Using Audio EDLs for Dual System Sound

As with film productions, 24p video productions almost always record the sound separately from the picture, with a separate sound recorder. This is referred to as using dual system sound. This audio is often simultaneously recorded onto the videotape of the 24p VTR, making it easy to later capture both the video and audio, with the audio already synced to the video for the edit.

Figure. Diagram of a dual system sound workflow.

In most cases, once you have finished editing, you will want to recapture the audio from the original production sound rolls and finish it at an audio post-production facility. The difficulty is that the EDL from Final Cut Pro does not know the roll numbers and audio timecode of the original production sound rolls; it only has the videotape information. Because the production sound recorder is started and stopped independently of the VTR, its timecode will not match the VTR’s.

Using its database feature, Cinema Tools can match the edits using the videotape audio with the original production sound rolls and generate an audio EDL that can then be used to recapture and finish the audio.

You must create a Cinema Tools database before you can use this feature. See Creating and Configuring a New Database for details about creating a database and Exporting an Audio EDL for details about exporting an audio EDL from Cinema Tools.