SMC: Implement additional DLS+ fields

[hairmare]

On Digris, we also generate STATIONNAME.LONG:

nowplaying/nowplaying/track/observers/dab_audio_companion.py

Lines 76 to 86 in 586ab9c

	message = DLPlusMessage()
	# track.artist contains station name if no artist is set
	message.add_dlp_object(DLPlusObject("STATIONNAME.LONG", track.artist))
	# TODO complete integration w/o f-string
	# PROGAMME.NOW for show name needs a carousel + deleting
	# message.add_dlp_object(DLPlusObject("PROGRAMME.NOW", track.show.name))
	message.add_dlp_object(DLPlusObject("ITEM.TITLE", delete=True))
	message.add_dlp_object(DLPlusObject("ITEM.ARTIST", delete=True))
	message.build(f"$STATIONNAME.LONG - {track.show.name}")
	params["dls"] = str(ODRPadEncRenderer(message))
	self.last_frame_was_dl_plus = False

We should clarify it that is still possible on SMC.

It would be nice to also start expanding on the tags and also add the running and maybe next show.

Most likely this will contain converting the current naive SCM_FTP integration to fully use https://github.com/radiorabe/nowplaypadgen, most likely with some kind of adapter to match SCM's field naming.

• check options, ask for list of fields
• re-add stationname.long
• decide on other fields to implement and add them
• grab some frames from an SDR and check if they work properly once implemented

[hairmare]

I talked about this with the responsible person from Sumatronic at this years Swiss Radio Day.

Currently, fields other than title and artist are not supported.

Sumatronic is aware of our requirement and would like to support it as well, but there currently is no ETA supporting additional DLS+ fields.