The QVideoSurfaceFormat class specifies the stream format of a video presentation surface. More...
| Header: | #include <QVideoSurfaceFormat> |
| qmake: | QT += multimedia |
| enum | Direction { TopToBottom, BottomToTop } |
| enum | YCbCrColorSpace { YCbCr_Undefined, YCbCr_BT601, YCbCr_BT709, YCbCr_xvYCC601, YCbCr_xvYCC709, YCbCr_JPEG } |
| QVideoSurfaceFormat() | |
| QVideoSurfaceFormat(const QSize &size, QVideoFrame::PixelFormat format, QAbstractVideoBuffer::HandleType type = QAbstractVideoBuffer::NoHandle) | |
| QVideoSurfaceFormat(const QVideoSurfaceFormat &other) | |
| ~QVideoSurfaceFormat() | |
| int | frameHeight() const |
| qreal | frameRate() const |
| QSize | frameSize() const |
| int | frameWidth() const |
| QAbstractVideoBuffer::HandleType | handleType() const |
| bool | isMirrored() const |
| bool | isValid() const |
| QSize | pixelAspectRatio() const |
| QVideoFrame::PixelFormat | pixelFormat() const |
| QVariant | property(const char *name) const |
| QList<QByteArray> | propertyNames() const |
| QVideoSurfaceFormat::Direction | scanLineDirection() const |
| void | setFrameRate(qreal rate) |
| void | setFrameSize(const QSize &size) |
| void | setFrameSize(int width, int height) |
| void | setMirrored(bool mirrored) |
| void | setPixelAspectRatio(const QSize &ratio) |
| void | setPixelAspectRatio(int horizontal, int vertical) |
| void | setProperty(const char *name, const QVariant &value) |
| void | setScanLineDirection(QVideoSurfaceFormat::Direction direction) |
| void | setViewport(const QRect &viewport) |
| void | setYCbCrColorSpace(QVideoSurfaceFormat::YCbCrColorSpace space) |
| QSize | sizeHint() const |
| QRect | viewport() const |
| QVideoSurfaceFormat::YCbCrColorSpace | yCbCrColorSpace() const |
| bool | operator!=(const QVideoSurfaceFormat &other) const |
| QVideoSurfaceFormat & | operator=(const QVideoSurfaceFormat &other) |
| bool | operator==(const QVideoSurfaceFormat &other) const |
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.
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. |
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 a wider range of colors. |
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 dimensions 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 must be the same as that of the surface format.
Returns true if the surface is mirrored around its vertical axis. This is typically needed for video frames coming from a front camera of a mobile device.
Note: The mirroring here differs from QImage::mirrored, as a vertically mirrored QImage will be mirrored around its x-axis.
This function was introduced in Qt 5.11.
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 if the surface is mirrored around its vertical axis. This is typically needed for video frames coming from a front camera of a mobile device. Default value is false.
Note: The mirroring here differs from QImage::mirrored, as a vertically mirrored QImage will be mirrored around its x-axis.
This function was introduced in Qt 5.11.
See also isMirrored().
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.
Trying to set a read only property will be ignored.
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 this video format, and false if they are the same.
Assigns the values of other to this object.
Returns true if other is the same as this video format, and false if they are different.
