[MEncoder-users] Weird audio codec problem.

[Giacomo Comes]

On Tue, Aug 01, 2006 at 12:10:45PM -0700, Lee wrote:
> It took me awhile to figure out what was going on but I have an instance
> 
> where MEncoder is ignoring a first pass through lame and is outputting 
> AC3, meaning that AC3 codecs need to be installed on playback.
> 
> First pass command:
> mencoder -ovc frameno -o frameno.avi -oac mp3lame -lameopts cbr:br=128 
> test.vob
> 
> Second pass command
> mencoder -oac copy -ovc lavc -lavcopts 
> vcodec=mpeg4:vhq:vbitrate=1049:vpass=1 -ffourcc XVID -vf 
> crop=720:464:0:6 test.vob -o /dev/null
> 
> At this point MEncoder spits out the following
> 
> AUDIO: 48000 Hz, 2 ch, s16le, 192.0 kbit/12.50% (ratio: 24000->192000)
> Selected audio codec: [a52] afm: liba52 (AC3-liba52)
> 
> Continuing on to the 3rd pass with the same audio output message above.....
> mencoder -oac copy -ovc lavc -lavcopts 
> vcodec=mpeg4:vhq:vbitrate=1049:vpass=2 -ffourcc XVID -vf 
> crop=720:464:0:6 test.vob -o test.avi
> 
> Sure enough the AVI has AC3 encoded audio. Why the total disregard of 
> the first pass and MP3 encoding at 128kb?
> 
> Installed versions:
> lame-3.96.1
> MPlayer-1.0pre8
> xvidcore-1.1.0

The three pass encoding method you are using is very old and deprecated.
Read the documetation that comes with mplayer in order to find examples
of good two pass encoding.
If you insist in using that method you should use the option -frameno-file.

Giacomo