QAbstractPlanarVideoBuffer Class

The QAbstractPlanarVideoBuffer class is an abstraction for planar video data. 更多...

头: #include <QAbstractPlanarVideoBuffer>
qmake: QT += multimedia
Since: Qt 5.4
继承: QAbstractVideoBuffer

该类在 Qt 5.4 引入。

公共函数

QAbstractPlanarVideoBuffer (QAbstractVideoBuffer::HandleType type )
virtual ~QAbstractPlanarVideoBuffer ()
virtual int map (QAbstractVideoBuffer::MapMode mode , int * numBytes , int [4] bytesPerLine = 4, uchar *[4] data = 4) = 0

详细描述

QAbstractPlanarVideoBuffer extends QAbstractVideoBuffer to support mapping non-continuous planar video data. Implement this instead of QAbstractVideoBuffer when the abstracted video data stores planes in separate buffers or includes padding between planes which would interfere with calculating offsets from the bytes per line and frame height.

另请参阅 QAbstractVideoBuffer::mapPlanes ().

成员函数文档编制

QAbstractPlanarVideoBuffer:: QAbstractPlanarVideoBuffer ( QAbstractVideoBuffer::HandleType type )

Constructs an abstract planar video buffer of the given type .

[虚拟] QAbstractPlanarVideoBuffer:: ~QAbstractPlanarVideoBuffer ()

Destroys an abstract planar video buffer.

[pure virtual] int QAbstractPlanarVideoBuffer:: map ( QAbstractVideoBuffer::MapMode mode , int * numBytes , int [ 4 ] bytesPerLine = 4, uchar *[ 4 ] data = 4)

将视频缓冲内容映射到内存。

映射 mode indicates whether the contents of the mapped memory should be read from and/or written to the buffer. If the map mode includes the QAbstractVideoBuffer::ReadOnly flag the mapped memory will be populated with the content of the buffer when initially mapped. If the map mode includes the QAbstractVideoBuffer::WriteOnly flag the content of the possibly modified mapped memory will be written back to the buffer when unmapped.

When access to the data is no longer needed be sure to call the unmap () function to release the mapped memory and possibly update the buffer contents.

Returns the number of planes in the mapped video data. For each plane the line stride of that plane will be returned in bytesPerLine , and a pointer to the plane data will be returned in data . The accumulative size of the mapped data is returned in numBytes .

另请参阅 QAbstractVideoBuffer::map (), QAbstractVideoBuffer::unmap (),和 QAbstractVideoBuffer::mapMode ().