Batch removal of second language

[mate]

I have a bunch of AVI files with Japaneese on the left audio channel and English on the right. I want to keep just the English, which is done easily with VirtualDub.

But, since there is a whole bunch of files I would like to do this in a batch process (i.e. probably using command line tools). I can create an AviSynth script with does this for me, but how would I (batch-wise) put the AviSynth output in a new .avi file?

I also tried AVIMaster, which I could not get to remove only left or right. I tried to combine AviSynth and AVIMaster, since AVIMaster can output a new file, but AVIMaster could not read the AviSynth script.

Ideas???
What other command line AVI tools are there?

[celtic_druid]

Problem with AVISynth is that unless you use the DSynth mod, you have to re-encode the video to.

Should be possible using mencoder with -ovc copy, say -oac mp3lame. Can't remember the command to control the audio channels off the top of my head though though.

Anyway, once you have it setup you can just use a for command to process all the avi's.

ffmpeg should also be able to do it.

[mate]

mencoder seems to do the job. Thanks!