Stewart Pinkerton wrote:

On Mon, 08 Nov 2004 21:30:27 +1100, Tat Chan
wrote:


Jim Lesurf wrote:



However the channel bit stream is encoded on a number of levels between the
sample data and the disc.


did you mean 'cross interleaved code' when you said 'encoded on a number of
levels between the sample data and the disc'?


It's a cross-interleaved Reed-Solomon (CIRC) code, using eight to
fourteen (EFM) modulation. Pick your preferred alphabet soup! :-_

All that work to correct burst errors (CIRC) and ensure that the bits
can be read off the disc in a practical way (EFM), eh?

I suppose the mathematicians laid the foundation to ensure the data on
the disc would be self-correcting (up to a certain number of bits) and
the engineers found a practical way of getting the data off the disc in
real time!