[MPlayer-dev-eng] [PATCH] AltiVec IMDCT for liba52 & AltiVec detection code (for real this time...)

[Romain Dolbeau]

Sorry for the message w/o the attachement, my
memory missed a refresh cycle somehow.

#####

Hello all,

The attached patch includes

1) An AltiVec-enhanced IMDCT for liba52 (liba52/imdct.c)
    It's nearly bit-perfect, I have a couple of lsb
    changed in a 128 frames sample. I can't hear the
    differences :-).
    (My bet is the difference in rounding inside the
     fused multiply-add).

2) AltiVec detection code ("borrowed" from FFmpeg) &
    enough code to enable the AltiVec IMDCT in liba52

3) The libavcodec AltiVec-enable patch sent previously
    (configure one-liner)

BTW, is there a 'good' way to check for codec speed ?
I tried -benchmark but it's not nearly precise enough
to estimate the AltiVec speed-up (or even if it's > 1 :-)

Also, maybe I should send the patch to the liba52
project, but it seems there's no CPU-specific
optimizations in their source tree.

-- 
Romain Dolbeau

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