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Audio

It used to be relatively straightforward to get BBC radio's streaming audio (both live and listen-again) as Real Audio, but as of late July 2008 they've changed the way they deliver it. Their flash-based iPlayer currently uses a DRM-encumbered ("protected") mp3 stream which they plan to change to AAC later ["Under the iPlayer hood for radio" - BBC radio labs]. They claim that they will continue to provide Real Audio streams alongside the newer wizzy formats, and their abysmal text-only "accessible" pages rely on these versions: however maintaining these evidently requires a degree of manual intervention which their shambolic organisation is not always up to, so the Real versions are not always available. In such instances, and to access the supposedly higher-quality mp3/AAC streams, one has to adopt other methods. But first the old way...

Real Audio

If I want to listen to the radio on the computer I can run a command like

aoss realplay rtsp://rmlive.bbc.co.uk/bbc-rbs/rmlive/ev7/live24/radio3/live/r3_dsat_g2.ra

(I've got that packaged up into a one-line script). aoss is necessary on my system for reasons I don't really understand.

Alternatively:

gmplayer rtsp://rmlive.bbc.co.uk/bbc-rbs/rmlive/ev7/live24/radio3/live/r3_dsat_g2.ra

Real player is a bit more elegant than gmplayer: it starts playing quicker, without throwing unnecessary windows and dialogue boxes onto the screen, and I prefer the look of it. I haven't been able to compile the excellent smplayer on my Debian system (it's already packaged for ubuntu so I have it on my laptop) otherwise I'd use that.

What I can do with mplayer, however, is download a Real Audio stream to a file, like:

mplayer -dumpstream -dumpfile outfile url

(which I've packaged up into a Perl script I call getreal). This produces a .ra file which can be replayed by realplayer or mplayer, or converted by ffmpeg into .wav, .flac, .mp3 or whatever other audio format ffmpeg understands.

I've since found

• a page on hacking BBC Real Audio streams at Beebhack
• a Perl program get_iplayer (README) which fetches a list of all available programmes and downloads not only Real Audio but the BBC's video iPlayer output also. (The programme listing works but I haven't tried either the audio or video download capability.)
• Linux hacker Ian Barton's page on downloading BBC Real Audio (and much else of hackerish interest besides.)

iPlayer ng

Attempting to capture the audio stream used by the flash-based iPlayer is non-trivial:

1. it is (possibly?) streamed using Adobe's proprietary RTMP protocol (presumably tunnelled over HTTP)
2. the encoding employs some sort of DRM scheme, and in any case is set to change.

However in any FLOSS OS the audio output of any application, no matter how obfuscated or DRM-"protected", must be available in the clear to be played. In older systems vsound allowed one to capture the output of arbitrary applications, but this doesn't work for ALSA (the default sound system on popular current distros including Debian and Ubuntu). To capture sound output with ALSA the following (from the alsa.opensrc.org wiki) can be used:

amixer set 'Mix' cap
(see the wiki link above for further commands which may be required depending on your hardware)

arecord -t wav -f cd outfile.wav

Then run the application (e.g. konqueror http://www.bbc.co.uk/iplayer/console/episode/pid where pid is the BBC's programme id)
When the programme has finished kill arecord.
outfile.wav should then contain the programme audio.

If arecord isn't stopped after the programme ends it will probably go on writing to its output file, potentially filling up the disk. This could possibly be worked around by making it part of a script which would kill it after the programme ends. (The duration of the programme would have to be given to the script.)

Another issue is that any application outputting to ALSA (including possibly system beeps and so on) may perhaps get recorded along with the desired programme.

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