[FFmpeg-devel] [RFC] [PATCH] Indicate better when transposing zigzag scantables is needed in some codecs

Christophe GISQUET christophe.gisquet
Sat Jan 19 13:13:30 CET 2008


Christophe GISQUET a ?crit :
> pseudo-code would be:
> if (idct!=idct_c && idct!=idct_ppc) // or (idct==idct_mmx)
>   transpose4x4;

In that case, as there is no 4x4 idct for ppc, this approach can be used.

I haven't noticed any BOFH in a 50m radius, so I expect the attached
patch to change the code so that it performs a conditional transpose of
the 4x4 zz scantable. I've decided to split it from the mmx patch
because it belonged more to that topic, although it does nothing by
itself and is a prerequisite for the mmx patch.

I can also add it back as a 2nd patch along the mmx patch over the other
thread if that's preferred.
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