🚀 go-pugleaf

Apologies to everyone for posting what was meant to be private e-mail. But
my mail keeps getting bounced back to me. Could you (J. Johnston) send a
reply with an e-mail address with which I might have better luck? Thanks.
--------------------------------------------------------------------------------
J. Johnston,

Thank you for providing one of the few sound voices of reason on
rec.audio, especially in the talk about jitter. I have a request for
clarification, and a repeat of a question that came back to me as
undelivered e-mail.

I had asked whether there would be generational loss in MD or DCC
copying, specifically whether COMP(DECOMP(X)) would equal X. You
responded by saying that the compression was lossy (I was aware of
this), and I sensed an implied "So of course they can't be equal." Was I
misreading you?

It is possible to have lossy compression that does not degrade with
repeated application. To take a simple example, suppose you compress a
digital image by saving only every other line. The image will be
(imperfectly) rendered by filling in the missing lines with copies of
the previous lines. If you apply the process again, the same lines will
get saved, and the same decompressed results will be produced. After an
initial 50% loss in information, the situation will remain entirely
stable with repeated applications.

It should be possible for a lossy audio compression scheme (even though
obviously far more complex) to have the same characteristic of
preserving the information retained by a first application of the
compression. What I'd like to know is do either ATRAC or PASC have this
characteristic. It seems unlikely.


The other thing I meant to ask you was this: Do you have some way of
getting standard CD audio data into a computer (preferably a Macintosh).
CD-ROM drives that I have used don't allows audio sectors to be loaded
from a disc. Something that you wrote earlier indicated that you had the
ability to examine the audio data on a CD.

-Kerry