I think Sonos sued the heck out of Google for those, and it caused those devices to disappear for a few years. Sonos lost that case late last year though, so hopefully we'll see a resurgence?
I am fairly certain that the academic open source community had already published prior art for delay correction and volume control of speaker groups (which are obvious problems when you add multiple speakers to a system with transmission delay). IIRC there was a microsoft research blog post with a list of open source references for distributed audio from prior to 2006 for certain. (Which further invalidates the patent claims in question).
Before they locked Chromecast protocol down, it was easy to push audio from a linux pulseaudio sound server to Chromecast device(s).
> I think Sonos sued the heck out of Google for those, and it caused those devices to disappear for a few years.
Oh so that was why they disappeared? Seriously, it's time to rework the entire patents system. You should only get a patent granted when you attach a reasonable (!) price tag and agree to non-discriminatory licensing.
I think that's the reason, but I can't be sure. It probably didn't help, that's for sure...
Had I known Sonos would be like that, I wouldn't have bought their products. Their latest app also totally broke the speakers. Stay far far away from Sonos.
Before they locked Chromecast protocol down, it was easy to push audio from a linux pulseaudio sound server to Chromecast device(s).
The patchbay interface in soundsync looks neat. Also patch bay interfaces: BespokeSynth, HoustonPatchBay, RaySession, patchance, org.pipewire.helvum (GTK), easyeffects (GTK4 + GStreamer), https://github.com/BespokeSynth/BespokeSynth/issues/1614#iss...
pipewire handles audio and video streams. soundsync with video would be cool too.
FWIU Matter Casting is an open protocol which device vendors could implement.