Resuming playback
mpv is capable of storing the playback position of the currently playing
file and resume from there the next time that file is played. This is
done with the commands quit-watch-later (bound to Shift+Q by default)
and write-watch-later-config, and with the --save-position-on-quit
option.
The difference between always quitting with a key bound to
quit-watch-later and using --save-position-on-quit is that the
latter will save the playback position even when mpv is closed with a
method other than a keybinding, such as clicking the close button in the
window title bar. However if mpv is terminated abruptly and doesn't have
the time to save, then the position will not be saved. For example, if
you shutdown your system without closing mpv beforehand.
mpv also stores options other than the playback position when they have
been modified after playback began, for example the volume and selected
audio/subtitles, and restores their values the next time the file is
played. Which options are saved can be configured with the
--watch-later-options option.
When playing multiple playlist entries, mpv checks if one them has a
resume config file associated, and if it finds one it restarts playback
from it. For example, if you use quit-watch-later on the 5th episode
of a show, and later play all the episodes, mpv will automatically
resume playback from episode 5.
More options to configure this functionality are listed in Watch Later.