AS I know CD stores data uncompressed. I wonder, if it is possible to continue life for Audio CD by integrating some kind of lossless compression audio codec and to make audio quality more perfect. You can answer - there is DVD audio and SACD, but DVD audio uses lossy compression, and SACD still stores uncompresed data as far as i know. (or have i missed something?)

more perfect?

And any effort to implement such modification to CDs would automatically break the CDDA standard and break compatibility with millions of CD players worldwide.

So, to answer the thread title question: It's possible, but it's also senseless.



Huh????

MLP is a lossless format!



Nope. SACD stores losslessly compressed DSD streams.

Robert, please be more exact and complete in your postings,

DVD-Audio can have the lossless formats, MLP packed, like
2/24/192
5(+1) channel/24/96
5/24/48
2/24/96 (specified in the DVD-V standard, too),
but a DVD-A disc is also downwards compatible, so the lossy DVD-V formats are also possible, like 5.1 dts, since some time there is 5.1 dts in 24/96, would be interesting to klnow, which psychoacustic models they apply for the content from 20 - 48 kHz... !
even the crappy 5.1 ac3 in low bitrate.


Some Queen DVD-A contain the lossy 24/96 dts eg., as well as lossless high sampling stuff.

But there's no sense in making a lossy only DVD-A, because you could put the information onto a DVD-V. So any DVD-A disc will always contain a lossless version.


SenatR The Last,

You can't use lossless packing on a CD, and still use that CD in a normal CD player. However, you can just burn FLAC files to a CD-R (incompatible), store DTS data on a CD-DA (needs an external decoder + a normal CD player).

There are many possible compatible extensions to CD-DA too:

1. HDCD

2. Hiding lossy multi-channel data in the last few bit of a standard stereo audio CD (AES paper by Gerzon suggested this, don't have the reference - it was never used commercially).

3. And, of course, the original red book CD standard defines four channels on CD. That's right - CD is a four channel medium. But this was never used, and it's uncertain what existing players would do with a four channel disc.

4. Then there's noise shaped dither, which allows a greater perceived dynamic range (widely used in mastering)

5. subtractive dither, which allows you to gain an extra bit of information by letting the CD player know the dither sequence, and subtract it (never used for CD)

6. pre-emphasis, which can be used to decrease the noise at higher frequencies (defined in the original CD standard, but rarely used).

(can anyone think of any more existing or possible compatible extensions to CD-DA?)


But if you're going to do "more" than a standard CD, you might as well do it on DVD - DVD players are what, $50 now? What advantage is there to "extending" the CD format when DVD offers so much more, and the hardware is so readily and cheaply available?


Cheers,
David.

Blah! An ultra-fast Google search for "DVD-Audio" or "SACD" provides much more information about these formats than I could provide.

BTW, it's Roberto. Robert is the Lame developer.

fine, you got the irony.