Contents

• Public Types
• Public Functions
• Detailed Description

Detailed Description

TheQVideoSurfaceFormat class specifies the stream format of a video presentation surface.

A video surface presents a stream of video frames. The surface's format describes the type of the frames and determines how they should be presented.

The core properties of a video stream required to setup a video surface are the pixel format given bypixelFormat(), and the frame dimensions given byframeSize().

If the surface is to present frames using a frame's handle a surface format will also include a handle type which is given by thehandleType() function.

The region of a frame that is actually displayed on a video surface is given by theviewport(). A stream may have a viewport less than the entire region of a frame to allow for videos smaller than the nearest optimal size of a video frame. For example the width of a frame may be extended so that the start of each scan line is eight byte aligned.

Other common properties are thepixelAspectRatio(),scanLineDirection(), andframeRate(). Additionally a stream may have some additional type specific properties which are listed by the dynamicPropertyNames() function and can be accessed using theproperty(), andsetProperty() functions.

Member Type Documentation

enum QVideoSurfaceFormat::Direction

Enumerates the layout direction of video scan lines.

enum QVideoSurfaceFormat::YCbCrColorSpace

Enumerates the Y'CbCr color space of video frames.

Member Function Documentation

QVideoSurfaceFormat::QVideoSurfaceFormat()

Constructs a null video stream format.

QVideoSurfaceFormat::QVideoSurfaceFormat(constQSize & size,QVideoFrame::PixelFormat format,QAbstractVideoBuffer::HandleType type = QAbstractVideoBuffer::NoHandle)

Contructs a description of stream which receives stream oftype buffers with given framesize and pixelformat.

QVideoSurfaceFormat::QVideoSurfaceFormat(constQVideoSurfaceFormat & other)

Constructs a copy ofother.

QVideoSurfaceFormat::~QVideoSurfaceFormat()

Destroys a video stream description.

int QVideoSurfaceFormat::frameHeight() const

Returns the height of frame in a video stream.

qreal QVideoSurfaceFormat::frameRate() const

Returns the frame rate of a video stream in frames per second.

See alsosetFrameRate().

QSize QVideoSurfaceFormat::frameSize() const

Returns the size of frames in a video stream.

See alsosetFrameSize(),frameWidth(), andframeHeight().

int QVideoSurfaceFormat::frameWidth() const

Returns the width of frames in a video stream.

See alsoframeSize() andframeHeight().

QAbstractVideoBuffer::HandleType QVideoSurfaceFormat::handleType() const

Returns the type of handle the surface uses to present the frame data.

If the handle type isQAbstractVideoBuffer::NoHandle buffers with any handle type are valid provided they can bemapped with theQAbstractVideoBuffer::ReadOnly flag. If the handleType() is notQAbstractVideoBuffer::NoHandle then the handle type of the buffer be the same as that of the surface format.

bool QVideoSurfaceFormat::isValid() const

Identifies if a video surface format has a valid pixel format and frame size.

Returns true if the format is valid, and false otherwise.

QSize QVideoSurfaceFormat::pixelAspectRatio() const

Returns a video stream's pixel aspect ratio.

See alsosetPixelAspectRatio().

QVideoFrame::PixelFormat QVideoSurfaceFormat::pixelFormat() const

Returns the pixel format of frames in a video stream.

QVariant QVideoSurfaceFormat::property(constchar * name) const

Returns the value of the video format'sname property.

See alsosetProperty().

QList<QByteArray> QVideoSurfaceFormat::propertyNames() const

Returns a list of video format dynamic property names.

Direction QVideoSurfaceFormat::scanLineDirection() const

Returns the direction of scan lines.

See alsosetScanLineDirection().

void QVideoSurfaceFormat::setFrameRate(qreal rate)

Sets the framerate of a video stream in frames per second.

See alsoframeRate().

void QVideoSurfaceFormat::setFrameSize(constQSize & size)

Sets the size of frames in a video stream tosize.

This will reset theviewport() to fill the entire frame.

See alsoframeSize().

void QVideoSurfaceFormat::setFrameSize(int width,int height)

This is an overloaded function.

Sets thewidth andheight of frames in a video stream.

This will reset theviewport() to fill the entire frame.

void QVideoSurfaceFormat::setPixelAspectRatio(constQSize & ratio)

Sets a video stream's pixel aspectratio.

See alsopixelAspectRatio().

void QVideoSurfaceFormat::setPixelAspectRatio(int horizontal,int vertical)

This is an overloaded function.

Sets thehorizontal andvertical elements of a video stream's pixel aspect ratio.

void QVideoSurfaceFormat::setProperty(constchar * name, constQVariant & value)

Sets the video format'sname property tovalue.

See alsoproperty().

void QVideoSurfaceFormat::setScanLineDirection(Direction direction)

Sets thedirection of scan lines.

See alsoscanLineDirection().

void QVideoSurfaceFormat::setViewport(constQRect & viewport)

Sets the viewport of a video stream toviewport.

See alsoviewport().

void QVideoSurfaceFormat::setYCbCrColorSpace(YCbCrColorSpace space)

Sets the Y'CbCr colorspace of a video stream. It is only used with raw YUV frame types.

See alsoyCbCrColorSpace().

QSize QVideoSurfaceFormat::sizeHint() const

Returns a suggested size in pixels for the video stream.

This is the size of the viewport scaled according to the pixel aspect ratio.

QRect QVideoSurfaceFormat::viewport() const

Returns the viewport of a video stream.

The viewport is the region of a video frame that is actually displayed.

By default the viewport covers an entire frame.

See alsosetViewport().

YCbCrColorSpace QVideoSurfaceFormat::yCbCrColorSpace() const

Returns the Y'CbCr color space of a video stream.

See alsosetYCbCrColorSpace().

bool QVideoSurfaceFormat::operator!=(constQVideoSurfaceFormat & other) const

Returns true ifother is different to a video format, and false if they are the same.

QVideoSurfaceFormat & QVideoSurfaceFormat::operator=(constQVideoSurfaceFormat & other)

Assigns the values ofother to a video stream description.

bool QVideoSurfaceFormat::operator==(constQVideoSurfaceFormat & other) const

Returns true ifother is the same as a video format, and false if they are the different.