[MPlayer-dev-eng] [PATCH] remove mp3lib

Carl Eugen Hoyos cehoyos at ag.or.at
Wed Sep 21 02:18:25 CEST 2011


Reimar Döffinger <Reimar.Doeffinger <at> gmx.de> writes:

> I am still interested in seeing performance numbers and statistics from
> ffmp3 vs. mp3lib when ffmp3 is slower,

When I tested (after FFmpeg optimisations were committed), ffmp2float was faster
on systems where it does not matter (including 64bit C, SSE2 and Altivec), but
slower than internal libmp3 on systems where I believe it does make a
difference, namely 32bit MMX and SSE.

I did not test external libmp3.

I was sure I sent detailed results once to one of the lists, but cannot find
them now, what I found is what I wrote to Vitor after he committed some
optimisations:
[quote]
I just tested compilation of MPlayer with a 32 bit compiler on the Core2 Duo,
and the resulting binary is significantly slower with -ac ffmp2float with our
sample file than -ac mp3: 10.1 vs 8.8 seconds.
[/quote}

His answer was:
[quote]
mp3lib uses a crazy scheme of mixing floating and fixed point to be able to
use MMX instructions for windowing
[/quote]

Carl Eugen



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