Snapcast client, set media.role in the OPTS to use ducking with pulseaudio

[gianfer14]

Is your feature request related to a problem? Please describe.
I am using multiple input sink in pulseaudio and Snapcast client is one of them.
When I try to use pulseaudio ducking feature (lowering volume to allow a announcement stream to be heard), currently the snapcast stream does not get quiter.

Describe the solution you'd like
It would be great to pass the following option to snapcast and add a media.role parameter, for example:
snapclient -s 0 -h 192.168.1.10 --player pulse:server=127.0.0.1,stream-properties="props,media.role=music
current options for pulseaudio are limited to the following:

snapclient --player pulse:?
Options are a comma separated list of:
 "buffer_time=<buffer size [ms]>" - default 100, min 10
 "server=<PulseAudio server>" - default not-set: use the default server

Describe alternatives you've considered
I tried to set the ducking to operate on a global level, with no success.
I tried to send the string snapclient -s 0 -h 192.168.1.10 --player pulse:server=127.0.0.1,stream-properties="props,media.role=music in different ways, but as not currently supported it didn't set the media.role parameter.
I then ran into this page, and found out that:
every stream may have the “media.role” property provided by application

Additional context
Currently, caling pacmd list-sink-inputs shows the parameter whic needs to be updated is module-stream-restore.id.
Below a working input stream:
module-stream-restore.id = "sink-input-by-media-role:music"
And below current equivalent for Snapcast:
module-stream-restore.id = "sink-input-by-application-name:Snapcast"

[kingosticks]

Could that media role property be hard-coded rather than a configuration option? Or is there a situation you wouldn't want this i.e. might you be using a snapcast stream as the actual announcement?

[badaix]

Hi, would prefer hard coding, because the role will be music, any other role does not match:

PA_PROP_MEDIA_ROLE "media.role" For streams: logic role of this media.

One of the strings "video", "music", "game", "event", "phone", "animation", "production", "a11y", "test"

Plus: it will be just a one-liner

[gianfer14]

Hi, Thanks for the feedback.
I thought about an user selectable option to make it more customisable by others, but I have now found the same limited list of options mentioned above....
it's interesting because I am using also the announce and phone options, to trigger the ducking in my case. I have found them on a tutorial on how to achieve ducking, but I cannot find them in the pulseaudio documentation.

Anyway, even having it hard coded would be great, and as the overall change is reduced to a single line of code, it makes it even better!

This is my very first feature request, and I am not sure on what the next steps are. I am very happy to give it a try with my limited and rusty programming skills if needed!

[kingosticks]

I was thinking there might be those out there using snapcast as a multi-room PA or one-way intercom system where they'd want the "event" or "phone" roles so that everything else on the system is "ducking" and it's snapcast that gets heard over the top of some other music player. I'm only playing devils advocate here, hard-coding "music" sounds perfectly reasonable since that is the projects intended usage.

[badaix]

@gianfer14 I'm even less experienced, I never opened a feature request somewhere :)
For Snapcast there is no fixed process. In this case I did the implementation yesterday evening (I'm quite busy at the moment, but could spent an hour).
With the commit 432e4df you can now add multiple properties with property=<key>=<value>, e.g. --player pulse:property=media.role=phone,property=some.other=value. The media.role property is set per default to music and can be changed by setting this property manually or deleted by explicitly setting it to an empty value with --player pulse:property=media.role=. Empty properties will be dropped and not passed to PulseAudio.
You can download a snapshot package in actions and test if it's working.

[gianfer14]

Thanks a lot @badaix !
I've tried the 432e4df commit, works perfectly!

[badaix]

Released in Snapcast v0.25.0