[FFmpeg-devel] [PATCH] SSE2 Xvid idct

Michael Niedermayer michaelni
Sun Apr 6 14:58:15 CEST 2008

On Sun, Apr 06, 2008 at 12:19:58AM -0400, Alexander Strange wrote:
> This adds skal's sse2 idct and uses it as the xvid idct when available.
> I merged two shuffles into the permutation and changed the zero-skipping 
> some - it's fastest in MMX and not really worth doing for the first three 
> rows. Their right halfs are still usually all zero, but adding the branch 
> to check for it is a net loss. The best thing for speed would be switching 
> IDCTs by counting the last nonzero coefficient position, but that's 
> something for later.
> xvididctheader - makes a new header so I don't add any more extern 
> declarations in .c files.
> sse2-permute - the new permutation; it might not have a specific enough 
> name, but it should work as well for simpleidct as this if I can get back 
> to that.
> sse2-xvid-idct.diff + idct_sse2_xvid.c - the IDCT

Can you also post dct-test -i 0/1/2 output please!

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct awnser.
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