Created attachment 323385 [details] [review]
mpeg2: treat profile 422 as main profile

Intel driver can handle MPEG2 422 profile as main profile, either with 4:2:2
chroma or 4:2:0

In theory , it is not right to map MPGE 422 to Simple or Main always. At lease i can see features  supported in 422 which are not in simple/main. For eg: chroma_intra_quantiser/chroma_non_intra_quantiser matrices are need not be supported by the decoder for Simple/Main. Also coded_block_pattern_1 (4:2:2) also need not be supported by Simple/Main. 

Of course, there is no attribute setting for chroma format  in libva api or in intel-driver(as per what i can see from source) for mpeg2 decode.


IMHO,
-- As per spec we can't map 422 profile to Main always
-- If we only considering intel-vaapi-driver, we can consider this patch. But someone have to test it in the older SandyBridge platform and the stream should have chroma_intra_quantiser/chroma_non_intra_quantiser matrices.

Also would be good if you can ask about this in libva mailing list.

let's close this issue. If it comes up later, we could reconsider this patch.