James Montgomerie wrote:
> Remember that 'clipping' is not the same as just losing a bit of data.
<also polite voice... although somewhat fed up of this thread because of its
complete irrelevance to the actual problem>
There are many types of clipping. Register or data clipping is where bits of
data are clipped from either end of a stream. The most common method for this is
truncation where LSBs are removed. Waveform clipping occurs not in data transfer
but in calculation such as applying digital gain through ,multiplication arrays,
or adding data sets together. This type of clipping (the type we more commonly
see via the "over" indicator is associated with the data registers going into an
"Overflow" situation, where the number to be stored is too large for the
register, resulting in a flag being set and the register (dependant on CPU)
holding the maximum allowed value.
> Anyway, all this is academic, as TosLink should transmit the 16-bit data
> exactly as it receives it from a CD - it's /impossible/ (not just
> improbable, but impossible) that what is being discussed on this thread is
> caused by any form of 'clipping' or truncating of the data from the CD.
Yes, I know, but Mr Rat seems to insist otherwise. I agree that there must be
*something* causing his drop-outs, but it cannot be clipping. The only thing I
can think of that would cause drop-outs in consistant places is a problem either
with the S/PDIF output on the CD player being triggered by soething *or* errors
on the CD which are enough to cause the S/PDIF output to "break", resulting in a
drop-out, but which are not large enough for the ear to percieve the brief break
in the signal on an analogue system. The drop-out may be smply because the MD
needs to re-sync.
> P.S. the idea floating around about sign bits is probably also a red
> herring - there are MANY different ways to store a sign in binary, [and none
> of them is the 'right' one, though some are easier to handle than others].
> Anyway, I would imagine (though I don't know - perhaps I need some polite
> correction too?) that MD uses a straight 16-bit positive binary number to
> store data, and doesn't dabble into any of this negative nastiness.
I would imagine internally that MD uses straight 16 bit data, but the decoder
chips I have supply signed 16bit data in 2s compliment form from S/PDIF input,
so I presume that this is the standard.
--
Magic
Location : Portsmouth, England, UK
Homepage : http://www.mattnet.freeserve.co.uk
EMail : mailto:[EMAIL PROTECTED]
"Creativity is more a birthright than an acquisition, and the power of sound is
wisdom and understanding applied to the power of vibration."
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