技术领域technical field
本发明涉及媒体直播技术领域，特别是互联网协议(internet protocol，IP)实时媒体直播技术。本发明尤其涉及一种用于实时媒体流系统中的用户设备中的帧同步的方法、一种用于实时媒体流系统中的转播服务器中的帧同步的方法、一种用于实时媒体流系统中的帧同步的方法、实时媒体流系统中的一种用户设备、实时媒体流系统中的一种转播服务器、一种实时媒体流系统，以及一种计算机程序产品，该计算机程序产品在计算设备上执行时用于实施帧同步方法。The invention relates to the field of media live broadcast technology, in particular to the Internet protocol (internet protocol, IP) real-time media live broadcast technology. In particular, the present invention relates to a method for frame synchronization in user equipment in a real-time media streaming system, a method for frame synchronization in a rebroadcast server in a real-time media streaming system, and a method for frame synchronization in a real-time media streaming system A method of frame synchronization in a real-time media streaming system, a user equipment in a real-time media streaming system, a rebroadcast server in a real-time media streaming system, a real-time media streaming system, and a computer program product in a computing device Used to implement the frame synchronization method when executing above.
具体而言，本发明建议通过同步图像组(group of picture，GOP)帧来提供帧同步方法。Specifically, the present invention proposes to provide a frame synchronization method by synchronizing group of picture (GOP) frames.
背景技术Background technique
媒体是指使用不同内容形式的组合的内容。这包括使用纯文本等基本计算机显示的媒体，但是在多媒体的情况下，还包括文本、音频、图片、动画、视频或交互式内容形式的组合。多媒体可以录音并播放、显示，可以是动态的，可以与电脑化设备和电子设备等信息内容处理设备交互或者由这些设备访问，并且可以是实况演出的一部分。Media refers to content that uses a combination of different content forms. This includes media using basic computer displays such as plain text, but in the case of multimedia, combinations of text, audio, pictures, animation, video or interactive content forms. Multimedia can be recorded and played, displayed, animated, interacted with or accessed by information content processing devices such as computerized and electronic devices, and can be part of a live performance.
媒体流系统是接收提供商传送的媒体数据并将它们呈现到终端用户的用户设备的系统。这样，用户设备能够在整个文件都传输完成之前就开始呈现媒体数据。A media streaming system is a system that receives media data delivered by a provider and presents them to an end user's user equipment. In this way, the user device can start rendering media data before the entire file has been transferred.
现今，媒体可以按直播或按点播进行流式传输。直播流一般通过称为“真实流式传输”的方式提供。真实流式传输直接向用户设备发送信息而不保存内容。点播流式传输通过称为顺序流式传输的方式提供。顺序流式传输在用户设备处保存媒体内容，然后从该位置开始播放该媒体内容。点播流常在用户设备和/或服务器处保存较长时间，因此终端用户基本上选择媒体播放时间和特定兴趣点，这样该终端用户可以在任何时候快进或倒回到所需兴趣点。相反，直播流仅可用一次，例如，仅在足球赛期间可用。Today, media can be streamed live or on demand. Live streams are generally provided through what is known as "real streaming". True streaming sends information directly to the user device without saving the content. On-demand streaming is provided through what is known as sequential streaming. Sequential streaming saves the media content at the user device and then starts playing the media content from that location. On-demand streams are often stored for a longer period of time at the user device and/or server, so the end user basically selects the media playback time and specific points of interest so that the end user can fast-forward or rewind to the desired point of interest at any time. Instead, the live stream is only available once, for example, only during a football game.
因此，在直播媒体流式传输期间，内容通过合适的物理信道，例如通过互联网实况传送，所以称为实时。直播流式传输使用编码器技术来将媒体内容数字化，以通过物理信道实时传送。音频内容本身可使用音频编解码器，例如MPEG-1或MPEG-2音频层III、MP3或Vorbis或者高级音频编码(advanced audio coding，AAC)进行压缩。视频内容本身可使用视频编解码器，例如MPEG-4第10部分高级视频编码(MPEG-4Part 10advanced videocoding，MPEG-4AVC)，还称为H.264，或高效视频编码(high efficiency video coding，HEVC)，还称为MPEG-H第2部分(H.265)，或者VP8进行压缩。Thus, during live media streaming, the content is delivered live over a suitable physical channel, such as the Internet, so it is called real-time. Live streaming uses encoder technology to digitize media content for real-time delivery over physical channels. The audio content itself may be compressed using an audio codec, such as MPEG-1 or MPEG-2 Audio Layer III, MP3 or Vorbis, or advanced audio coding (AAC). The video content itself may use a video codec such as MPEG-4 Part 10 advanced video coding (MPEG-4 AVC), also known as H.264, or high efficiency video coding (HEVC ), also known as MPEG-H Part 2 (H.265), or VP8 for compression.
然后将已编码的音频和视频流组装到容器比特流，例如MP4、flash视频(flashvideo，FLV)、WebM、高级流格式(advanced streaming format，ASF)或互联网流媒体联盟(Internet Streaming Media Alliance，ISMA)。The encoded audio and video streams are then assembled into container bitstreams such as MP4, flash video (flashvideo, FLV), WebM, advanced streaming format (ASF), or Internet Streaming Media Alliance (ISMA ).
比特流使用一种传输协议，例如Microsoft媒体服务器(Microsoft mediaserver，MMS)或实时传输协议(real-time transport protocol，RTP)，从媒体内容提供商传送到用户设备。用户设备可使用一种控制协议，例如MMS或实时流协议(real-time-streaming protocol，RTSP)，与流内容提供商交互。The bit stream is transmitted from the media content provider to the user equipment using a transport protocol, such as Microsoft media server (Microsoft media server, MMS) or real-time transport protocol (real-time transport protocol, RTP). The user equipment can use a control protocol, such as MMS or real-time-streaming protocol (RTSP), to interact with the streaming content provider.
RTSP是一种在娱乐和通信系统中用来控制流媒体服务器的网络控制协议。该协议用于在端点之间建立和控制媒体会话。流数据自身的传输并不是RTSP的任务。RTSP is a network control protocol used in entertainment and communication systems to control streaming media servers. This protocol is used to establish and control media sessions between endpoints. The transmission of streaming data itself is not the task of RTSP.
现今，RTSP服务器将RTP与实时控制协议(real-time control protocol，RTCP)结合使用，以进行媒体流传送。Today, RTSP servers use RTP in conjunction with real-time control protocol (RTCP) for media streaming.
RTP是用于通过IP网络传送音频和视频的网络协议。RTP广泛用于涉及流媒体的通信和娱乐系统，流媒体包括电话、视频电话会议应用、电视业务和基于web的即按即说特征等。RTP is a network protocol for transmitting audio and video over IP networks. RTP is widely used in communication and entertainment systems involving streaming media, including telephony, video teleconferencing applications, television services, and web-based push-to-talk features.
RTP与RTCP结合使用。RTP携带媒体流(例如，音频和视频)，而RTCP用来监控传输统计和服务质量(quality of service，QoS)并协助多个流的同步。RTP is used in conjunction with RTCP. RTP carries media streams (eg, audio and video), while RTCP is used to monitor transmission statistics and quality of service (QoS) and to assist in the synchronization of multiple streams.
从P.Yang在2009年3月8日发表的“用于快速同步的RTCP的扩展(Extensions toRTCP for Rapid Synchronization)”可知，RTP为视频传送业务提供实时特性，例如视频广播，在视频广播中，接收方可以在不同的多播媒体流间频繁地切换。为了实现快速同步并降低这些多播流之间的同步延迟，在媒体内容提供商与用户设备之间实施转播服务器。转播服务器用于将对应于多播媒体流的单播流从媒体内容提供商发送到暂时替代多播会话的请求用户设备。From the "Extensions to RTCP for Rapid Synchronization" published by P. Yang on March 8, 2009, it can be seen that RTP provides real-time features for video transmission services, such as video broadcasting. In video broadcasting, Receivers may frequently switch between different multicast media streams. To achieve fast synchronization and reduce synchronization delays between these multicast streams, a relay server is implemented between the media content provider and the user equipment. The relay server is configured to send a unicast stream corresponding to the multicast media stream from the media content provider to the requesting user equipment temporarily replacing the multicast session.
压缩媒体内容使得媒体以帧结构提供。在视频编码中，图像组(group ofpictures，GOP)结构指定帧内和帧间排列的顺序。GOP是已编码视频流中的一组连续的图像。每个已编码视频流都包括连续的GOP。用户设备从包含在其中的图像生成可见帧。Compressing the media content enables the media to be presented in a frame structure. In video coding, a group of pictures (GOP) structure specifies the order of intra-frame and inter-frame arrangement. A GOP is a group of consecutive pictures in an encoded video stream. Each encoded video stream consists of consecutive GOPs. The user device generates visible frames from the images contained therein.
为了正确地对媒体内容进行解码，用户设备必须从转播服务器获得的第一帧是所谓的I帧。I帧是最小可压缩帧，但是无需对其它视频帧进行解码。这意味着根据RTCP，转播服务器需要以针对当时广播的正在进行的GOP帧的I帧来启动朝向用户设备的单播流，用户连接新频道。为了保持频道切换时间尽可能短，转播服务器不会等待下一个I帧的到来；其将一直从其高速缓存内存转发最后一个I帧。In order to correctly decode the media content, the first frame that the user equipment must obtain from the relay server is a so-called I-frame. An I-frame is the smallest compressible frame, but no other video frames need to be decoded. This means that according to RTCP the relay server needs to start the unicast stream towards the user equipment with an I frame for the ongoing GOP frame being broadcast at the time the user connects to the new channel. In order to keep the channel switching time as short as possible, the relay server will not wait for the next I frame to arrive; it will always forward the last I frame from its cache memory.
