Instead of downloading/extracting the youtube audio and then trying to split it based on the separate list, one should consider that such music-video files may he chapters, with a separate chapter for each track (as the file in question had).
There is a youtube-dl fork that has an option to download the chapters separately (in fact it downloads also the full audio and then splits it).
It is called yt-dlp.
In order to download the best m4a audio in separate tracks:
yt-dlp -f ba[ext=m4a] --split-chapters URL
In order to first list the ailable formats:
yt-dlp -F URL
which gives something like:
[youtube] QsmFrf-1wYE: Downloading webpage [youtube] QsmFrf-1wYE: Downloading android player API JSON [info] Available formats for QsmFrf-1wYE: ID EXT RESOLUTION FPS CH │ FILESIZE TBR PROTO │ VCODEC VBR ACODEC ABR ASR MORE INFO ────────────────────────────────────────────────────────────────────────────────────────────────────────────── sb2 mhtml 48x27 0 │ mhtml │ images storyboard sb1 mhtml 80x45 0 │ mhtml │ images storyboard sb0 mhtml 160x90 0 │ mhtml │ images storyboard 599 m4a audio only 2 │ 14.00MiB 31k https │ audio only mp4a.40.5 31k 22k ultralow, m4a_dash 600 webm audio only 2 │ 17.51MiB 39k https │ audio only opus 39k 48k ultralow, webm_dash 139 m4a audio only 2 │ 22.18MiB 49k https │ audio only mp4a.40.5 49k 22k low, m4a_dash 249 webm audio only 2 │ 25.65MiB 56k https │ audio only opus 56k 48k low, webm_dash ...and then download the desired audio format while splitting per chapter:
yt-dlp -f 139 --split-chapters URLSource: here, here and here.
In order to automate that a bit, I he installed xclip. A shortcut can trigger the whole process (first selecting url, then using the shortcut) with a command like:
konsole --noclose -e yt-dlp -f ba[ext=m4a] --split-chapters $(xclip -o)Or a desktop/panel launcher can be created, containing the same command:
[Desktop Entry] Exec=konsole --noclose -e yt-dlp -f ba[ext=m4a] --split-chapters $(xclip -o) Icon=im-youtube Name[en_US]=Download youtube chapters Name=Download youtube chaptersAfter dragging it onto the Plasma panel, just select the URL and click the button:
UPDATE on Plasma: in Plasma KDE, xclip is not needed in fact, if the clipboard actions are used. More details in my related answers under here and here.