title: combine two audio files with a command line tool
body: <p>I've to merge two (or more) audio files (like a guitar and a drum track) into a single file.
  I'm running over linux CentOS and I'd need a command line tool to do so, because I've got to run this as part of a background process, triggered via crontab of a custom bash script.
  I also need to be able to change the pan, volume, trim and start time (i.e I want the guitar track to start after 1.25ms after the drum track so that they can be both in sync with each other).</p>
  
  <p>My first choice would be ffmpeg, but I was wondering if there could be something more specific, reliable and less fuzzy than ffmpeg.</p>
  
  <p>thx a ton!
  -k-</p>