[MPlayer-users] Audio encoding speed?

[Josef Wolf]

[ sorry for the late response, but encoding retries take sooo long that I
  could not get results earlier.]

On Wed, Jan 26, 2005 at 01:12:13AM -0800, Jack wrote:
> Josef Wolf wrote:

> >So here are the results:
> >
> > mencoder -ni -cache 4096 in.vdr -o out.avi \
> >   -ovc lavc -lavcopts vcodec=mpeg4:vqmin=2:mbd=0:vpass=1 \
> >   -oac mp3lame -lameopts q=0:vbr=0:aq=0             # about 5 hours
>
> q=0 is pointless, because vbr=0 sets it to CBR mode.

OK, I removed vbr=0.  I have no idea why I put it there.

> >So obviously, about 3.5 hours are lost somewhere.  Any ideas what I can
> >do next to find the cause why the 3.5 hours are lost?
>
> aq=0.

That's it.  With aq=1 I get reasonable encoding speed.

> >PS: I can not find an equivalent to the aq=0 option in lame's options.
> >   What does this aq=0 mean?
>
> It is equal to -q 0 on the lame command line.

I find it somewhat confusing that aq=0 corresponds to -q0 and q=0
corresponds to yet another wired option =:).  And how do I specify
lame's -V0 option?

> >BTW: I noticed that the dumped mp2 file is even shorter than the
> >    resulting mp3 file (154MB vs. 166MB).  So I wondered whether it is
> >    really worth to reencode the audio. 
> >
> No, no it isn't worth it.  Reencoding like this would be totally 
> pointless, and just lose more quality.  If you gain some space by 
> reencoding to VBR or to a lower bitrate, that would be worth it.

But the dumped mp2 file seems to be broken (I noted in my prevoius mail
that mpg123 can't play it), so I guess it is worth to reencode just to get
a non-broken file.

Thanks for your help!

-- 
No software patents!
-- Josef Wolf -- jw at raven.inka.de --