码图片31可以是形成视频序列的图片序列的一部分，或者形成该图片序列。The inter-frame prediction unit 244 may include a motion estimation (ME) unit (not shown in FIG. 2 ) and a motion compensation (MC) unit (not shown in FIG. 2 ). The motion estimation unit is used to receive or obtain a picture image block 203 (a current picture image block 203 of a current picture 201 ) and a decoded picture 231 , or at least one or more previously reconstructed blocks, for example, reconstructed blocks of one or more other/different previously decoded pictures 231 , to perform motion estimation. For example, a video sequence may include a current picture and a previously decoded picture 31 , or in other words, the current picture and the previously decoded picture 31 may be part of a picture sequence forming a video sequence, or form the picture sequence.
例如，编码器20可以用于从多个其它图片中的同一或不同图片的多个参考块中选择参考块，并向运动估计单元(图2中未示出)提供参考图片和/或提供参考块的位置(X、Y坐标)与当前图像块的位置之间的偏移(空间偏移)作为帧间预测参数。该偏移也称为运动向量(motion vector，MV)。For example, the encoder 20 may be used to select a reference block from a plurality of reference blocks of the same or different pictures in a plurality of other pictures, and provide the reference picture and/or provide the offset (spatial offset) between the position (X, Y coordinates) of the reference block and the position of the current image block as an inter-frame prediction parameter to a motion estimation unit (not shown in FIG. 2 ). The offset is also referred to as a motion vector (MV).
运动补偿单元用于获取帧间预测参数，并基于或使用帧间预测参数执行帧间预测来获取帧间预测块245。由运动补偿单元(图2中未示出)执行的运动补偿可以包含基于通过运动估计(可能执行对子像素精确度的内插)确定的运动/块向量取出或生成预测块。内插滤波可从已知像素样本产生额外像素样本，从而潜在地增加可用于编码图片块的候选预测块的数目。一旦接收到用于当前图片块的PU的运动向量，运动补偿单元246可以在一个参考图片列表中定位运动向量指向的预测块。运动补偿单元246还可以生成与块和视频条带相关联的语法元素，以供解码器30在解码视频条带的图片块时使用。The motion compensation unit is used to obtain inter-frame prediction parameters and perform inter-frame prediction based on or using the inter-frame prediction parameters to obtain an inter-frame prediction block 245. Motion compensation performed by the motion compensation unit (not shown in Figure 2) may include retrieving or generating a prediction block based on a motion/block vector determined by motion estimation (possibly performing interpolation to sub-pixel accuracy). Interpolation filtering can generate additional pixel samples from known pixel samples, thereby potentially increasing the number of candidate prediction blocks that can be used to encode the picture block. Upon receiving the motion vector for the PU of the current picture block, the motion compensation unit 246 can locate the prediction block pointed to by the motion vector in a reference picture list. The motion compensation unit 246 can also generate syntax elements associated with blocks and video slices for use by the decoder 30 when decoding picture blocks of the video slice.
具体的，上述帧间预测单元244可向熵编码单元270传输语法元素，所述语法元素包括帧间预测参数(比如遍历多个帧间预测模式后选择用于当前图像块预测的帧间预测模式的指示信息)。可能应用场景中，如果帧间预测模式只有一种，那么也可以不在语法元素中携带帧间预测参数，此时解码端30可直接使用默认的预测模式进行解码。可以理解的，帧间预测单元244可以用于执行帧间预测技术的任意组合。Specifically, the inter-frame prediction unit 244 may transmit syntax elements to the entropy coding unit 270, wherein the syntax elements include inter-frame prediction parameters (such as indication information of selecting an inter-frame prediction mode for current image block prediction after traversing multiple inter-frame prediction modes). In possible application scenarios, if there is only one inter-frame prediction mode, the inter-frame prediction parameters may not be carried in the syntax elements, and the decoding end 30 may directly use the default prediction mode for decoding. It can be understood that the inter-frame prediction unit 244 can be used to perform any combination of inter-frame prediction techniques.
帧内预测单元254用于获取，例如接收同一图片的图片块203(当前图片块)和一个或多个先前经重构块，例如经重构相相邻块，以进行帧内估计。例如，编码器20可以用于从多个(预定)帧内预测模式中选择帧内预测模式。The intra prediction unit 254 is used to obtain, for example, receive a picture block 203 (current picture block) of the same picture and one or more previously reconstructed blocks, for example, reconstructed adjacent blocks, for intra estimation. For example, the encoder 20 can be used to select an intra prediction mode from a plurality of (predetermined) intra prediction modes.
编码器20的实施例可以用于基于优化标准选择帧内预测模式，例如基于最小残差(例如，提供最类似于当前图片块203的预测块255的帧内预测模式)或最小码率失真。Embodiments of the encoder 20 may be configured to select an intra prediction mode based on an optimization criterion, such as minimum residual (eg, the intra prediction mode that provides a prediction block 255 most similar to the current picture block 203) or minimum rate distortion.
帧内预测单元254进一步用于基于如所选择的帧内预测模式的帧内预测参数确定帧内预测块255。在任何情况下，在选择用于块的帧内预测模式之后，帧内预测单元254还用于向熵编码单元270提供帧内预测参数，即提供指示所选择的用于块的帧内预测模式的信息。在一个实例中，帧内预测单元254可以用于执行帧内预测技术的任意组合。The intra prediction unit 254 is further configured to determine an intra prediction block 255 based on the intra prediction parameters of the selected intra prediction mode. In any case, after selecting the intra prediction mode for the block, the intra prediction unit 254 is further configured to provide the intra prediction parameters, i.e., information indicating the selected intra prediction mode for the block, to the entropy encoding unit 270. In one example, the intra prediction unit 254 can be configured to perform any combination of intra prediction techniques.
具体的，上述帧内预测单元254可向熵编码单元270传输语法元素，所述语法元素包括帧内预测参数(比如遍历多个帧内预测模式后选择用于当前图像块预测的帧内预测模式的指示信息)。可能应用场景中，如果帧内预测模式只有一种，那么也可以不在语法元素中携带帧内预测参数，此时解码端30可直接使用默认的预测模式进行解码。Specifically, the intra prediction unit 254 may transmit a syntax element to the entropy coding unit 270, wherein the syntax element includes an intra prediction parameter (e.g., indication information of selecting an intra prediction mode for current image block prediction after traversing multiple intra prediction modes). In a possible application scenario, if there is only one intra prediction mode, the intra prediction parameter may not be carried in the syntax element, and the decoding end 30 may directly use the default prediction mode for decoding.
熵编码单元270用于将熵编码算法或方案(例如，可变长度编码(variable lengthcoding，VLC)方案、上下文自适应VLC(context adaptive VLC，CAVLC)方案、算术编码方案、上下文自适应二进制算术编码(context adaptive binary arithmetic coding，CABAC)、基于语法的上下文自适应二进制算术编码(syntax-based context-adaptive binaryarithmetic coding，SBAC)、概率区间分割熵(probability interval partitioningentropy，PIPE)编码或其它熵编码方法或技术)应用于经量化残差系数209、帧间预测参数、帧内预测参数和/或环路滤波器参数中的单个或所有上(或不应用)，以获取可以通过输出272以例如经编码比特流21的形式输出的经编码图片数据21。可以将经编码比特流传输到视频解码器30，或将其存档稍后由视频解码器30传输或检索。熵编码单元270还可用于熵编码正被编码的当前视频条带的其它语法元素。The entropy coding unit 270 is used to apply an entropy coding algorithm or scheme (e.g., a variable length coding (VLC) scheme, a context adaptive VLC (CAVLC) scheme, an arithmetic coding scheme, a context adaptive binary arithmetic coding (CABAC), a syntax-based context-adaptive binary arithmetic coding (SBAC), a probability interval partitioning entropy (PIPE) coding, or other entropy coding methods or techniques) to a single or all (or none) of the quantized residual coefficients 209, inter-frame prediction parameters, intra-frame prediction parameters, and/or loop filter parameters to obtain the encoded picture data 21 that can be output through the output 272 in the form of, for example, an encoded bitstream 21. The encoded bitstream can be transmitted to the video decoder 30 or archived for later transmission or retrieval by the video decoder 30. The entropy coding unit 270 can also be used to entropy encode other syntax elements of the current video slice being encoded.
视频编码器20的其它结构变型可用于编码视频流。例如，基于非变换的编码器20可以在没有针对某些块或帧的变换处理单元206的情况下直接量化残差信号。在另一实施方式中，编码器20可具有组合成单个单元的量化单元208和逆量化单元210。Other structural variations of the video encoder 20 may be used to encode the video stream. For example, a non-transform based encoder 20 may directly quantize the residual signal without a transform processing unit 206 for certain blocks or frames. In another embodiment, the encoder 20 may have a quantization unit 208 and an inverse quantization unit 210 combined into a single unit.
具体的，在本申请实施例中，编码器20可用于实现后文实施例中描述的视频编码过程。Specifically, in the embodiment of the present application, the encoder 20 may be used to implement the video encoding process described in the embodiments below.
应当理解的是，本申请中的视频编码器可以只包括视频编码器20中的部分模块，例如，本申请中的视频编码器可以包括图像解码单元和划分单元。其中，图像解码单元可以由熵解码单元、预测单元、反变换单元和反量化单元中的一种或者多种单元组成。It should be understood that the video encoder in the present application may include only some modules in the video encoder 20. For example, the video encoder in the present application may include an image decoding unit and a partitioning unit. The image decoding unit may be composed of one or more units of an entropy decoding unit, a prediction unit, an inverse transform unit, and an inverse quantization unit.
另外，视频编码器20的其它的结构变化可用于编码视频流。例如，对于某些图像块或者图像帧，视频编码器20可以直接地量化残差信号而不需要经变换处理单元206处理，相应地也不需要经逆变换处理单元212处理；或者，对于某些图像块或者图像帧，视频编码器20没有产生残差数据，相应地不需要经变换处理单元206、量化单元208、逆量化单元210和逆变换处理单元212处理；或者，视频编码器20可以将经重构图像块作为参考块直接地进行存储而不需要经滤波器220处理；或者，视频编码器20中量化单元208和逆量化单元210可以合并在一起。环路滤波器220是可选的，以及针对无损压缩编码的情况下，变换处理单元206、量化单元208、逆量化单元210和逆变换处理单元212是可选的。应当理解的是，根据不同的应用场景，帧间预测单元244和帧内预测单元254可以是被选择性的启用。In addition, other structural changes of the video encoder 20 can be used to encode the video stream. For example, for some image blocks or image frames, the video encoder 20 can directly quantize the residual signal without processing by the transform processing unit 206, and accordingly, it does not need to be processed by the inverse transform processing unit 212; or, for some image blocks or image frames, the video encoder 20 does not generate residual data, and accordingly, it does not need to be processed by the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210 and the inverse transform processing unit 212; or, the video encoder 20 can directly store the reconstructed image block as a reference block without processing by the filter 220; or, the quantization unit 208 and the inverse quantization unit 210 in the video encoder 20 can be combined together. The loop filter 220 is optional, and in the case of lossless compression encoding, the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210 and the inverse transform processing unit 212 are optional. It should be understood that according to different application scenarios, the inter-frame prediction unit 244 and the intra-frame prediction unit 254 can be selectively enabled.
参见图3，图3示出用于实现本申请实施例的解码器30的实例的示意性/概念性框图。视频解码器30用于接收例如由编码器20编码的经编码图片数据(例如，经编码比特流)21，以获取经解码图片231。在解码过程期间，视频解码器30从视频编码器20接收视频数据，例如表示经编码视频条带的图片块的经编码视频比特流及相关联的语法元素。3, which shows a schematic/conceptual block diagram of an example of a decoder 30 for implementing an embodiment of the present application. The video decoder 30 is used to receive, for example, coded picture data (e.g., coded bitstream) 21 encoded by the encoder 20 to obtain a decoded picture 231. During the decoding process, the video decoder 30 receives video data from the video encoder 20, such as a coded video bitstream representing picture blocks of a coded video slice and associated syntax elements.
在图3的实例中，解码器30包括熵解码单元304、逆量化单元310、逆变换处理单元312、重构单元314(例如求和器314)、缓冲器316、环路滤波器320、经解码图片缓冲器330以及预测处理单元360。预测处理单元360可以包含帧间预测单元344、帧内预测单元354和模式选择单元362。在一些实例中，视频解码器30可执行大体上与参照图2的视频编码器20描述的编码遍次互逆的解码遍次。3 , decoder 30 includes an entropy decoding unit 304, an inverse quantization unit 310, an inverse transform processing unit 312, a reconstruction unit 314 (e.g., summer 314), a buffer 316, a loop filter 320, a decoded picture buffer 330, and a prediction processing unit 360. Prediction processing unit 360 may include an inter-prediction unit 344, an intra-prediction unit 354, and a mode selection unit 362. In some examples, video decoder 30 may perform a decoding pass that is generally reciprocal to the encoding pass described with reference to video encoder 20 of FIG. 2 .
熵解码单元304用于对经编码图片数据21执行熵解码，以获取例如经量化系数309和/或经解码的编码参数(图3中未示出)，例如，帧间预测、帧内预测参数、环路滤波器参数和/或其它语法元素中(经解码)的任意一个或全部。熵解码单元304进一步用于将帧间预测参数、帧内预测参数和/或其它语法元素转发至预测处理单元360。视频解码器30可接收视频条带层级和/或视频块层级的语法元素。The entropy decoding unit 304 is used to perform entropy decoding on the encoded picture data 21 to obtain, for example, quantized coefficients 309 and/or decoded coding parameters (not shown in FIG. 3 ), such as any one or all of (decoded) inter-frame prediction, intra-frame prediction parameters, loop filter parameters, and/or other syntax elements. The entropy decoding unit 304 is further used to forward the inter-frame prediction parameters, intra-frame prediction parameters, and/or other syntax elements to the prediction processing unit 360. The video decoder 30 may receive syntax elements at the video slice level and/or the video block level.
逆量化单元310功能上可与逆量化单元110相同，逆变换处理单元312功能上可与逆变换处理单元212相同，重构单元314功能上可与重构单元214相同，缓冲器316功能上可与缓冲器216相同，环路滤波器320功能上可与环路滤波器220相同，经解码图片缓冲器330功能上可与经解码图片缓冲器230相同。The inverse quantization unit 310 may be functionally the same as the inverse quantization unit 110, the inverse transform processing unit 312 may be functionally the same as the inverse transform processing unit 212, the reconstruction unit 314 may be functionally the same as the reconstruction unit 214, the buffer 316 may be functionally the same as the buffer 216, the loop filter 320 may be functionally the same as the loop filter 220, and the decoded picture buffer 330 may be functionally the same as the decoded picture buffer 230.