在直播媒体流式传输期间，目前不可能对齐和/或调整用户设备来同时播放相同的帧。特定用户根据时刻连接提供直播媒体内容的频道，基于始终优先传送I帧的需求，体验到GOP中的用户特定延迟。这引起不同用户间的随机延迟，延迟可以长达一个完整的GOP。During live media streaming, it is currently not possible to align and/or adjust user devices to simultaneously play the same frame. Specific users connect to channels that provide live media content according to time, and experience user-specific delays in the GOP based on the requirement that I frames are always preferentially transmitted. This causes random delays between different users, which can be as long as a full GOP.
GOP可具有数秒的持续时间。因此，在最差的情况下，接收完全一样的媒体直播流的用户实际上可以体验到彼此间多达数秒的直播流延迟。该用户特定延迟的典型结果是，在体育赛事期间，例如在足球直播电视流期间，一些终端用户将听到邻居已为进球欢呼，而这些终端用户的屏幕上尚未发生进球。A GOP can have a duration of several seconds. As a result, users receiving the exact same live stream of media can actually experience up to a few seconds of live stream delay between each other in the worst case. A typical consequence of this user-specific delay is that during a sporting event, such as during a football live TV stream, some end-users will hear neighbors cheering a goal that has not yet occurred on those end-users' screens.
已知GOP传送引起的另一个问题是，只要观看直播流频道，具有用户特定一致延迟的用户设备就需要缓冲与它们的用户特定一致延迟对应的传入数据包，因此影响了用户设备的有效缓冲能力。It is known that another problem caused by GOP delivery is that whenever a live streaming channel is watched, user devices with user-specific consistent delays need to buffer incoming packets corresponding to their user-specific consistent delays, thus affecting effective buffering of user devices ability.
发明内容Contents of the invention
鉴于上述问题和缺点，本发明旨在改进最新技术，特别是上述帧同步机制。In view of the above-mentioned problems and disadvantages, the present invention aims to improve the state-of-the-art, especially the above-mentioned frame synchronization mechanism.
本发明的目的是针对媒体流系统中的终端用户对齐媒体流以及有效地降低用户设备中的缓冲需求。本发明应很容易地在现有直播流媒体系统中实施。本发明还旨在解决所有上述缺点。本发明的目的通过所附独立权利要求中提供的方案实现。本发明的有利实施形式在从属权利要求中进一步定义。It is an object of the present invention to align media streams for end users in a media streaming system and effectively reduce buffering requirements in user equipment. The present invention should be easily implemented in existing live streaming media systems. The present invention also aims to solve all the above mentioned disadvantages. The objects of the invention are achieved by the solutions presented in the appended independent claims. Advantageous embodiments of the invention are further defined in the dependent claims.
具体而言，本发明利用直播TV媒体流的帧同步机制。Specifically, the present invention utilizes the frame synchronization mechanism of live TV media streams.
本发明的第一方面提供一种用于实时媒体流系统中的用户设备中的帧同步的方法。所述方法包括以下步骤：向转播服务器发送频道切换请求；响应于所述频道切换请求，从所述转播服务器接收频道切换响应，其中所述频道切换响应包括帧偏移信息，所述帧偏移信息指示参考媒体流的帧与所述用户设备从所述转播服务器收到的对应媒体流的帧之间的帧偏移；基于所述帧偏移信息计算帧速率加速时长；以及将所述对应媒体流的帧速率加速所述计算出的帧速率加速时长，以将所述转播服务器提供的所述对应媒体流的所述帧同步到所述参考媒体流的所述帧。A first aspect of the present invention provides a method for frame synchronization in a user equipment in a real-time media streaming system. The method includes the following steps: sending a channel switch request to a relay server; in response to the channel switch request, receiving a channel switch response from the relay server, wherein the channel switch response includes frame offset information, and the frame offset The information indicates the frame offset between the frame of the reference media stream and the frame of the corresponding media stream received by the user equipment from the relay server; calculate the frame rate acceleration duration based on the frame offset information; and convert the corresponding The frame rate of the media stream is accelerated by the calculated frame rate acceleration duration, so as to synchronize the frame of the corresponding media stream provided by the relay server with the frame of the reference media stream.
或者，将所述参考媒体流而不是将所述对应媒体流加速所述加速时长。此时，所述加速时长存储在所述用户设备中，并在所述转播服务器的频道切换过程中应用到所述参考媒体流而非所述对应媒体流。Alternatively, the reference media stream is accelerated for the acceleration duration instead of the corresponding media stream. At this time, the acceleration duration is stored in the user equipment, and is applied to the reference media stream instead of the corresponding media stream during the channel switching process of the relay server.
转播服务器是用户设备与内容提供商之间的实体，其优选地由于RTCP而执行快速频道切换请求。根据RTCP，频道切换请求优选地是快速同步请求(rapid synchronizationrequest，RSR)，频道切换响应优选地是快速同步指示(rapid synchronizationindication，RSI)。转播服务器向用户设备提供对应的单播多媒体流以加快频道切换过程。The Rebroadcast Server is the entity between the user equipment and the content provider, which performs fast channel switching requests, preferably due to RTCP. According to RTCP, the channel switching request is preferably a rapid synchronization request (rapid synchronization request, RSR), and the channel switching response is preferably a rapid synchronization indication (rapid synchronization indication, RSI). The relay server provides the corresponding unicast multimedia stream to the user equipment to speed up the channel switching process.
用户设备优选地是机顶盒(set-top box，STB)。STB是信息家电设备，其通常包括直播流媒体输入并向电视机和外部信号源显示输出，从而将源信号转变为内容，该内容的格式是一种随后可以在电视屏幕或终端用户侧的其它显示设备上显示的格式。根据通过IP提供的直播流媒体内容传送，STB是小型计算设备，也称为IPTV接收器，从而提供IP网络上的双向通信并对视频流媒体进行解码。用于IP相关媒体流的STB具有一个内置家庭网络接口，该接口可以是根据IEEE 802.11g、n、ac，或者根据HomePNA或ITU-T G.hn标准等现有有线家庭网络技术之一的以太网、无线网络，这提供了一种使用现有家庭线路创建高速—高达1Gbit/s—局域网(local area network，LAN)的方式。The user equipment is preferably a set-top box (STB). STBs are information appliances that typically include live streaming inputs and display outputs to televisions and external sources, thereby converting the source signal into content in a format that can then be displayed on the TV screen or other Displays the format displayed on the device. In terms of live streaming content delivery over IP, STBs are small computing devices, also known as IPTV receivers, that provide two-way communication over IP networks and decode video streams. The STB for IP-related media streaming has a built-in home network interface which can be Ethernet according to IEEE 802.11g, n, ac, or one of the existing wired home network technologies such as HomePNA or ITU-T G.hn standards Internet, wireless networks, which provide a way to create high-speed—up to 1Gbit/s—local area networks (LANs) using existing home wiring.
这种直播流业务优选地不同于传统的网络电视，并涉及通过互联网提供不受本地系统运营商控制的第三方媒体内容。This live streaming service is preferably different from traditional Internet TV and involves providing third-party media content over the Internet that is not controlled by the local system operator.
参考媒体流优选地是IP多播媒体流。IP多播是一种用于网络中的IP基础设施上的一对多通信的技术。例如对于网络电视，当用户从一个TV频道换到另一个时，用户设备发送频道切换请求。多播通过以下方式有效地使用网络基础设施：要求多媒体源仅发送一次数据包，即使其需要通过用户数据报协议(user datagram protocol，UDP)传送给大量接收方。The reference media stream is preferably an IP multicast media stream. IP multicasting is a technique for one-to-many communication over an IP infrastructure in a network. For Internet TV, for example, when the user changes from one TV channel to another, the user equipment sends a channel switch request. Multicast efficiently uses network infrastructure by requiring a multimedia source to send a data packet only once, even if it needs to be delivered to a large number of recipients via the user datagram protocol (UDP).
参考媒体流优选地由媒体内容提供商提供。媒体内容提供商是通过IP传送流媒体数据的媒体流服务器，IP支持RTP、RTSP和RTCP。其是指专用计算机装置或专用应用软件。The reference media stream is preferably provided by a media content provider. A media content provider is a media streaming server that transmits streaming media data through IP, and IP supports RTP, RTSP, and RTCP. It refers to a dedicated computer device or dedicated application software.
根据本发明，用户发送频道切换请求并获得帧偏移信息，帧偏移信息主要表示在连接转播服务器时，媒体内容服务器提供的参考媒体流与转播服务器提供的媒体流之间的帧偏移。该帧偏移信息在频道切换响应中被传送给用户设备。用户设备用于读取偏移帧信息，并且能够基于帧偏移信息计算出帧速率加速时长。基于帧偏移，用户设备用于将媒体流的帧速率加速特定时长，以便对齐参考媒体流与该媒体流，使得这两种媒体流的帧同步。According to the present invention, the user sends a channel switching request and obtains frame offset information. The frame offset information mainly indicates the frame offset between the reference media stream provided by the media content server and the media stream provided by the relay server when connecting to the relay server. This frame offset information is communicated to the user equipment in the zapping response. The user equipment is used to read the offset frame information, and can calculate the frame rate acceleration duration based on the frame offset information. Based on the frame offset, the user equipment is used to accelerate the frame rate of the media stream for a specific period of time, so as to align the reference media stream with the media stream, so that the frames of the two media streams are synchronized.
在帧速率加速时长后，观看媒体内容提供商的该媒体流，例如通过IPTV直播的足球比赛，的所有用户同时获得该媒体流的GOP帧。这在连接频道时避免了上述的一致用户特定延迟。因此，如果邻近用户观看相同的IPTV直播足球比赛，则提供时间同步的媒体流，这两个邻居同时看到进球。After the frame rate is accelerated for a period of time, all users watching the media stream of the media content provider, for example, a football match broadcast live via IPTV, simultaneously obtain the GOP frame of the media stream. This avoids the consistent user-specific delays described above when connecting channels. So, if neighboring users watch the same live IPTV football match, providing a time-synchronized media stream, both neighbors see the goal at the same time.
