Trouble Syncing Two Audio Tracks From Different Videos

[Spiralagnus]

I have two copies of a video: one has superior video quality, and the other has superior audio quality. Naturally, I'd like to combine them.

The problem is that the two audio tracks are out of sync with each other in some strange ways. One of the videos is encoded in HEVC and VBR while the other is AVC and CBR. I can strip the two audio tracks and sync them up manually at the start, but a few minutes later, they're out of sync again. If I try to slightly adjust the speed of one of the audio tracks, it now syncs up in some areas but goes out of sync in others.

I think part of the issue is that, due to the video encoding, there are spots where the two audio tracks are not identical. For instance, the time between two lines of dialogue on one track might be 1.0 seconds, while on the other track, it's 1.01 seconds, even though the speed and sampling rate of both tracks is the same. In fact, I've noticed that the audio tracks suddenly start to go out of sync after a scene change in the video.

It's not realistic for me to sit and fine-tune each audio track by hand, since I have a whole batch of videos to process. I'd ideally like to find some (free) software that can automatically sync up the two audio tracks at the start and then make continuous adjustments to the second track to keep it aligned with the first. I welcome any suggestions the community can provide. Thanks!

NOTE: I did try converting the HEVC file to a CBR before stripping the audio, but it doesn't seem to have helped.

[johns0]

You have to edit the audio as it plays,there's no program that will fix your issue,since the audios don't match your stuck trying to edit them.

[davexnet]

Yeah I did the movie "From hell to Texas" using a video from Russia that had a fair picture but Russian voice over
and an english language version from another (poorer) video. Did it by hand, took about 1 1/2 hours to get the locations where it went out
and the associated delays, then about another hour adding the info to an Avisynth script and testing it.

Izotope RX has its "Azimuth" module which supposedly can align the left and right channels in a stereo file, that's about the closest
functionality I've seen

[forart.it]

FFMatch - which is open source - may help you.

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