预测处理单元360可以包括帧间预测单元344和帧内预测单元354，其中帧间预测单元344功能上可以类似于帧间预测单元244，帧内预测单元354功能上可以类似于帧内预测单元254。预测处理单元360通常用于执行块预测和/或从经编码数据21获取预测块365，以及从例如熵解码单元304(显式地或隐式地)接收或获取预测相关参数和/或关于所选择的预测模式的信息。The prediction processing unit 360 may include an inter-frame prediction unit 344 and an intra-frame prediction unit 354, wherein the inter-frame prediction unit 344 may be functionally similar to the inter-frame prediction unit 244, and the intra-frame prediction unit 354 may be functionally similar to the intra-frame prediction unit 254. The prediction processing unit 360 is generally used to perform block prediction and/or obtain a prediction block 365 from the encoded data 21, and receive or obtain prediction related parameters and/or information about the selected prediction mode from, for example, the entropy decoding unit 304 (explicitly or implicitly).
当视频条带经编码为经帧内编码(I)条带时，预测处理单元360的帧内预测单元354用于基于信号表示的帧内预测模式及来自当前帧或图片的先前经解码块的数据来产生用于当前视频条带的图片块的预测块365。当视频帧经编码为经帧间编码(即B或P)条带时，预测处理单元360的帧间预测单元344(例如，运动补偿单元)用于基于运动向量及从熵解码单元304接收的其它语法元素生成用于当前视频条带的视频块的预测块365。对于帧间预测，可从一个参考图片列表内的一个参考图片中产生预测块。视频解码器30可基于存储于DPB 330中的参考图片，使用默认建构技术来建构参考帧列表：列表0和列表1。When the video slice is encoded as an intra-coded (I) slice, the intra-prediction unit 354 of the prediction processing unit 360 is used to generate a prediction block 365 for a picture block of the current video slice based on the signaled intra-prediction mode and data from a previously decoded block of the current frame or picture. When the video frame is encoded as an inter-coded (i.e., B or P) slice, the inter-prediction unit 344 (e.g., motion compensation unit) of the prediction processing unit 360 is used to generate a prediction block 365 for the video block of the current video slice based on the motion vector and other syntax elements received from the entropy decoding unit 304. For inter-prediction, the prediction block may be generated from one of the reference pictures within one of the reference picture lists. Video decoder 30 may construct reference frame lists: List 0 and List 1 using a default construction technique based on the reference pictures stored in DPB 330.
预测处理单元360用于通过解析运动向量和其它语法元素，确定用于当前视频条带的视频块的预测信息，并使用预测信息产生用于正经解码的当前视频块的预测块。在本申请的一实例中，预测处理单元360使用接收到的一些语法元素确定用于编码视频条带的视频块的预测模式(例如，帧内或帧间预测)、帧间预测条带类型(例如，B条带、P条带或GPB条带)、用于条带的参考图片列表中的一个或多个的建构信息、用于条带的每个经帧间编码视频块的运动向量、条带的每个经帧间编码视频块的帧间预测状态以及其它信息，以解码当前视频条带的视频块。在本申请的另一实例中，视频解码器30从比特流接收的语法元素包含接收自适应参数集(adaptive parameter set，APS)、序列参数集(sequenceparameter set，SPS)、图片参数集(picture parameter set，PPS)或条带标头中的一个或多个中的语法元素。The prediction processing unit 360 is configured to determine prediction information for a video block of a current video slice by parsing motion vectors and other syntax elements, and to generate a prediction block for the current video block being decoded using the prediction information. In one example of the present application, the prediction processing unit 360 uses some of the received syntax elements to determine a prediction mode (e.g., intra-frame or inter-frame prediction) for encoding a video block of a video slice, an inter-frame prediction slice type (e.g., a B slice, a P slice, or a GPB slice), construction information of one or more of a reference picture list for the slice, a motion vector for each inter-frame coded video block of the slice, an inter-frame prediction state of each inter-frame coded video block of the slice, and other information to decode the video block of the current video slice. In another example of the present application, the syntax elements received by the video decoder 30 from the bitstream include syntax elements received in one or more of an adaptive parameter set (APS), a sequence parameter set (SPS), a picture parameter set (PPS), or a slice header.
逆量化单元310可用于逆量化(即，反量化)在比特流中提供且由熵解码单元304解码的经量化变换系数。逆量化过程可包含使用由视频编码器20针对视频条带中的每一视频块所计算的量化参数来确定应该应用的量化程度并同样确定应该应用的逆量化程度。Inverse quantization unit 310 may be used to inverse quantize (i.e., dequantize) quantized transform coefficients provided in the bitstream and decoded by entropy decoding unit 304. The inverse quantization process may include using quantization parameters calculated by video encoder 20 for each video block in a video slice to determine a degree of quantization that should be applied and likewise a degree of inverse quantization that should be applied.
逆变换处理单元312用于将逆变换(例如，逆DCT、逆整数变换或概念上类似的逆变换过程)应用于变换系数，以便在像素域中产生残差块。The inverse transform processing unit 312 is used to apply an inverse transform (eg, an inverse DCT, an inverse integer transform, or a conceptually similar inverse transform process) to the transform coefficients to generate a residual block in the pixel domain.
重构单元314(例如，求和器314)用于将逆变换块313(即经重构残差块313)添加到预测块365，以在样本域中获取经重构块315，例如通过将经重构残差块313的样本值与预测块365的样本值相加。The reconstruction unit 314 (e.g., the summer 314) is used to add the inverse transform block 313 (i.e., the reconstructed residual block 313) to the prediction block 365 to obtain the reconstructed block 315 in the sample domain, for example, by adding the sample values of the reconstructed residual block 313 to the sample values of the prediction block 365.
环路滤波器单元320(在编码循环期间或在编码循环之后)用于对经重构块315进行滤波以获取经滤波块321，从而顺利进行像素转变或提高视频质量。在一个实例中，环路滤波器单元320可以用于执行下文描述的滤波技术的任意组合。环路滤波器单元320旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset，SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元320在图3中示出为环内滤波器，但在其它配置中，环路滤波器单元320可实施为环后滤波器。The loop filter unit 320 (during or after the encoding cycle) is used to filter the reconstructed block 315 to obtain the filtered block 321, so as to smoothly perform pixel conversion or improve video quality. In one example, the loop filter unit 320 can be used to perform any combination of filtering techniques described below. The loop filter unit 320 is intended to represent one or more loop filters, such as a deblocking filter, a sample adaptive offset (sample-adaptive offset, SAO) filter or other filter, such as a bilateral filter, an adaptive loop filter (adaptive loop filter, ALF), or a sharpening or smoothing filter, or a collaborative filter. Although the loop filter unit 320 is shown as an in-loop filter in FIG. 3, in other configurations, the loop filter unit 320 can be implemented as a post-loop filter.
随后将给定帧或图片中的经解码视频块321存储在存储用于后续运动补偿的参考图片的经解码图片缓冲器330中。The decoded video blocks 321 in a given frame or picture are then stored in a decoded picture buffer 330 which stores reference pictures for subsequent motion compensation.
解码器30用于例如，藉由输出332输出经解码图片31，以向用户呈现或供用户查看。Decoder 30 is operable to output decoded picture 31 , eg, via output 332 , for presentation to or viewing by a user.
视频解码器30的其它变型可用于对压缩的比特流进行解码。例如，解码器30可以在没有环路滤波器单元320的情况下生成输出视频流。例如，基于非变换的解码器30可以在没有针对某些块或帧的逆变换处理单元312的情况下直接逆量化残差信号。在另一实施方式中，视频解码器30可以具有组合成单个单元的逆量化单元310和逆变换处理单元312。Other variations of the video decoder 30 may be used to decode the compressed bitstream. For example, the decoder 30 may generate an output video stream without the loop filter unit 320. For example, a non-transform based decoder 30 may directly inverse quantize the residual signal without the inverse transform processing unit 312 for certain blocks or frames. In another embodiment, the video decoder 30 may have the inverse quantization unit 310 and the inverse transform processing unit 312 combined into a single unit.
具体的，在本申请实施例中，解码器30用于实现后文实施例中描述的视频解码法。Specifically, in the embodiment of the present application, the decoder 30 is used to implement the video decoding method described in the embodiments below.
应当理解的是，本申请中的视频编码器可以只包括视频编码器30中的部分模块，例如，本申请中的视频编码器可以包括划分单元和图像编码单元。其中，图像编码单元可以由预测单元、变换单元、量化单元和熵编码单元中的一种或者多种单元组成。It should be understood that the video encoder in the present application may include only some modules in the video encoder 30. For example, the video encoder in the present application may include a partition unit and an image encoding unit. The image encoding unit may be composed of one or more units of a prediction unit, a transform unit, a quantization unit, and an entropy encoding unit.
另外，视频解码器30的其它结构变化可用于解码经编码视频位流。例如，视频解码器30可以不经滤波器320处理而生成输出视频流；或者，对于某些图像块或者图像帧，视频解码器30的熵解码单元304没有解码出经量化的系数，相应地不需要经逆量化单元310和逆变换处理单元312处理。环路滤波器320是可选的；以及针对无损压缩的情况下，逆量化单元310和逆变换处理单元312是可选的。应当理解的是，根据不同的应用场景，帧间预测单元和帧内预测单元可以是被选择性的启用。In addition, other structural changes of the video decoder 30 can be used to decode the encoded video bitstream. For example, the video decoder 30 can generate an output video stream without being processed by the filter 320; or, for some image blocks or image frames, the entropy decoding unit 304 of the video decoder 30 does not decode the quantized coefficients, and accordingly does not need to be processed by the inverse quantization unit 310 and the inverse transform processing unit 312. The loop filter 320 is optional; and for lossless compression, the inverse quantization unit 310 and the inverse transform processing unit 312 are optional. It should be understood that, according to different application scenarios, the inter-frame prediction unit and the intra-frame prediction unit can be selectively enabled.
应当理解的是，本申请的编码器20和解码器30中，针对某个环节的处理结果可以经过进一步处理后，输出到下一个环节，例如，在插值滤波、运动矢量推导或环路滤波等环节之后，对相应环节的处理结果进一步进行钳位(clip)或移位(shift)等操作。It should be understood that in the encoder 20 and decoder 30 of the present application, the processing result of a certain link can be output to the next link after further processing. For example, after the interpolation filtering, motion vector derivation or loop filtering links, the processing result of the corresponding link can be further clamped (clip) or shifted (shift) and other operations.
例如，按照相邻仿射编码块(采用仿射运动模型进行预测的编码块可以称为仿射编码块)的运动矢量推导得到的当前图像块的控制点的运动矢量，或者推导得到的当前图像块的子块的运动矢量，可以做进一步的处理，本申请对此不做限定。例如，对运动矢量的取值范围进行约束，使其在一定的位宽内。假设允许的运动矢量的位宽为bitDepth，则运动矢量的范围为-2^(bitDepth-1)～2^(bitDepth-1)-1，其中“^”符号表示幂次方。如bitDepth为16，则取值范围为-32768～32767。如bitDepth为18，则取值范围为-131072～131071。For example, the motion vector of the control point of the current image block derived from the motion vector of the adjacent affine coding block (the coding block predicted by the affine motion model can be called an affine coding block), or the motion vector of the sub-block of the current image block derived, can be further processed, and this application does not limit this. For example, the value range of the motion vector is constrained so that it is within a certain bit width. Assuming that the bit width of the allowed motion vector is bitDepth, the range of the motion vector is -2^(bitDepth-1)~2^(bitDepth-1)-1, where the "^" symbol represents the power. If bitDepth is 16, the value range is -32768~32767. If bitDepth is 18, the value range is -131072~131071.
再如，还可以对运动矢量(例如一个8x8图像块内的四个4x4子块的运动矢量MV)的取值进行约束，使得所述四个4x4子块MV的整数部分之间的最大差值不超过N(例如，N可以取1)个像素。For example, the value of the motion vector (for example, the motion vector MV of four 4x4 sub-blocks in an 8x8 image block) can also be constrained so that the maximum difference between the integer parts of the four 4x4 sub-blocks MV does not exceed N (for example, N can be 1) pixels.
参见图4，图4是根据一示例性实施例的包含图2的编码器20和/或图3的解码器30的视频译码系统40的实例的说明图。视频译码系统40可以实现本申请实施例的各种技术的组合。在所说明的实施方式中，视频译码系统40可以包含成像设备41、编码器20、解码器30(和/或藉由处理单元46的逻辑电路47实施的视频编/解码器)、天线42、一个或多个处理器43、一个或多个存储器44和/或显示设备45。Referring to FIG. 4 , FIG. 4 is an illustrative diagram of an example of a video decoding system 40 including the encoder 20 of FIG. 2 and/or the decoder 30 of FIG. 3 according to an exemplary embodiment. The video decoding system 40 may implement a combination of various techniques of the embodiments of the present application. In the illustrated embodiment, the video decoding system 40 may include an imaging device 41, an encoder 20, a decoder 30 (and/or a video codec implemented by a logic circuit 47 of a processing unit 46), an antenna 42, one or more processors 43, one or more memories 44, and/or a display device 45.
如图4所示，成像设备41、天线42、处理单元46、逻辑电路47、编码器20、解码器30、处理器43、存储器44和/或显示设备45能够互相通信。如所论述，虽然用编码器20和解码器30绘示视频译码系统40，但在不同实例中，视频译码系统40可以只包含编码器20或只包含解码器30。4, imaging device 41, antenna 42, processing unit 46, logic circuit 47, encoder 20, decoder 30, processor 43, memory 44, and/or display device 45 are capable of communicating with each other. As discussed, although video decoding system 40 is illustrated with encoder 20 and decoder 30, in different examples, video decoding system 40 may include only encoder 20 or only decoder 30.
在一些实例中，天线42可以用于传输或接收视频数据的经编码比特流。另外，在一些实例中，显示设备45可以用于呈现视频数据。在一些实例中，逻辑电路47可以通过处理单元46实施。处理单元46可以包含专用集成电路(application-specific integratedcircuit，ASIC)逻辑、图形处理器、通用处理器等。视频译码系统40也可以包含可选的处理器43，该可选处理器43类似地可以包含专用集成电路(application-specific integratedcircuit，ASIC)逻辑、图形处理器、通用处理器等。在一些实例中，逻辑电路47可以通过硬件实施，如视频编码专用硬件等，处理器43可以通过通用软件、操作系统等实施。另外，存储器44可以是任何类型的存储器，例如易失性存储器(例如，静态随机存取存储器(staticrandom access memory，SRAM)、动态随机存储器(dynamic random access memory，DRAM)等)或非易失性存储器(例如，闪存等)等。在非限制性实例中，存储器44可以由超速缓存内存实施。在一些实例中，逻辑电路47可以访问存储器44(例如用于实施图像缓冲器)。在其它实例中，逻辑电路47和/或处理单元46可以包含存储器(例如，缓存等)用于实施图像缓冲器等。In some examples, antenna 42 can be used to transmit or receive a coded bit stream of video data. In addition, in some examples, display device 45 can be used to present video data. In some examples, logic circuit 47 can be implemented by processing unit 46. Processing unit 46 can include application-specific integrated circuit (ASIC) logic, graphics processor, general processor, etc. Video decoding system 40 can also include optional processor 43, which can similarly include application-specific integrated circuit (ASIC) logic, graphics processor, general processor, etc. In some examples, logic circuit 47 can be implemented by hardware, such as video encoding dedicated hardware, etc., and processor 43 can be implemented by general software, operating system, etc. In addition, memory 44 can be any type of memory, such as volatile memory (e.g., static random access memory (SRAM), dynamic random access memory (DRAM), etc.) or non-volatile memory (e.g., flash memory, etc.). In a non-limiting example, memory 44 can be implemented by cache memory. In some examples, logic circuitry 47 may access memory 44 (eg, for implementing an image buffer). In other examples, logic circuitry 47 and/or processing unit 46 may include memory (eg, cache, etc.) for implementing an image buffer, etc.
