2014-07-15 To extract the audio track from a video, use: avconv -i foo.mp4 -vn foo.mp3 (`-vn' stands for ``video none'') To reverse an audio track, use: sox in.mp3 out.mp3 reverse This might be useful if you want to listen to backmasked mes- sages. [0] [0] http://en.wikipedia.org/wiki/Backmasking http://marmaro.de/lue/ markus schnalke