Re: Announcing cdrskin-0.4.4

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

Hi,

> >  i made some changes to the WRITE12 streaming commands.
> Now it works with both DVD-RAM and BD-RE!
> md5sums match.

I'm good in guessing :))

Now it works for your one BD-RE drive, your DVD-RAM drive
and my DVD-RAM drives.
At least it gives hope that a substantial fraction
of other drives would work like intended, too.

One problem with the general validity is the
fact that WRITE12 is obviously not intended
for media with defect management.
Each implementer of drive firmware has the
freedom to impose own constraints or even
to refuse on this combination.


> So, basically, using streaming i/o will compensate "for free" (I mean
> you get exactly the same result on disc as not using streaming) the
> slow down caused by defect management?

It depends on the number and pattern of bad
spots on the media.

No bad spots will make  stream_recording=on
the winner.

A few bad spots with fast defect repair will
make stream_recording=off better, because you
do not have to repeat the burn run and your
verification.

Many bad spots or slow defect repair will make
defect management uneconomic. In that situation
it would probably be better to have a quick failure
and to retry with better media.


With my Philips DVD-RAM drive it is clear that
defect management is only helpful if i have to
write a small amount of important data.
In case of several defects it is unbearably slow.

So if i were struck with DVD-RAM i would trash those
which have bad spots and use the others with 
stream_recording=on.
But i got my DVD-RAM only for testing purposes.
For the same reason i got that whimpy Philips drive.
It produces more problems than any other of my drives.
Today it declared a DVD+R closed which two other
drives see as appendable. Shrug.

With BD-RE and their high capacity and price, one
may well decide to keep faulty ones and operate
them without stream_recording.


Important advise:

You should make a full scale write test with your
media and 25 GB of data.


I myself will have to learn more about formatting
of DVD-RAM and BD-RE now.


Have a nice day :)

Thomas