Show HN: Remove Silence from Videos with Ffmpeg

There was recently a Show HN for a program that lets one remove silence from video files [0]. I was almost certain that ffmpeg could do this...

But after searching for it, it turned out I was wrong: ffmpeg can't do this out of the box, and also can't read input from an EDL file [1].

So I set out to write a solution, as simple as possible: produce a list of select filters that are applied to video and audio, and retain only the non-silent parts.

The 'silencedetect' audio filter detects silences, and produces timestamps for when silences start and end. So one can pipe the output of that to a Python script, that builds an ffmpeg command with the appropriate select filters.

The resulting ffmpeg command can be run to re-encode the video without the silent parts.

Hope this helps.

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Notes:

1/ I did find something somewhat similar to what I ended up doing [2], but it's complicated, and does the video encoding inside of Python. Granted, moviepy uses ffmpeg under the hood, but it's still better if ffmpeg does all the encoding directly.

2/ This solution doesn't produce a myriad of intermediary files that it would recombine afterwards; there is just one encoding of the output video file. 'silencedetect' is very fast, so all in all running this should be pretty fast.

[0] https://news.ycombinator.com/item?id=31767830

[1] https://en.wikipedia.org/wiki/Edit_decision_list

[2] https://donaldfeury.xyz/remove-the-silent-parts-of-a-video-u...