macOS: Concatenating videos on macOS

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Sometimes I’m out and I record many videos on my GoPro and then I import them on my Mac, but then I want to have a single big video for a day, instead of multiple videos.

I really don’t want to edit, hate editing videos.

So what I do is, I put them all in a folder, I go into it, then I run this command:

ls -t *.MP4 | sort | awk '{print "file \x27"$0"\x27"}' > list.txt && ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4

This concatenates all .MP4 videos, rather quickly, to an output.mp4 file.

It uses ffmpeg, so you’ve got to have it installed, with Homebrew use brew install ffmpeg

One time I ran this and videos were encoded badly and footage resulted faster than the original, and the end of the video was just black.

You might see a warning in this case, something like “ Non-monotonic DTS; ……… This may result in incorrect timestamps in the output file.”

I have no idea why this happened, I wasn’t able to fix this with ffmpeg but I used the native macOS QuickTime Player app, basically you open the first video file and drag and drop the second. Then the third, and so on. You’ll see an interface show up that shows you the file is being appended.

Then you export that file to a 4K video.

Lessons in this unit:

0: Introduction
1: How to use the macOS terminal
2: Productivity gains of using a Mac and an iOS device
3: A way to set up automations in macOS easily
4: How to hide a file or folder in macOS Finder
5: How to install a local SSL certificate in macOS
6: Reverting a file to a previous version, on a Mac
7: Take screenshots as JPG on macOS
8: Convert an image or resize it using macOS Shortcuts
9: ▶︎ Concatenating videos on macOS
10: Fix files creation date in macOS
11: Freeing space on a Mac
12: How to add an “Open in Terminal” icon in macOS Finder
13: How to add an “Open in VS Code” icon in macOS Finder
14: How to find the bundle ID of a Mac app
15: How to Fix the "Your CLT does not support macOS 11" error in macOS
16: How to play a sound from the macOS command line
17: How to remove the shadow from window screenshots in macOS
18: Removing all Homebrew stuff
19: Run a Node.js script from your macOS menu bar