(Up to: Linux )

Audio:

mplayer -vc dummy -vo null -ao pcm:file=file.pcm -playlist playlist.ram

(then use Lame)

N.B. to record Radio 4 as it gets broadcast, use this:

mplayer -vc dummy -vo null -ao pcm:file=r4.pcm -playlist http://www.bbc.co.uk/radio4/realplayer/media/fmg2.ram

Video:

mencoder -oac lavc -ovc lavc -lavcopts abitrate=128:vhq url -o output.avi