To sync up the Audio Description track, the client requires a separate Control Track, which I gather is an output of timecode that matches the audio sync. Anyone familiar with this notion, and how would I do this through software? I am using Pro Tools 10 and Final Cut Pro 7.


  • While I haven't had time to read it yet, the BBC has a nice paper on the topic.
    – AJ Henderson
    Commented Jun 20, 2013 at 19:08
  • This is incredibly helpful information, thanks AJ!
    – Laura
    Commented Jun 21, 2013 at 18:51

2 Answers 2


I don't think either FCP or PT can generate LTC in software. Higher-end systems (like smoke) can.

The usual trick is to digitize the LTC track from a beta deck or similar, and add that as an audio track in your project.

If this is a continuing requirement, a sync-locked hardware TC gen isn't very expensive. Horita has one for under $300. http://www.horita.com/

I've written s/w to do this, but I've never commercialized it -- at least since the Apple II version (-:

  • It does not appear that the control has anything to do with timecode, but rather with pan and fade information for the track.
    – AJ Henderson
    Commented Jun 20, 2013 at 19:10
  • This is really interesting. The client indicated that it was simply the LTC timecode that is needed to sync up the track, but it makes sense that there should be pan and fade info, otherwise the voice description track would get lost in the mix.
    – Laura
    Commented Jun 21, 2013 at 18:53
  • I knew about Descriptive Video (US term) but didn't make the connection to your need, and wasn't aware that it's been mandated in some situations. I gather you found a solution in BWF Timecoder? Poking around the web I didn't see any straight-up LTC generating s/w, so maybe I'll package mine up for free. Windows only, though.
    – Jim Mack
    Commented Jun 21, 2013 at 22:08

From what I can gather, it looks like a pretty specialized form of encoding that would need software or hardware designed specifically for writing and encoding the Audio Description information. I don't think such features are built in to Pro Tools or Final Cut. In fact, I could find very little information about any vendors with a solution for this. It seems exceptionally limited. I was unable to find anything in the way of plugins for using the mono-track with control track approach that the BBC uses.

  • After hours of searching, I landed on this site one-n.com/bwftimecoder.html It's a program that takes the timecode stamped BWF and strips out the LTC information into a timecode track.
    – Laura
    Commented Jun 21, 2013 at 18:52
  • 1
    As well, in case you are interested, I was referred here after a few hours of searching: softelgroup.com/audio-description
    – Laura
    Commented Jun 21, 2013 at 18:55

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