[Ffmpeg-devel] [PATCH] qpel approximation

Rich Felker dalias
Sat Feb 18 06:00:35 CET 2006

On Fri, Feb 17, 2006 at 05:59:08PM -0800, Loren Merritt wrote:
> This patch adds approximate bilinear qpel mc functions, enabled for 
> B-frames only, with -lavdopts fast.
> Comments: does it look ok? should it have a separate option?
> 16x16 mc costs, averaged over all subpel positions:
> mpeg4 qpel:   1443 cycles
> h264 qpel:    1148 cycles
> bilinear qpel: 174 cycles
> mpeg4 hpel:     99 cycles
> total speedup: ~12% in mpeg4, ~5% in h264.

Like I said on IRC, it would be nice if you had the same choices for
this as for skip_* options. i.e.:

- use bilinear on all frames
- use bilinear on B frames
- use bilinear on non-reference frames
- ...

The option could even be called skip_homc (high order motion comp).


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