ImperialViolet

BBC Vorbis Streaming (05 Jul 2003)

Firstly, an email I sent to the BBC Online Services Support list today:

Three sysadmins from Imperial College (http://www.doc.ic.ac.uk/csg),   
myself included, are temporarily living in White City - just up the
road from the main BBC complex. We would very much like to see the
Ogg Vorbis streams of BBC Radio running again.

The last entry on http://support.bbc.co.uk/ogg/ reads (in part)
"we simply do not have time right now to get the ogg streams running again"
With this in mind, we would like to offer our services to help with
this project in any way.

Is there any way that this is possible?

Now, I'm almost certain that this will either generate a polite brush-off or will just be ignored. With this in mind, I've worked out how to do it myself:

BBC Vorbis Streaming HOWTO

Firstly, you need recent versions of libxml, libxslt, libvorbis and icecast2. The first three are pretty standard, but Icecast2 is only available from CVS snapshots. The modules you'll need are icecast, ices2 and libshout. libshout is required to build ices2.

You'll also need RealPlayer for Linux, since this is the only source of BBC Radio data at the moment. You could just pipe a radio into the linein, but the quality of this is likely to be a bit crappy. Though it would get rid of the nasty time lag in BBC Real streams.

We'll setup icecast in a minute, but we also need to download dsproxy. This traps data sent to /dev/dsp and outputs it as PCM data. Download and build dsproxy (needs root to insmod). I run devfs, so my /dev/dsp etc are just symlinks into /dev/sound/, so I can replace them at any time but realplay is going to need to see the dsproxy devices when it starts up. You could chroot RealPlayer and point the sound devices in the chroot to dsproxy, but I haven't played with that. At the moment I'm setting up the devices to start realplay and then switching them back to the OSS devices for normal usage. However you decide to do it, here are the device numbers:

So, for the moment, create the dsproxy devices as /dev/dsp and /dev/mixer (cd /dev ; rm dsp mixer ; mknod dsp c 121 2 ; mknod mixer c 121 3). Now we are ready to start the reader and realplay, so we configure icecast.

Icecast has two parts - the server and the source. The server is icecast, the source is ices2. My config for the icecast server is here. Note that the password is XYZ and it puts stuff in /tmp/icecast (you may need to create /tmp/icecast/[log|web|admin]). My config for ices2 is here. You may wish to have a look in the example configs as well to see the other options available.

You should now be able to startup icecast (pass the -c option to specify the config file). In another terminal goto the dsproxy source directory and run ./reader -x -e -s | /path/to/ices-2.0-Beta2/src/ices /path/to/ices-2.0-Beta2/src/ices.xml.public. That should start the source up, it will log to the terminal. Now start realplay and run the Radio 4 stream (http://www.bbc.co.uk/radio4/realplayer/media/fmg2.rpm). You should be able to stream from http://testhost:8000/radio4.ogg.

It's pretty rough still, but it's working for me at the moment.