Probe all media devices and its linked video devices to locate a video
device that support stateless decoding of the specific codec using the
V4L2 Request API.
A video device is deemed capable when all tests pass, e.g. kernel
drivers support the coded pixel format and the frame size is supported.
Basic flow for initialization follows the kernel Memory-to-memory
Stateless Video Decoder Interface > Initialization [1].
[1] https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/dev-stateless-decoder.html#initialization
Co-developed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Co-developed-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Add a hwdevice type for use with V4L2 Request API stateless decoding.
AVV4L2RequestFramesContext is expected to be filled with a V4L2 coded
pixel format and optional codec-specific extended controls before an
AVHWFramesContext is initialized.
Once initialized AVV4L2RequestFramesContextInternal describe the opened
V4L2 stateless decoder session, with details about media/video file
descriptors, formats of CAPTURE/OUTPUT queues and buffer pools for
creating CAPTURE/OUTPUT buffers.
AVHWFramesContext.pool defaults to create frame descriptors around a
CAPTURE buffer, and frames are returned with AVFrame.data[0] pointing
to a AVDRMFrameDescriptor and AVFrame.data[1] the CAPTURE buffer index.
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
