I recently got hold of some DVD .iso images of some live concerts. Naturally, I wanted to extract the audio streams to obtain some MP3 files. This turned out to be easier than expected. I first extracted the .iso image using tar (apparently, not all versions of tar can extract ISO 9660 images—luckily, the FreeBSD version can). I then used ffmpeg to extract the audio streams:

for file in *.VOB; do ffmpeg -i "$file" -ab 256k -f mp3 "${file%.VOB}.mp3"; done

This tells ffmpeg to create MP3 files with a bitrate of 256 kBit/s. Unfortunately, splitting required manual work because the live convert did not contain completely silent parts. Audacity proved to be useful here because it offers a spectral visualization which allowed me to quickly find the short speaking parts between two songs.

Readers from Germany, aufgemerkt: Obviously, the DVD image was created from one of my own DVDs. I am not inciting anyone to break the law.