[MPlayer-dev-eng] mp3 decoding performance on ARM (was: mplayer libtremor patch)

[Siarhei Siamashka]

On Sunday 13 August 2006 22:44, Diego Biurrun wrote:

> Have you tried ffmp3?  The MP3 decoder in FFmpeg is integer-only.  I'd
> be interested to know how it performs compared to libmad.

Nokia 770, ARM926EJS 250MHz cpu

128kbit constant bitrate soundtrack, length 6:13
MPlayer 1.0pre8, libmad 0.15.1b

time ./mplayer -quiet -ac mad -ao pcm:fast:file=/dev/null -vo null -vc null 
test.mp3
...
real    0m 46.92s
user    0m 46.22s
sys     0m 0.50s

time ./mplayer -quiet -ac ffmp3 -ao pcm:fast:file=/dev/null -vo null -vc null 
test.mp3
...
real    1m 27.84s
user    1m 26.91s
sys     0m 0.64s

So libmad is still faster, maybe because of ARM assembler optimizations.
But I also found the following link which is advertised to have fast fixed
point mp3 decoder (17MHz for decoding 128kbit soundtrack):
https://datatype.helixcommunity.org/mp3dec.html

Using above statistics, libmad cpu requirements estimate is 31MHz, and it is
somewhat higher than helix decoder advertised numbers. Surely mplayer itself
adds some overhead in demuxing and buffering, but probably helix decoder is
worth trying. Now trying to figure out how to get its sources from CVS and 
what is that RPSL license :-)