[icecast] memory, processor, bandwidth

Moritz Grimm gtgbr at gmx.net
Thu May 23 15:11:44 UTC 2002

"Luis M. Gallardo D." wrote:
> It doesn't say if it's using stereo or mono quality. You should read the
> MP3-HOWTO. In the bandwidth considerations section you'll find:
> "Consider this scenario. A T1 link has a capacity of approx. 1.55
> Mb/Sec. If you stream your MP3's at 128K/Bps stereo, each connecting
> player will use 256K/Bps, so only 6 users could connect to your MP3
> server at any time without problems."
> So, if you want to broadcast to 100 listeners at 24 kbps (mono), you'll
> need about 24 kbps x 100 = 2.4 Mbps of bandwidth, and you must double it
> if you want to broadcast at 24 kbps (stereo)

Errrm, that's bull*. No MP3 i've ever seen was judged by "bitrate per
channel". It's always "overall bitrate". So an ugly-sounding 128kbps
full-stereo MP3 would have 64kbps per channel.

If you want to stream a 128kbps stereo MP3, you have a 128kbps stream +
some minor tcp- and http overhead. Let's say 130kbps for that whole

On the other hand, if you're streaming 128kbps mono and you want the
same audio quality in stereo, you'd have to stream at 256kbps
full-stereo or maybe 192kbps stereo (in case this equals the lossless
stereo coupling i know from Vorbis) or 160kbps joint-stereo.


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