[comp.dsp] Format of CD digital bitstream

qac@occrsh.ATT.COM (Quentin_Conner) (11/07/89)

I would like to capture the digital output from my C.D. player.  There is
a jack on the back which provides access to this, but I don't know the
format of the bitstream.  I know that digital audio is 16 bit linear PCM
at a sampling rate of 44.1(?) kHz but what I don't know is what kind of
framing and timing information they stick in the bitstream.  Is there
any kind of industry standard for these 'digital outputs' or am I out
of luck?

It would be nice to also grab the subcode data also.  I know of at least
one released C.D. that has some type of graphics in the subcode that can
be displayed on a monitor or T.V. while the music is playing (with some
probably proprietary adapter).

Analog Devices has a 'Industry standard pinout' DAC in a 16 pin package
(AD1856) which has three digital inputs - CLK, LE, DATA.  I take it that
the serial bitstream coming into this device is standardized - probably
just the linear PCM audio signal.  They also make an 18 bit version.

Thanks,

Quentin Conner
--------------
qac@occrsh.att.com

qac@occrsh.ATT.COM (Quentin_Conner) (11/09/89)

hedley@imagen.UUCP (Hedley Rainnie) writes:

>You are in luck. kchen@Apple gave me the following reference which
>a friend of mine has used to construct a circuit to do just what you are after.

>] The AES/EBU digital audio format is described in the *second* edition
>] of Ken Pohlmann's "Principles of Digital Audio", Howard Sams & Co, 1989.
>] ISBN 0-672-22634-0.  

>Hedley

>-- 
>{decwrl!sun}!imagen!iit!hedley
>hedley@imagen.com

Sounds like a good source.  Thanks for the help guys.

Quentin