I often use "mplayer -dumpaudio" to play with video. Since this doesn't work with .ogm I tried VLC's file audio output module. The resulting .wav had the right length but was just noise in QuickTime Player. I tried u16 and s16. Perhaps a problem with endianness?
... or the correct transcoding. You may want to have a look at the stream-output-functionality of VLC. Everything is explained in the Streaming-HOWTO.
Saving audio to WAV usually works fine for me using s16l. These files are playable with QT without any problems.
VideoLAN
Felix Paul Kühne
Medic. VLC developer for appleOS since before you were born.
Blog: https://www.feepk.net