I am super interested in this topic. I've searched the forums but didn't find an answer to my question...
I've been dreaming of having some setup where I can use a mobile device to select music on my server and pipe it to a player. I must have been living under a rock because I only recently connected the dots that this could be achieved via upnp, well only 95%.. I'll try and keep it short...
I've been doing a lot of research into this, and in upnp land, my server is the library (running minimserver - absolutely fantastic), my raspberry pi is the renderer (xbmc - also absolutely fantastic) and my mobile device is the control point (bubble upnp - yep you guessed it, also fantastic).
Anyway, to my complete dismay, the entire setup breaks down for me for two (what I consider to be) absolutely critical reasons..
1) once my mobile / control point goes to sleep, the renderer (xbmc) doesn't know what to do, and it's most important job is to play the next track. that's all i want.
2) if i grab another mobile device and it becomes the control point, it has no idea of what's been going on
The neat thing about bubble upnp is that it can act as a renderer, library and control point, so while screwing in the settings, I noticed one of super high interest - "enable an OpenHome renderer" so that it can advance the playlist when the control point sleep.
What is this Open Home I googled? holy @#$ some peeps are already on this with the ohnet stack. Check it out:
http://www.openhome.org/wiki/OhNet
and to answer the original post, it supports gapless playback because the renderer has the info to make it happen. If you look at the reference applications, you'll see they've been implemented by Linn
So now the question becomes - does XBMC have plans to incorporate the ohnet upnp stack? If not, I'll have to make a formal request.
PS If anyone is wondering why I'm running xbmc on my pi instead of a lighter alternative, it's because I've been using xbmc since it was xbmp and because I can preload and configure it on the pi in literally 5 minutes.
UPDATE: nevermind, I've come to the conclusion this is just a spec, someone would have to implement it in an open source fashion, and if XBMC is using Platinum UPNP as their upnp provider / spec implementation, someone would have to write an open home implementation and make it available for xbmc or the platinum folks would have to update their implementation.
UPATE2: It turns out that BubbleUPNPs server does more than transcode, it can wrap existing upnp renderers into open home ones (and exposes open home versions of them) so it can handle the issues I listed. It looks like it depends on the source renderer to support gapless playback though. Regardless, this is amazing, its exactly what I need. I tested with multiple mobile devices. All work well together to see what's going on with the playlist and neither need to be on for the playlist to advance!
