Re: 'emms-player-mpv ipc-error: error running command' on FLAC files

[Mike Kazantsev]

On Tue, 14 Dec 2021 11:01:26 -0500
Maxim Cournoyer <maxim.cournoyer@gmail.com> wrote:

> Hello!
> 
> Following a potent upgrade on my Guix System, EMMS can no longer play
> FLAC files and throws the error every time I try to play a FLAC track:
...
> 
> I tried debugging the problem and this about where it occurs:
...
>   emms-player-mpv-start((*track* (type . playlist) (name . 
> "/home/maxim/Music/Thrice/Thrice - Palms/Thrice - P...") (info-albumartist . 
> "Thrice") (info-tracknumber . "2") (info-album . "Palms") (info-date . 
> "2018") (info-artist . "Thrice") (info-title . "The Grey")))
>   funcall(emms-player-mpv-start (*track* (type . playlist) (name . 
> "/home/maxim/Music/Thrice/Thrice - Palms/Thrice - P...") (info-albumartist . 
> "Thrice") (info-tracknumber . "2") (info-album . "Palms") (info-date . 
> "2018") (info-artist . "Thrice") (info-title . "The Grey")))

I think this line shows the issue - track got mis-classified as a
playlist, so emms-player-mpv passed it as a playlist to an mpv.
While it's not actually a playlist ofc, so mpv rejected it.

Iirc similar issue was reported before on this ML, but I don't remember
why track got mis-identified as a playlist there.

Maybe you've added it via emms-add-playlist-file by accident, or it was
mis-identified based on filename as such somewhere?
(long-ish filename is cut in strings above, but maybe it's something
trivial like uppercase .FLAC or .Flac not handled correctly somewhere)


You might want to look at how such tracks get added to emms playlist,
until running e.g.:

  (emms-track-get (emms-playlist-current-selected-track) 'type)

...returns proper 'file instead of 'playlist.

Also, when testing adding these tracks, might be a good idea to disable
emms metadata cache via e.g. "M-x emms-cache-toggle", so that it won't
mask the results, though not sure if it applies here.

Which function are you using to add these tracks to emms playlist buffer?


> I'm not sure how to debug this further.  Help welcome :-).

In general you can do something like this (at any time):

  (setq emms-player-mpv-debug t)

And check for full log of messages between mpv and emms backend in
*Messages* buffer, where it should be easy to see what command gets
sent and exact error mpv returns, along with any other events from it.
Set that variable back to nil later to disable that logging.

Don't think it's needed here, as there seem to be pretty clear issue
indicated above already, which would cause mpv error.

Should be possible to fallback from "loadlist" to "loadfile" in mpv,
so that errors like this won't happen, but I think it's a bad idea,
as it'd mask the actual problem where tracks get added with the wrong
type in the first place.


-- 
Mike Kazantsev // fraggod.net