Well. On Linux (Ubuntu 10.10) this is what I do..
Had a load of .ogm files that won't play on default player.. so...
I have a file called convert_vids.sh
> touch convert_vids.sh
Make sure you can run it..
> chmod +x convert_vids.sh
Open in a text editor
> nano convert_vids.sh
Then copy & paste this into it..
for z in *.ogm
echo Converting file "$z" to "$z".avi
mencoder "$z" -aid 1 -slang en -ovc xvid -oac mp3lame -lameopts br=192 -mc 0 -xvidencopts pass=1:bitrate=1000 -o "$z".avi
And run it in the directory you wish to convert
Just use the main function if you only want to convert a single file or to test it works first!
mencoder thefilm.ogm -aid 1 -slang en -ovc xvid -oac mp3lame -lameopts br=192 -mc 0 -xvidencopts pass=1:bitrate=1000 -o thefilm.avi
You can play with the settings but basically it'll pick the first audio track, English subtitles, and encode it to xvid with a video bitrate of 1000kbps and mp3 audio of 192kbps and output the file with the same name as before but .avi added to the end. (These settings might be higher than some people want, but I like to future proof them..)
I like my manga in the original language with subs..