[NBLUG/talk] Audio CD question

[Eric Eisenhart]

On Fri, Jun 20, 2003 at 10:20:41PM -0700, Jim Bianchi wrote:
> 	I've a question regarding audio CDs (under RH 8.0). Just as a
> matter of idle curiosity, I'd like to know if it is possible to do the
> equivalent of, say, mount /mnt/cdrom; cd /mnt/cdrom; ls; when there is an
> audio CD in the drive. I've tried this once and failed. Apparantly audio
> CDs have flags that say they are audio CDs, and this prevents mounting and
> examining them (as opposed to data CDs, which can be mounted and examined).
> Like I say, this is merely idle curiosity; but if I could mount an audio
> CD like this and examine it (using ls), what would I see?

It's not quite a matter of "flags", though there are "flags" involved.

A CD consists of a series of sessions, each of which contains a series of
tracks.  Almost any commercially purchased audio CD is going to be a single
session with a series of audio tracks.  There's some kind of header for each
track indicating how long it is and whether it's audio or data.

Note: there's no filesystem.

Most commercially purchased software CDs are a single session with a single
data track.  On that data track is a filesystem in a given format; usually
the iso9660 format.  When you "mount /mnt/cdrom" you're generally actually
doing "mount -t iso9660 /dev/cdrom /mnt/cdrom" which looks for an iso9660
filesystem on the first data track it finds on the last session.

(DVDs are much the same except they use UDF instead of iso9660 and it's
almost always a filesystem with files instead -- UDF is basically a newer,
smarter version of iso9660)

I think somebody did make a filesystem driver that presents a series of
audio tracks as files, but it's not "the usual" and due to the way CDs read
audio, it's probably can't do what you'd really want, anyways.  I recommend
"cdparanoia -Q" to get a track listing, instead.  (and cdparanoia to rip
them to wav files, too, if that's what you want -- though if you want to rip
and then make mp3s or Ogg/Vorbis files, something like "grip" does the other
details you'd want for you)
-- 
Eric Eisenhart
NBLUG Co-Founder & Vice-President Pro Tempore
The North Bay Linux Users Group
http://nblug.org/
eric at nblug.org, IRC: Freiheit at freenode, AIM: falschfreiheit, ICQ: 48217244