[MPlayer-users] Audio encoding speed?

[Giacomo Comes]

On Mon, Jan 24, 2005 at 06:05:05PM +0100, Josef Wolf wrote:
> On Sun, Jan 23, 2005 at 08:54:37PM +0300, Phil Oleynik wrote:
> > Josef Wolf wrote:
> 
> > >I noticed that encoding mpeg2 TS streams to divx with 
> > >
> > > 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
> > >
> > >takes about four times longer than with
> > >
> > > mencoder -ni -cache 4096 in.vdr -o out.avi \
> > >   -ovc lavc -lavcopts vcodec=mpeg4:vqmin=2:mbd=0:vpass=1 \
> > >   -oac copy
> > >
> > >This would mean that audio encoding takes about three times longer than
> > >video encoding.
> >
> > Try to encode some sound with lame standalone - to see where is the BUG
> > lies.
> 
> Hmm, I tried:
> 
>    mplayer -dumpaudio blah.vdr
> 
> which results in a 154MB file (Indiana Jones, broadcasted yesterday over
> Astra on german pro7 channel).  But this file seems not to be a valid
> audio stream.  When I try to encode this file with lame, I get a mp3 file
> with only noise :-(  How do I properly dump the audio stream that I can
> encode it with standalone lame?

The audio is most probably mp2. 'mplayer blah.vdr -v' should show that.
Once you dump the audio with 'mplayer -dumpaudio blah.vdr'
you can play directly the dumped audio stream with mpg123.
You can use mplayer too, but mplayer need to be told that the stream is
mp2 (mplayer -rawaudio on:format=0x50 stream.dump).

Giacomo