pointer to the picture/channel planes.
This might be different from the first allocated byte
Some decoders access areas outside 0,0 - width,height, please
see avcodec_align_dimensions2(). Some filters and swscale can read
up to 16 bytes beyond the planes, if these filters are to be used,
then 16 extra bytes must be allocated.
NOTE: Except for hwaccel formats, pointers not needed by the format
MUST be set to NULL.
pointer to the picture/channel planes. This might be different from the first allocated byte
Some decoders access areas outside 0,0 - width,height, please see avcodec_align_dimensions2(). Some filters and swscale can read up to 16 bytes beyond the planes, if these filters are to be used, then 16 extra bytes must be allocated.
NOTE: Except for hwaccel formats, pointers not needed by the format MUST be set to NULL.