[MEncoder-users] mp4 audio slipping when played back in Quicktime

[Bram]

Hi,

> I that case I'd recommend encoding the audio and video streams 
> separately and hand these to mp4box (gpac). Mp4box cannot handle h264 in 
> avi... (which is the reason I do not use mencoder to encode to h264 in 
> the first place)
> 
I'd like to jump in here for a sec.. how would you go about and encode
both audio and video as separate streams using just mencoder? I couldn't
figure out how to get mencoder to just encode audio, for instance. I am
currently using ffmpeg to extract raw audio from a video stream, and
then passing it on to faac in a pipe, while using mencoder to encode the
video stream without sound. Then, in the end, I mux everything together
using mp4box. This seems to work, but the problem is that I need ffmpeg
to extract the raw audio to feed it to a faac, while mencoder should be
able to encode directly to just an audiostream. I used to use mencoder
to do encoding of both audio and video and muxing in 1 go, but this
causes the feared a/v sync issues on some files.

On a side note, I noticed that there's a piece of software called
mediacoder (http://mediacoder.sf.net/) which uses a special syntax to
have mencoder decode a video stream into multiple output streams. E.g.
the command line it uses looks like this:

".\codecs\mencoder.exe" -quiet -of rawvideo -ovc raw -rawvidopts pipe=5 
-ofps 25 -subcp cp1252 -sub-fuzziness 1 -subfont-autoscale 3 -subfont-blur 2
-subfont-outline 2 -aid 1 -vf harddup,format=i420 -af channels=2 -oac pcm
-pcmopts pipe=7 "Y:\test_videos\sample.wmv" -o NUL

Now I have checked mplayer's source tree, and the mediacoder source
tree, but I cannot for the life of me find where there 'pcmopts',
'rawvidopts' and their 'pipe=' parameters come from. This would be very
neat to have, as it allows one to have a single mencoder process decode
audio and video in 1 go. Does the author of this software have a
secretly hidden patch up his sleeve? Or would it be easy to patch this
into the mainstream mplayer tree?

Bram