THE PROBLEM
In my original posting, I inquired about reading data from audio
CD's using Sun's CD-ROM player. Basically, I was able to read the
table of contents, but attempts to read the data yielded "I/O Error"
faults. I suspected that there might be some sort of digital read
protection that this CD-player provides for audio discs.
MY QUESTION:
Can anyone confirm/refute this suspicion?
ANSWERS:
A sample reply (oilean!joe@sgi.sgi.com):
> The Sony cdrom drive firmware doesn't support reading audio data
> directly from the disk. The subcode information on the disk does
> make a distinction between audio and digital data (even though
> it's really all just bits). My guess is that it is a simple form
> of copy protection.
There was some disagreement as to whether the audio read limitation
was put into the CDROM drive (a Sony device, I think) or into the Sun
device driver.
Several people indicated that the SGI Indigo *CAN* read audio data.
One person suggested that I try to re-route the audio playback
from the Sun audio port to somewhere else, thereby "capturing" the
audio data for later perusal. However, as far as I can tell, the
CDROM audio playback feature can only work with the headphone jack
on the front of the CD player--data is never routed through the
SCSI interface up to the sun for playback via the /dev/audio port.
If anyone knows differently, please speak up!
OTHER INFO:
The "xcdplayer" software in the X11R5 contrib software works quite
well if you want to use your CDROM drive as a audio CD-player. It
provides a small window control panel for start/stop/track-select/
eject/etc.... The only problem that I could see was that the
volume control slider needs to be re-calibrated to map the quite-
loud range over the full range of the slider. Now all I need is one
of those cordless headphones....
If anyone wants my humble "cdtoc" (table-of-contents) and "cdread"
(read cd track) programs you can grab them via anonymous ftp from
uw-isdl.ee.washington.edu or send me email for a copy. The "cdtoc"
program just lists tracks, min/sec/frames, subcode, etc. The "cdread"
program doesn't work of course, but might be ported to a SGI Indigo
fairly easily :-)
CREDITS:
Thanks to the following people for taking the time to reply:
g9129499@uow.edu.au (Jeremy Lawrence)
pomeranz@isis.dccs.upenn.edu (Hal Pomeranz)
oilean!joe@sgi.sgi.com (Joe McGuckin)
harvard!scubed!crash.cts.com!jester@cs.washington.edu (Ken Bibb)
dd@mips.com (David DiGiacomo)
guy@auspex.com (Guy Harris)
Bernhard.Schneck@Physik.TU-Muenchen.DE (Bernhard Schneck)
-steve
Steven Venema
Interactive Systems Design Laboratory
Dept. of Electrical Engineering
University of Washington
Seattle, WA USA
Email: venema@ee.washington.edu
This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:06:35 CDT