[MPlayer-users] does debug compile affect performance?

Vladimir Mosgalin mosgalin at VM10124.spb.edu
Mon Sep 8 21:46:46 CEST 2003


On Mon, 8 Sep 2003, Vladimir Mosgalin wrote:

VM>OK, I'll recompile mplayer right now with -g3 and without -g and tell
VM>the results - how rss will change and how speed of encoding will

I tried it right now. While playing 640x480 1.5 min mpeg4 file with
bunch of filters, RSS of mplayer (size 4.8M) was 15-17M average. Playing
same file with mplayer compiled with -g3 (size 54M), RSS was 15-18M, as
expected. Try this yourself if you don't believe...

Of course speed of mencoders (re-encoding file with lavc to /dev/null)
was the same.

I also tried compiling with MP_DEBUG=1, but the speed remained exactly
the same. Code with #ifdef MP_DEBUG isn't widely used in mplayer, and
since most of playing/encoding time is spent in lavc and various
filters, setting MP_DEBUG does nothing to speed. From critical parts,
it's only used in swscaler.

However, --enable-debug not only sets MP_DEBUG and adds -g to compiler
options, but also removes some optimizations (-O4 -> -O2, removes
-ffast-math and -fomit-frame-pointer), this should affect performance
somehow...

-- 

Vladimir



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