此外，在帧速率加速时长后，用户设备并不立刻缓冲GOP帧来补偿用户特定时间延迟，因为在加速时长后没有发生时间延迟，因此用户设备并不需要一直缓冲流，这使得用户设备的缓冲区得到释放。In addition, after the frame rate acceleration period, the user equipment does not immediately buffer the GOP frame to compensate for the user-specific time delay, because no time delay occurs after the acceleration period, so the user equipment does not need to buffer the stream all the time, which makes the buffering of the user equipment area is released.
根据所述第一方面，在所述方法的第一实施形式中，所述参考媒体流的所述帧是所述参考媒体流的GOP序列的帧，优选地是I帧；来自所述转播服务器的所述对应媒体流的所述帧是所述媒体流的对应GOP序列的对应帧，优选地是I帧。或者，所述参考媒体流的所述GOP序列的所述帧以及所述媒体流的对应GOP序列的其对应帧可以是支持解码器在没有额外信息的情况下重建图像的任何帧，或包含完整图像信息的任何帧。According to the first aspect, in the first implementation form of the method, the frame of the reference media stream is a frame of the GOP sequence of the reference media stream, preferably an I frame; from the relay server The frame of the corresponding media stream is a corresponding frame of a corresponding GOP sequence of the media stream, preferably an I frame. Alternatively, the frame of the GOP sequence of the reference media stream and its corresponding frame of the corresponding GOP sequence of the media stream may be any frame that supports the decoder to reconstruct an image without additional information, or contain a complete Any frame of image information.
压缩的视频流包括根据H.264或H.265标准的多个GOP序列。因此，每个GOP序列包括不同帧类型的帧。这些帧类型中的一种是所谓的I帧。I帧是帧内编码图像，意味着该图像独立于GOP中的所有其它图像进行编码。每个GOP在解码顺序中开始于I帧。I帧包含完整的图像信息，不需要任何额外的信息来重建图像。通常，编码器使用GOP结构，GOP结构使每个I帧都是一个完全的随机接入点，使得GOP结构中的任何误差都通过下一个I帧校正。The compressed video stream comprises a sequence of multiple GOPs according to the H.264 or H.265 standard. Therefore, each GOP sequence includes frames of different frame types. One of these frame types is the so-called I-frame. An I-frame is an intra-coded picture, meaning that the picture is coded independently of all other pictures in the GOP. Each GOP starts with an I frame in decoding order. I-frames contain complete image information and do not require any additional information to reconstruct the image. Typically, encoders use a GOP structure that makes each I-frame a complete random access point such that any errors in the GOP structure are corrected through the next I-frame.
通常，视频流的I帧越多，其就越可编辑。但是，具有更多的I帧实质上提高了对视频进行编码所需的比特速率。因此，为了获得视频流中的压缩字符，并非GOP序列中的所有帧都是I帧。还存在P帧，P帧是预测编码图像，意味着它们包含相对于先前解码图像，例如I帧，的运动补偿差信息。还存在B帧，B帧是双向预测编码图像，意味着它们包含相对于先前解码图像，例如I帧或P帧，的运动补偿差信息。In general, the more I-frames a video stream has, the more editable it is. However, having more I-frames substantially increases the bit rate required to encode the video. Therefore, in order to obtain compressed characters in the video stream, not all frames in the GOP sequence are I-frames. There are also P-frames, which are predictively coded pictures, meaning that they contain motion-compensated difference information relative to a previously decoded picture, such as an I-frame. There are also B-frames, which are bidirectionally predictively coded pictures, meaning that they contain motion-compensated difference information relative to a previously decoded picture, such as an I-frame or a P-frame.
根据如上所述第一方面或根据所述第一方面的所述第一实施形式，在所述方法的第二实施形式中，所述帧速率加速限于预定义的百分比，优选地低于来自所述媒体内容服务器的所述参考媒体流的所述帧速率的10％，更优选地在7％到9％之间。According to the first aspect as described above or according to the first implementation form of the first aspect, in a second implementation form of the method, the frame rate acceleration is limited to a predefined percentage, preferably lower than that from the 10% of the frame rate of the reference media stream of the media content server, more preferably between 7% and 9%.
对媒体流加速使得以较高的帧速率进行播放。如果遵守预先确定的低于10％的阈值，则终端用户很难注意到该加速。建议帧速率加速的这一限制是为了避免影响用户的体验质量(quality of experience，QoE)，因为用户无法跟随视频流。然而，阈值优选地在测试阶段检测，并且可以相应地应用。因此媒体流根据帧速率加速时长计算进行加速。Accelerating the media stream enables playback at a higher frame rate. If a predetermined threshold of less than 10% is observed, the speedup is hardly noticeable to the end user. This limitation of frame rate acceleration is recommended to avoid affecting the user's quality of experience (QoE), since the user cannot follow the video stream. However, the threshold is preferably detected during the testing phase and can be applied accordingly. Therefore, the media stream is accelerated according to the frame rate acceleration duration calculation.
根据如上所述第一方面或根据所述第一方面的任一前述实施形式，在所述方法的第三实施形式中，所述方法还包括：所述用户设备确定从所述转播服务器收到的所述对应媒体流的所述帧速率，其中所述确定的帧速率等于所述参考媒体流的所述帧速率。According to the above first aspect or any of the aforementioned implementation forms of the first aspect, in the third implementation form of the method, the method further includes: the user equipment determines that the The frame rate of the corresponding media stream, wherein the determined frame rate is equal to the frame rate of the reference media stream.
因为来自转播服务器的媒体流的帧速率对于用户设备是已知的，所以通过来自转播服务器的对应媒体流的帧速率加速而将参考媒体流的I帧同步到对应媒体流的I帧以一种简单的方式实现。Because the frame rate of the media stream from the relay server is known to the user equipment, the I frame of the reference media stream is synchronized to the I frame of the corresponding media stream by accelerating the frame rate of the corresponding media stream from the relay server in a Simple way to achieve.
根据本发明的第二方面，提供了一种用于实时媒体流系统中的转播服务器中的帧同步的方法。所述方法包括以下步骤：从用户设备接收频道切换请求；确定参考媒体流的帧与要提供给所述用户设备的对应媒体流的帧之间的帧偏移；生成指示所述帧偏移的帧偏移信息；以及向所述用户设备发送响应于所述收到的频道切换请求的频道切换响应，其中所述频道切换响应包括所述偏移信息。According to a second aspect of the present invention, a method for frame synchronization in a rebroadcast server in a real-time media streaming system is provided. The method comprises the steps of: receiving a zapping request from a user equipment; determining a frame offset between a frame of a reference media stream and a frame of a corresponding media stream to be provided to the user equipment; generating a frame offset indicative of the frame offset frame offset information; and sending a zapping response to the user equipment in response to the received zapping request, wherein the zapping response includes the offset information.
或者，将所述参考媒体流而不是将所述对应媒体流加速所述加速时长。此时，所述加速时长存储在所述用户设备中，并在所述转播服务器的频道切换过程中应用到所述参考媒体流而非所述对应媒体流。Alternatively, the reference media stream is accelerated for the acceleration duration instead of the corresponding media stream. At this time, the acceleration duration is stored in the user equipment, and is applied to the reference media stream instead of the corresponding media stream during the channel switching process of the relay server.
根据所述第二方面，在所述方法的第一实施形式中，所述参考媒体流的所述帧是所述参考媒体流的GOP序列的帧，优选地是I帧；来自所述转播服务器的所述对应媒体流的所述帧是所述对应媒体流的对应GOP序列的对应帧，优选地是I帧。或者，所述参考媒体流的所述GOP序列的所述帧以及所述媒体流的对应GOP序列的其对应帧可以是支持解码器在没有额外信息的情况下重建图像的任何帧，或包含完整图像信息的任何帧。According to the second aspect, in the first implementation form of the method, the frame of the reference media stream is a frame of the GOP sequence of the reference media stream, preferably an I frame; from the relay server The frame of the corresponding media stream is a corresponding frame of a corresponding GOP sequence of the corresponding media stream, preferably an I frame. Alternatively, the frame of the GOP sequence of the reference media stream and its corresponding frame of the corresponding GOP sequence of the media stream may be any frame that supports the decoder to reconstruct an image without additional information, or contain a complete Any frame of image information.
根据如上所述第二方面或根据所述第二方面的所述第一实施形式，在所述方法的第二实施形式中，所述帧速率加速限于预定义的百分比，优选地低于来自所述媒体内容服务器的所述参考媒体流的所述帧速率的10％，更优选地在7％到9％之间。According to the second aspect as described above or according to the first implementation form of the second aspect, in a second implementation form of the method, the frame rate acceleration is limited to a predefined percentage, preferably lower than that from the 10% of the frame rate of the reference media stream of the media content server, more preferably between 7% and 9%.
根据如上所述第二方面或根据所述第二方面的任一前述实施形式，在所述方法的第三实施形式中，所述方法还包括：所述转播服务器确定从所述内容媒体服务器收到的所述参考媒体流的所述帧速率并将所述确定的帧速率提供给所述用户设备。According to the above-mentioned second aspect or any of the aforementioned implementation forms according to the second aspect, in the third implementation form of the method, the method further includes: the rebroadcast server determines that the The frame rate of the received reference media stream and provide the determined frame rate to the user equipment.
所述第二方面的方法或其实施形式实现了所述第一方面的方法或其实施形式的上述所有优点。The method of the second aspect or its implementation forms achieves all the above-mentioned advantages of the method of the first aspect or its implementation forms.