在一些实例中，通过逻辑电路实施的编码器20可以包含(例如，通过处理单元46或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的编码器20，以实施参照图2和/或本文中所描述的任何其它编码器系统或子系统所论述的各种模块。逻辑电路可以用于执行本文所论述的各种操作。In some examples, encoder 20 implemented by logic circuits may include an image buffer (e.g., implemented by processing unit 46 or memory 44) and a graphics processing unit (e.g., implemented by processing unit 46). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include encoder 20 implemented by logic circuits 47 to implement the various modules discussed with reference to FIG. 2 and/or any other encoder system or subsystem described herein. The logic circuits may be used to perform the various operations discussed herein.
在一些实例中，解码器30可以以类似方式通过逻辑电路47实施，以实施参照图3的解码器30和/或本文中所描述的任何其它解码器系统或子系统所论述的各种模块。在一些实例中，逻辑电路实施的解码器30可以包含(通过处理单元2820或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的解码器30，以实施参照图3和/或本文中所描述的任何其它解码器系统或子系统所论述的各种模块。In some examples, the decoder 30 may be implemented by logic circuit 47 in a similar manner to implement the various modules discussed with reference to the decoder 30 of FIG. 3 and/or any other decoder systems or subsystems described herein. In some examples, the decoder 30 implemented by logic circuit may include an image buffer (implemented by processing unit 2820 or memory 44) and a graphics processing unit (implemented, for example, by processing unit 46). The graphics processing unit may be communicatively coupled to the image buffer. The graphics processing unit may include the decoder 30 implemented by logic circuit 47 to implement the various modules discussed with reference to FIG. 3 and/or any other decoder systems or subsystems described herein.
在一些实例中，天线42可以用于接收视频数据的经编码比特流。如所论述，经编码比特流可以包含本文所论述的与编码视频帧相关的数据、指示符、索引值、模式选择数据等，例如与编码分割相关的数据(例如，变换系数或经量化变换系数，(如所论述的)可选指示符，和/或定义编码分割的数据)。视频译码系统40还可包含耦合至天线42并用于解码经编码比特流的解码器30。显示设备45用于呈现视频帧。In some examples, antenna 42 may be used to receive an encoded bitstream of video data. As discussed, the encoded bitstream may include data related to the encoded video frames discussed herein, indicators, index values, mode selection data, etc., such as data related to the encoded partitions (e.g., transform coefficients or quantized transform coefficients, (as discussed) optional indicators, and/or data defining the encoded partitions). Video decoding system 40 may also include decoder 30 coupled to antenna 42 and used to decode the encoded bitstream. Display device 45 is used to present the video frames.
应理解，本申请实施例中对于参考编码器20所描述的实例，解码器30可以用于执行相反过程。关于信令语法元素，解码器30可以用于接收并解析这种语法元素，相应地解码相关视频数据。在一些例子中，编码器20可以将语法元素熵编码成经编码视频比特流。在此类实例中，解码器30可以解析这种语法元素，并相应地解码相关视频数据。It should be understood that in the embodiments of the present application, for the examples described with reference to encoder 20, decoder 30 can be used to perform the reverse process. With respect to signaling syntax elements, decoder 30 can be used to receive and parse such syntax elements and decode the associated video data accordingly. In some examples, encoder 20 can entropy encode the syntax elements into an encoded video bitstream. In such examples, decoder 30 can parse such syntax elements and decode the associated video data accordingly.
参见图5，图5是本申请实施例提供的视频译码设备400(例如视频编码设备400或视频解码设备400)的结构示意图。视频译码设备400适于实施本文所描述的实施例。在一个实施例中，视频译码设备400可以是视频解码器(例如图3的解码器30)或视频编码器(例如图2的编码器20)。在另一个实施例中，视频译码设备400可以是上述图3的解码器30或图2的编码器20中的一个或多个组件。Referring to FIG. 5 , FIG. 5 is a schematic diagram of the structure of a video decoding device 400 (e.g., a video encoding device 400 or a video decoding device 400) provided in an embodiment of the present application. The video decoding device 400 is suitable for implementing the embodiments described herein. In one embodiment, the video decoding device 400 may be a video decoder (e.g., the decoder 30 of FIG. 3 ) or a video encoder (e.g., the encoder 20 of FIG. 2 ). In another embodiment, the video decoding device 400 may be one or more components of the decoder 30 of FIG. 3 or the encoder 20 of FIG. 2 .
视频译码设备400包括：用于接收数据的入口端口410和接收单元(Rx)420，用于处理数据的处理器、逻辑单元或中央处理器(CPU)430，用于传输数据的发射器单元(Tx)440和出口端口450，以及，用于存储数据的存储器460。视频译码设备400还可以包括与入口端口410、接收器单元420、发射器单元440和出口端口450耦合的光电转换组件和电光(EO)组件，用于光信号或电信号的出口或入口。The video decoding device 400 includes: an inlet port 410 and a receiving unit (Rx) 420 for receiving data, a processor, a logic unit or a central processing unit (CPU) 430 for processing data, a transmitter unit (Tx) 440 and an outlet port 450 for transmitting data, and a memory 460 for storing data. The video decoding device 400 may also include an optical-to-electrical conversion component and an electro-optical (EO) component coupled to the inlet port 410, the receiver unit 420, the transmitter unit 440 and the outlet port 450 for the outlet or inlet of an optical signal or an electrical signal.
处理器430通过硬件和软件实现。处理器430可以实现为一个或多个CPU芯片、核(例如，多核处理器)、FPGA、ASIC和DSP。处理器430与入口端口410、接收器单元420、发射器单元440、出口端口450和存储器460通信。处理器430包括译码模块470(例如编码模块470或解码模块470)。编码/解码模块470实现本文中所公开的实施例，以实现本申请实施例所提供的图像预测方法。例如，编码/解码模块470实现、处理或提供各种编码操作。因此，通过编码/解码模块470为视频译码设备400的功能提供了实质性的改进，并影响了视频译码设备400到不同状态的转换。或者，以存储在存储器460中并由处理器430执行的指令来实现编码/解码模块470。The processor 430 is implemented by hardware and software. The processor 430 can be implemented as one or more CPU chips, cores (e.g., multi-core processors), FPGAs, ASICs, and DSPs. The processor 430 communicates with the inlet port 410, the receiver unit 420, the transmitter unit 440, the outlet port 450, and the memory 460. The processor 430 includes a decoding module 470 (e.g., an encoding module 470 or a decoding module 470). The encoding/decoding module 470 implements the embodiments disclosed herein to implement the image prediction method provided in the embodiments of the present application. For example, the encoding/decoding module 470 implements, processes, or provides various encoding operations. Therefore, the encoding/decoding module 470 provides substantial improvements to the functions of the video decoding device 400 and affects the conversion of the video decoding device 400 to different states. Alternatively, the encoding/decoding module 470 is implemented with instructions stored in the memory 460 and executed by the processor 430.
存储器460包括一个或多个磁盘、磁带机和固态硬盘，可以用作溢出数据存储设备，用于在选择性地执行这些程序时存储程序，并存储在程序执行过程中读取的指令和数据。存储器460可以是易失性和/或非易失性的，可以是只读存储器(ROM)、随机存取存储器(RAM)、随机存取存储器(ternary content-addressable memory，TCAM)和/或静态随机存取存储器(SRAM)。The memory 460 includes one or more disks, tape drives, and solid-state drives, and can be used as an overflow data storage device for storing programs when these programs are selectively executed, and for storing instructions and data read during program execution. The memory 460 can be volatile and/or non-volatile, and can be a read-only memory (ROM), a random access memory (RAM), a ternary content-addressable memory (TCAM), and/or a static random access memory (SRAM).
参见图6，图6是根据一示例性实施例的可用作图1中的源设备12和目的地设备14中的任一个或两个的装置500的简化框图。装置500可以实现本申请实施例的图像预测方法。换言之，图6为本申请实施例的编码设备或解码设备(简称为译码设备500)的一种实现方式的示意性框图。其中，译码设备500可以包括处理器510、存储器530和总线系统550。其中，处理器和存储器通过总线系统相连，该存储器用于存储指令，该处理器用于执行该存储器存储的指令。译码设备的存储器存储程序代码，且处理器可以调用存储器中存储的程序代码执行本申请描述的各种视频编码或解码方法，尤其是各种新的图像块的划分方法。为避免重复，这里不再详细描述。Referring to FIG. 6 , FIG. 6 is a simplified block diagram of an apparatus 500 that can be used as either or both of the source device 12 and the destination device 14 in FIG. 1 according to an exemplary embodiment. The apparatus 500 can implement the image prediction method of the embodiment of the present application. In other words, FIG. 6 is a schematic block diagram of an implementation method of the encoding device or decoding device (referred to as the decoding device 500 ) of the embodiment of the present application. Among them, the decoding device 500 may include a processor 510, a memory 530 and a bus system 550. Among them, the processor and the memory are connected via a bus system, the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory. The memory of the decoding device stores program code, and the processor can call the program code stored in the memory to execute various video encoding or decoding methods described in the present application, especially various new image block division methods. To avoid repetition, it is not described in detail here.
在本申请实施例中，该处理器510可以是中央处理单元(central processingunit，CPU)，该处理器510还可以是其他通用处理器、数字信号处理器(DSP)、专用集成电路(ASIC)、现成可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。In the embodiment of the present application, the processor 510 may be a central processing unit (CPU), and the processor 510 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.
该存储器530可以包括只读存储器(ROM)设备或者随机存取存储器(RAM)设备。任何其他适宜类型的存储设备也可以用作存储器530。存储器530可以包括由处理器510使用总线550访问的代码和数据531。存储器530可以进一步包括操作系统533和应用程序535，该应用程序535包括允许处理器510执行本申请描述的视频编码或解码方法的至少一个程序。例如，应用程序535可以包括应用1至N，其进一步包括执行在本申请描述的视频编码或解码方法的视频编码或解码应用(简称视频译码应用)。The memory 530 may include a read-only memory (ROM) device or a random access memory (RAM) device. Any other suitable type of storage device may also be used as the memory 530. The memory 530 may include code and data 531 accessed by the processor 510 using the bus 550. The memory 530 may further include an operating system 533 and an application 535, which includes at least one program that allows the processor 510 to perform the video encoding or decoding method described in the present application. For example, the application 535 may include applications 1 to N, which further include a video encoding or decoding application (referred to as a video decoding application) that executes the video encoding or decoding method described in the present application.
该总线系统550除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。但是为了清楚说明起见，在图中将各种总线都标为总线系统550。The bus system 550 may include, in addition to the data bus, a power bus, a control bus, a status signal bus, etc. However, for the sake of clarity, various buses are labeled as the bus system 550 in the figure.
可选的，译码设备500还可以包括一个或多个输出设备，诸如显示器570。在一个示例中，显示器570可以是触感显示器，其将显示器与可操作地感测触摸输入的触感单元合并。显示器570可以经由总线550连接到处理器510。Optionally, the decoding device 500 may further include one or more output devices, such as a display 570. In one example, the display 570 may be a touch-sensitive display that combines a display with a touch-sensitive unit operable to sense touch input. The display 570 may be connected to the processor 510 via the bus 550.
图7是本申请实施例的视频通信系统的示意性框图。FIG. 7 is a schematic block diagram of a video communication system according to an embodiment of the present application.
图7所示的视频通信系统500包括源装置600和目的地装置700，其中，源装置600能够对获取到的视频进行编码，并将编码后的视频码流传输给接收装置700，目的地装置700能够对接收到的视频码流进行解析，得到视频图像，并通过显示装置显示该视频。The video communication system 500 shown in Figure 7 includes a source device 600 and a destination device 700, wherein the source device 600 can encode the acquired video and transmit the encoded video stream to the receiving device 700, and the destination device 700 can parse the received video stream to obtain a video image and display the video through a display device.
本申请实施例的图像预测方法可以应用于视频编码器的熵编码处理或者视频解码器的熵解码处理。如图7所示，本申请实施例的图像预测方法可以由源装置600或者目的地装置700来执行。具体地，本申请实施例的图像预测方法可以由视频编码器603或者视频解码器702来执行。The image prediction method of the embodiment of the present application can be applied to the entropy encoding process of the video encoder or the entropy decoding process of the video decoder. As shown in Figure 7, the image prediction method of the embodiment of the present application can be performed by the source device 600 or the destination device 700. Specifically, the image prediction method of the embodiment of the present application can be performed by the video encoder 603 or the video decoder 702.
上述视频通信系统500还可以称为视频编解码系统，源装置600也可以被称为视频编码装置或视频编码设备，目的地装置700也可以被称为视频解码装置或视频解码设备。The video communication system 500 may also be referred to as a video coding and decoding system, the source device 600 may also be referred to as a video coding device or a video coding apparatus, and the destination device 700 may also be referred to as a video decoding device or a video decoding apparatus.
在图7中，源装置600包含视频俘获装置601、视频存储器602、视频编码器603以及发射器604。视频存储器602可以存储视频俘获装置601获得的视频，视频编码器603可以编码来自视频存储器602和视频俘获装置601的视频数据。在一些实例中，源装置600经由发射器604将编码后的视频数据直接发射到目的地装置700。编码后的视频数据还可存储于存储媒体或文件服务器上以供目的地装置700稍后提取以用于解码及/或播放。7 , source device 600 includes video capture device 601, video memory 602, video encoder 603, and transmitter 604. Video memory 602 may store video obtained by video capture device 601, and video encoder 603 may encode video data from video memory 602 and video capture device 601. In some examples, source device 600 transmits the encoded video data directly to destination device 700 via transmitter 604. The encoded video data may also be stored on a storage medium or a file server for later retrieval by destination device 700 for decoding and/or playback.
在图7中，目的地装置700包含接收器701、视频解码器702及显示装置703。在一些实例中，接收器701可经由信道800接收编码后的视频数据。显示装置703可与目的地装置700整合或可在目的地装置7000外部。一般来说，显示装置700显示解码后的视频数据。显示装置700可包括多种显示装置，例如液晶显示器、等离子体显示器、有机发光二极管显示器或其它类型的显示装置。7 , destination device 700 includes a receiver 701, a video decoder 702, and a display device 703. In some examples, receiver 701 may receive encoded video data via channel 800. Display device 703 may be integrated with destination device 700 or may be external to destination device 700. In general, display device 700 displays decoded video data. Display device 700 may include a variety of display devices, such as a liquid crystal display, a plasma display, an organic light emitting diode display, or other types of display devices.
