Re: Real-world steganography

[Paul Krumviede]

--On Monday, 30 September, 2002 22:15 -0500 Jeremey Barrett 
[EMAIL PROTECTED] wrote:

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 Paul Krumviede wrote:
| i've seen comments in reviews of professional CD mastering
| gear that there are other, seemingly preferred, technologies,
| although i've never found details of them.
|

 The other formats of note are probably SACD and then DVD-Audio. SACD
 is multichannel 16-bit/44.1kHz... so multichannel CD without additional
 sample resolution (if I recall). SACD is not backwards compatible
 though, whereas HDCD is.

although we're wandering a bit far afield here, the other other format(s)
i was referring to are all supposedly backwards compatible, with the
original CD spec (wasn't that also some colored book?). i couldn't
tell from the review, or don't remember, what, if anything, they required
on the decoder side (but if they didn't require anything, then could it
be steganography?).

-paul

Re: Real-world steganography

[Paul Krumviede]

--On Tuesday, 01 October, 2002 13:54 +1200 Peter Gutmann 
[EMAIL PROTECTED] wrote:

 I recently came across a real-world use of steganography which hides extra
 data in the LSB of CD audio tracks to allow (according to the vendor) the
 equivalent of 20-bit samples instead of 16-bit and assorted other
 features. According to the vendors, HDCD has been used in the recording
 of more than 5,000 CD titles, which include more than 250 Billboard Top
 200 recordings and more than 175 GRAMMY nominations, so it's already
 fairly widely deployed.

maybe. i'm not sure how many players support it (my spectral D/A
convertor does, but then some of the people at spectral seem to
have invented HDCD). while the CDs i have that use it sound
pretty good, i don't have any good way to compare them when
played back over a non-HDCD capable convertor (i could hook
up one of my computer CD drives, but that doesn't seem fair
compared to the spectral transport-D/A combination).

but when i do play such CDs on other gear, i don't notice any
audible degradation, so it isn't obviously harmful.

i've seen comments in reviews of professional CD mastering
gear that there are other, seemingly preferred, technologies,
although i've never found details of them.

-paul