根据本发明的第三方面，提供了一种用于实时媒体流系统中的帧同步的方法。所述方法包括以下步骤：从用户设备向转播服务器发送频道切换请求；确定参考媒体流的帧与要提供给所述用户设备的对应媒体流的帧之间的帧偏移；生成指示所述帧偏移的帧偏移信息；响应于所述频道切换请求，从所述转播服务器接收频道切换响应，其中所述频道切换响应包括帧偏移信息，所述帧偏移信息指示参考媒体流的帧与所述用户设备从所述转播服务器收到的对应媒体流的帧之间的帧偏移；基于所述帧偏移信息计算帧速率加速时长；以及将所述对应媒体流的帧速率加速所述计算出的帧速率加速时长，以将所述转播服务器提供的所述媒体流的所述帧同步到所述参考媒体流的所述帧。According to a third aspect of the present invention, a method for frame synchronization in a real-time media streaming system is provided. The method comprises the steps of: sending a channel switching request from the user equipment to the rebroadcast server; determining a frame offset between a frame of a reference media stream and a frame of a corresponding media stream to be provided to the user equipment; generating an instruction indicating the frame offset frame offset information; in response to the zapping request, receiving a zapping response from the relay server, wherein the zapping response includes frame offset information indicating a frame of a reference media stream and the frame offset between the frames of the corresponding media stream received by the user equipment from the relay server; calculating the frame rate acceleration duration based on the frame offset information; and accelerating the frame rate of the corresponding media stream by the The calculated frame rate is accelerated for a duration, so as to synchronize the frame of the media stream provided by the relay server with the frame of the reference media stream.
根据所述第三方面，在所述方法的第一实施形式中，所述参考媒体流的所述帧是所述参考媒体流的GOP序列的帧，优选地是I帧；来自所述转播服务器的所述对应媒体流的所述帧是所述媒体流的对应GOP序列的对应帧，优选地是I帧。或者，所述参考媒体流的所述GOP序列的所述帧以及所述媒体流的对应GOP序列的其对应帧可以是支持解码器在没有额外信息的情况下重建图像的任何帧，或包含完整图像信息的任何帧。According to the third aspect, in the first implementation form of the method, the frame of the reference media stream is a frame of the GOP sequence of the reference media stream, preferably an I frame; from the relay server The frame of the corresponding media stream is a corresponding frame of a corresponding GOP sequence of the media stream, preferably an I frame. Alternatively, the frame of the GOP sequence of the reference media stream and its corresponding frame of the corresponding GOP sequence of the media stream may be any frame that supports the decoder to reconstruct an image without additional information, or contain a complete Any frame of image information.
根据如上所述第三方面或根据所述第三方面的所述第一实施形式，在所述方法的第二实施形式中，所述帧速率加速限于预定义的百分比，优选地低于来自所述媒体内容服务器的所述媒体流的所述帧速率的10％，更优选地在7％到9％之间。According to the third aspect as described above or according to the first implementation form of the third aspect, in a second implementation form of the method, the frame rate acceleration is limited to a predefined percentage, preferably lower than that from the 10% of the frame rate of the media stream of the media content server, more preferably between 7% and 9%.
根据如上所述第三方面或根据所述第三方面的任一前述实施形式，在所述方法的第三实施形式中，所述方法还包括：所述用户设备确定从所述转播服务器收到的所述媒体流的所述帧速率，其中所述确定的帧速率等于所述参考媒体流的所述帧速率。According to the above third aspect or any of the aforementioned implementation forms of the third aspect, in the third implementation form of the method, the method further includes: the user equipment determines that the The frame rate of the media stream, wherein the determined frame rate is equal to the frame rate of the reference media stream.
根据如上所述第三方面或根据所述第三方面的任一前述实施形式，在所述方法的第四实施形式中，所述方法还包括：所述转播服务器确定从所述内容媒体服务器收到的所述参考媒体流的所述帧速率并将所述确定的帧速率提供给所述用户设备。According to the above third aspect or any of the aforementioned implementation forms of the third aspect, in the fourth implementation form of the method, the method further includes: the rebroadcast server determines to receive from the content media server The frame rate of the received reference media stream and provide the determined frame rate to the user equipment.
所述第三方面的方法或其实施形式实现了所述第一方面的方法或其实施形式的上述所有优点。The method of the third aspect or its implementation forms achieves all the above-mentioned advantages of the method of the first aspect or its implementation forms.
根据本发明的第四方面，提供了实时媒体流系统中的一种用户设备。所述用户设备包括：发送构件，用于向转播服务器发送频道切换请求；接收构件，用于：响应于所述频道切换请求，从所述转播服务器接收频道切换响应，其中所述频道切换响应包括帧偏移信息，所述帧偏移信息指示参考媒体流的帧与所述转播服务器提供的对应媒体流的帧之间的帧偏移；以及处理构件，用于基于所述帧偏移信息计算帧速率加速时长，还用于将所述对应媒体流的帧速率加速所述计算出的帧速率加速时长，以将所述转播服务器提供的所述媒体流的所述帧同步到所述参考媒体流的所述帧。According to a fourth aspect of the present invention, a user equipment in a real-time media streaming system is provided. The user equipment includes: sending means for sending a channel switching request to the relay server; receiving means for: in response to the channel switching request, receiving a channel switching response from the relay server, wherein the channel switching response includes Frame offset information, the frame offset information indicating the frame offset between the frame of the reference media stream and the frame of the corresponding media stream provided by the relay server; and processing means for calculating based on the frame offset information The frame rate acceleration duration is also used to accelerate the frame rate of the corresponding media stream to the calculated frame rate acceleration duration, so as to synchronize the frame of the media stream provided by the relay server to the reference media The frame of the stream.
或者，将所述参考媒体流而不是将所述对应媒体流加速所述加速时长。此时，所述加速时长存储在所述用户设备中，并在所述转播服务器的频道切换过程中应用到所述参考媒体流而非所述对应媒体流。Alternatively, the reference media stream is accelerated for the acceleration duration instead of the corresponding media stream. At this time, the acceleration duration is stored in the user equipment, and is applied to the reference media stream instead of the corresponding media stream during the channel switching process of the relay server.
根据所述第四方面，在所述用户设备的第一实施形式中，所述处理构件还用于确定所述转播服务器提供的所述媒体流的所述帧速率，所述确定的帧速率等于所述参考媒体流的所述帧速率。According to the fourth aspect, in the first implementation form of the user equipment, the processing component is further configured to determine the frame rate of the media stream provided by the relay server, and the determined frame rate is equal to The frame rate of the reference media stream.
根据所述第四方面，在所述用户设备的第二实施形式中，所述处理构件还用于将所述帧速率加速限为预定义的百分比，优选地低于来自所述媒体内容服务器的所述参考媒体流的所述帧速率的10％，更优选地在7％到9％之间。According to said fourth aspect, in a second implementation form of said user equipment, said processing means are further configured to limit said frame rate acceleration to a predefined percentage, preferably lower than that from said media content server 10%, more preferably between 7% and 9%, of said frame rate of said reference media stream.
根据如上所述第四方面或根据所述第四方面的任一前述实施形式，在所述用户设备的第三实施形式中，所述用户设备的所述处理构件还用于确定从所述转播服务器收到的所述媒体流的所述帧速率，其中所述确定的帧速率等于所述参考媒体流的所述帧速率。According to the fourth aspect as described above or any preceding implementation form according to the fourth aspect, in the third implementation form of the user equipment, the processing means of the user equipment is further configured to determine from the rebroadcast The frame rate of the media stream received by the server, wherein the determined frame rate is equal to the frame rate of the reference media stream.
所述第四方面的用户设备或其实施形式实现了所述第一方面的方法或其实施形式的上述所有优点。The user equipment of the fourth aspect or its implementation form achieves all the above advantages of the method of the first aspect or its implementation form.
根据本发明的第五方面，提供了实时媒体流系统中的一种转播服务器。所述转播服务器包括：接收构件，用于从用户设备接收频道切换请求；处理构件，用于确定参考媒体流的帧与提供给所述用户设备的对应媒体流的帧之间的帧偏移，还用于生成指示所述帧偏移的帧偏移信息；以及发送构件，用于：响应于所述频道切换请求，向所述用户设备发送频道切换响应，其中所述频道切换响应包括所述偏移信息。According to a fifth aspect of the present invention, a relay server in a real-time media streaming system is provided. The rebroadcast server includes: receiving means for receiving a channel switching request from a user equipment; processing means for determining a frame offset between a frame of a reference media stream and a frame of a corresponding media stream provided to the user equipment, Also for generating frame offset information indicating the frame offset; and sending means for: in response to the zapping request, sending a zapping response to the user equipment, wherein the zapping response includes the offset information.
根据所述第五方面，在所述转播服务器的第一实施形式中，所述处理构件用于将所述帧偏移信息作为一个八位字节信息插入到所述频道切换响应中。According to said fifth aspect, in a first implementation form of said rebroadcast server, said processing means is configured to insert said frame offset information into said zapping response as one octet information.
根据RTCP，频道切换请求优选地是快速同步请求(rapid synchronizationrequest，RSR)，频道切换响应优选地是快速同步指示(rapid synchronizationindication，RSI)。RSI优选地根据P.Yang在2009年3月8日发表的论文“用于快速同步的RTCP的扩展(Extensions to RTCP for Rapid Synchronization)”来构成。RSI优选地包括大小为一个八位字节的预留字段。该预留字段优选地用于将帧偏移信息包括到用户设备。因此，RTCP无需调整；现有结构可以在没有其它消息类型或字段的情况下用来提供帧偏移信息。According to RTCP, the channel switching request is preferably a rapid synchronization request (rapid synchronization request, RSR), and the channel switching response is preferably a rapid synchronization indication (rapid synchronization indication, RSI). The RSI is preferably constructed according to the paper "Extensions to RTCP for Rapid Synchronization" published by P. Yang on March 8, 2009. The RSI preferably includes a reserved field of size one octet. This reserved field is preferably used to include frame offset information to the user equipment. Therefore, RTCP requires no adjustments; existing structures can be used to provide frame offset information without additional message types or fields.
根据所述第五方面，在所述转播服务器的第二实施形式中，所述处理构件还用于确定所述内容媒体服务器提供的所述参考媒体流的所述帧速率并将其提供给所述用户设备。According to the fifth aspect, in the second implementation form of the relay server, the processing component is further configured to determine the frame rate of the reference media stream provided by the content media server and provide it to the user equipment.
