📖 Add chapters to merged video

[tgotwig]

Create the first merged video in the tmp directory and the final one with the chapters in it, in the same one as the input videos.

Create a file like this in the tmp directory which defines the chapters:

;FFMETADATA1

[CHAPTER]
TIMEBASE=1/1000
START=0
END=430000
title=Titel 1

[CHAPTER]
TIMEBASE=1/1000
START=430000
END=605000
title=Titel 2

...

The title values should be the file names without the extensions.

Then they should be merged by something like this:

ffmpeg -i input_video.webm -i chapters.txt -map_metadata 1 -codec copy out.webm

With chapters in the video it would look like this (with IINA player on MacOS):