[theora-dev] [PATCH] thusnelda keyframe only speedup

xiphmont at xiph.org xiphmont at xiph.org
Sat Mar 15 22:20:15 PDT 2008

On Sat, Mar 15, 2008 at 4:01 PM, Philip Heron <phil at sanslogic.co.uk> wrote:
> Hi all,
>  Attached is a trivial patch that speeds up encoding for key frame only
>  streams. It skips the motion vector search which is not needed when
>  there are never going to be any delta frames. It was made against
>  thusnelda SVN revision 14589.

The results of the current frame's (and previous frame's) MV search
are needed by subsequent frames to seed constant speed and constant
accelleration candidates.  That includes INTRA frames. This breaks
that part of the analysis.

It would be valid to skip MV analysis on scene-change INTRA frames so
long as you also reset the persistent MV analysis state, but it is
incorrect behavior for INTRA frames forced by the keyframe max

That said-- I appreciate that others are looking at (and hacking on)
the Thusnelda branch :-)


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