For hardware encoders configured to use a hwaccel pixel format, this
field should be set by the caller to a reference to the AVHWFramesContext
describing input frames. AVHWFramesContext.format must be equal to
AVCodecContext.pix_fmt.
This field should be set before avcodec_open2() is called and is
afterwards owned and managed by libavcodec.
Encoding only.
For hardware encoders configured to use a hwaccel pixel format, this field should be set by the caller to a reference to the AVHWFramesContext describing input frames. AVHWFramesContext.format must be equal to AVCodecContext.pix_fmt.
This field should be set before avcodec_open2() is called and is afterwards owned and managed by libavcodec.