Syncing alternate audio to video?

[Towncivilian]

I've got a VHS containing a pretty good audience video recording of Depeche Mode in concert in Milwaukee from 1993-10-19. The audio is less than stellar, but I have an alternate audio source which is quite good (https://www.depechemode-live.com/wik...,_USA/Source_1).

I'd like to use the alternate audio source as the primary audio track and leave the original camera audio as a secondary track, but I do not know how to sync up the better audio to the video. The alternate source runs at a different speed (slower - though it is the more accurate speed) and also is missing some audience noise from the beginning that the video has. There is also a tape flip halfway through.

Does anyone have any hints on how to proceed?

[dpalomaki]

Is the audio off by a consistent amount (e.g., 0.1% slow or fast)?
If so you could use a program such as Audition to stretch the audio waveform while preserving pitch.

There are a variety of ways to do this. I would use a decent NLE system to do it precisely.
- Capture the video to a file
- Download the audio file
- Put both on the timeline, use the audio waveforms to sync audio.
- Use the NLE's capability to "stretch" the files as necessary to maintain sync to your satisfaction. (Typically a couple frames is close enough for live events recorded from a distance. Depending on the material it may be possible to do it simply by cutting out portions of "dead air" between numbers.
- When you have satisfactory sync, mute the unwanted audio tracks and export to you file format of choice.