Cause of DV lost audio bug

If you are attempting to work with DV/HDV video or import it from an old camcorder (typical miniDV type from 15-20 years ago), you may have run into the problem that the video imports OK, but it appears as if there's no audio track. If you have, I can tell you the cause, and a fix for one of the two macOS / ProVideo Formats bugs that causes the problem.

The first problem is that the current DV codec downloads DV video into a Quicktime container with three tracks: a video track, an audio track, and a timecode track. There doesn't appear to be any issue with the video track, and the codec does store the audio data in the QuickTime file. However, for most DV video sources, the new version of the codec cannot decide what the channel layout of the audio is (it properly detects how many channels there are). When it cannot detect the channel layout, it has no sensible default and sets it to something like '2 channels (UNSD+UNSD)' and refuses to play or load the audio. Older versions of the codec properly identified the channel layout and worked fine. Further, the new codec cannot read the audio it stored in the QuickTime file either, even though it wrote the data. There's no work around for this bug. As far as I can tell DV footage import is simply broken now.

The other issue: the current codec will not load audio tracks from a Quicktime DV file if there's a timecode track. You can use a much older Mac to import DV video using iMovie or older versions of Final Cut Pro, and you can work with the files there without issue, but if you copy them to Mac with a newer version of the DV codec, the audio tracks won't load when you try to play them in Quicktime, load them in iMovie or Final Cut Pro X. For this, however, there is a simple fix. You can use Ffmpeg to remove the offending timecode track:

ffmpeg -i original.mov -c copy -write_tmcd 0 fixed.mov

... and without the timecode track, the audio tracks (stereo or mono) will load into QT, iMovie, and FCPX just fine.

If you have access to a Linux computer (or VM), the open source dvgrab tool does precisely what you want at zero cost; you can even use Ffmpeg to wrap the DV output in a QuickTime container to use on the Mac. There are also plenty of options for Windows.

This should be simple for Apple to fix, but the bug has existed for years and is very well known. I don't think it will ever be fixed (a shame since it used to be so seamless to import the footage and work with it). For what it is worth, I actually spent the better part of an hour with Apple tech support on this issue and their advice was to use something other than a Mac to import the footage and then copy the files over.