[EMAIL PROTECTED] wrote:
>
> On Mon, Sep 27, 1999 at 10:26:46AM +0200, Ralph Smeets wrote:
> >
> > [EMAIL PROTECTED] wrote:
> > >
> > > But what the accuracy of the data comes down to is that whilst the error
> > > correction my cause the errors on the discs, etc to be unnoticable, it is
> > > still ony the machine's best guess as to what should be there, so it isn't
> > > exactly what the original should sound like. It may only be the difference
> > > that a fanatic audiophile or experienced engineer may notice but it is still
> > > there.
> >
> > Wrong,
> >
> > as long as the Block Error Rate stays bellow 220 errors a second (Thanks Eric
> > Woudenberg for the correction ;-) ), the ATRAC-DSP will be able to recon-
> > struct the data as it was. Ie, There will be absolutely no difference. (Don't
> > compare MD with CD. The error correction system in a CD-player is bassed on
> > guessing,
>
> >From my memory (its been years since I actually *knew* any of this),
> the CD error correction system is two level. First, it does error
> correction and can precisely reconstruct the data if the errors are
> within some threshold (similar to MD, I suppose). Its only if the error
> correction fails that it will then "guess" (interpolate) at the signal.
You're correct here. But the error correction system only accepts single bit
errors...
Ie, guessing mode is entered very quicly. (A dust particle is sufficient!)
> > the error-correction system in a MD-player is based on storing
> > extra data that makes it possible to reconstruct excactly the original
> > signal! This is where MD is far superior).
>
> I am not familiar with the MD error correction system, but I'm quite
> certain that CDs do this as well as stated above (though perhaps not as
> well as MD, afterall, MD is about a 10-year new technology).
>
AFAIK, the ATRAC error correction takes place before 'decompression'. If
I understood the IEEE-ATRAC document correctly (Eric please help me out),
MD has no guessing mode. Ie, It can either correct the error or you get
a moment without sound.
Cheers,
Ralph
--
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Ralph Smeets Functional Verification Centre Of Competence - CMG
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"For many years, mankind lived just like the animals. And then some-
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to talk."
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