所述第五方面的转播服务器或其实施形式实现了所述第一方面的方法或其实施形式的上述所有优点。The rebroadcast server of the fifth aspect or its implementation form realizes all the above-mentioned advantages of the method of the first aspect or its implementation form.
根据本发明的第六方面，提供了一种用于帧同步的实时媒体流系统。所述系统包括：根据如上所述本发明第四方面或根据所述第四方面的任一实施形式的用户设备；根据如上所述本发明第五方面或根据所述第五方面的任一实施形式的转播服务器；以及用于提供媒体流的媒体内容服务器。所述用户设备用于向所述转播服务器发送频道切换请求；所述转播服务器用于基于所述频道切换请求向所述用户设备发送频道切换响应，其中所述频道切换响应包括帧偏移信息，所述帧偏移信息指示来自所述媒体内容服务器的参考媒体流的帧与从所述转播服务器提供给所述用户设备的对应媒体流的帧之间的帧偏移；所述用户设备用于基于所述偏移信息计算帧速率加速时长，所述用户设备还用于将所述媒体流的帧速率加速所述计算出的帧速率加速时长，以将所述转播服务器提供的所述媒体流的所述帧同步到来自所述媒体内容服务器的所述参考媒体流的所述帧。According to a sixth aspect of the present invention, a real-time media streaming system for frame synchronization is provided. The system includes: the user equipment according to the fourth aspect of the present invention or according to any implementation form of the fourth aspect; according to the fifth aspect of the present invention above or according to any implementation form of the fifth aspect form of rebroadcasting servers; and media content servers for providing media streams. The user equipment is configured to send a channel switching request to the relay server; the relay server is configured to send a channel switching response to the user equipment based on the channel switching request, wherein the channel switching response includes frame offset information, The frame offset information indicates the frame offset between the frame of the reference media stream from the media content server and the frame of the corresponding media stream provided from the relay server to the user equipment; the user equipment is used for Calculate the frame rate acceleration duration based on the offset information, and the user equipment is further configured to accelerate the frame rate of the media stream by the calculated frame rate acceleration duration, so as to use the media stream provided by the relay server The frame of is synchronized to the frame of the reference media stream from the media content server.
或者，将所述参考媒体流而不是将所述对应媒体流加速所述加速时长。此时，所述加速时长存储在所述用户设备中，并在所述转播服务器的频道切换过程中应用到所述参考媒体流而非所述对应媒体流。Alternatively, the reference media stream is accelerated for the acceleration duration instead of the corresponding media stream. At this time, the acceleration duration is stored in the user equipment, and is applied to the reference media stream instead of the corresponding media stream during the channel switching process of the relay server.
根据所述第六方面，在所述系统的第一实施形式中，所述媒体流系统是基于RTCP的媒体流系统。According to said sixth aspect, in a first implementation form of said system, said media streaming system is an RTCP based media streaming system.
根据如上所述第六方面或根据所述第六方面的所述系统的所述第一实施形式，在所述系统的第二实施形式中，所述媒体内容服务器用于提供多播参考媒体流；所述转播服务器用于提供单播对应媒体流。According to the sixth aspect as described above or the first implementation form of the system according to the sixth aspect, in a second implementation form of the system, the media content server is configured to provide a multicast reference media stream ; The rebroadcast server is used to provide unicast corresponding media streams.
根据如上所述第六方面或根据所述第六方面的所述系统的任一前述实施形式，在所述系统的第三实施形式中，所述处理构件用于将所述帧偏移信息作为一个八位字节信息插入到所述频道切换响应中。According to the sixth aspect as described above or any preceding implementation form of the system according to the sixth aspect, in a third implementation form of the system, the processing means is configured to use the frame offset information as One octet of information is inserted into the Zapping Response.
根据如上所述第六方面或根据所述第六方面的所述系统的任一前述实施形式，在所述系统的第四实施形式中，所述转播服务器的所述处理构件还用于确定所述内容媒体服务器提供的所述参考媒体流的所述帧速率并将其提供给所述用户设备。According to the sixth aspect as described above or any preceding implementation form of the system according to the sixth aspect, in a fourth implementation form of the system, the processing means of the relay server is further configured to determine the The frame rate of the reference media stream provided by the content media server and provided to the user equipment.
根据如上所述第六方面或根据所述第六方面的所述系统的任一前述实施形式，在所述系统的第五实施形式中，所述用户设备的所述处理构件还用于确定所述转播服务器提供的所述媒体流的所述帧速率，所述确定的帧速率等于所述参考媒体流的所述帧速率。According to the sixth aspect as above or any preceding implementation form of the system according to the sixth aspect, in a fifth implementation form of the system, the processing means of the user equipment is further configured to determine the The frame rate of the media stream provided by the relay server, the determined frame rate is equal to the frame rate of the reference media stream.
根据如上所述第六方面或根据所述第六方面的所述系统的任一前述实施形式，在所述系统的第六实施形式中，所述参考媒体流的所述帧是所述参考媒体流的GOP序列的帧，优选地是I帧；来自所述转播服务器的所述对应媒体流的所述帧是所述媒体流的对应GOP序列的对应帧，优选地是I帧。或者，所述参考媒体流的所述GOP序列的所述帧以及所述媒体流的对应GOP序列的其对应帧可以是支持解码器在没有额外信息的情况下重建图像的任何帧，或包含完整图像信息的任何帧。According to the sixth aspect as described above or any preceding implementation form of the system according to the sixth aspect, in the sixth implementation form of the system, the frame of the reference media stream is the reference media The frame of the GOP sequence of the stream is preferably an I frame; the frame of the corresponding media stream from the relay server is a corresponding frame of the corresponding GOP sequence of the media stream, preferably an I frame. Alternatively, the frame of the GOP sequence of the reference media stream and its corresponding frame of the corresponding GOP sequence of the media stream may be any frame that supports the decoder to reconstruct an image without additional information, or contain a complete Any frame of image information.
根据如上所述第六方面或根据所述第六方面的所述系统的任一前述实施形式，在所述系统的第七实施形式中，所述帧速率加速限于预定义的百分比，优选地低于来自所述媒体内容服务器的所述参考媒体流的所述帧速率的10％，更优选地在7％到9％之间。According to the sixth aspect as above or any of the preceding implementation forms of the system according to the sixth aspect, in a seventh implementation form of the system, the frame rate acceleration is limited to a predefined percentage, preferably a low 10% of the frame rate of the reference media stream from the media content server, more preferably between 7% and 9%.
所述第六方面的系统或其实施形式实现了所述第一方面的方法或其实施形式的上述所有优点。The system of the sixth aspect or its implementation form achieves all the above-mentioned advantages of the method of the first aspect or its implementation form.
本发明的所述第七方面提供了一种计算机程序产品，当在计算设备上执行时，所述计算机程序产品用于实施根据所述第一方面及其任一实施形式，或根据所述第二方面及其任一实施形式，或根据所述第三方面及其任一实施形式的帧同步方法。Said seventh aspect of the present invention provides a computer program product for implementing, when executed on a computing device, the method according to said first aspect and any of its implementation forms, or according to said first aspect. The second aspect and any implementation form thereof, or the frame synchronization method according to the third aspect and any implementation form thereof.
通过所述计算机程序产品实施所述方法可以实现其所有优点。Implementation of the method by the computer program product achieves all its advantages.
须注意，本申请中描述的所有设备、元件、单元和构件都可以在软件或硬件元件或其任意类型的组合中实施。本申请中描述的各种实体执行的所有步骤和所描述的将由各种实体执行的功能旨在表明各个实体适于或用于执行各自的步骤和功能。即使在下文的特定实施例描述中，执行一特定步骤或功能的那个实体的特定详细元件的描述中未体现那个特定功能或步骤，其中，该特定功能或步骤将完全由永恒实体形成，技术人员也应清楚，这些方法和功能可以在各个软件或硬件元件或其任意类型的组合中实施。It should be noted that all devices, elements, units and components described in this application may be implemented in software or hardware elements or any type of combination thereof. All steps performed by various entities described in this application and functions described to be performed by the various entities are intended to indicate that the respective entities are adapted or used to perform the respective steps and functions. Even in the following description of a specific embodiment, a specific function or step is not reflected in the description of specific detailed elements of the entity that performs a specific step or function, wherein the specific function or step will be formed entirely by the eternal entity, the skilled person It should also be clear that these methods and functions can be implemented in individual software or hardware elements or any type of combination thereof.
附图说明Description of drawings
结合所附附图，下面具体实施例的描述将阐述上述本发明的各方面及其实现形式，其中：In conjunction with the accompanying drawings, the following description of specific embodiments will set forth aspects of the present invention and their implementation forms, wherein:
图1所示为根据本发明第一实施例的方法的流程图。Fig. 1 is a flowchart of a method according to a first embodiment of the present invention.
图2所示为根据本发明第二实施例的方法的流程图。Fig. 2 is a flowchart of a method according to a second embodiment of the present invention.
图3所示为根据本发明第三实施例的方法的流程图。Fig. 3 is a flowchart of a method according to a third embodiment of the present invention.
图4所示为根据本发明一实施例的用户设备。Fig. 4 shows a user equipment according to an embodiment of the present invention.
图5所示为根据本发明一实施例的转播服务器。Fig. 5 shows a relay server according to an embodiment of the present invention.
图6所示为根据本发明一实施例的系统。Figure 6 illustrates a system according to an embodiment of the invention.
图7所示为根据本发明第四特定实施例的方法的流程图。Fig. 7 shows a flowchart of a method according to a fourth specific embodiment of the present invention.
图8所示为根据本发明特定实施例的系统的帧同步。Figure 8 illustrates frame synchronization of a system according to certain embodiments of the invention.
具体实施方式Detailed ways
根据图1至图6的实施例描述了实时媒体系统中的帧同步的方法和实体的基本实施例。这些基本概念结合图7和图8的实施例更详细地说明。因此，图7和图8的说明对于根据图1至图6的基本概念同样有效。The basic embodiments of the method and entity of frame synchronization in the real-time media system are described according to the embodiments of FIG. 1 to FIG. 6 . These basic concepts are explained in more detail in conjunction with the embodiments of FIGS. 7 and 8 . The descriptions of FIGS. 7 and 8 are therefore equally valid for the basic concept according to FIGS. 1 to 6 .
