Quote:
Originally Posted by shon3i
From H264 specification by formula Int(MaxDPB * 1024 / 1.5 / (w * h)) where w=width, h=height and MaxDPB from table A-1 (H264 specs), give max 4 reference frames for 1080p with level 4.1 or 4.0, and 9 for 720p. But according Blu-Ray specs for 720p is alowed max 6 reference frames for level 4.1 or 4.0 and 4 ref frames for 1080p. Encoders such Sonic Cinevision and Elecard in their BD profiles always lock for more than 4 refs. So 4 ref, are safe value for all resolutions including SD material
|
H264 specification is one thing and Blu-ray one is another. It's almost obvious that BD one is going to have more restrictions.
Another thing is that quite often pro encoders have even bigger limitation than BD spec.
Andrew