QAbstractVideoBuffer露

PyQt5.QtMultimedia.QAbstractVideoBuffer

Description露

The QAbstractVideoBuffer class is an abstraction for video data.

The QVideoFrame class makes use of a QAbstractVideoBuffer internally to reference a buffer of video data. Quite often video data buffers may reside in video memory rather than system memory, and this class provides an abstraction of the location.

In addition, creating a subclass of QAbstractVideoBuffer will allow you to construct video frames from preallocated or static buffers, in cases where the QVideoFrame constructors taking a QByteArray or a QImage do not suffice. This may be necessary when implementing a new hardware accelerated video system, for example.

The contents of a buffer can be accessed by mapping the buffer to memory using the map() function, which returns a pointer to memory containing the contents of the video buffer. The memory returned by map() is released by calling the unmap() function.

The handle() of a buffer may also be used to manipulate its contents using type specific APIs. The type of a buffer鈥檚 handle is given by the handleType() function.

See also

QVideoFrame.

Enums露

HandleType

Identifies the type of a video buffers handle.

See also

handleType().

Member

Value

Description
CoreImageHandle

3

The handle contains pointer to macOS CIImage.
EGLImageHandle

TODO

The handle of the buffer is an EGLImageKHR.
GLTextureHandle

1

The handle of the buffer is an OpenGL texture ID.
NoHandle

0

The buffer has no handle, its data can only be accessed by mapping the buffer.
QPixmapHandle

4

The handle of the buffer is a QPixmap.
UserHandle

1000

Start value for user defined handle types.
XvShmImageHandle

2

The handle contains pointer to shared memory XVideo image.
MapMode

Enumerates how a video buffer鈥檚 data is mapped to system memory.

See also

mapMode(), map().

Member

Value

Description
NotMapped

0x00

The video buffer is not mapped to memory.
ReadOnly

0x01

The mapped memory is populated with data from the video buffer when mapped, but the content of the mapped memory may be discarded when unmapped.
ReadWrite

ReadOnly | WriteOnly

The mapped memory is populated with data from the video buffer, and the video buffer is repopulated with the content of the mapped memory when it is unmapped.
WriteOnly

0x02

The mapped memory is uninitialized when mapped, but the possibly modified content will be used to populate the video buffer when unmapped.

Methods露

__init__(HandleType)

Constructs an abstract video buffer of the given type.

handle() → Any

Returns a type specific handle to the data buffer.

The type of the handle is given by handleType() function.

See also

handleType().

handleType() → HandleType

Returns the type of a video buffer鈥檚 handle.

See also

handle().

map(MapMode) → (sip.voidptr, int, int)

TODO

mapMode() → MapMode

TODO

release()

TODO

unmap()

TODO