When looking at various UPnP media servers, one of the features I wanted was the ability to play back my music collection through my PlayStation 3. The complicating factor is that most of my collection is encoded in Vorbis format, which is not yet supported by the PS3 (at this point, it doesn't seem likely that it ever will).

Both MediaTomb and Rygel could handle this to an extent, transcoding the audio to raw LPCM data to send over the network. This doesn't require much CPU power on the server side, and only requires 1.4 Mbit/s of bandwidth, which is manageable on most home networks. Unfortunately the only playback controls enabled in this mode are play and stop: if you want to pause, fast forward or rewind then you're out of luck.

One of the features of Rygel that I found most interesting was the external media server support. It looked like an easy way to publish information on the network without implementing a full UPnP/DLNA media server (i.e. handling the UPnP multicast traffic, transcoding to a format that the remote system can handle, etc).

As a small test, I put together a server that exposes the ABC's iView service to UPnP media renderers. The result is a bit rough around the edges, but the basic functionality works. The source can be grabbed using Bazaar:

In my last post, I said I had trouble getting Rygel's tracker backend to function and assumed that it was expecting an older version of the API. It turns out I was incorrect and the problem was due in part to Ubuntu specific changes to the Tracker package and the unusual way Rygel was trying to talk to Tracker.

The Tracker packages in Ubuntu remove the D-Bus service activation file for the "org.freedesktop.Tracker" bus name so that if the user has not chosen to run the service (or has killed it), it won't be automatically activated. Unfortunately, instead of just calling a Tracker D-Bus method, Rygel was trying to manually activate Tracker via a StartServiceByName() call. This would fail even if Tracker was running, hence my assumption that it was a tracker API version problem.

I promised Zeeshan that I'd have a look at his Rygel UPnP Media Server a few months back, and finally got around to doing so. For anyone else who wants to give it a shot, I've put together some Ubuntu packages for Jaunty and Karmic in a PPA here:

• https://launchpad.net/~jamesh/+archive/upnp

Most of the packages there are just rebuilds or version updates of existing packages, but the Rygel ones were done from scratch. It is the first Debian package I've put together from scratch and it wasn't as difficult as I thought it might be. The tips from the "Teach me packaging" workshop at the Canonical All Hands meeting last month were quite helpful.

One of the nice features of the PlayStation 3 is the UPNP/DLNA media renderer. Unfortunately, the set of codecs is pretty limited, which is a problem since most of my music is encoded as Vorbis. MediaTomb was suggested to me as a server that could transcode the files to a format the PS3 could understand.

Unfortunately, I didn’t have much luck with the version included with Ubuntu 8.10 (Intrepid), and after a bit of investigation it seems that there isn’t a released version of MediaTomb that can send PCM audio to the PS3. So I put together a package of a subversion snapshot in my PPA which should work on Intrepid.