源装置600和目的地装置700的具体实现形式可以是如下设备中的任意一种：台式计算机、移动计算装置、笔记本(例如，膝上型)计算机、平板计算机、机顶盒、智能电话、手持机、电视、相机、显示装置、数字媒体播放器、视频游戏控制台、车载计算机，或者其它类似的设备。The specific implementation form of the source device 600 and the destination device 700 can be any of the following devices: a desktop computer, a mobile computing device, a notebook (e.g., laptop) computer, a tablet computer, a set-top box, a smart phone, a handheld device, a television, a camera, a display device, a digital media player, a video game console, a car computer, or other similar devices.
目的地装置700可以经由信道800接收来自源装置600编码后的视频数据。信道800可包括能够将编码后的视频数据从源装置600移动到目的地装置700的一个或多个媒体及/或装置。在一个实例中，信道800可以包括使源装置600能够实时地将编码后的视频数据直接发射到目的地装置700的一个或多个通信媒体，在此实例中，源装置600可以根据通信标准(例如，无线通信协议)来调制编码后的视频数据，并且可以将调制后的视频数据发射到目的地装置700。上述一个或多个通信媒体可以包含无线及/或有线通信媒体，例如射频(radio frequency，RF)频谱或一根或多根物理传输线。上述一个或多个通信媒体可以形成基于包的网络(例如，局域网、广域网或全球网络(例如，因特网))的部分。上述一个或多个通信媒体可以包含路由器、交换器、基站，或者实现从源装置600到目的地装置700的通信的其它设备。The destination device 700 may receive the encoded video data from the source device 600 via the channel 800. The channel 800 may include one or more media and/or devices capable of moving the encoded video data from the source device 600 to the destination device 700. In one example, the channel 800 may include one or more communication media that enable the source device 600 to transmit the encoded video data directly to the destination device 700 in real time, in which case the source device 600 may modulate the encoded video data according to a communication standard (e.g., a wireless communication protocol) and may transmit the modulated video data to the destination device 700. The one or more communication media may include wireless and/or wired communication media, such as a radio frequency (RF) spectrum or one or more physical transmission lines. The one or more communication media may form part of a packet-based network (e.g., a local area network, a wide area network, or a global network (e.g., the Internet)). The one or more communication media may include routers, switches, base stations, or other devices that enable communication from the source device 600 to the destination device 700.
在另一实例中，信道800可包含存储由源装置600产生的编码后的视频数据的存储媒体。在此实例中，目的地装置700可经由磁盘存取或卡存取来存取存储媒体。存储媒体可包含多种本地存取式数据存储媒体，例如蓝光光盘、高密度数字视频光盘(digital videodisc，DVD)、只读光盘(compact disc read-only memory，CD-ROM)、快闪存储器，或用于存储经编码视频数据的其它合适数字存储媒体。In another example, channel 800 may include a storage medium storing the encoded video data generated by source device 600. In this example, destination device 700 may access the storage medium via disk access or card access. The storage medium may include a variety of locally accessible data storage media, such as Blu-ray discs, digital video discs (DVDs), compact disc read-only memories (CD-ROMs), flash memory, or other suitable digital storage media for storing encoded video data.
在另一实例中，信道800可包含文件服务器或存储由源装置600产生的编码后的视频数据的另一中间存储装置。在此实例中，目的地装置700可经由流式传输或下载来存取存储于文件服务器或其它中间存储装置处的编码后的视频数据。文件服务器可以是能够存储编码后的视频数据且将所述编码后的视频数据发射到目的地装置700的服务器类型。例如，文件服务器可以包含全球广域网(world wide web，Web)服务器(例如，用于网站)、文件传送协议(file transfer protocol，FTP)服务器、网络附加存储(network attachedstorage，NAS)装置以及本地磁盘驱动器。In another example, channel 800 may include a file server or another intermediate storage device storing the encoded video data generated by source device 600. In this example, destination device 700 may access the encoded video data stored at the file server or other intermediate storage device via streaming or downloading. The file server may be a type of server capable of storing the encoded video data and transmitting the encoded video data to destination device 700. For example, the file server may include a world wide web (Web) server (e.g., for a website), a file transfer protocol (FTP) server, a network attached storage (NAS) device, and a local disk drive.
目的地装置700可经由标准数据连接(例如，因特网连接)来存取编码后的视频数据。数据连接的实例类型包含适合于存取存储于文件服务器上的编码后的视频数据的无线信道、有线连接(例如，缆线调制解调器等)，或两者的组合。编码后的视频数据从文件服务器的发射可为流式传输、下载传输或两者的组合。Destination device 700 can access the encoded video data via a standard data connection (e.g., an Internet connection). Example types of data connections include a wireless channel suitable for accessing the encoded video data stored on a file server, a wired connection (e.g., a cable modem, etc.), or a combination of both. The transmission of the encoded video data from the file server can be a streaming transmission, a download transmission, or a combination of both.
基于上下文自适应的二进制算术编码(context-based adaptive binaryarithmetic coding,CABAC)是一种常用的熵编码(entropy coding)技术，用于语法元素值的编码和解码处理，它应用于H.264/AVC、H.265/HEVC和H.266/VVC等标准中。Context-based adaptive binary arithmetic coding (CABAC) is a commonly used entropy coding technology for encoding and decoding syntax element values. It is used in standards such as H.264/AVC, H.265/HEVC and H.266/VVC.
熵编码处理，以HEVC中的普通模式(regular mode)为例，主要包括三个步骤：Entropy coding, taking the regular mode in HEVC as an example, mainly includes three steps:
(1)将一个语法元素二值化为一个或多个二值的位元(bin)，每个位元的取值为0或1；(1) Binarize a syntax element into one or more binary bits (bins), where each bit has a value of 0 or 1;
(2)对每一个位元，根据上下文信息(例如，该语法元素对应节点周围已重建区域内的编码信息)确定这个位元的上下文模型；(2) for each bit, determining a context model for the bit based on context information (e.g., coding information in a reconstructed region around the node corresponding to the syntax element);
(3)根据该位元的上下文模型中的概率值对位元进行编码，并根据位元的值更新该上下文模型中的概率值。(3) Encode the bit according to the probability value in the context model of the bit, and update the probability value in the context model according to the value of the bit.
相应地，熵解码处理主要包括三个步骤：Accordingly, the entropy decoding process mainly includes three steps:
(1)对每一个位元，根据上下文信息(例如，该语法元素对应节点周围已重建区域内的编码信息)确定这个位元的上下文模型；(1) for each bit, determine the context model of the bit based on context information (e.g., the coding information in the reconstructed region around the node corresponding to the syntax element);
(2)根据上下文模型中的概率值对位元进行解码，并根据位元的值更新上下文模型中的概率值；(2) decoding the bit according to the probability value in the context model, and updating the probability value in the context model according to the value of the bit;
(3)根据解码得到的一个或多个位元的值，得到语法元素的值。(3) Obtain the value of the syntax element based on the value of one or more bits obtained by decoding.
上述根据上下文信息确定位元的上下文模型的过程，也可以称为上下文建模。通常，在编码处理和解码处理过程中，上下文建模方法是相同的。The above process of determining the context model of a bit element according to the context information may also be referred to as context modeling. Generally, the context modeling method is the same in the encoding process and the decoding process.
需要说明的是，上述语法元素二值化后得到的位元可以称为该语法元素对应的位元，位元的上下文模型是指语法元素对应的位元的上下文模型。下面为了便于理解，统一将语法元素对应的位元的上下文模型简称为语法元素对应的上下文模型。It should be noted that the bit obtained after binarization of the above syntax element can be called the bit corresponding to the syntax element, and the context model of the bit refers to the context model of the bit corresponding to the syntax element. For ease of understanding, the context model of the bit corresponding to the syntax element is uniformly referred to as the context model corresponding to the syntax element.
在VTM5中，一个语法元素对应的上下文模型可有多个，例如，根据周围块的编码信息的不同，一个语法元素可以有2个、3个、6个或9个上下文模型，这样的语法元素包括split_cu_flag、split_qt_flag、cu_skip_flag、pred_mode_flag及pred_mode_ibc_flag，编码处理和解码处理时会根据当前编码单元的相邻图像块的编码信息来确定该当前编码单元的语法元素对应的上下文模型编号。In VTM5, a syntax element may correspond to multiple context models. For example, depending on the coding information of the surrounding blocks, a syntax element may have 2, 3, 6 or 9 context models. Such syntax elements include split_cu_flag, split_qt_flag, cu_skip_flag, pred_mode_flag and pred_mode_ibc_flag. During encoding and decoding, the context model number corresponding to the syntax element of the current coding unit will be determined based on the coding information of the adjacent image blocks of the current coding unit.
在HEVC中，编码树节点的亮度块和色度块使用相同的划分方式划分为子节点，称为单一树(single tree)划分结构，因此，一个编码单元中包含了亮度像素和色度像素。而在VTM5中，对帧内图像(I picture)允许采用分离树(separate tree)划分结构，此时，从编码树上的某一节点A开始，节点A的亮度块可以采用亮度编码树(luma coding tree)划分，亮度编码树的叶节点为亮度编码单元(luma CU)，其中只包含亮度像素；节点A的色度块可以采用色度编码树(chroma coding tree)划分，色度编码树的叶节点为色度编码单元(chroma CU)，其中只包含色度像素。In HEVC, the luminance block and chrominance block of the coding tree node are divided into sub-nodes using the same division method, which is called a single tree division structure. Therefore, a coding unit contains luminance pixels and chrominance pixels. In VTM5, a separate tree division structure is allowed for intra-frame images (I picture). At this time, starting from a node A on the coding tree, the luminance block of node A can be divided using a luma coding tree, and the leaf node of the luma coding tree is a luma coding unit (luma CU), which only contains luminance pixels; the chrominance block of node A can be divided using a chroma coding tree, and the leaf node of the chroma coding tree is a chroma coding unit (chroma CU), which only contains chrominance pixels.
对于单一树划分结构，任意一个位置的亮度块的编码信息和该位置的色度块的编码信息是相同的；而对分离树划分结构，可能存在一个位置的亮度块的编码信息不同于该位置的色度块的编码信息的情况，例如，一个位置的亮度块的预测模式为帧内块拷贝预测模式(MODE_IBC)，而该位置的色度块的预测模式为帧内预测模式(MODE_INTRA)；又例如，一个位置的亮度块的宽为4，而该位置色度块的宽为16；又例如，一个位置的亮度块的四叉树深度为3，而该位置的色度块的四叉树深度为1。For a single tree partitioning structure, the encoding information of the luminance block at any position is the same as the encoding information of the chrominance block at that position; while for a separate tree partitioning structure, there may be a situation where the encoding information of the luminance block at one position is different from the encoding information of the chrominance block at that position, for example, the prediction mode of the luminance block at one position is the intra block copy prediction mode (MODE_IBC), while the prediction mode of the chrominance block at that position is the intra prediction mode (MODE_INTRA); for another example, the width of the luminance block at one position is 4, while the width of the chrominance block at that position is 16; for another example, the quadtree depth of the luminance block at one position is 3, while the quadtree depth of the chrominance block at that position is 1.
VTM5中，色度编码单元的pred_mode_ibc_flag的上下文模型编号确定方式中condL为左相邻块的亮度块的预测模式等于MODE_IBC，condA为上相邻块的亮度块的预测模式等于MODE_IBC。In VTM5, in the context model number determination method of pred_mode_ibc_flag of the chroma coding unit, condL is the prediction mode of the luminance block of the left adjacent block, which is equal to MODE_IBC, and condA is the prediction mode of the luminance block of the upper adjacent block, which is equal to MODE_IBC.
因此，在当前编码单元为色度编码单元的情况下，在编码处理和解码处理时，使用相邻的亮度块的编码信息来确定当前编码单元的上下文模型编号，会导致编解码效率较低。Therefore, when the current coding unit is a chroma coding unit, using the coding information of the adjacent luminance block to determine the context model number of the current coding unit during the encoding and decoding processes will result in low encoding and decoding efficiency.
针对上述问题，本申请提出一种图像预测方法，可以提高视频编解码的压缩效率，从而能够提高编解码效率。In view of the above problems, the present application proposes an image prediction method, which can improve the compression efficiency of video encoding and decoding, thereby improving the encoding and decoding efficiency.
下面结合具体附图对本申请实施例的图像预测方法进行详细的介绍。The image prediction method of the embodiment of the present application is described in detail below with reference to specific drawings.
图8是本申请实施例的图像预测方法的示意性流程图。图8所示的图像预测方法可以由图像预测装置(该图像预测装置可以位于图像解码装置(系统)或者图像编码装置(系统)中)执行，具体地，图8所示的方法可以图像编码装置或者图像解码装置执行。图8所示的方法既可以在编码端执行，也可以在解码端执行，图8所示的方法800包括步骤810、820及830，下面对这些步骤进行详细的介绍。FIG8 is a schematic flow chart of an image prediction method according to an embodiment of the present application. The image prediction method shown in FIG8 can be performed by an image prediction device (the image prediction device can be located in an image decoding device (system) or an image encoding device (system)). Specifically, the method shown in FIG8 can be performed by an image encoding device or an image decoding device. The method shown in FIG8 can be performed at the encoding end or at the decoding end. The method 800 shown in FIG8 includes steps 810, 820, and 830. These steps are described in detail below.
S810，确定当前编码单元的类型。S810, determine the type of the current coding unit.
所述当前编码单元的类型可以为亮度色度编码单元、亮度编码单元或色度编码单元。其中，亮度色度编码单元指包括亮度块和色度块的编码单元，亮度编码单元指包括亮度块的编码单元，色度编码单元指包括色度块的编码单元。The type of the current coding unit may be a luma-chroma coding unit, a luma coding unit or a chroma coding unit, wherein the luma-chroma coding unit refers to a coding unit including a luma block and a chroma block, the luma coding unit refers to a coding unit including a luma block, and the chroma coding unit refers to a coding unit including a chroma block.
S820，根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定当前编码单元的预测模式。S820: Determine a prediction mode of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block.
其中，所述当前编码单元中的图像块与所述相邻图像块为空间相邻的图像块，所述相邻图像块包括相邻的亮度块和/或相邻的色度块。The image block in the current coding unit and the adjacent image block are spatially adjacent image blocks, and the adjacent image blocks include adjacent luminance blocks and/or adjacent chrominance blocks.
可选地，所述根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定当前编码单元的预测模式，可以包括：根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定所述当前编码单元的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码单元的预测模式。Optionally, determining the prediction mode of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block may include: determining a context model number corresponding to the syntax element of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block; and determining the prediction mode of the current coding unit according to the context model number.
上下文模型编号可以用ctxInc表示，例如，可以通过下述公式(1)确定上下文模型编号ctxInc。The context model number can be represented by ctxInc. For example, the context model number ctxInc can be determined by the following formula (1).
