Re: Help: Burning multisession DVD+R with cdrecord 2.01.01a37

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

Eric Wanchic:
> Looks Great ! TAO was executed.
Rob Bogus:
> Thomas, perhaps you can clarify the SAO vs. TAO options and actual

Actually it is a packet write type.
"TAO" and "SAO" are rather aliases for a certain
behavior as it is known from good old CD media.
 
With DVD+R there is only this one write type.
cdrskin calls "TAO" a run without pre-announced size
and "SAO" a run with such an announcement.

MMC-5 4.3.6.2.2
"The Host views a DVD+R fragment as a fixed packet track
where the packet size is 16."
The following text describes command RESERVE TRACK
as optional for reserving a fixed track size.


> > Supported modes: PACKET SAO LAYER_JUMP

That must have been wodim or cdrecord.
cdrskin has no DVD DL support yet. So LAYER_JUMP
is not among its announcements.


>  Total size:       18 MB (02:05.93) = 9295 sectors

This might be one of the reasons why growisofs
proposes to do that strange
  growisofs -M /dev/dvd=/dev/zero

I had no propblems with appendable or partially
filled DVD+R. But my images were a bit larger than 18 MB.

If you omit option -multi with cdrskin, then
the media will get closed by a MMC command
"CLOSE SESSION, 101b, Finalize with minimal radius".
which is described in the specs as
"In order to assure maximum interchange compatibility
with read only devices, Guard Zone 2 shall be recorded to
a device defined PSN that approximates a disc radius
of 30 mm. Suggested value: 70DE0h (462 304)."

That looks somewhat like 900 MB minimum size.

Nevertheless strange that a burner drive will
not mount smaller images.
What happens if you count the readable bytes
from _not_ mounted media:

  dd if=/dev/hda bs=32K | wc


Have a nice day :)

Thomas