[rivviepop]

Originally Posted by tuxi

        -oac mp3lame \

Using mp3lame gave me a usable video with audio that was fine. There may be some fine tuning for this, but I haven't done too much more fiddling with it.

Yeah, mencoder/mplayer can be compiled with all sorts of different stuff, it's a very confusing set of options they've got going on. If you need to use -oac mp3lame, then you want a line with -lameopts for the bitrate (and anything else), like so:

        -oac mp3lame \
        -lameopts abr:br=$ABR \

...and edit the -lavcopts line to remove the audio options now:

        -lavcopts vcodec=mpeg4:vbitrate=$VBR

Complete:

mencoder "$FILE" \
        -o "${FILE%.*}_bb.avi" \
        -of avi \
        -ovc lavc \
        -oac mp3lame \
        -lavcopts vcodec=mpeg4:vbitrate=$VBR \
        -lameopts abr:br=$ABR \
        -vf scale=$RES

Obviously tweak the -lameopts as much as you'd like and/or need, but the defaults should work pretty good.