Posted by Eeyore on 11/29/07 04:47

Doug McDonald wrote:

> Eeyore wrote:
> >
> > ALL audio compression schemes rely on 'throwing away' information to get the
> > desired result. Advances in 'technology' will not ever affect that fundamental
> > principle.
>
> While that is true, there is a big caveat.
>
> That is that above a certain bitrate, the "error" that remains can sound
> just like ordinary noise. If say 128 kbps actually results in an
> error signal that sounds allows you to tell what the piece is, 160 kbps
> might sound like 1/3 octave noise generators that are tuned with the
> frequencies in the piece. 192 could very well sound like pink noise.
> I'm not implying that those numbers are meaningful in an absolute sense ...
> it could be 128 -> 256 -> 320.
> Once you get to that point the effect of throwing away info is the same
> as just adding ordinary noise. People, most people, didn't scream
> and shout about added noise from tape or LPs. And they didn't talk about
> "losing information" even though that indeed was what was happening.

Added noise can be relatively inoccuous.

The same doesn't apply to lost information. Your comparison isn't valid.

Check out the effect of audio compression on different styles of music. The more
detailed it is, the more damaging it is.

Graham

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