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QVideoSurfaceFormat Class Reference
^{^{[QtMultimedia module]}}

The QVideoSurfaceFormat class specifies the stream format of a video presentation surface. More...

Types

enum Direction { TopToBottom, BottomToTop }
enum YCbCrColorSpace { YCbCr_Undefined, YCbCr_BT601, YCbCr_BT709, YCbCr_xvYCC601, YCbCr_xvYCC709, YCbCr_JPEG }

Methods

__init__ (self)
__init__ (self, QSize size, QVideoFrame.PixelFormat format, QAbstractVideoBuffer.HandleType type = QAbstractVideoBuffer.NoHandle)
__init__ (self, QVideoSurfaceFormat format)
int frameHeight (self)
float frameRate (self)
QSize frameSize (self)
int frameWidth (self)
QAbstractVideoBuffer.HandleType handleType (self)
bool isValid (self)
QSize pixelAspectRatio (self)
QVideoFrame.PixelFormat pixelFormat (self)
QVariant property (self, str name)
unknown-type propertyNames (self)
Direction scanLineDirection (self)
setFrameRate (self, float rate)
setFrameSize (self, QSize size)
setFrameSize (self, int width, int height)
setPixelAspectRatio (self, QSize ratio)
setPixelAspectRatio (self, int width, int height)
setProperty (self, str name, QVariant value)
setScanLineDirection (self, Direction direction)
setViewport (self, QRect viewport)
setYCbCrColorSpace (self, YCbCrColorSpace colorSpace)
QSize sizeHint (self)
QRect viewport (self)
YCbCrColorSpace yCbCrColorSpace (self)

Special Methods

bool __eq__ (self, QVideoSurfaceFormat format)
bool __ne__ (self, QVideoSurfaceFormat format)

Detailed Description

The QVideoSurfaceFormat 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 by pixelFormat(), and the frame dimensions given by frameSize().

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 the handleType() function.

The region of a frame that is actually displayed on a video surface is given by the viewport(). 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 the pixelAspectRatio(), scanLineDirection(), and frameRate(). Additionally a stream may have some additional type specific properties which are listed by the dynamicPropertyNames() function and can be accessed using the property(), and setProperty() functions.

Type Documentation

QVideoSurfaceFormat.Direction

Enumerates the layout direction of video scan lines.

Constant	Value	Description
`QVideoSurfaceFormat.TopToBottom`	`0`	Scan lines are arranged from the top of the frame to the bottom.
`QVideoSurfaceFormat.BottomToTop`	`1`	Scan lines are arranged from the bottom of the frame to the top.

QVideoSurfaceFormat.YCbCrColorSpace

Enumerates the Y'CbCr color space of video frames.

Constant	Value	Description
`QVideoSurfaceFormat.YCbCr_Undefined`	`0`	No color space is specified.
`QVideoSurfaceFormat.YCbCr_BT601`	`1`	A Y'CbCr color space defined by ITU-R recommendation BT.601 with Y value range from 16 to 235, and Cb/Cr range from 16 to 240. Used in standard definition video.
`QVideoSurfaceFormat.YCbCr_BT709`	`2`	A Y'CbCr color space defined by ITU-R BT.709 with the same values range as YCbCr_BT601. Used for HDTV.
`QVideoSurfaceFormat.YCbCr_xvYCC601`	`3`	The BT.601 color space with the value range extended to 0 to 255. It is backward compatibile with BT.601 and uses values outside BT.601 range to represent wider colors range.
`QVideoSurfaceFormat.YCbCr_xvYCC709`	`4`	The BT.709 color space with the value range extended to 0 to 255.
`QVideoSurfaceFormat.YCbCr_JPEG`	`5`	The full range Y'CbCr color space used in JPEG files.

Method Documentation

QVideoSurfaceFormat.init (self)

Constructs a null video stream format.

QVideoSurfaceFormat.init (self, QSize size, QVideoFrame.PixelFormat format, QAbstractVideoBuffer.HandleType type = QAbstractVideoBuffer.NoHandle)

Contructs a description of stream which receives stream of type buffers with given frame size and pixel format.

QSize QVideoSurfaceFormat.frameSize (self)

Returns the size of frames in a video stream.

See also setFrameSize(), frameWidth(), and frameHeight().

int QVideoSurfaceFormat.frameWidth (self)

Returns the width of frames in a video stream.

QAbstractVideoBuffer.HandleType QVideoSurfaceFormat.handleType (self)

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

If the handle type is QAbstractVideoBuffer.NoHandle buffers with any handle type are valid provided they can be mapped with the QAbstractVideoBuffer.ReadOnly flag. If the handleType() is not QAbstractVideoBuffer.NoHandle then the handle type of the buffer be the same as that of the surface format.