On Sun, 26 Sep 2010 17:42:01 +0100, "DAB sounds worse than FM"
wrote:

YouTube uses 'progressive download', because the videos are watched
on-demand. The R3 320k stream was a live stream, so you can't download what
hasn't been played out live yet.

As for the buffer size on the live streams, unless they're using some fast
stream start technology (and they've never mentioned that they are), the
delay from pressing play to when you hear the audio start playing (assuming
instantaneous data transfer and stream setup) equals the size of the buffer
in seconds - i.e. if the stream takes 5 seconds to start playing after you
press play, then the buffer holds 5 seconds' worth of audio, or at 320 kbps
the buffer size would be 5 x 320k / 8 = 200 kB.

IMO, they should've used a longer buffer size than they did for that
experiment, because the bit rate level was higher.


This is true, but the same thing applies to iPlayer, which is a
pretty good equivalent of Youtube for its basic functionality. Despite
the whole file being available on the server, on a small amount of
buffer is available at any instant. It seems that for a slightly flaky
connection such as Jim's, the amount is inadequate.

d