[MPlayer-dev-eng] [RFC] internal library copies

[Reimar Döffinger]

On Thu, Mar 25, 2010 at 07:09:56PM +0100, Diego Biurrun wrote:
> On Wed, Mar 17, 2010 at 07:50:08PM +0100, Reimar Döffinger wrote:
> > On Wed, Mar 17, 2010 at 01:03:21PM +0100, Diego Biurrun wrote:
> > > * liba52
> > > 
> > > The internal copy was disabled some time ago, FFmpeg is both faster and
> > > more featureful.  We support building against the external version.  Our
> > > copy is patched, but upstream is dead and the patches have been rejected
> > > IIRC.
> > > verdict: drop
> > 
> > Hm? IIRC FFmpeg was a lot slower originally and even now is still a bit slower.
> > And upstream is a lot slower, so it seems to me that removing it would remove
> > the fastest decoder available.
> > Not that I mind much.
> 
> Hmm, you disabled liba52.  Can somebody provide numbers?  I think FFmpeg
> was faster, even for my K6-III...

These are the numbers I got back then:
As of 2010-01-04 mplayer/ffmpeg-mt:
$ time mplayer -nocache -novideo -vc null -vo null \
-ao pcm:fast:nowaveheader:file=/dev/null -benchmark /path/to/file.mkv

2ch/224kbps/-aid 0
liba52: real    0m10.027s user   0m9.433s sys   0m0.424s
ffac3:  real    0m11.079s user  0m10.289s sys   0m0.532s
6ch/448kbps->downmix 2ch/-aid 1 -channels 2
liba52: real    0m17.246s user  0m16.269s sys   0m0.564s
ffac3:  real    0m19.884s user  0m18.873s sys   0m0.536s
6ch/448kbps->6ch/-aid 1 -channels 6
liba52: real    0m26.187s user  0m24.410s sys   0m0.816s
ffac3:  real    0m27.093s user  0m25.790s sys   0m0.808s

> > > * libmpeg2
> > > 
> > > Nowadays FFmpeg is faster and should be better maintained.  Unfortunately
> > > we cannot compile against the external version.  This should not be hard
> > > to fix.  If it gets fixed, we could remove libmpeg2 IMO.
> > > Is anybody interested in fixing external libmpeg2 compilation?
> > 
> > Not particularly, but I wonder when FFmpeg got faster?
> > IIRC it was always slower... Of course that might depend on the CPU,
> > libmpeg2 only supports up to SSE I think, so with CPUs that support
> > more than that libavcodec probably has a chance.
> 
> Well, you switched to FFmpeg as the default decoder for MPEG-2 (IIRC)..
> I don't think there is a point in keeping local copies of libraries that
> are not even used by default...

That was due to stability reasons, not speed.
However I don't really mind removing it if nobody has any reasons to use it I forgot
(does dvdnav work with ffmpeg12 nowadays?).

There's one missing:
mp3lib.
IIRC everything relevant has been merged into libmpg123, development on that is still active,
so all that's needed is someone either writing a ad_mpg123 or changing ad_mp3lib to work with
the external one and we can remove it IMO.