图1所示为根据本发明第一实施例的方法的流程图。方法100用于实时媒体流系统600中的用户设备400中的帧同步。根据图1的方法100包括向转播服务器500发送101频道切换请求的步骤。方法100还包括响应于频道切换请求从转播服务器500接收102频道切换响应的步骤，其中频道切换响应包括帧偏移信息，帧偏移信息指示参考媒体流的帧与用户设备400从转播服务器500收到的对应媒体流的帧之间的帧偏移。方法100还包括基于帧偏移信息计算103帧速率加速时长的步骤。方法100还包括将对应媒体流的帧速率加速104计算出的帧速率加速时长的步骤，以将转播服务器500提供的对应媒体流的帧同步到参考媒体流的帧。Fig. 1 is a flowchart of a method according to a first embodiment of the present invention. The method 100 is used for frame synchronization in a user equipment 400 in a real-time media streaming system 600 . The method 100 according to FIG. 1 comprises the step of sending 101 a channel switching request to the relay server 500 . The method 100 also includes the step of receiving 102 a channel switching response from the relay server 500 in response to the channel switching request, wherein the channel switching response includes frame offset information indicating that the frame of the reference media stream is the same as that received by the user equipment 400 from the relay server 500. The frame offset between the frames of the corresponding media stream. The method 100 also includes a step of calculating 103 a frame rate acceleration duration based on the frame offset information. The method 100 further includes a step of accelerating the frame rate of the corresponding media stream by the time period calculated by the frame rate acceleration 104, so as to synchronize the frame of the corresponding media stream provided by the relay server 500 with the frame of the reference media stream.
图2所示为根据本发明第二实施例的方法200的流程图。方法200用于实时媒体流系统600中的转播服务器500中的帧同步。根据图2的方法200包括从用户设备400接收201频道切换请求的步骤。方法200还包括确定202参考媒体流的帧与要提供给用户设备400的对应媒体流的帧之间的帧偏移的步骤。方法200还包括生成203指示帧偏移的帧偏移信息的步骤。方法200还包括响应于收到的频道切换请求向用户设备400发送204频道切换响应的步骤，其中频道切换响应包括帧偏移信息。FIG. 2 is a flowchart of a method 200 according to a second embodiment of the present invention. The method 200 is used for frame synchronization in the relay server 500 in the real-time media streaming system 600 . The method 200 according to FIG. 2 comprises the step of receiving 201 a channel change request from a user equipment 400 . The method 200 also comprises the step of determining 202 a frame offset between a frame of the reference media stream and a frame of the corresponding media stream to be provided to the user equipment 400 . The method 200 also includes the step of generating 203 frame offset information indicating the frame offset. The method 200 also includes the step of sending 204 a zapping response to the user equipment 400 in response to the received zapping request, wherein the zapping response includes frame offset information.
图3所示为根据本发明第三实施例的方法300的流程图。方法300用于实时媒体流系统600中的帧同步。根据图3的方法300包括从用户设备100向转播服务器500发送301频道切换请求的步骤。方法300还包括确定302参考媒体流的帧与要提供给用户设备400的对应媒体流的帧之间的帧偏移的步骤。方法300还包括生成303指示帧偏移的帧偏移信息的步骤。方法300还包括响应于频道切换请求从转播服务器500接收304频道切换响应的步骤，其中频道切换响应包括帧偏移信息，帧偏移信息指示参考媒体流的帧与用户设备400从转播服务器500收到的对应媒体流的帧之间的帧偏移。方法300还包括基于帧偏移信息计算305帧速率加速时长的步骤。方法300还包括将对应媒体流的帧速率加速306计算出的帧速率加速时长的步骤，以将转播服务器500提供的对应媒体流的帧同步到参考媒体流的帧。FIG. 3 is a flowchart of a method 300 according to a third embodiment of the present invention. The method 300 is used for frame synchronization in a real-time media streaming system 600 . The method 300 according to FIG. 3 comprises the step of sending 301 a channel switching request from the user equipment 100 to the relay server 500 . The method 300 also comprises the step of determining 302 a frame offset between a frame of the reference media stream and a frame of the corresponding media stream to be provided to the user equipment 400 . The method 300 also includes the step of generating 303 frame offset information indicating the frame offset. The method 300 also includes the step of receiving 304 a channel switching response from the relay server 500 in response to the channel switching request, wherein the channel switching response includes frame offset information indicating that the frame of the reference media stream is the same as that received by the user equipment 400 from the relay server 500. The frame offset between the frames of the corresponding media stream. The method 300 also includes the step of calculating 305 a frame rate acceleration duration based on the frame offset information. The method 300 further includes the step of accelerating the frame rate of the corresponding media stream by the calculated frame rate for a period of time, so as to synchronize the frame of the corresponding media stream provided by the relay server 500 with the frame of the reference media stream.
图4所示为根据本发明一实施例的实时媒体流系统600中的用户设备400。用户设备400包括：发送构件401，用于向转播服务器500发送频道切换请求；接收构件402，用于：响应于频道切换请求，从转播服务器500接收频道切换响应，其中频道切换响应包括帧偏移信息，帧偏移信息指示参考媒体流的帧与转播服务器500提供的对应媒体流的帧之间的帧偏移；以及处理构件403，用于基于帧偏移信息计算帧速率加速时长，还用于将对应媒体流的帧速率加速计算出的帧速率加速时长，以将转播服务器500提供的对应媒体流的帧同步到参考媒体流的帧。FIG. 4 shows a user equipment 400 in a real-time media streaming system 600 according to an embodiment of the present invention. The user equipment 400 includes: a sending component 401, configured to send a channel switching request to the relay server 500; a receiving component 402, configured to: receive a channel switching response from the relay server 500 in response to the channel switching request, wherein the channel switching response includes a frame offset Information, the frame offset information indicates the frame offset between the frame of the reference media stream and the frame of the corresponding media stream provided by the relay server 500; and the processing component 403 is used to calculate the frame rate acceleration duration based on the frame offset information, and also use The frame rate acceleration duration calculated by accelerating the frame rate of the corresponding media stream is used to synchronize the frame of the corresponding media stream provided by the relay server 500 to the frame of the reference media stream.
图5所示为根据本发明一实施例的实时媒体流系统600中的转播服务器500。转播服务器500包括：接收构件501，用于从用户设备400接收频道切换请求；处理构件503，用于确定参考媒体流的帧与提供给用户设备400的对应媒体流的帧之间的帧偏移，还用于生成指示帧偏移的帧偏移信息；以及发送构件502，用于：响应于频道切换请求，向用户设备400发送频道切换响应，其中频道切换响应包括帧偏移信息。FIG. 5 shows a relay server 500 in a real-time media streaming system 600 according to an embodiment of the present invention. The rebroadcast server 500 includes: a receiving component 501 for receiving a channel switching request from the user equipment 400; a processing component 503 for determining the frame offset between the frame of the reference media stream and the frame of the corresponding media stream provided to the user equipment 400 , is further configured to generate frame offset information indicating the frame offset; and a sending component 502, configured to: send a channel switch response to the user equipment 400 in response to the channel switch request, wherein the channel switch response includes the frame offset information.
图6所示为根据本发明第四实施例的用于帧同步的实时媒体流系统600。系统600包括根据图4的用户设备400。系统600还包括根据图5的转播服务器500。系统600包括用于提供参考媒体流106的媒体内容服务器601。FIG. 6 shows a real-time media streaming system 600 for frame synchronization according to a fourth embodiment of the present invention. The system 600 comprises the user equipment 400 according to FIG. 4 . The system 600 also includes the relay server 500 according to FIG. 5 . System 600 includes a media content server 601 for providing reference media stream 106 .
图7所示为第四特定实施例的系统600。如上文所述，下文提供的描述适用于图1至图6中定义的基本概念。Figure 7 shows a system 600 of a fourth particular embodiment. As mentioned above, the description provided below applies to the basic concepts defined in FIGS. 1 to 6 .
系统600包括根据图4的用户设备400。用户设备400可以是例如STB，特别是IPTV接收器。STB是提供到IP网络，优选地到转播服务器500，的双向通信的小型计算机，用于对转播服务器500提供的视频流媒体进行解码。IP机顶盒具有内置家庭网络接口，该接口可以是根据IEEE 802.11g、n、ac，或者根据现有有线家庭网络技术之一的以太网、无线LAN。STB400是信息家电设备，其通常包括电视调谐器输入并向电视机和外部信号源显示输出，从而将源信号转变为内容，该内容的格式是一种随后可以在电视屏幕或其它显示设备上显示的格式。The system 600 comprises the user equipment 400 according to FIG. 4 . The user equipment 400 may be eg a STB, in particular an IPTV receiver. The STB is a small computer providing two-way communication to the IP network, preferably to the relay server 500 , for decoding the video streaming media provided by the relay server 500 . The IP set top box has a built-in home network interface which can be Ethernet, wireless LAN according to IEEE 802.11g, n, ac, or according to one of the existing wired home network technologies. The STB400 is an information appliance device that typically includes a TV tuner input and display output to the TV and external sources, thereby converting the source signal into content in a format that can then be displayed on a TV screen or other display device format.
