[FFmpeg-devel] [PATCH] vf_ass: add yuv overlay

Nicolas George nicolas.george at normalesup.org
Thu Mar 15 09:55:12 CET 2012

Le sextidi 26 ventôse, an CCXX, yann.lepetitcorps at free.fr a écrit :
> Are the width and height of the bitmap stored into the FFDrawContext ?

No, I just forgot them. FFDrawContext is a structure that sores anything
that may be useful to efficiently draw in a surface of a particular pixel
format. It makes reference to
and is already more or less ready for inclusion.

> On other side, I think tat the luma and chroma calculations can be a
> little optimised by the use of big table that to can be precomputed with
> something like this
> AlphaLumaChromaTable[256][256][256];

It makes 16 megabytes of data with random access just to eliminate two
multiplications: did you benchmark that the effect on cache is not more than
the benefit?


  Nicolas George
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