RFC - Archiving Music CDs for Backup Purposes

[andrew clarke]

On Sat 2009-12-12 09:38:30 UTC+0200, Amichai Rotman (amichai at iglu.org.il) wrote:

> I'd like to make a backup of my 200 and some music CDs. My idea is to
> use the 'dd' command to convert each of them to an ISO file I could
> later burn to an empty media (CD-R) and get an exact copy - in case
> the original gets unusable...

I suspect using dd won't work with an audio CD, but even if it does,
I'd assume you'll just end up with a single large file with no useful
track information.  The TOC (Table of Contents) of audio CDs isn't
stored in the data part of the disc, so wouldn't be copied.

Most likely regular music player software won't be able to deal with
that file you just (theoretically) made.

Purpose-made CD ripping software has existed for at least 10 years to
rip CDs properly.  It talks to the CD-ROM drive to determine the TOC
information.  Back in the early days there was AudioCatalyst (for
Windows) and more recently Apple's iTunes.  Both will rip an audio
CD's tracks to an uncompressed .wav file if configured properly.

There is equivalent software for Linux.  The only one I've had
personal experience with is RubyRipper, with good success.

https://help.ubuntu.com/community/CDRipping

Ideally you'd rip to a lossless format like WAV or FLAC if you want to
burn the tracks to CD-R later.  FLAC is good because it compresses the
data down to about 50% of the original, and there is plenty of
software to edit the ID tags of each FLAC file.  RubyRipper will
collect this information for each CD from the Internet automatically.
Transcoding from FLAC to lossy MP3 is then easily done, and if you use
the right software the ID tags will be copied to the MP3.  Or you can
tell RubyRipper to save in both file formats.

Note that after burning your CD's tracks to CD-R, you still won't get
an exact replica of the original CD because the beginning and ending
offsets of the audio rip process are only approximate (within a few
milliseconds).  The TOC will be slightly different.  Also, the TOC
contains information about the length of intentional silence between
each track, and this info is often not recorded by ripping software.

Regards
Andrew