Re: Announcing cdrskin-0.4.4

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

Hi,

> cdrecord -atip says
>
> Supported modes: PACKET SAO LAYER_JUMP

A precise answer would be "not applicable" or "OVERWRITEABLE".
We try to squeeze those media into our CD inspired
media models.

The MMC specs clearly state that a BD-RE is random access
overwriteable. Like DVD-RAM or like a SCSI hard disk.
So there is no "write mode" as with CD.
One writes. Period.


> cdrskin: NOTE : greying out all drives besides given dev='/dev/sg1'

Your operating system seems to be a kernel 2.4.
(Else cdrskin should use a /dev/sr* address rather
than /dev/sg* )

On modern 2.6 it is supposed that one can write to the
formatted area of BD-RE via the plain block device.
  dd if=test.iso of=/dev/sr0 bs=32K
On kernel 2.4 this would work with DVD-RAM. No idea
whether your kernel will accept BD-RE.

If this works, cdrskin should be able to use this
drive address and declare the media a "stdio-drive":
  cdrskin --allow_emulated_drives dev=stdio:/dev/sr0 ...

---------

My interest as burn programmer with BD-RE is about
completeness iof the media zoo and later the finer
stunts, like disabling the slow verification process
and defect handling.

For that i need to learn how to handle it by MMC
commands directly. (The stdio: drive uses POSIX calls
to talk to the block device driver which then issues
MMC commands. I would have to guess ioctls to do stunts.)

I'm still testing whether i understand the reason for
today's failure and hope to have found a remedy.
For now it looks like a small negligence in predicting
the pseudo-capabilities of the media.
The false speed factor and the false RAW mode have
turned out to be mere display bugs with no further
consequences.


Have a nice day :)

Thomas