I'm looking for a program that can synchronize audio and video from separate files. PluralEyes does this. I'm looking for something that runs on Linux and preferably is open source.

I imagine a CLI that goes like this:

$ clappersyncoffsets in.pm4 in.wav
0s 3.876s

3 Answers 3


It's a webtool but seems interesting:


This other is open, but - AFAIK - just for Windows:



I assume that you have a sound channel recorded on the camera which is in sync with the picture. In that case you only have to find the offset between the audio channels.

This tool claims just that: https://github.com/bbc/audio-offset-finder

I never tried it yet, but I would be very interested on your experiences if you would give it a try.

  • I think the asker allread has the diffrence of 3.876 seconds. So he only needs to copy the audio to the video Feb 25, 2019 at 15:59
  • @beemtee: this is a very interesting project. It seems that it mostly calls out to github.com/cournape/talkbox for actual functionality. One can probably build what I'm looking for out of talkbot. In the meantime, I have been focusing on a hardware solution for embedding actual timecode (LTC) in the fiels during production. Here's my first pass at a decoder for that: github.com/arikrupnik/ltcsync
    – iter
    Feb 25, 2019 at 20:11
  • Timothy Lukas H: @beemtee has it right. In the hypothetical terminal capture in my question, "0m 3.876s" represents the output of the hypothetical clappersyncoffsets program.
    – iter
    Feb 25, 2019 at 20:14


We've finally collected (almost all ?) open source synch software tools here: https://github.com/forart/HyMPS/blob/main/A_Tools.md#alignmentsynch-

Enjoy !

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