normalize audio of DVD tracks

This assumes that you have the tracks already in the proper MPEG format (MPEG-PS) for DVD. The steps are simple: extract the audio of all tracks, normalize them, put the audio back in.

If you haven't already, install dvdauthor, mjpegtools, mplayer, and normalize.

• demultiplex the audio and the video from the MPEG files:
  mpeg2desc -a 0 -o clip.mpa < clip.mpg > /dev/null
  mpeg2desc -v 0 -o clip.m2v < clip.mpg > /dev/null
• convert the MPEG audio file to WAV:
  mplayer -ao pcm:fast clip.mpa
  mv audiodump.wav clip.wav
• once you're doing creating WAV files for all tracks, normalize them:
  normalize -m *.wav
• and convert them back to MPEG audio:
  mp2enc -o clip.mpa < clip.wav
• and multiplex them back in:
  mplex -f 8 -o clip.mpg clip.m2v clip.mpa