[MPlayer-users] Encoding pcm stream with -oac mp3lame

[Frank Boehme]

Hi gang,

I hope this is not an faq. First, I tought it was a libmp3lame issue,
but now I think it really has to do with mencoder. I searched the list
archive and the dox, but I couldn't find any ref to the problem.

I have a couple of avi files which came from a Canon PowerShot S45
digital camera. The files contain a bog standard mjpeg video stream, an
uncompressed pcm audio stream and no index (barely enough to write on
the tin "This camera can also record digital video."). Mplayer plays
these file without problems (it plays nearly everything, these days).

At least, mjpeg is convenient for cutting with avidemux (since there are
no such things like P or B frames). But I would like to encode these
files to something more intelligent and less bandwith eating. No problem
with the video. But I can't get the sound encoded with -oac mp3lame,
whatever lameopts I supply and whichever version of libmp3lame I use
(including current cvs). mencoder keeps reporting nan for the resulting
audio stream size and there is no audio in the resulting avi. Could that
be an issue with the demultiplexer? On the other hand, mplayer does play
the original file with sound and I believe it uses the same demuxer code
for reading which is used by mplayer.

Or perhaps the pcm audio is somehow bad (clipped?)

Has anybody got some hints on how I could tackle/diagnose this?

TIA,

Frank