[comp.multimedia] Get audio data out of CD_ROM

yuan@hatteras.cs.unc.edu (Xialin Yuan) (06/08/91)

Does someone know how to get the Mac to read audio data from CD-ROM,
and would like to give me a pointer to the directions. I have been
looking for help for quite some time.

What I would like to do is to copy lots of our CD sound into Mac directly,
(of course I have to convert into appropiate formats ) so we would have
sound more easily available in Mac, our sound server. I tried SCSI manager, 
and it seemed that it did not work out it quite right.

Your help would be greatly appreciated.

Xialin
Computer Science
University of North Carolina

msc@ramoth.esd.sgi.com (Mark Callow) (06/11/91)

In article <4271@borg.cs.unc.edu>, yuan@hatteras.cs.unc.edu (Xialin Yuan) writes:
|> Does someone know how to get the Mac to read audio data from CD-ROM,
|> and would like to give me a pointer to the directions. I have been
|> looking for help for quite some time.

This is not possible with any current CD-ROM products for any type of
computer system.  The closest you can come is to plug a cable from the
headphone output of the CD-ROM drive into the input of an audio digitizer
on your system of choice.

CD-ROM drives need both hardware and firmware modifications to read audio
data from audio CD's (called CD-DA) across the SCSI bus.  In other words
the manufacturers have to produce new products.

|> 
|> What I would like to do is to copy lots of our CD sound into Mac directly,
|> (of course I have to convert into appropiate formats ) so we would have
|> sound more easily available in Mac, our sound server. I tried SCSI manager, 
|> and it seemed that it did not work out it quite right.
|> 

What out for copyrights on the CD's.
-- 
From the TARDIS of Mark Callow
msc@ramoth.sgi.com, ...{ames,decwrl}!sgi!msc
"Spirits of genius are always opposed by mediocre minds" - Albert Einstein

bowdidge@cs.ucsd.edu (Robert Bowdidge) (06/11/91)

In article <4271@borg.cs.unc.edu>, yuan@hatteras.cs.unc.edu (Xialin Yuan) writes:
|> Does someone know how to get the Mac to read audio data from CD-ROM,
|> and would like to give me a pointer to the directions. I have been
|> looking for help for quite some time.
|> 
|> What I would like to do is to copy lots of our CD sound into Mac directly,
|> (of course I have to convert into appropiate formats ) so we would have
|> sound more easily available in Mac, our sound server. I tried SCSI manager, 
|> and it seemed that it did not work out it quite right.


As I understand it, most CD-ROM players are set up so you can't access
the data.  I think the reason is that the CD's firmware won't let you
access the CD's data on a byte-by-byte level.  It might also be due to
a flag on the disk that indicates it _shouldn't_ be accessible as raw
data.  The CD-ROM players may just not send data when they see this
bit, while a music-CD player will allow it to be played.

Two solutions I've seen: I believe some hackers in Germany figured out
how to get an Atari CD-ROM player to read the music data.  I do
remember the instructions were published in some book available ove
there.  The other solution is similar to what some folks in Berkeley
tried -- watching the data lines for a certain CD player so that they
could grab the data as it was read off disk.


As far as I know, there's no easier solution. :(

-- Robert bowdidge@cs.ucsd.edu

adam@flammulated.rice.edu (Adam Justin Thornton) (06/11/91)

I don't know about capturing the sound that comes out, but it's actually
quite easy to _play_ an audio CD through a CD-ROM player.  Apple makes a CD
Audio Toolkit that adds play capabilities to Hypercard, and there are other,
similar packages out there (not that I know much about them).  I would
suspect that if you had some sampling capability it would be very easy to read
an audio CD and store the sound on the fly.  I think most references on the ISO
9660 format also include a little bit about the various codes that tell the player
where an audio track starts and such (ours certainly does, but it's pretty
archaic--1988, I think.
-- 
Adam Thornton  |  Opinions are mine alone, though Rice is welcome to them.
adam@owlnet.rice.edu | adam@is.rice.edu | adam@vm1.rice.edu | :-) :-) :-)
    -->Welcome to Alpha Complex!  The Computer is your Friend!<--
"None of us will be free until nerd persecution ends."  |  64,928

eric@mcrware.UUCP (Eric Miller) (06/13/91)

In article <4271@borg.cs.unc.edu>, yuan@hatteras.cs.unc.edu (Xialin Yuan) writes:
> [ .... Paraphrase ... ] I want to copy CD-DA audio sectors from a CD to my
>                         hard disk.
>

Although my experience with Mac CD-ROM is limited, I agree with the other
folks here that you cannot (from the CD-ROM interface) get access to Red
(CD-DA) Sectors.  I know that this is the case even with CD-I, which in general
is much more open than CD-ROM.

But it is possible to get that data.  We have a high-end CD-DA player with
Digital Outputs.  We connect this digital out to a VME system with a digital
audio capture card.  From there, we can pipe the PCM data back out and into
a system like the DigiDesign "SoundTools", or simply transfer it via Ethernet
to our favorite system for editing and further encoding to ADPCM.

If you have other specific questions you can contact me directly.

Eric Miller
uucp!mcrware!eric

515-224-1929