[Ffmpeg-devel] [PATCH] increase max numbers of B frames

skal skal
Tue Feb 21 13:44:39 CET 2006

	Hi Loren and all,

On Mon, 2006-02-20 at 12:58 -0800, Loren Merritt wrote:
> PBBBPBBBP: again, each frame is bigger than it would be in 2 consecutive, 
> and now there's a decent chance that 67%->75% B-frames isn't enough to 
> pay off. Though it's a bit more useful than in mpeg4, due to B-pyramid 
> (which I won't detail here) and miscellaneous other improvements in the 
> codec.

   Maybe this point is worth some details: h264 permits use the middle
   B-slice as reference, making the reference anchors not so far from
   the remaining inbetween b-slices (non-refs). So, you're back to 
   deciding PbBbP over PbPbP for the refs, which is quite similar to
   the PBP vs. PPP decision, as far as refs placement is concerned.
   Well, this is quite an uncharted (and slippery) land, but some
   are advocating use of GOPs as big as 32 (!):



(ps: any other references on this topic is most welcome)

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