QVideoSurfaceFormat Class ReferenceThe QVideoSurfaceFormat class specifies the stream format of a video presentation surface. More... #include <QVideoSurfaceFormat> This class was introduced in Qt 4.6. Public Types
Public Functions
Detailed DescriptionThe 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. Member Type Documentation
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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. |
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. |
Constructs a null video stream format.
Contructs a description of stream which receives stream of type buffers with given frame size and pixel format.
Constructs a copy of other.
Destroys a video stream description.
Returns the height of frame in a video stream.
Returns the frame rate of a video stream in frames per second.
See also setFrameRate().
Returns the size of frames in a video stream.
See also setFrameSize(), frameWidth(), and frameHeight().
Returns the width of frames in a video stream.
See also frameSize() and frameHeight().
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.
Identifies if a video surface format has a valid pixel format and frame size.
Returns true if the format is valid, and false otherwise.
Returns a video stream's pixel aspect ratio.
See also setPixelAspectRatio().
Returns the pixel format of frames in a video stream.
Returns the value of the video format's name property.
See also setProperty().
Returns a list of video format dynamic property names.
Returns the direction of scan lines.
See also setScanLineDirection().
Sets the frame rate of a video stream in frames per second.
See also frameRate().
Sets the size of frames in a video stream to size.
This will reset the viewport() to fill the entire frame.
See also frameSize().
This is an overloaded function.
Sets the width and height of frames in a video stream.
This will reset the viewport() to fill the entire frame.
Sets a video stream's pixel aspect ratio.
See also pixelAspectRatio().
This is an overloaded function.
Sets the horizontal and vertical elements of a video stream's pixel aspect ratio.
Sets the video format's name property to value.
See also property().
Sets the direction of scan lines.
See also scanLineDirection().
Sets the viewport of a video stream to viewport.
See also viewport().
Sets the Y'CbCr color space of a video stream. It is only used with raw YUV frame types.
See also yCbCrColorSpace().
Returns a suggested size in pixels for the video stream.
This is the size of the viewport scaled according to the pixel aspect ratio.
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 also setViewport().
Returns the Y'CbCr color space of a video stream.
See also setYCbCrColorSpace().
Returns true if other is different to a video format, and false if they are the same.
Assigns the values of other to a video stream description.
Returns true if other is the same as a video format, and false if they are the different.