Re: BD-R formatting help
Hi,
> It's just that last- and first-session mounts will be
> equivalent.
Yes. And thus the real first session will not
be mountable because its volume descriptors
are overwritten.
> First session effectively grows and it has nothing to do with drive
> recognizing multi-session.
So you leave the track open ?
I assumed you fork a new track, write the
session, use POW to patch LBA 0 to 31 and
then close the track.
(I did not examine growisofs.c for that,
i have to confess.)
> > With overwriteables i write the first session
> > to LBA 32
> Cool.
You can do this easily with mkisofs too:
-C 0,32 (but no -M)
Just start writing at LBA 32 and do the LBA 0
patching when the session is done.
More is not needed.
Well, maybe a dvd+rw-toc command.
xorriso would do that for growisofs too. It has
an alias name especially for that:
export MKISOFS="xorrisofs"
growisofs -Z /dev/dvd /some/files
growisofs -M /dev/dvd /more/files
Emulation of -C goes up to the -C 16,x bug. :))
Even incremental backups are possible:
growisofs -Z /dev/dvd -- outdev - -update_r /my/files /files
growisofs -M /dev/dvd -- outdev - -update_r /my/files /files
(Btw: would it be possible to lift the ban on
options like "-outdev", "-overwrite",
"-options_from_file", ... ? They all are
mistaken for -o.)
> other sessions would have to be identified by
> looking at track start addresses instead of volume size round ups.
I assume there is a regular pattern of gaps
between two sessions. And even if not:
one can scan for ISO 9660 heads quite effectively.
I got a brain damaged DVD-ROM drive which cannot
recognize multi-session DVD-R or DVD+R. But with
a generous gap estimation of 16 MB i can collect
a Table Of Content anyway.
> Drives don't need it! Some OSes would.
Aha. I extrapolated the brain damaged DVD drives
to brain damaged BD-ROM drives.
My fault.
Whatever, to save the mount entry of session 1
seems worthwhile if it is possible.
Sessions 2 can then be found after the end
of session 1 since the PVD of session 1 is
at LBA 48 and tells how long session 1 was.
Then we hop over the orphan gap, round up
to the next 32 blocks and should find the
next System Area and Volume Descriptors.
(Naively spoken, i confess. It is about
replaying NWA generation.)
--------------------------------------------
A remark about
http://fy.chalmers.se/~appro/linux/DVD+RW/Blu-ray/
Your text can make the reader believe that POW
consumes Spares. But it messes up the logical address
space instead. (If you write to an orphan then you
create a new orphan. Cough.) MMC-5 4.5.3.5.4.1:
"When a SRM disc has the POW capability, the Logical
Overwrite of a Cluster is redirected to the NWA of
some open Logical Track"
Only "information about the redirections is
stored in the Defect List."
--------------------------------------------
Have a nice day :)
Thomas
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