A reference to the AVHWDeviceContext describing the device which will
be used by a hardware encoder/decoder. The reference is set by the
caller and afterwards owned (and freed) by libavcodec.
This should be used if either the codec device does not require
hardware frames or any that are used are to be allocated internally by
libavcodec. If the user wishes to supply any of the frames used as
encoder input or decoder output then hw_frames_ctx should be used
instead. When hw_frames_ctx is set in get_format() for a decoder, this
field will be ignored while decoding the associated stream segment, but
may again be used on a following one after another get_format() call.
For both encoders and decoders this field should be set before
avcodec_open2() is called and must not be written to thereafter.
Note that some decoders may require this field to be set initially in
order to support hw_frames_ctx at all - in that case, all frames
contexts used must be created on the same device.
A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/decoder. The reference is set by the caller and afterwards owned (and freed) by libavcodec.
This should be used if either the codec device does not require hardware frames or any that are used are to be allocated internally by libavcodec. If the user wishes to supply any of the frames used as encoder input or decoder output then hw_frames_ctx should be used instead. When hw_frames_ctx is set in get_format() for a decoder, this field will be ignored while decoding the associated stream segment, but may again be used on a following one after another get_format() call.
For both encoders and decoders this field should be set before avcodec_open2() is called and must not be written to thereafter.
Note that some decoders may require this field to be set initially in order to support hw_frames_ctx at all - in that case, all frames contexts used must be created on the same device.