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3(1)ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3(1)
其中，availableL＝1表示当前编码单元的左侧相邻的图像块可得，availableL＝0表示当前编码单元的左侧相邻的图像块不可得；availableA＝1表示当前编码单元的上侧相邻的图像块可得，availableA＝0表示当前编码单元的上侧相邻的图像块不可得。condL和condA为二值变量，即condL和condA的取值为0或1，所述condL用于指示左侧相邻的图像块的预测模式是否为帧内块拷贝预测，所述condA用于指示上侧相邻的图像块的预测模式是否为帧内块拷贝预测，ctxSetIdx为上下文组的编号，ctxSetIdx可以为0，或者ctxSetIdx可以由当前编码单元的编码信息确定。Wherein, availableL=1 indicates that the image block adjacent to the left of the current coding unit is available, and availableL=0 indicates that the image block adjacent to the left of the current coding unit is not available; availableA=1 indicates that the image block adjacent to the upper side of the current coding unit is available, and availableA=0 indicates that the image block adjacent to the upper side of the current coding unit is not available. condL and condA are binary variables, that is, the values of condL and condA are 0 or 1, the condL is used to indicate whether the prediction mode of the image block adjacent to the left is intra-frame block copy prediction, the condA is used to indicate whether the prediction mode of the image block adjacent to the upper side is intra-frame block copy prediction, ctxSetIdx is the number of the context group, ctxSetIdx can be 0, or ctxSetIdx can be determined by the encoding information of the current coding unit.
VTM5中预测模式包括三种：帧内预测模式(MODE_INTRA)、帧间预测模式(MODE_INTER)和帧内块拷贝预测模式(MODE_IBC)。There are three prediction modes in VTM5: intra prediction mode (MODE_INTRA), inter prediction mode (MODE_INTER) and intra block copy prediction mode (MODE_IBC).
需要说明的是，上述相邻的图像块可得是指：该图像块已经解码且在视频图像内；相邻的图像块不可得是指：该图像块没有解码，或不在视频图像内。不同视频编码标准中，图像块是否可得还可能包含其它约束条件，例如HEVC中，如果图像块和相邻图像块不在同一个条带内，则相邻图像块也认为不可能。It should be noted that the adjacent image block is available, which means that the image block has been decoded and is in the video image; the adjacent image block is not available, which means that the image block has not been decoded or is not in the video image. In different video coding standards, whether an image block is available may also include other constraints. For example, in HEVC, if an image block and an adjacent image block are not in the same stripe, the adjacent image block is also considered impossible.
当语法元素对应的ctxSetIdx为0时，公式(1)可以简化为下述公式(2)，此时，可以通过上述公式(2)确定上下文模型编号ctxInc，ctxInc的值只有三种取值，即0、1、2。When the ctxSetIdx corresponding to the syntax element is 0, formula (1) can be simplified to the following formula (2). At this time, the context model number ctxInc can be determined by the above formula (2). The value of ctxInc has only three values, namely 0, 1, and 2.
ctxInc＝(condL&&availableL)+(condA&&availableA) (2)ctxInc＝(condL&&availableL)+(condA&&availableA) (2)
在本申请中，所述语法元素可以为pred_mode_ibc_flag，所述语法元素可以用于标识所述当前编码单元是否使用帧内块拷贝预测，相应地，所述语法元素对应的ctxSetIdx为0。In the present application, the syntax element may be pred_mode_ibc_flag, and the syntax element may be used to identify whether the current coding unit uses intra block copy prediction. Accordingly, the ctxSetIdx corresponding to the syntax element is 0.
其中，公式(2)中condL、condA、availableL及availableA的含义与公式(1)中一样，这里不再赘述。The meanings of condL, condA, availableL and availableA in formula (2) are the same as those in formula (1) and are not repeated here.
在本申请中，根据当前编码单元的类型不同，确定所述上下文模型编号的方法，具体可以包括以下两种方法。In the present application, the method for determining the context model number may specifically include the following two methods depending on the type of the current coding unit.
方法一：method one:
在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，可以根据左侧相邻的亮度块的预测模式确定condL，可以根据上侧相邻的亮度块的预测模式确定condA；可以根据所述condL和所述condA，确定所述上下文模型编号；In the case where the current coding unit is a luminance chrominance coding unit or a luminance coding unit, condL may be determined according to a prediction mode of a luminance block adjacent to the left, and condA may be determined according to a prediction mode of a luminance block adjacent to the upper side; and the context model number may be determined according to the condL and the condA;
在所述当前编码单元为色度编码单元的情况下，可以根据左侧相邻的色度块的预测模式确定condL，可以根据上侧相邻的色度块的预测模式确定condA；可以根据所述condL和所述condA，确定所述上下文模型编号；In the case where the current coding unit is a chroma coding unit, condL may be determined according to a prediction mode of a chroma block adjacent to the left, and condA may be determined according to a prediction mode of a chroma block adjacent to the upper side; and the context model number may be determined according to the condL and the condA;
其中，所述condL与所述condA为二值变量，取值例如为0和1。Wherein, the condL and the condA are binary variables, and their values are, for example, 0 and 1.
例如，在方法一中，可以通过上述公式(1)确定condL和condA。For example, in method one, condL and condA can be determined by the above formula (1).
在所述当前编码单元的语法元素为pred_mode_ibc_flag的情况下，ctxSetIdx可以为0，此时，可以通过上述公式(2)确定condL和condA。When the syntax element of the current coding unit is pred_mode_ibc_flag, ctxSetIdx may be 0. In this case, condL and condA may be determined by the above formula (2).
其中，condL的取值可以为CuPredMode[chType][xNbL][yNbL]＝＝MODE_IBC的判决结果，CuPredMode[chType][xNbL][yNbL]＝＝MODE_IBC表示左侧相邻的图像块(xNbL,yNbL)的预测模式为帧内块拷贝预测，即在CuPredMode[chType][xNbL][yNbL]＝＝MODE_IBC为真的情况下，condL的取值为1，在CuPredMode[chType][xNbL][yNbL]＝＝MODE_IBC为假的情况下，condL的取值为0；Among them, the value of condL can be the judgment result of CuPredMode[chType][xNbL][yNbL]==MODE_IBC, CuPredMode[chType][xNbL][yNbL]==MODE_IBC indicates that the prediction mode of the left adjacent image block (xNbL, yNbL) is intra block copy prediction, that is, when CuPredMode[chType][xNbL][yNbL]==MODE_IBC is true, the value of condL is 1, and when CuPredMode[chType][xNbL][yNbL]==MODE_IBC is false, the value of condL is 0;
其中，condA的取值可以为CuPredMode[chType][xNbA][yNbA]＝＝MODE_IBC的判决结果，CuPredMode[chType][xNbA][yNbA]＝＝MODE_IBC表示左侧相邻的图像块(xNbA,yNbA)的预测模式为帧内块拷贝预测，即在CuPredMode[chType][xNbA][yNbA]＝＝MODE_IBC为真的情况下，condA的取值为1，在CuPredMode[chType][xNbA][yNbA]＝＝MODE_IBC为假的情况下，condA的取值为0；Among them, the value of condA can be the judgment result of CuPredMode[chType][xNbA][yNbA]==MODE_IBC, CuPredMode[chType][xNbA][yNbA]==MODE_IBC indicates that the prediction mode of the left adjacent image block (xNbA, yNbA) is intra block copy prediction, that is, when CuPredMode[chType][xNbA][yNbA]==MODE_IBC is true, the value of condA is 1, and when CuPredMode[chType][xNbA][yNbA]==MODE_IBC is false, the value of condA is 0;
其中，(xNbL，yNbL)表示左侧相邻的图像块在视频图像中的位置，(xNbA，yNbA)表示上侧相邻的图像块在视频图像中的位置，CuPredMode[1][x][y]表示坐标位置为(x，y)的色度块的预测模式，CuPredMode[0][x][y]表示坐标位置为(x，y)的亮度块的预测模式，ctxSetIdx为上下文组的编号，chType由当前编码单元类型确定。例如，在所述当前编码单元为色度编码单元的情况下，chType可以为1，在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，chType可以为0。Wherein, (xNbL, yNbL) represents the position of the image block adjacent to the left in the video image, (xNbA, yNbA) represents the position of the image block adjacent to the upper side in the video image, CuPredMode[1][x][y] represents the prediction mode of the chroma block with coordinate position (x, y), CuPredMode[0][x][y] represents the prediction mode of the luminance block with coordinate position (x, y), ctxSetIdx is the number of the context group, and chType is determined by the type of the current coding unit. For example, when the current coding unit is a chroma coding unit, chType can be 1, and when the current coding unit is a luminance chroma coding unit or a luminance coding unit, chType can be 0.
可选地，将当前编码单元左上角在视频图像中的坐标记为(x0，y0)，将当前编码单元的宽记为cbWidth，将当前编码单元的高记为cbHeight，以亮度像素为单位，则左侧相邻的图像块(xNbL，yNbL)的坐标可以为(x0-1，y0)，上侧相邻的图像块(xNbA，yNbA)的坐标可以为(x0,y0-1)；或者，左侧相邻的图像块(xNbL，yNbL)的坐标也可以为(x0-1，y0+cbHeight/2)，左侧相邻的图像块(xNbA，yNbA)的坐标也可以为(x0+cbWidth/2,y0-1)。Optionally, the coordinates of the upper left corner of the current coding unit in the video image are marked as (x0, y0), the width of the current coding unit is recorded as cbWidth, and the height of the current coding unit is recorded as cbHeight. In units of brightness pixels, the coordinates of the image block adjacent to the left (xNbL, yNbL) may be (x0-1, y0), and the coordinates of the image block adjacent to the top (xNbA, yNbA) may be (x0, y0-1); alternatively, the coordinates of the image block adjacent to the left (xNbL, yNbL) may also be (x0-1, y0+cbHeight/2), and the coordinates of the image block adjacent to the left (xNbA, yNbA) may also be (x0+cbWidth/2, y0-1).
综上可知，在方法一中，根据当前编码块的类型、及上述公式(1)或公式(2)，就可以确定出所述当前编码单元的语法元素对应的上下文模型编号ctxInc。In summary, in method one, according to the type of the current coding block and the above formula (1) or formula (2), the context model number ctxInc corresponding to the syntax element of the current coding unit can be determined.
方法二：Method Two:
在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，可以根据左侧相邻的亮度块的预测模式确定condL，可以根据上侧相邻的亮度块的预测模式确定condA；可以根据所述condL和所述condA，确定所述上下文模型编号；In the case where the current coding unit is a luminance chrominance coding unit or a luminance coding unit, condL may be determined according to a prediction mode of a luminance block adjacent to the left, and condA may be determined according to a prediction mode of a luminance block adjacent to the upper side; and the context model number may be determined according to the condL and the condA;
在所述当前编码单元为色度编码单元的情况下，所述condL与所述condA可以为预设值；可以根据condL和condA，确定所述上下文模型编号；In the case where the current coding unit is a chroma coding unit, the condL and the condA may be preset values; the context model number may be determined according to condL and condA;
其中，所述condL与所述condA为二值变量。Wherein, the condL and the condA are binary variables.
例如，在方法二中，在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，可以通过上述公式(1)确定condL和condA。For example, in method 2, when the current coding unit is a luminance and chrominance coding unit or a luminance coding unit, condL and condA can be determined by the above formula (1).
在所述当前编码单元的语法元素为pred_mode_ibc_flag的情况下，ctxSetIdx可以为0，此时，可以通过上述公式(2)确定condL和condA。When the syntax element of the current coding unit is pred_mode_ibc_flag, ctxSetIdx may be 0. In this case, condL and condA may be determined by the above formula (2).
其中，condL的取值可以为CuPredMode[xNbL][yNbL]＝＝MODE_IBC的判决结果，CuPredMode[xNbL][yNbL]＝＝MODE_IBC表示左侧相邻的图像块(xNbL,yNbL)的预测模式为帧内块拷贝预测模式，即在CuPredMode[xNbL][yNbL]＝＝MODE_IBC为真的情况下，condL的取值为1，在CuPredMode[xNbL][yNbL]＝＝MODE_IBC为假的情况下，condL的取值为0；Among them, the value of condL can be the judgment result of CuPredMode[xNbL][yNbL]==MODE_IBC, CuPredMode[xNbL][yNbL]==MODE_IBC indicates that the prediction mode of the left adjacent image block (xNbL, yNbL) is the intra block copy prediction mode, that is, when CuPredMode[xNbL][yNbL]==MODE_IBC is true, the value of condL is 1, and when CuPredMode[xNbL][yNbL]==MODE_IBC is false, the value of condL is 0;
其中，condA的取值可以为CuPredMode[xNbA][yNbA]＝＝MODE_IBC的判决结果，CuPredMode[xNbA][yNbA]＝＝MODE_IBC表示左侧相邻的图像块(xNbA,yNbA)的预测模式为帧内块拷贝预测模式，即在CuPredMode[xNbA][yNbA]＝＝MODE_IBC为真的情况下，condA的取值为1，在CuPredMode[xNbA][yNbA]＝＝MODE_IBC为假的情况下，condA的取值为0。Among them, the value of condA can be the judgment result of CuPredMode[xNbA][yNbA]＝＝MODE_IBC, CuPredMode[xNbA][yNbA]＝＝MODE_IBC indicates that the prediction mode of the left adjacent image block (xNbA, yNbA) is the intra-frame block copy prediction mode, that is, when CuPredMode[xNbA][yNbA]＝＝MODE_IBC is true, the value of condA is 1, and when CuPredMode[xNbA][yNbA]＝＝MODE_IBC is false, the value of condA is 0.
公式(1)及公式(2)中的其他变量(或参数)的描述与方法一类似，这里不再赘述。The description of other variables (or parameters) in formula (1) and formula (2) is similar to that of method 1 and will not be repeated here.
在当前编码单元为色度编码单元的情况下，condL与condA可以为预设值。When the current coding unit is a chroma coding unit, condL and condA may be preset values.
例如，condL与condA都可以设置为0。此时，若ctxSetIdx为0，则根据上述公式(2)可知，当前编码单元的语法元素对应的上下文模型编号ctxInc也为0。For example, both condL and condA can be set to 0. At this time, if ctxSetIdx is 0, then according to the above formula (2), the context model number ctxInc corresponding to the syntax element of the current coding unit is also 0.
也就是说，在所述当前编码单元为色度编码单元的情况下，相当于，上下文模型编号ctxInc预设为0。That is to say, when the current coding unit is a chroma coding unit, it is equivalent to that the context model number ctxInc is preset to 0.
应理解，上述举例仅为示例而非限定，condL与condA也可以设置为其他数值，这里再赘述。It should be understood that the above examples are only illustrative and not limiting, and condL and condA may also be set to other values, which will not be described in detail here.
根据上述方法二中的方法，可以确定出所述当前编码单元的语法元素对应的上下文模型编号ctxInc。According to the method in the above method 2, the context model number ctxInc corresponding to the syntax element of the current coding unit can be determined.