系统600还包括根据图5的转播服务器500。转播服务器500优选地是快速频道切换服务器(fast channel change，FCC)500。随着IPTV的出现，用户对频道搜索的体验已随着可能在多达24秒内测到的频道切换而倒退。FCC 500将切换时间恢复为不到一秒。这使IPTV运营商能够提供具有最佳用户体验的优质高清(high definition，HD)质量IPTV业务。在使用FCC 500时，QoE明显提高。FCC 500功能在网络边缘处实施，这明显地将单播对应媒体流107从FCC 500卸载并避免了成本高且耗时的网络升级。该方法还通过减少时延和数据拥塞来进一步提高QoE。FCC 500提供直播UDP的转播，这消除了丢包。根据图6，FCC 500设置在用户设备400与内容提供商601之间。The system 600 also includes the relay server 500 according to FIG. 5 . The relay server 500 is preferably a fast channel change server (fast channel change, FCC) 500 . With the advent of IPTV, the user's experience with channel searching has regressed with channel switches that can be measured in as much as 24 seconds. FCC 500 restores the switching time to less than one second. This enables IPTV operators to provide high-definition (high definition, HD) quality IPTV services with the best user experience. When using FCC 500, the QoE is significantly improved. The FCC 500 functionality is implemented at the edge of the network, which significantly offloads unicast corresponding media streams 107 from the FCC 500 and avoids costly and time-consuming network upgrades. This approach further improves QoE by reducing latency and data congestion. FCC 500 provides retransmission of live UDP, which eliminates packet loss. According to FIG. 6 , FCC 500 is arranged between user equipment 400 and content provider 601 .
系统600包括媒体内容服务器601，用于提供参考媒体流106。媒体内容提供商是通过IP传送多播参考媒体流106的媒体流服务器，IP支持RTP、RTSP和RTCP。其是指专用计算机装置或专用应用软件。The system 600 includes a media content server 601 for providing the reference media stream 106 . The media content provider is a media stream server that transmits the multicast reference media stream 106 via IP, which supports RTP, RTSP and RTCP. It refers to a dedicated computer device or dedicated application software.
系统600支持RTP和RTCP标准。其基本功能和数据包结构在第3550号请求注解(request for comments，RFC)中定义。RTCP提供RTP会话的带外统计和控制信息。其在传送和打包多媒体数据时与RTP合作，但是其自己不传输任何媒体数据。RTCP的主要功能是通过周期性地向流多媒体会话中的参与者发送统计信息来提供对媒体分发中的服务质量(quality of service，QoS)的反馈。System 600 supports the RTP and RTCP standards. Its basic functions and packet structure are defined in Request for Comments (RFC) No. 3550. RTCP provides out-of-band statistics and control information for RTP sessions. It cooperates with RTP in delivering and packaging multimedia data, but does not transmit any media data itself. The main function of RTCP is to provide feedback on quality of service (QoS) in media distribution by periodically sending statistical information to participants in a streaming multimedia session.
根据图7，媒体内容提供商601向FCC 500提供多个多播参考媒体流107。According to FIG. 7 , the media content provider 601 provides the FCC 500 with a plurality of multicast reference media streams 107 .
当用户进行IPTV频道切换时，STB 400根据方法步骤301基于RTCP向FCC服务器500发送单播频道切换请求RSR。FCC 500根据步骤302确定内容服务器601提供的参考媒体流602与用户连接新频道的时刻之间的帧偏移705。然后FCC 500根据步骤303生成帧偏移信息。优选地，帧偏移信息是参考媒体流107的I帧与表示用户连接新频道的时刻的对应媒体流106的对应I帧之间的帧数量。帧偏移信息优选地是一个八位字节信息，因此可以由FCC500包含在频道切换响应RSI中，优选地包含在RSI的预留字段八位字节中。When the user performs IPTV channel switching, the STB 400 sends a unicast channel switching request RSR to the FCC server 500 based on RTCP according to method step 301 . The FCC 500 determines the frame offset 705 between the reference media stream 602 provided by the content server 601 and the moment when the user connects to the new channel according to step 302 . Then FCC 500 generates frame offset information according to step 303 . Preferably, the frame offset information is the number of frames between the I-frame of the reference media stream 107 and the corresponding I-frame of the corresponding media stream 106 representing the moment when the user connects to the new channel. The frame offset information is preferably one octet of information and thus can be included by the FCC 500 in the Zapping Response RSI, preferably in a reserved field octet of the RSI.
随后，FCC 500使用发往用户设备400的RSI来回复RSR，RSI包括如在步骤303中生成的帧偏移信息。在步骤603中，FCC 500还将以对应I帧开始的新频道的对应多媒体流106单播给STB 400。Subsequently, the FCC 500 replies with an RSR using the RSI sent to the user equipment 400 , the RSI including the frame offset information as generated in step 303 . In step 603, the FCC 500 also unicasts to the STB 400 the corresponding multimedia stream 106 of the new channel starting with the corresponding I frame.
在收到RSI中的帧偏移信息后，STB 400将在步骤305中计算帧速率加速时长。帧速率加速时长基本上是达到参考媒体流106的I帧与对应媒体流107中的对应I帧之间的帧同步所需的加速时间。STB 400能够读取RSI消息中的帧偏移。After receiving the frame offset information in the RSI, the STB 400 will calculate the frame rate acceleration duration in step 305 . The frame rate acceleration duration is basically the acceleration time required to achieve frame synchronization between an I frame in the reference media stream 106 and a corresponding I frame in the corresponding media stream 107 . The STB 400 is able to read the frame offset in the RSI message.
在收到帧偏移信息且查看内容的帧速率后，STB 400将计算其必须以较高的帧速率播放多少秒，以便与参考媒体流106同步。After receiving the frame offset information and looking at the frame rate of the content, the STB 400 will calculate how many seconds it has to play at the higher frame rate in order to synchronize with the reference media stream 106 .
然后其以根据步骤306的加速帧速率来播放收到的单播媒体流(步骤603)。It then plays the received unicast media stream at the accelerated frame rate according to step 306 (step 603).
FCC 500提供的单播对应媒体流106以比来自内容提供商601的正常多播参考媒体流107帧速率更快的速度提供，以与后续多播流107保持一致。如果FCC 500确定单播对应媒体流107与STB 400中的多播流107保持一致，则其根据步骤604中的SCN消息通知STB 400加入新频道的多播组。The unicast corresponding media stream 106 provided by the FCC 500 is provided at a faster frame rate than the normal multicast reference media stream 107 from the content provider 601 to be consistent with subsequent multicast streams 107 . If the FCC 500 determines that the unicast corresponding media stream 107 is consistent with the multicast stream 107 in the STB 400 , it notifies the STB 400 to join the multicast group of the new channel according to the SCN message in step 604 .
然后STB 400根据步骤605用多播因特网组管理协议(Internet GroupManagement Protocol，IGMP)加入消息来通知内容提供商601。同时，FCC 500根据步骤606降低单播对应媒体流106的发送速度。Then the STB 400 notifies the content provider 601 according to step 605 by using a multicast Internet Group Management Protocol (Internet Group Management Protocol, IGMP) join message. At the same time, the FCC 500 reduces the sending speed of the unicast corresponding media stream 106 according to step 606 .
当STB 400从内容提供商601收到多播参考媒体流107时，STB 400根据步骤607向FCC 500发送第一多播数据包的序列号(Sequence Number，SN)值。SN值是用于标识正在传输的数据包的标识号。在步骤608中，FCC 500停止提供单播流。When the STB 400 receives the multicast reference media stream 107 from the content provider 601 , the STB 400 sends the sequence number (Sequence Number, SN) value of the first multicast data packet to the FCC 500 according to step 607 . The SN value is an identification number used to identify the packet being transmitted. In step 608, FCC 500 stops providing the unicast stream.
在一替代性实施例中，帧速率的加速应用到参考媒体流107而非对应媒体流106。在这种情况下，当内容提供商601向STB 400提供参考媒体流107时，STB 400保存计算出的帧速率加速时长并同时应用加速。In an alternative embodiment, the frame rate acceleration is applied to the reference media stream 107 instead of the corresponding media stream 106 . In this case, when the content provider 601 provides the reference media stream 107 to the STB 400, the STB 400 saves the calculated frame rate acceleration duration and applies the acceleration at the same time.
在帧速率加速后，对应媒体流106的I帧同步到参考媒体流107的I帧。这样，媒体内容提供商601提供的媒体流在时间上同步到连接该IPTV频道的所有用户。此外，可以避免参考媒体流106的缓冲，该缓冲是为了根据用户特定延迟在时间上同步媒体流106。因此STB400中的缓冲能力得到释放。After frame rate acceleration, the I-frames of the corresponding media stream 106 are synchronized to the I-frames of the reference media stream 107 . In this way, the media stream provided by the media content provider 601 is time-synchronized to all users connected to the IPTV channel. Furthermore, buffering of reference media stream 106 in order to synchronize media stream 106 in time according to user-specific delays can be avoided. The cushioning capacity in the STB400 is thus released.
在优选实施例中，STB 400向FCC 500提供确认信息。出于改进的原因，如果由于媒体流系统600中的时延而导致帧同步不在预先确定的范围中，则FCC 500可确定帧同步并发送另一帧偏移信息。In a preferred embodiment, STB 400 provides confirmation information to FCC 500 . For improvement reasons, the FCC 500 may determine frame synchronization and send another frame offset information if the frame synchronization is not within a predetermined range due to latency in the media streaming system 600 .
在图8中，针对三个不同的STB 400、404和405示出了帧同步方案。在使用FCC 500来应用快速频道切换之后，所有STB 400、404、405从内容提供商601获得多播参考媒体流106。或者，STB 400、404、405从FCC 500获得单播对应媒体流107。In FIG. 8 , the frame synchronization scheme is shown for three different STBs 400 , 404 and 405 . All STBs 400 , 404 , 405 obtain the multicast reference media stream 106 from the content provider 601 after applying fast channel switching using the FCC 500 . Alternatively, the STB 400 , 404 , 405 obtains the unicast corresponding media stream 107 from the FCC 500 .
