Parameters:
- Mpeg2SeqHdr *hdr
- Pointer to previously allocated and initialized Mpeg2SeqHdr structure.
Return value:
Integer chromaninance format code.
Description:
Returns chrominance format as either "411", "420", or "444". 411 indicates chroma planes are subsampled by 2 in both directions. 420 indicates chroma planes are subsampled by 2 in only the horizontal direction. 444 indicates no subsampling.