Re: [mpg123-users] How to use a play list in remote mode?

[Thomas O. <tho...@or...>]

Am Sun, 30 Mar 2025 20:05:14 -0500
schrieb Seamus de Mora <sea...@gm...>: 

> Yes - I can see that would complicate things. However, in my case I do not
> need "both sides" controlling the playing;
> i.e. *"if <remote mode>; then <disable local mode>; fi"*
> This is how I *imagined* it would work. I am not a fan of complexity!

Well, the implementation is different. The remote control mode is
kindof a separate main program, its own control loop, where the normal
mpg123 control flow, optionally with terminal control keys, is a
different one.

> So - First: what is '$n' in your loadlist command? - does it refer to a
> single line/track from 'playlist.m3u' ?  (sorry, but the remote help is
> unclear to me in this respect)

$n is any number between 1 and the number of tracks in the list,
causing mpg123 to start playing that track from the list. The value 0
would start the last track, -1 causes the listing only.

> Another question is wrt the meaning of '<url>'. Is this for playing a
> "streaming radio station"??

This means any file path or HTTP(S) URL for remote playlists. Playlist
support is strongly linked to web radio streams, as they usually come
in form of a playlist URL.

> I don't follow this command...  I tried it on my system; I got no errors,
> and no response. ?
> […]
> pi@rpi3a:~/soundfiles $ playlist=$(echo loadlist -1
> /home/pi/soundfiles/plist.m3u | mpg123 -R - | grep '^@I LISTENTRY' | cut -f
> 4- -d ' ')

It just stores the playlist in the variable named 'playlist'.

$ echo "$playlist"

should print something. But working with this relies on your track file
names not having spaces in them, so is fragile.

> Here's the result in terminal 1:
> 
> @I {
> @I LISTENTRY 1: /home/pi/soundfiles/Sinatra-Morning.mp3
> @I LISTENTRY 2: /home/pi/soundfiles/Sinatra-String.mp3
> @I LISTENTRY 3: /home/pi/soundfiles/Sinatra-TakeAway.mp3
> @I LISTENTRY 4: /home/pi/soundfiles/Sinatra-Watch.mp3
> @I }

This is your playlist, parsed by mpg123 code. Of course not that useful
for simple m3u files without comments, etc.

> And then again from terminal 2, the ONLY thing that seemed to yield a
> result was this:
> 
> 'echo "load /home/pi/soundfiles/Sinatra-Morning.mp3" > /tmp/mpg123_fifo'

Though

	loadlist 1 plist.m3u

should do the same. If not, I got a serious bug at my hands.

> IOW - I can find no way to initiate playing a list via the (-R) remote
> mode; this is what I need to be able to do. ???

Currently, you can issue the playing of a single track from the list
only. Your frontend script would need to wait until mpg123 signals end
of playback and then issue loading of the next track.

> And just one other Q re remote mode (-R)...  when I did manage to play a
> song, <MANY> of these strings appeared in terminal 1:
> 
> ...
> @F 6484 448 169.38 11.70
> @F 6485 447 169.40 11.68
> @F 6486 446 169.43 11.65
> ...
> 
> How do I stop this?

silence

(see `help silence').

> No - I'm not interested in "fine-grained control of playback"; as I said
> I'd like to have a command (remote or otherwise) that simply "loop plays" a
> playlist from beginning to end, and recognizes a "pause" command to toggle
> the playback process.

Ah … you want the playlist in a loop? Or shuffled? There's a number of
options there. Right now the only way to have mpg123 play a list of
files by itself is running it normal/terminal control mode (which you
could also automate, btw.). If we add playlist playing to the remote
control mode, looping and shuffling should also be included, probably
via extra commands. This is not too bad, as the concerned code has been
factored out of the main program in the meantime, just the clear demand
should be there. I'm not totally opposed to doing that, it's not really
hard and a detour from that Windows portability mess.

> WRT "--continue mode", I see nothing about continue mode in the remote
> help... are you suggesting that from 'terminal 1' I enter this?:

This is something independent of remote control mode. See --continue in
the man page. It results in something like

[CONTINUE] track 3 frame 3083

being printed when mpg123 is interrupted (`pkill -INT mpg123` works,
too). You can use this data to re-start mpg123 on the correct track and
offset again.


Alrighty then,

Thomas