[TriLUG] why can't I dd an audio CD?
Joseph Mack NA3T
jmack at wm7d.net
Thu Dec 25 20:41:59 EST 2008
I just tried dd'ing some audio CDs. The audio CDs behave
normally under Linux (can mount -t cdfs and see all the wav
files, and can copy with cdda2wav), but dd=/dev/cdrom
of=foo.out fails with a bad read on the first sector. dd on
an iso9660 (data) cdrom works as expected.
Google isn't terribly helpful, apart from confirming that dd
fails for everyone on audio CDs. I found postings which said
o audio CDs have a single spiral track (one posting) (but
counter to this, cdda2wav sees the disks as sectors)
o dd doesn't read everything and in particular doesn't work
for audio tracks
So dd fails, but I don't know why dd fails. I would have
thought a CD just a pile of bits like a regular hard disk.
What am I missing?
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
Homepage http://www.austintek.com/ It's GNU/Linux!
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