Watch-later using m3u

Expected behavior of the wanted feature

Currently, mpv saves playing position and speed values within a file named after the md5sum of the file it was playing.

Suggestion: use m3u for that. It makes it more compatible with other media players, and offers a way for standardizing tracking audiobooks.

$ cat "$XDG_STATE_HOME"/mpv/watch_later/2AB1F29BA4B6CD60CB58FF71191813DA
start=30.207838
speed=1.440000
volume=104.000000

Use instead:

#EXTM3U
#EXTINF:30.207838, Audiobook Chapter1 - History of Lorem Ipsum
#EXT-X-HASH:MD5:2AB1F29BA4B6CD60CB58FF71191813DA
#EXT-X-SPEED:1.440000
#EXT-X-VOLUME:104.000000
path/to/file.mp4

#EXTINF:51.307838, Audiobook Chapter2 - Next chapter
...

Files with only two lines have too much fragmentation. Just check:

$ ls -1 "$XDG_STATE_HOME"/mpv/watch_later | wc -l

A playlist is a more neat and portable option (think about syncing audiobooks status between desktop and mobile by only syncing a single m3u file).

Alternative behavior of the wanted feature

No response

Log File

No response

Sample Files

No response

Start by locating mpv's current watch_later handling and any tests for saved playback state. Compare that implementation with the proposed m3u structure and assess compatibility, migration, and synchronization behavior. Done means the design is agreed and the complete watch-later workflow, including persistence and reading, is covered.