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Old May 22nd 04, 02:52 AM posted to rec.audio.tech,rec.audio.misc,rec.audio.pro,uk.rec.audio
Les Cargill
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Posts: 2
Default Digital audio stream terms?

DaveC wrote:

On Fri, 21 May 2004 10:44:41 -0700, Stimpy wrote
(in article ):


Bit Rate: 24 Kbps
Audio Codec: Windows Media Audio 9
20 kbps, 32kHz, mono 1-pass CBR

Can someone please clarify what the bit rate means and what the
audio codec numbers (20 kbps & 32 KHz) mean?



With streaming audio, the kbps figure represents the number of Kilo Bits Per
Second being streamed down into your computer. The kHz figure represents
the sample rate, i.e. the number of samples per second when the source was
sampled.

CBR = Constant bit rate. That is to say the sample/rip was taken at a fixed
kbps value. Some encoders can calculate the 'best' (a-hem) bit rate on the
fly, this is known as VBR (Variable Bit Rate).



So the 24 Kbps is how fast it's being delivered over the 'net;
32 KHz is the sample rate it was digitized at the source;
and 20 Kbps is ... hmm, I'm getting a bit lost here.


I think 20 kpbs is the encodde rate, and 24 is the
delivery/streaming rate - 4 kbps of overhead.

I *think*.

An audio CD is digitized at 44.1 KHz, but there's no Kbps rating associated
with the digitizing, that I'm aware of.


Sure there is. It's 1.44 M(bit)ps or something. It shows
up in Winamp when you play back 44.1 .wav files.


Clarification?

Thanks,



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Les Cargill