STB 400、404、405获得实时直播IPTV对应媒体流106。对应媒体流106被划分为不同的GOP，其中第一GOP 701通过第一I帧703指示，第二GOP 702通过另一I帧703指示。每个GOP 701、702包含18帧，包括每个GOP 701、702开始处的I帧703。每个GOP701、702中的剩余17帧是P帧。很明显，这是一个例子，GOP还可包括不同于I或P帧的替代帧或其它帧。The STBs 400, 404, and 405 obtain the media stream 106 corresponding to the real-time live IPTV. The corresponding media stream 106 is divided into different GOPs, wherein a first GOP 701 is indicated by a first I-frame 703 and a second GOP 702 is indicated by another I-frame 703 . Each GOP 701,702 contains 18 frames, including the I-frame 703 at the beginning of each GOP 701,702. The remaining 17 frames in each GOP 701, 702 are P frames. Obviously, this is an example, and a GOP may also include alternative or other frames than I or P frames.
当GOP 701中的第六帧将要在实时流107中传输时，STB 400连接IPTV频道。由于第六帧不是I帧，所以FCC 500从最后一个可用I帧703开始向STB 400发送单播流106。这会使STB 400与来自内容提供商601的参考媒体流106之间存在五帧的恒定偏移时间。When the sixth frame in the GOP 701 is to be transmitted in the real-time stream 107, the STB 400 connects to the IPTV channel. Since the sixth frame is not an I frame, the FCC 500 sends the unicast stream 106 to the STB 400 starting from the last available I frame 703 . This would result in a constant offset time of five frames between the STB 400 and the reference media stream 106 from the content provider 601 .
当GOP 701中的第十四帧将要传输时，第二STB 404连接频道，因此第二用户设备404与参考媒体流602之间存在十三帧的偏移705。When the fourteenth frame in the GOP 701 is about to be transmitted, the second STB 404 is connected to the channel, so there is an offset 705 of thirteen frames between the second user equipment 404 and the reference media stream 602 .
最后，当第二GOP 702中的第九帧将要传输时，第三STB 405连接频道，因此在该第三用户405与参考媒体流601之间产生八帧的帧偏移705。Finally, when the ninth frame in the second GOP 702 is about to be transmitted, the third STB 405 connects the channel, thus creating a frame offset 705 of eight frames between the third user 405 and the reference media stream 601 .
因此，STB 400和STB 404在彼此间将存在八帧的相对时间延迟。使用每秒50帧的帧速率，STB 400与STB 404之间的时间延迟将为8:50＝0.16秒。更一般来说，时间延迟将由帧数量方面的延迟与参考帧107的帧速率之间的比率给出。因为GOP时间可以是数秒，所以该用户特定时间可以使用发明的帧同步来避免。Therefore, STB 400 and STB 404 will have a relative time delay of eight frames between each other. Using a frame rate of 50 frames per second, the time delay between STB 400 and STB 404 would be 8:50 = 0.16 seconds. More generally, the time delay will be given by the ratio between the delay in number of frames and the frame rate of the reference frame 107 . Since the GOP time can be seconds, this user specific time can be avoided using the inventive frame synchronization.
为了避免该帧偏移，用户设备400、404和405获得帧偏移信息以计算帧速率加速时长，从而减少帧偏移705并将I帧703同步到参考媒体流107的I帧。FCC 500将帧速率值提供给各个STB 400。To avoid the frame offset, the UEs 400 , 404 and 405 obtain the frame offset information to calculate the frame rate acceleration duration, thereby reducing the frame offset 705 and synchronizing the I frame 703 to the I frame of the reference media stream 107 . The FCC 500 provides the frame rate value to each STB 400 .
加速帧速率可限制为参考媒体流107或对应媒体流106的帧速率的约8％。The accelerated frame rate may be limited to approximately 8% of the frame rate of the reference media stream 107 or the corresponding media stream 106 .
一旦已设置所需加速速率，就有可能计算出每秒的附加帧数量以及用户设备通过对对应媒体流106进行加速来赶上延迟所需的时间。所需的时间由延迟(帧数量)与计算出的每秒的附加帧之间的比率给出。Once the desired acceleration rate has been set, it is possible to calculate the number of additional frames per second and the time required for the user equipment to catch up to the delay by accelerating the corresponding media stream 106 . The time required is given by the ratio between the latency (number of frames) and the calculated additional frames per second.
例如，应采用帧速率为每秒50帧、帧偏移为十帧的补偿。应使用8％的有限加速速率，以便具有预期的QoE值。因此，STB 400将帧速率从每秒50帧加速到每秒54帧，帧加速时长为2.5秒，以实现GOP帧同步。这样补偿了帧偏移。STB 400缓冲区利用得到优化，因为只要用户持续观看该新IPTV频道，缓冲区就无需不断地存储长达三秒。For example, a compensation with a frame rate of 50 frames per second and a frame offset of ten frames should be used. A limited acceleration rate of 8% should be used in order to have the expected QoE value. Therefore, the STB 400 accelerates the frame rate from 50 frames per second to 54 frames per second with a frame acceleration period of 2.5 seconds to achieve GOP frame synchronization. This compensates for frame offset. STB 400 buffer utilization is optimized because the buffer does not need to be continuously stored for up to three seconds as long as the user continues to watch the new IPTV channel.
与在参考媒体流106中使用的标准帧速率相比，STB 400能够以较高的帧速率进行播放。STB 400 is capable of playing at a higher frame rate than the standard frame rate used in reference media stream 106 .
已经结合作为实例的不同实施例以及实施方案描述了本发明。但本领域技术人员通过实践所请发明，研究附图、本公开以及独立权项，能够理解并获得其他变体。在权利要求以及描述中，术语“包括”不排除其他元件或步骤，且“一个”并不排除复数可能。单个元件或其它单元可满足权利要求书中所叙述的若干实体或项目的功能。在仅凭某些措施被记载在相互不同的从属权利要求书中这个单纯的事实并不意味着这些措施的结合不能在有利的实现方式中使用。The invention has been described in conjunction with various embodiments and implementations which were taken as examples. However, other variants can be understood and obtained by those skilled in the art by practicing the claimed invention, studying the drawings, the disclosure and the independent claims. In the claims as well as in the description, the term "comprising" does not exclude other elements or steps, and "a" does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP2015/076443WO2017080603A1 (en) | 2015-11-12 | 2015-11-12 | Frame alignment technique for live stream television |
| Publication Number | Publication Date |
|---|---|
| CN108353073Atrue CN108353073A (en) | 2018-07-31 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201580084561.7APendingCN108353073A (en) | 2015-11-12 | 2015-11-12 | Frame Synchronization Technology for Live TV |
| Country | Link |
|---|---|
| CN (1) | CN108353073A (en) |
| WO (1) | WO2017080603A1 (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111050208A (en)* | 2019-12-23 | 2020-04-21 | 深圳市豪恩汽车电子装备股份有限公司 | Real-time monitoring video playing device and method for motor vehicle |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101854533A (en)* | 2010-06-10 | 2010-10-06 | 华为技术有限公司 | Channel switching method, device and system |
| CN101938456A (en)* | 2009-06-30 | 2011-01-05 | 华为技术有限公司 | A method, device and system for reducing media delay |
| US8321905B1 (en)* | 2009-10-02 | 2012-11-27 | Adobe Systems Incorporated | Fast switching of media streams |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080022320A1 (en)* | 2006-06-30 | 2008-01-24 | Scientific-Atlanta, Inc. | Systems and Methods of Synchronizing Media Streams |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101938456A (en)* | 2009-06-30 | 2011-01-05 | 华为技术有限公司 | A method, device and system for reducing media delay |
| US8321905B1 (en)* | 2009-10-02 | 2012-11-27 | Adobe Systems Incorporated | Fast switching of media streams |
| CN101854533A (en)* | 2010-06-10 | 2010-10-06 | 华为技术有限公司 | Channel switching method, device and system |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111050208A (en)* | 2019-12-23 | 2020-04-21 | 深圳市豪恩汽车电子装备股份有限公司 | Real-time monitoring video playing device and method for motor vehicle |
| Publication number | Publication date |
|---|---|
| WO2017080603A1 (en) | 2017-05-18 |
| Publication | Publication Date | Title |
|---|---|---|
| US8218654B2 (en) | Method for reducing channel change startup delays for multicast digital video streams | |
| JP5363473B2 (en) | Method and apparatus for improved media session management | |
| JP6317872B2 (en) | Decoder for synchronizing the rendering of content received over different networks and method therefor | |
| JP5788101B2 (en) | Network streaming of media data | |
| EP2472857B1 (en) | Media stream processing method and communication system and related devices | |
| CA2761846C (en) | Method, apparatus and system for reducing media delay | |
| CN101523908A (en) | Multimedia management | |
| US20120030707A1 (en) | Methods and Arrangements for Channel Change in an IPTV Network | |
| CN1893364A (en) | Milestone synchronization in broadcast multimedia streams | |
| WO2007005194A1 (en) | Apparatuses and methods for delivering data stream content to consumer devices | |
| KR101642380B1 (en) | Method of transmission of a digital content stream and corresponding method of reception | |
| WO2009103343A1 (en) | Method and apparatus for distributing media over a communications network | |
| KR100792025B1 (en) | How to transfer video data when changing channel in IPTV system | |
| Kim et al. | An adaptive buffering method for practical HTTP live streaming on smart OTT STBs | |
| CN101860471B (en) | Method, device and system for media stream switching | |
| Uzunalioglu | Channel change delay in IPTV systems | |
| CN108353073A (en) | Frame Synchronization Technology for Live TV | |
| CN106937155B (en) | Access device, Internet Protocol Television (IPTV) system and channel switching method | |
| Sarni et al. | A novel scheme for a fast channel change in multicast IPTV system | |
| Bhat et al. | Optimization of tune-in and end-to-end delay in DASH broadcast over ROUTE | |
| KR20220068636A (en) | System and method for providing ultra low latency over the top service | |
| KR20050042301A (en) | Decoding method using error correction | |
| Yoon et al. | Analysis of techniques for accelerating IPTV channel change | |
| Niteesh Bhat et al. | Optimization of Tune-in and End-to-end Delay in DASH Broadcast over ROUTE | |
| Suzuki et al. | Personalized MPEG2 Video-Data Transmission System |
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|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | Application publication date:20180731 | |
| RJ01 | Rejection of invention patent application after publication |