此时，根据上下文模型编号ctxInc，可以对所述当前编码单元的语法元素对应的位元进行解码，得到语法元素(例如pred_mode_ibc_flag)的值。例如，可以按照CABAC中的普通模式解码位元，具体可以参照现有技术，这里不再赘述。At this time, according to the context model number ctxInc, the bits corresponding to the syntax elements of the current coding unit can be decoded to obtain the value of the syntax element (e.g., pred_mode_ibc_flag). For example, the bits can be decoded according to the normal mode in CABAC. For details, please refer to the prior art and will not be repeated here.
可选地，根据语法元素的值，可以确定当前编码单元的预测模式，并保存当前编码单元的预测模式信息。Optionally, according to the value of the syntax element, the prediction mode of the current coding unit may be determined, and prediction mode information of the current coding unit may be saved.
下面以pred_mode_ibc_flag为例进行说明。The following description is given by taking pred_mode_ibc_flag as an example.
例如，若pred_mode_ibc_flag值为1，则当前编码单元的预测模式为MODE_IBC，相应地，可以将当前编码单元覆盖的任一位置的CuPredMode[chType][x][y]值设置为MODE_IBC，以保存当前编码单元的预测模式，其中，chType与确定方式方法一中相同，x0≤x<x0+cbWidth,y0≤y<y0+cbHeight。For example, if the pred_mode_ibc_flag value is 1, the prediction mode of the current coding unit is MODE_IBC. Accordingly, the CuPredMode[chType][x][y] value of any position covered by the current coding unit can be set to MODE_IBC to save the prediction mode of the current coding unit, where chType is the same as that in determination method 1, x0≤x<x0+cbWidth, y0≤y<y0+cbHeight.
若pred_mode_ibc_flag值为0，则当前编码单元的预测模式可以由另一语法元素pred_mode_flag确定，若pred_mode_flag为0，则当前编码单元的预测模式为MODE_INTER，相应地，可以将当前编码单元覆盖的任一位置的CuPredMode[chType][x][y]值设置为MODE_INTER，以保存当前编码单元的预测模式；否则，当前编码单元的预测模式为MODE_INTRA，相应地，可将当前编码单元覆盖的任一位置的CuPredMode[chType][x][y]值设置为MODE_INTRA。If the pred_mode_ibc_flag value is 0, the prediction mode of the current coding unit can be determined by another syntax element pred_mode_flag. If pred_mode_flag is 0, the prediction mode of the current coding unit is MODE_INTER. Accordingly, the CuPredMode[chType][x][y] value of any position covered by the current coding unit can be set to MODE_INTER to save the prediction mode of the current coding unit. Otherwise, the prediction mode of the current coding unit is MODE_INTRA. Accordingly, the CuPredMode[chType][x][y] value of any position covered by the current coding unit can be set to MODE_INTRA.
S830，根据所述当前编码单元的预测模式，对所述当前编码单元中的图像块进行预测。S830: Predict an image block in the current coding unit according to a prediction mode of the current coding unit.
可选地，在获得当前编码单元的预测模式后，对当前编码单元进行预测信息解析、残差信息解析、预测、反量化、反变换、重建等处理，从而得到当前编码单元的重建像素。Optionally, after the prediction mode of the current coding unit is obtained, the current coding unit is subjected to prediction information analysis, residual information analysis, prediction, inverse quantization, inverse transformation, reconstruction and other processing to obtain the reconstructed pixels of the current coding unit.
本申请实施例中对如何实现这些处理并不限定，例如，可以使用HEVC或VVC中的预测信息解析、残差信息解析、帧内预测、帧间预测、帧内块拷贝预测、反量化、反变换、重建等处理，得到当前编码单元的重建像素，具体可以参照现有技术，这里不再赘述。The embodiments of the present application do not limit how to implement these processes. For example, prediction information analysis, residual information analysis, intra-frame prediction, inter-frame prediction, intra-frame block copy prediction, inverse quantization, inverse transformation, reconstruction and other processes in HEVC or VVC can be used to obtain the reconstructed pixels of the current coding unit. The specific details can be referred to the existing technology and will not be repeated here.
下面结合具体附图对本申请实施例的编码树节点划分方法进行详细的介绍。The coding tree node division method of the embodiment of the present application is described in detail below with reference to specific drawings.
图9是本申请实施例的编码树节点划分方法的示意性流程图。图9所示的编码树节点划分方法可以由编码树节点划分装置(该编码树节点划分装置可以位于图像解码装置(系统)或者图像编码装置(系统)中)执行，具体地，图9所示的方法可以图像编码装置或者图像解码装置执行。图9所示的方法既可以在编码端执行，也可以在解码端执行，图9所示的方法900包括步骤910、920及930，下面对这些步骤进行详细的介绍。Figure 9 is a schematic flow chart of the coding tree node division method of an embodiment of the present application. The coding tree node division method shown in Figure 9 can be performed by a coding tree node division device (the coding tree node division device can be located in an image decoding device (system) or an image encoding device (system)). Specifically, the method shown in Figure 9 can be performed by an image encoding device or an image decoding device. The method shown in Figure 9 can be performed at the encoding end or at the decoding end. The method 900 shown in Figure 9 includes steps 910, 920 and 930, and these steps are described in detail below.
S910，确定当前编码树节点的类型。S910, determine the type of the current coding tree node.
其中，所述当前编码树节点的类型为亮度色度编码树节点、亮度编码树节点或色度编码树节点。亮度色度编码树节点指包括亮度块和色度块的编码树节点，亮度编码树节点指包括亮度块的编码树节点，色度编码树节点指包括色度块的编码树节点。The type of the current coding tree node is a luma-chroma coding tree node, a luma coding tree node or a chroma coding tree node. The luma-chroma coding tree node refers to a coding tree node including a luma block and a chroma block, the luma coding tree node refers to a coding tree node including a luma block, and the chroma coding tree node refers to a coding tree node including a chroma block.
S920，根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定当前编码树节点的划分方式。S920: Determine a division method of the current coding tree node according to the type of the current coding tree node and/or coding information of adjacent image blocks.
其中，所述当前编码树节点中的图像块与所述相邻图像块为空间相邻的图像块，所述编码信息包括相邻图像块的四叉树深度(Quad-tree depth)和/或相邻图像块的宽和高，所述相邻图像块包括相邻的亮度块和/或相邻的色度块。Among them, the image block in the current coding tree node and the adjacent image block are spatially adjacent image blocks, the coding information includes the quad-tree depth (Quad-tree depth) of the adjacent image block and/or the width and height of the adjacent image block, and the adjacent image block includes adjacent luminance blocks and/or adjacent chrominance blocks.
可选地，所述根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定当前编码树节点的划分方式，可以包括：根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定所述当前编码树节点的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码树节点的划分方式。Optionally, determining the division method of the current coding tree node according to the type of the current coding tree node and/or the encoding information of the adjacent image blocks may include: determining the context model number corresponding to the syntax element of the current coding tree node according to the type of the current coding tree node and/or the encoding information of the adjacent image blocks; and determining the division method of the current coding tree node according to the context model number.
与图8中方法800中的实施例类似，上下文模型编号可以用ctxInc表示，由上述公式(1)和公式(2)确定，具体可以参照方法800中的描述，这里不再赘述。Similar to the embodiment of method 800 in FIG. 8 , the context model number can be represented by ctxInc and determined by the above formulas (1) and (2). For details, please refer to the description in method 800 and will not be repeated here.
在本申请中，根据当前编码单元的语法元素不同，确定所述上下文模型编号的方法，具体可以包括以下两种方法。In the present application, the method for determining the context model number according to different syntax elements of the current coding unit may specifically include the following two methods.
方法一：method one:
可选地，所述当前编码单元的语法元素可以用于标识当前编码树节点是否使用四叉树划分，例如，所述语法元素可以为split_qt_flag。Optionally, the syntax element of the current coding unit may be used to identify whether the current coding tree node uses quadtree partitioning, for example, the syntax element may be split_qt_flag.
在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，可以根据所述相邻的亮度块的四叉树深度和当前编码树节点的四叉树深度，确定所述上下文模型编号；In the case where the current coding tree node is a luma chroma coding tree node or a luma coding tree node, the context model number may be determined according to the quadtree depth of the adjacent luma block and the quadtree depth of the current coding tree node;
在所述当前编码树节点为色度编码树节点的情况下，可以根据所述当前编码树节点的四叉树深度，确定所述当前编码树节点的语法元素的上下文模型编号。In the case where the current coding tree node is a chroma coding tree node, the context model number of the syntax element of the current coding tree node may be determined according to the quadtree depth of the current coding tree node.
例如，在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，可以通过上述公式(1)或公式(2)确定condL和condA。For example, when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, condL and condA may be determined by the above formula (1) or formula (2).
其中，condL的取值为cqtDepth[xNbL][yNbL]>cqtDepth的判决结果，condA的取值为cqtDepth[xNbA][yNbA]>cqtDepth的判决结果，cqtDepth[xNbL][yNbL]表示左侧相邻的图像块(xNbL,yNbL)的四叉树深度，cqtDepth[xNbA][yNbA]表示上侧相邻的图像块(xNbA,yNbA)的四叉树深度，cqtDepth表示当前编码树节点的四叉树深度。Among them, the value of condL is the judgment result of cqtDepth[xNbL][yNbL]>cqtDepth, the value of condA is the judgment result of cqtDepth[xNbA][yNbA]>cqtDepth, cqtDepth[xNbL][yNbL] represents the quadtree depth of the left adjacent image block (xNbL, yNbL), cqtDepth[xNbA][yNbA] represents the quadtree depth of the upper adjacent image block (xNbA, yNbA), and cqtDepth represents the quadtree depth of the current coding tree node.
公式(1)及公式(2)中的其他变量(或参数)的描述与S820中方法一类似，这里不再赘述。The description of other variables (or parameters) in formula (1) and formula (2) is similar to that of method 1 in S820 and will not be repeated here.
在当前编码单元为色度编码单元的情况下，condL与condA可以为预设值。When the current coding unit is a chroma coding unit, condL and condA may be preset values.
例如，condL与condA都可以设置为0。For example, both condL and condA can be set to 0.
此时，可以采用以下两种方式中的一种确定上下文模型编号ctxInc：At this time, the context model number ctxInc can be determined in one of the following two ways:
方式一：method one:
condL和condA预先设置为0，ctxSetIdx也设置为0，此时，根据上述公式(2)可知，当前编码单元的语法元素对应的上下文模型编号ctxInc也为0。condL and condA are preset to 0, and ctxSetIdx is also set to 0. At this time, according to the above formula (2), the context model number ctxInc corresponding to the syntax element of the current coding unit is also 0.
方式二：Method 2:
condL和condA预先设置为0，ctxSetIdx为(cqtDepth<2)？0:1，cqtDepth表示当前编码树节点的四叉树深度，根据上述公式(2)可知，若当前编码树节点的四叉树深度小于2，则ctxInc为0；否则，ctxInc为3。condL and condA are preset to 0, ctxSetIdx is (cqtDepth<2)?0:1, cqtDepth represents the quadtree depth of the current coding tree node. According to the above formula (2), if the quadtree depth of the current coding tree node is less than 2, ctxInc is 0; otherwise, ctxInc is 3.
可以看出，在当前编码树节点的类型为色度编码树节点的情况下，根据所述当前编码树节点的四叉树深度就可以确定所述上下文模型编号ctxInc，也就是说，上下文模型编号ctxInc的确定可以不依赖于相邻图像块的编码信息。It can be seen that when the type of the current coding tree node is a chroma coding tree node, the context model number ctxInc can be determined according to the quadtree depth of the current coding tree node, that is, the determination of the context model number ctxInc may not depend on the coding information of adjacent image blocks.
此时，根据上下文模型编号ctxInc，可以对所述当前编码单元的语法元素对应的位元进行解码，得到语法元素(split_qt_flag)的值。具体可以参照现有技术，这里不再赘述。At this time, according to the context model number ctxInc, the bits corresponding to the syntax element of the current coding unit can be decoded to obtain the value of the syntax element (split_qt_flag). For details, please refer to the prior art and will not be repeated here.
可选地，split_qt_flag可以指示当前编码树节点是否使用四叉树划分，例如，split_qt_flag为1表示当前节点使用四叉树划分方式划分为四个子节点，split_qt_flag为0表示当前节点不使用四叉树划分方式。Optionally, split_qt_flag may indicate whether the current coding tree node uses quadtree partitioning. For example, split_qt_flag is 1, indicating that the current node is divided into four child nodes using quadtree partitioning. Split_qt_flag is 0, indicating that the current node does not use quadtree partitioning.
可选地，根据语法元素(split_qt_flag)的值，可以确定当前编码树节点的划分方式，得到当前编码树节点下属的多个编码单元，并可以保存当前编码单元的四叉树深度。Optionally, according to the value of the syntax element (split_qt_flag), the division method of the current coding tree node can be determined to obtain multiple coding units under the current coding tree node, and the quadtree depth of the current coding unit can be saved.
例如，若当前编码单元的类型为亮度色度编码单元或者亮度编码单元，可以保存当前编码单元的四叉树深度到变量cqtDepth[x][y]，其中，cqtDepth[x][y]表示坐标位置为(x,y)的四叉树深度，x0≤x<x0+cbWidth,y0≤y<y0+cbHeight，cbWidth为当前编码单元的宽，cbHeight为当前编码单元的高。For example, if the type of the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, the quadtree depth of the current coding unit can be saved to the variable cqtDepth[x][y], where cqtDepth[x][y] represents the quadtree depth at the coordinate position (x, y), x0≤x<x0+cbWidth, y0≤y<y0+cbHeight, cbWidth is the width of the current coding unit, and cbHeight is the height of the current coding unit.
上述根据语法元素(split_qt_flag)的值确定当前编码树节点的划分方式为现有技术。例如，若split_qt_flag为1，则当前编码树节点使用四叉树划分方式划分为四个子节点，子节点的四叉树深度等于当前编码树节点的四叉树深度加1；若split_qt_flag为0，则当前编码树节点的划分方式为二叉树划分或三叉树划分中的一种，进一步解析码流确定节点的划分方式，其中，上述二叉树划分方式包括水平二分、竖直二分，上述三叉树划分包括水平三分、竖直三分。当前编码树节点的子节点可以继续划分或不划分。当编码树节点不划分时，它对应一个编码单元，编码单元的四叉树深度等于这个编码树节点的四叉树深度。The above-mentioned method of determining the division method of the current coding tree node according to the value of the syntax element (split_qt_flag) is an existing technology. For example, if split_qt_flag is 1, the current coding tree node is divided into four child nodes using a quadtree division method, and the quadtree depth of the child node is equal to the quadtree depth of the current coding tree node plus 1; if split_qt_flag is 0, the division method of the current coding tree node is one of binary tree division or ternary tree division, and the code stream is further parsed to determine the node division method, wherein the above-mentioned binary tree division method includes horizontal binary division and vertical binary division, and the above-mentioned ternary tree division includes horizontal trisection and vertical trisection. The child nodes of the current coding tree node can continue to be divided or not divided. When the coding tree node is not divided, it corresponds to a coding unit, and the quadtree depth of the coding unit is equal to the quadtree depth of this coding tree node.
