Re: [Libcdio-devel] Re: Retrieving DATA session from multisession audio disc

[Eric Shattow]

I've read the responses, thanks guys.

I want to do all these things using libcdio:

A) Extract a DATA track from a multi-session audio disc, output to ISO file
format. Duplicate the functionality of 'extricate'.

B) Interact with the ISO file that has strange offsets (in the case of
dumping data track 11 from the 10 track audio disc).  List contents of ISO,
extract contents.

C) Tool to modify in-place the "offset" of an ISO file sector references,
transforming the ISO file that has strange offsets into an ISO file that
existing tools can understand. Also to take a "normal" ISO and change the
offsets so that it is valid to burn as 2nd session and make your own
CD-EXTRA disc.

On Wed, Feb 17, 2010 at 8:24 AM, Thomas Schmitt <address@hidden> wrote:

> Hi,
>
> Eric Shattow wrote:
> > How to extract the data session from a multi-session audio cd and
> interact
> > with the resulting "offset" ISO using libcdio tools?
> > $ extricate /dev/sr0 8mm-songs_to_love_and_die_by.iso
> > ...
> > Remember, the path table and directory structure of the iso reflect
> > the fact that the ISO filesystem starts on sector 222145 (49:23:70)
> > of the CD.
>
> Robert William Fuller wrote:
> > modprobe loop
> > mount -o loop,sbsector=somenumber foo.iso /mnt
>
> -o sbsector=  points to the start block of the
> desired track if it is at the original position.
> But Eric's is displaced by 222145 blocks of 2 kB.
>
> Adventurous testers could try losetup option -o
> with a negative value or mount option "offset".
>
>
> I'd rather propose to put the ISO image onto a
> CD sized podium.
> First create a placeholder of 222145 blocks
> by writing one block to address 222144:
>
>  dd if=/dev/zero \
>     bs=2K count=1 seek=222144 \
>     of=cd_dummy.iso
>
> Then append the ISO 9660 track content
>
>  cat 8mm-songs_to_love_and_die_by.iso >>cd_dummy.iso
>
> This image should be mountable on GNU/Linux by
>
>  mount -t iso9660 -o loop,sbsector=222145 \
>        cd_dummy.iso /mnt
>
>
> Hopefully the placeholder becomes a sparse file
> which consumes only a few KB of disk space. Be
> aware that it might consume its full size when
> being copied.
>
>
> ------------------------------------------------
> For the first part of Eric's question:
>
> It should be possible to read the data track
> by normal shell commands. One needs to know
> where it begins. Nice to know is the size
> (can be tricky to evaluate, though).
>
> >  11: 49:23:70  222145 data   false  no
> > 170: 49:44:24  223674 leadout (501 MB raw, 501 MB formatted)
>
> Try:
>
>  dd if=/dev/sr0 bs=2K \
>     skip=222145 count=1529 \
>     of=8mm-songs_to_love_and_die_by.iso
>
>
> Have a nice day :)
>
> Thomas
>
>
>
>