方法二：Method Two:
可选地，所述当前编码单元的语法元素可以用于标识当前编码树节点是否划分，例如，所述语法元素可以为split_cu_flag。Optionally, the syntax element of the current coding unit may be used to identify whether the current coding tree node is split, for example, the syntax element may be split_cu_flag.
在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，可以根据所述相邻的亮度块的宽和高、及所述当前编码树节点划分方式的可用性，确定所述上下文模型编号；In the case where the current coding tree node is a luma chroma coding tree node or a luma coding tree node, the context model number may be determined according to the width and height of the adjacent luma block and the availability of the partitioning method of the current coding tree node;
在所述当前编码树节点为色度编码单元的情况下，可以根据所述当前编码树节点划分方式的可用性，确定所述当前编码树节点的语法元素的上下文模型编号。In the case where the current coding tree node is a chroma coding unit, the context model number of the syntax element of the current coding tree node can be determined according to the availability of the division method of the current coding tree node.
例如，在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，可以通过上述公式(1)或公式(2)确定condL和condA。For example, when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, condL and condA may be determined by the above formula (1) or formula (2).
其中，condL的取值为CbHeight[chType][xNbL][yNbL]<cbHeight的判决结果，condA的取值为CbWidth[chType][xNbA][yNbA]<cbWidth的判决结果，CbHeight[0][x][y]表示左侧相邻的亮度块(xNbL,yNbL)的高，CbWidth[0][x][y]表示左侧相邻的亮度块(xNbL,yNbL)的宽，cbHeight表示当前编码树节点的高，cbWidth表示当前编码树节点的宽。Among them, the value of condL is the judgment result of CbHeight[chType][xNbL][yNbL]<cbHeight, the value of condA is the judgment result of CbWidth[chType][xNbA][yNbA]<cbWidth, CbHeight[0][x][y] represents the height of the adjacent luminance block (xNbL, yNbL) on the left, CbWidth[0][x][y] represents the width of the adjacent luminance block (xNbL, yNbL) on the left, cbHeight represents the height of the current coding tree node, and cbWidth represents the width of the current coding tree node.
公式(1)及公式(2)中的其他变量(或参数)的描述与S820中方法一类似，这里不再赘述。The description of other variables (or parameters) in formula (1) and formula (2) is similar to that of method 1 in S820 and will not be repeated here.
在当前编码单元为色度编码单元的情况下，condL与condA可以为预设值。When the current coding unit is a chroma coding unit, condL and condA may be preset values.
此时，可以采用以下几种方式中的一种确定上下文模型编号ctxInc：At this time, the context model number ctxInc can be determined in one of the following ways:
方式一：method one:
condL预先设置为0、condA预先设置为0，ctxSetIdx也设置为0，此时，根据上述公式(2)可知，当前编码单元的语法元素对应的上下文模型编号ctxInc也为0。condL is preset to 0, condA is preset to 0, and ctxSetIdx is also set to 0. At this time, according to the above formula (2), the context model number ctxInc corresponding to the syntax element of the current coding unit is also 0.
方式二：Method 2:
condL预先设置为0、condA预先设置为1，ctxSetIdx设置为0，此时，根据上述公式(2)可知，当前编码单元的语法元素对应的上下文模型编号ctxInc为1。condL is preset to 0, condA is preset to 1, and ctxSetIdx is set to 0. At this time, according to the above formula (2), the context model number ctxInc corresponding to the syntax element of the current coding unit is 1.
方式三：Method 3:
condL预先设置为0、condA预先设置为0，此时，根据上述公式(1)可知，ctxInc等于3*ctxSetIdx，其中，ctxSetIdx的确定方法可以参照现有技术。condL is preset to 0, and condA is preset to 0. At this time, according to the above formula (1), ctxInc is equal to 3*ctxSetIdx, where the method for determining ctxSetIdx can refer to the prior art.
可选地，可以参照VTM5中根据当前编码树节点划分方式的可用性确定(split_cu_flag对应的)ctxSetIdx的方法。例如，在ctxSetIdx的取值为0、1、2情况下，上下文模型编号ctxInc分别等于0、3、6。Optionally, the method of determining ctxSetIdx (corresponding to split_cu_flag) according to the availability of the current coding tree node division method in VTM5 can be referred to. For example, when the value of ctxSetIdx is 0, 1, or 2, the context model number ctxInc is equal to 0, 3, or 6, respectively.
方式四：Method 4:
condA预先设置为0，condL可以由左侧相邻的色度块的高与当前编码单元的色度块的高确定，此时，可以由上述公式(1)得到上下文模型编号ctxInc，其中，ctxSetIdx的确定方法可以参照现有技术。condA is pre-set to 0, and condL can be determined by the height of the adjacent chroma block on the left and the height of the chroma block of the current coding unit. At this time, the context model number ctxInc can be obtained by the above formula (1), where the method for determining ctxSetIdx can refer to the prior art.
可选地，可以参照VTM5中根据当前编码树节点划分模式的可用性确定(split_cu_flag对应的)ctxSetIdx的方法。Optionally, the method of determining ctxSetIdx (corresponding to split_cu_flag) according to the availability of the current coding tree node partitioning mode in VTM5 may be referred to.
通过上述方式一至方式四可以看出，在当前编码树节点的类型为色度编码树节点的情况下，根据所述当前编码树节点划分方式的可用性就可以确定所述上下文模型编号ctxInc，也就是说，所述上下文模型编号ctxInc的确定可以不依赖于上相邻图像块的编码信息。It can be seen from the above-mentioned methods 1 to 4 that, when the type of the current coding tree node is a chrominance coding tree node, the context model number ctxInc can be determined according to the availability of the current coding tree node division method, that is, the determination of the context model number ctxInc may not depend on the encoding information of the upper adjacent image block.
此时，根据上下文模型编号ctxInc，可以对所述当前编码单元的语法元素对应的位元进行解码，得到语法元素(split_cu_flag)的值。具体可以参照现有技术，这里不再赘述。At this time, according to the context model number ctxInc, the bits corresponding to the syntax element of the current coding unit can be decoded to obtain the value of the syntax element (split_cu_flag). For details, please refer to the prior art and will not be repeated here.
可选地，split_cu_flag可以指示当前编码树节点是否划分。例如，split_cu_flag为1表示当前节点划分为子节点，split_cu_flag为0表示当前节点不划分。Optionally, split_cu_flag may indicate whether the current coding tree node is split. For example, split_cu_flag being 1 indicates that the current node is split into child nodes, and split_cu_flag being 0 indicates that the current node is not split.
可选地，根据语法元素(split_cu_flag)的值，可以确定当前编码树节点的划分方式，得到当前编码树节点下属的一个或多个编码单元。Optionally, according to the value of the syntax element (split_cu_flag), the division method of the current coding tree node can be determined to obtain one or more coding units under the current coding tree node.
例如，若(所述一个或多个编码单元中的一个)编码单元的类型为亮度色度编码单元或者亮度编码单元，可以将编码单元的亮度块的宽保存到变量CbWidth[0][x][y]，将编码单元的亮度块的高保存到变量CbHeight[0][x][y]，其中，x0≤x<x0+cbWidth1,y0≤y<y0+cbHeight1，cbWidth1为编码单元的宽，cbHeight1为编码单元的高；若编码单元类型为色度编码单元，可以将编码单元的色度块的宽保存到变量CbWidth[1][x][y]，将编码单元的色度块的高保存到变量CbHeight[1][x][y]，其中，x0≤x<x0+cbWidth1,y0≤y<y0+cbHeight1，cbWidth1为编码单元的宽，cbHeight1为编码单元的高。For example, if the type of the coding unit (one of the one or more coding units) is a luminance-chrominance coding unit or a luminance coding unit, the width of the luminance block of the coding unit can be saved to the variable CbWidth[0][x][y], and the height of the luminance block of the coding unit can be saved to the variable CbHeight[0][x][y], where x0≤x<x0+cbWidth1, y0≤y<y0+cbHeight1, cbWidth1 is the width of the coding unit, and cbHeight1 is the height of the coding unit; if the type of the coding unit is a chrominance coding unit, the width of the chrominance block of the coding unit can be saved to the variable CbWidth[1][x][y], and the height of the chrominance block of the coding unit can be saved to the variable CbHeight[1][x][y], where x0≤x<x0+cbWidth1, y0≤y<y0+cbHeight1, cbWidth1 is the width of the coding unit, and cbHeight1 is the height of the coding unit.
需要说明的是，当编码树节点不再划分时，它对应于一个编码单元。此时，编码单元的宽和高等于编码单元所属的编码树节点的宽和高，即，此时cbWidth1等于cbWidth，cbHeight1等于cbHeight。It should be noted that when a coding tree node is no longer divided, it corresponds to a coding unit. At this time, the width and height of the coding unit are equal to the width and height of the coding tree node to which the coding unit belongs, that is, at this time cbWidth1 is equal to cbWidth, and cbHeight1 is equal to cbHeight.
根据标志位split_cu_flag的值确定当前编码树节点的划分方式为现有技术。例如，若标志位split_cu_flag为1，则当前编码树节点划分为子节点；若split_cu_flag为0，则当前编码树节点不划分，其中，上述编码树节点划分为子节点的划分方式包括四分、水平二分、竖直二分、水平三分、竖直三分。当编码树节点继续划分时，具体的划分方式可由其它语法元素确定，例如split_qt_flag等。Determining the division method of the current coding tree node according to the value of the flag split_cu_flag is an existing technology. For example, if the flag split_cu_flag is 1, the current coding tree node is divided into sub-nodes; if split_cu_flag is 0, the current coding tree node is not divided, wherein the above-mentioned division method of the coding tree node into sub-nodes includes four divisions, horizontal two divisions, vertical two divisions, horizontal three divisions, and vertical three divisions. When the coding tree node continues to be divided, the specific division method can be determined by other syntax elements, such as split_qt_flag, etc.
S930，根据所述编码树节点的划分方式，对所述当前编码树节点进行划分。S930: Divide the current coding tree node according to the coding tree node division method.
本申请实施例中对如何实现S930处理并不限定，例如，可以使用VVC中的编码树节点划分方法，这里不再赘述。根据编码树划分可最终确定编码树上的叶节点，每个叶节点对应于一个编码单元，解码编码单元可以得到编码单元的重建图像。In the embodiment of the present application, there is no limitation on how to implement S930 processing. For example, the coding tree node division method in VVC can be used, which will not be described here. According to the coding tree division, the leaf nodes on the coding tree can be finally determined, each leaf node corresponds to a coding unit, and decoding the coding unit can obtain the reconstructed image of the coding unit.
上文结合图8和图9对本申请实施例的图像预测方法及编码树节点划分方法进行了详细的介绍，下面结合图10及图11对本申请实施例的图像预测装置及编码树节点划分装置进行介绍。应理解，图10所示的图像预测装置能够执行图8中图像预测方法800中的各个步骤。The above describes in detail the image prediction method and coding tree node division method of the embodiment of the present application in conjunction with Figures 8 and 9. The following describes the image prediction device and coding tree node division device of the embodiment of the present application in conjunction with Figures 10 and 11. It should be understood that the image prediction device shown in Figure 10 can perform each step in the image prediction method 800 in Figure 8.
图10是本申请实施例的图像预测装置的示意性框图。FIG. 10 is a schematic block diagram of an image prediction device according to an embodiment of the present application.
图10所示的图像预测装置1000包括：确定模块1010、处理模块1020和预测模块1030。The image prediction device 1000 shown in FIG. 10 includes: a determination module 1010 , a processing module 1020 and a prediction module 1030 .
确定模块1010，用于确定当前编码单元的类型，所述当前编码单元的类型为亮度色度编码单元、亮度编码单元或色度编码单元；A determination module 1010 is used to determine the type of a current coding unit, where the type of the current coding unit is a luma-chroma coding unit, a luma coding unit, or a chroma coding unit;
处理模块1020，用于根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定当前编码单元的预测模式，其中，所述当前编码单元中的图像块与所述相邻图像块为空间相邻的图像块，所述相邻图像块包括相邻的亮度块和/或相邻的色度块；A processing module 1020 is configured to determine a prediction mode of a current coding unit according to a type of the current coding unit and/or a prediction mode of an adjacent image block, wherein the image block in the current coding unit and the adjacent image block are spatially adjacent image blocks, and the adjacent image blocks include adjacent luminance blocks and/or adjacent chrominance blocks;
预测模块1030，用于根据所述当前编码单元的预测模式，对所述当前编码单元中的图像块进行预测。The prediction module 1030 is configured to predict the image blocks in the current coding unit according to the prediction mode of the current coding unit.
可选地，所述处理模块1020具体用于：根据所述当前编码单元的类型和/或相邻图像块的预测模式，确定所述当前编码单元的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码单元的预测模式。Optionally, the processing module 1020 is specifically used to: determine the context model number corresponding to the syntax element of the current coding unit according to the type of the current coding unit and/or the prediction mode of the adjacent image block; determine the prediction mode of the current coding unit according to the context model number.
可选地，所述处理模块1020具体用于：在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，根据左侧相邻的亮度块的预测模式确定condL，根据上侧相邻的亮度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；或在所述当前编码单元为色度编码单元的情况下，根据左侧相邻的色度块的预测模式确定condL，根据上侧相邻的色度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；其中，所述condL与所述condA为二值变量。Optionally, the processing module 1020 is specifically used for: when the current coding unit is a luminance-chrominance coding unit or a luminance coding unit, determining condL according to the prediction mode of the luminance block adjacent to the left, and determining condA according to the prediction mode of the luminance block adjacent to the upper side; determining the context model number according to the condL and the condA; or when the current coding unit is a chrominance coding unit, determining condL according to the prediction mode of the chrominance block adjacent to the left, and determining condA according to the prediction mode of the chrominance block adjacent to the upper side; determining the context model number according to the condL and the condA; wherein the condL and the condA are binary variables.
可选地，所述处理模块1020具体用于：在所述当前编码单元为亮度色度编码单元或亮度编码单元的情况下，根据左侧相邻的亮度块的预测模式确定condL，根据上侧相邻的亮度块的预测模式确定condA；根据所述condL和所述condA，确定所述上下文模型编号；或在所述当前编码单元为色度编码单元的情况下，根据预设的condL和condA，确定所述上下文模型编号；其中，所述condL与所述condA为二值变量。Optionally, the processing module 1020 is specifically used to: when the current coding unit is a luminance and chrominance coding unit or a luminance coding unit, determine condL according to the prediction mode of the luminance block adjacent to the left, and determine condA according to the prediction mode of the luminance block adjacent to the top; determine the context model number according to the condL and the condA; or when the current coding unit is a chrominance coding unit, determine the context model number according to preset condL and condA; wherein the condL and the condA are binary variables.
可选地，所述语法元素为pred_mode_ibc_flag，所述语法元素用于标识所述当前编码单元是否使用帧内块拷贝预测，所述condL用于指示左侧相邻的图像块的预测模式是否为帧内块拷贝预测，所述condA用于指示上侧相邻的图像块的预测模式是否为帧内块拷贝预测。Optionally, the syntax element is pred_mode_ibc_flag, which is used to identify whether the current coding unit uses intra block copy prediction, the condL is used to indicate whether the prediction mode of the left adjacent image block is intra block copy prediction, and the condA is used to indicate whether the prediction mode of the upper adjacent image block is intra block copy prediction.
应理解，图11所示的编码树节点划分装置能够执行图9中编码树节点划分方法900中的各个步骤。It should be understood that the coding tree node partitioning apparatus shown in FIG. 11 is capable of executing each step in the coding tree node partitioning method 900 in FIG. 9 .
图11是本申请实施例的编码树节点划分装置的示意性框图。FIG11 is a schematic block diagram of a coding tree node division device according to an embodiment of the present application.
图11所示的编码树节点划分装置1100包括：确定模块1110、处理模块1120和划分模块1130。The coding tree node division device 1100 shown in FIG. 11 includes: a determination module 1110 , a processing module 1120 and a division module 1130 .
确定模块1110，用于确定当前编码树节点的类型，所述当前编码树节点的类型为亮度色度编码树节点、亮度编码树节点或色度编码树节点；A determination module 1110 is used to determine the type of a current coding tree node, where the type of the current coding tree node is a luma-chroma coding tree node, a luma coding tree node, or a chroma coding tree node;
处理模块1120，用于根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定当前编码树节点的划分方式，其中，所述当前编码树节点中的图像块与所述相邻图像块为空间相邻的图像块，所述编码信息包括相邻图像块的四叉树深度和/或相邻图像块的宽和高，所述相邻图像块包括相邻的亮度块和/或相邻的色度块；The processing module 1120 is configured to determine a division mode of the current coding tree node according to the type of the current coding tree node and/or the coding information of the adjacent image blocks, wherein the image block in the current coding tree node and the adjacent image blocks are spatially adjacent image blocks, the coding information includes the quadtree depth of the adjacent image blocks and/or the width and height of the adjacent image blocks, and the adjacent image blocks include adjacent luminance blocks and/or adjacent chrominance blocks;
划分模块1130，用于根据所述编码树节点的划分方式，对所述当前编码树节点进行划分。The division module 1130 is used to divide the current coding tree node according to the division method of the coding tree node.
可选地，所述处理模块1120具体用于：根据所述当前编码树节点的类型和/或相邻图像块的编码信息，确定所述当前编码树节点的语法元素对应的上下文模型编号；根据所述上下文模型编号，确定所述当前编码树节点的划分方式。Optionally, the processing module 1120 is specifically used to: determine the context model number corresponding to the syntax element of the current coding tree node according to the type of the current coding tree node and/or the coding information of the adjacent image block; determine the division method of the current coding tree node according to the context model number.
可选地，所述处理模块1120具体用于：在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，根据所述相邻的亮度块的四叉树深度和当前编码树节点的四叉树深度，确定所述上下文模型编号；或在所述当前编码树节点为色度编码树节点的情况下，根据所述当前编码树节点的四叉树深度，确定所述当前编码树节点的语法元素的上下文模型编号。Optionally, the processing module 1120 is specifically used to: when the current coding tree node is a luminance coding tree node or a luminance coding tree node, determine the context model number according to the quadtree depth of the adjacent luminance block and the quadtree depth of the current coding tree node; or when the current coding tree node is a chrominance coding tree node, determine the context model number of the syntax element of the current coding tree node according to the quadtree depth of the current coding tree node.
可选地，所述语法元素为split_qt_flag，用于标识当前编码树节点是否使用四叉树划分。Optionally, the syntax element is split_qt_flag, which is used to identify whether the current coding tree node uses quadtree partitioning.
可选地，所述处理模块1120具体用于：在所述当前编码树节点为亮度色度编码树节点或亮度编码树节点的情况下，根据所述相邻的亮度块的宽和高、及所述当前编码树节点划分方式的可用性，确定所述上下文模型编号；在所述当前编码树节点为色度编码单元的情况下，根据所述当前编码树节点划分方式的可用性，确定所述当前编码树节点的语法元素的上下文模型编号。Optionally, the processing module 1120 is specifically used to: when the current coding tree node is a luminance and chrominance coding tree node or a luminance coding tree node, determine the context model number according to the width and height of the adjacent luminance block and the availability of the current coding tree node division method; when the current coding tree node is a chrominance coding unit, determine the context model number of the syntax element of the current coding tree node according to the availability of the current coding tree node division method.
可选地，所述语法元素为split_cu_flag，用于标识当前编码树节点是否划分。Optionally, the syntax element is split_cu_flag, which is used to identify whether the current coding tree node is split.
图12是本申请实施例的图像预测装置的示意性框图。FIG. 12 is a schematic block diagram of an image prediction device according to an embodiment of the present application.
图12所示的图像预测装置1200包括：处理模块1210和预测模块1220。The image prediction device 1200 shown in FIG. 12 includes: a processing module 1210 and a prediction module 1220 .
处理模块1210，用于在当前编码单元为色度编码单元的情况下，根据如下公式确定所述当前编码单元的语法元素对应的上下文模型编号：The processing module 1210 is configured to determine, when the current coding unit is a chroma coding unit, a context model number corresponding to a syntax element of the current coding unit according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得；所述condL表示所述左侧相邻的色度块的预测模式是否为帧内块拷贝预测，所述condA表示所述上侧相邻的色度块的预测模式是否为帧内块拷贝预测；或者，所述condL和所述condA均为预设值；Wherein, ctxInc is the context model number, ctxSetIdx is the number of the context group, availableL indicates whether the left adjacent chroma block is available, and availableA indicates whether the upper adjacent chroma block is available; the condL indicates whether the prediction mode of the left adjacent chroma block is intra block copy prediction, and the condA indicates whether the prediction mode of the upper adjacent chroma block is intra block copy prediction; or, both condL and condA are preset values;
所述处理模块1210，用于根据所述上下文模型编号，确定所述当前编码单元的预测模式；The processing module 1210 is used to determine the prediction mode of the current coding unit according to the context model number;
预测模块1220，用于根据所述当前编码单元的预测模式，对所述当前编码单元中的图像块进行预测。The prediction module 1220 is used to predict the image block in the current coding unit according to the prediction mode of the current coding unit.
图13是本申请实施例的编码树节点划分装置的示意性框图。FIG13 is a schematic block diagram of a coding tree node division device according to an embodiment of the present application.
图13所示的编码树节点划分装置1300包括：处理模块1310和划分模块1320。The coding tree node division device 1300 shown in FIG. 13 includes: a processing module 1310 and a division module 1320 .
处理模块1310，用于在当前编码树节点为色度编码树节点的情况下，根据如下公式确定所述当前编码树节点的语法元素对应的上下文模型编号：The processing module 1310 is configured to determine, when the current coding tree node is a chroma coding tree node, a context model number corresponding to a syntax element of the current coding tree node according to the following formula:
ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3ctxInc＝(condL&&availableL)+(condA&&availableA)+ctxSetIdx*3
其中，ctxInc为上下文模型编号，ctxSetIdx为上下文组的编号，availableL表示所述左侧相邻的色度块是否可得，availableA表示所述上侧相邻的色度块是否可得；所述condL和所述condA均为预设值；或者，所述condL由所述当前编码树节点确定，所述condA为预设值；Wherein, ctxInc is the context model number, ctxSetIdx is the context group number, availableL indicates whether the left adjacent chroma block is available, and availableA indicates whether the upper adjacent chroma block is available; both condL and condA are preset values; or, condL is determined by the current coding tree node, and condA is a preset value;
所述处理模块1310，用于根据所述上下文模型编号，确定所述当前编码树节点的划分方式；The processing module 1310 is used to determine the division method of the current coding tree node according to the context model number;
划分模块1320，用于根据所述编码树节点的划分方式，对所述当前编码树节点进行划分。The division module 1320 is used to divide the current coding tree node according to the division method of the coding tree node.
图14是本申请实施例提供的图像编码/解码装置的硬件结构示意图。图14所示的装置1400(该装置1400具体可以是一种计算机设备)包括存储器1410、处理器1420、通信接口1430以及总线1440。其中，存储器1410、处理器1420、通信接口1430通过总线1440实现彼此之间的通信连接。FIG14 is a schematic diagram of the hardware structure of an image encoding/decoding device provided in an embodiment of the present application. The device 1400 shown in FIG14 (the device 1400 may be a computer device) includes a memory 1410, a processor 1420, a communication interface 1430, and a bus 1440. The memory 1410, the processor 1420, and the communication interface 1430 are connected to each other through the bus 1440.
存储器1410可以是只读存储器(read only memory，ROM)，静态存储设备，动态存储设备或者随机存取存储器(random access memory，RAM)。存储器1410可以存储程序，当存储器1410中存储的程序被处理器1420执行时，处理器1420用于执行本申请实施例的图像预测方法的各个步骤。The memory 1410 may be a read only memory (ROM), a static storage device, a dynamic storage device or a random access memory (RAM). The memory 1410 may store a program. When the program stored in the memory 1410 is executed by the processor 1420, the processor 1420 is used to execute each step of the image prediction method of the embodiment of the present application.
处理器1420可以采用通用的中央处理器(central processing unit，CPU)，微处理器，应用专用集成电路(application specific integrated circuit，ASIC)，图形处理器(graphics processing unit，GPU)或者一个或多个集成电路，用于执行相关程序，以实现本申请方法实施例的图像预测方法。Processor 1420 can adopt a general central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), a graphics processing unit (GPU) or one or more integrated circuits to execute relevant programs to implement the image prediction method of the method embodiment of the present application.
处理器1420还可以是一种集成电路芯片，具有信号的处理能力。在实现过程中，本申请的图像预测方法的各个步骤可以通过处理器1420中的硬件的集成逻辑电路或者软件形式的指令完成。The processor 1420 may also be an integrated circuit chip with signal processing capability. In the implementation process, each step of the image prediction method of the present application may be completed by an integrated logic circuit of hardware in the processor 1420 or by instructions in the form of software.
上述处理器1420还可以是通用处理器、数字信号处理器(digital signalprocessing，DSP)、专用集成电路(ASIC)、现成可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件。可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件译码处理器执行完成，或者用译码处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器1420，处理器1420读取存储器1420中的信息，结合其硬件完成本图像预测装置中包括的单元所需执行的功能，或者执行本申请方法实施例的图像预测方法。The processor 1420 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, or discrete hardware components. The methods, steps, and logic block diagrams disclosed in the embodiments of the present application may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application may be directly embodied as being executed by a hardware decoding processor, or may be executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 1420, and the processor 1420 reads the information in the memory 1420, and completes the functions required to be performed by the units included in the image prediction device in combination with its hardware, or executes the image prediction method of the method embodiment of the present application.
通信接口1430使用例如但不限于收发器一类的收发装置，来实现装置1400与其他设备或通信网络之间的通信。例如，可以通过通信接口1430获取待构建的神经网络的信息以及构建神经网络过程中需要的训练数据。The communication interface 1430 uses a transceiver such as, but not limited to, a transceiver to implement communication between the device 1400 and other devices or communication networks. For example, the information of the neural network to be constructed and the training data required in the process of constructing the neural network can be obtained through the communication interface 1430.
总线1440可包括在装置1400各个部件(例如，存储器1410、处理器1420、通信接口1430)之间传送信息的通路。The bus 1440 may include a path for transmitting information between the various components of the device 1400 (eg, the memory 1410 , the processor 1420 , and the communication interface 1430 ).
上述图10中的装置1000中的确定模块1010、处理模块1020和预测模块1030相当于图像编码/解码装置1400中的处理器1420。The determination module 1010 , the processing module 1020 , and the prediction module 1030 in the apparatus 1000 in FIG. 10 described above are equivalent to the processor 1420 in the image encoding/decoding apparatus 1400 .
或者，上述图11中的装置1100中的确定模块1110、处理模块1120和划分模块1130相当于图像编码/解码装置1400中的处理器1420。Alternatively, the determination module 1110 , the processing module 1120 , and the division module 1130 in the device 1100 in FIG. 11 described above are equivalent to the processor 1420 in the image encoding/decoding device 1400 .
或者，上述图12中的装置1200中的处理模块1210和预测模块1220相当于图像编码/解码装置1400中的处理器1420。Alternatively, the processing module 1210 and the prediction module 1220 in the device 1200 in FIG. 12 described above are equivalent to the processor 1420 in the image encoding/decoding device 1400 .
或者，上述图13中的装置1300中的处理模块1310和划分模块1320相当于图像编码/解码装置1400中的处理器1420。Alternatively, the processing module 1310 and the dividing module 1320 in the device 1300 in FIG. 13 described above are equivalent to the processor 1420 in the image encoding/decoding device 1400 .
另外，当图像编码/解码装置1400对视频图像进行编码时，可以通过通信接口获取视频图像，然后对获取到的视频图像进行编码后得到编码后的视频数据，编码后的视频数据可以通过该通信接口1430传输给视频解码设备。In addition, when the image encoding/decoding device 1400 encodes a video image, it can obtain the video image through the communication interface, and then encode the obtained video image to obtain encoded video data, and the encoded video data can be transmitted to the video decoding device through the communication interface 1430.
当图像编码/解码装置1400对视频图像进行解码时，可以通过通信接口1430获取视频图像，然后对获取到的视频图像进行解码后得到待显示的视频图像。When the image encoding/decoding device 1400 decodes a video image, the video image may be acquired through the communication interface 1430 , and then the acquired video image may be decoded to obtain a video image to be displayed.
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(Read-Only Memory，ROM)、随机存取存储器(Random Access Memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118120229A (en)* | 2021-08-11 | 2024-05-31 | 抖音视界有限公司 | Method, device and medium for video processing |
| WO2025061062A1 (en)* | 2023-09-18 | 2025-03-27 | Douyin Vision Co., Ltd. | Method, apparatus, and medium for video processing |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109076210A (en)* | 2016-05-28 | 2018-12-21 | 联发科技股份有限公司 | Method and device for current image reference of video coding and decoding |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101739987B1 (en)* | 2010-12-28 | 2017-05-26 | 에스케이 텔레콤주식회사 | Video Encoding/Decoding Method and Apparatus Using Feature Vector of Adjacent Block |
| WO2016074147A1 (en)* | 2014-11-11 | 2016-05-19 | Mediatek Singapore Pte. Ltd. | Separated coding tree for luma and chroma |
| US10863207B2 (en)* | 2015-11-27 | 2020-12-08 | Mediatek Inc. | Method and apparatus of entropy coding and context modelling for video and image coding |
| CN109792516B (en)* | 2016-10-04 | 2021-05-25 | 联发科技股份有限公司 | Method and device for intra-frame chroma coding and decoding in image and video coding and decoding |
| CA3070507A1 (en)* | 2017-07-24 | 2019-01-31 | Arris Enterprises Llc | Intra mode jvet coding |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109076210A (en)* | 2016-05-28 | 2018-12-21 | 联发科技股份有限公司 | Method and device for current image reference of video coding and decoding |
| Publication number | Publication date |
|---|---|
| CN112135128A (en) | 2020-12-25 |
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|---|---|---|
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