Comment 15 for bug 656297

Hi,

i am the developer of libburn, which would probably be in charge
for burning underneath Brasero in younger Ubuntu versions.
(One can learn from Brasero logs, whether libburn is used as
 burn backend. Search for "Libburn".)

There was a bug when the application asked for minimum speed
and the firmware of the burner drive incorrectly answered
to the SCSI command that inquires the number of offered
speed values. That bug is fixed in libburn-1.2.8.

I cannot say whether Brasero did ask libburn for minimum speed
rather than for a particular speed value. If it did, then the
libburn bug would explain the use of maximum speed.

But given the original report, that Brasero offered speed 10
for CD-RW with label "1-4x" and that the user has chosen "4",
i doubt that Brasero triggered the libburn bug.
Possibly in 2010 it still used wodim a burn backend for CDs
and growisofs for DVDs.

In case the bug still persists, i offer my help with investigating
Brasero's doings. I am not a user of Brasero myself and my Debian 6
test machine has quite an old version installed. (It is not easy
to upgrade Brasero without upgrading the operating system.)

I would need a tester who has a much newer version of Brasero.
Further we would have to find a publicly readable repository
with the source code of that Brasero version.

Advise from Ubuntu experts would be welcome in this case.

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The youngest post of 2013-01-20 by paolode does not look like a
speed problem:
> doesn't burn correctly dvds (it is like it enters in an infinite cycle;

If libburn is involved as backend, then i would propose to do
experiments with my own command line burn applications cdrskin
or xorriso which can report the commands and replies of the SCSI
dialog between libburn and burner drive.

Both are offered by Ubuntu using the same libburn version as Brasero.
If newer versions are needed for the test, then it should make few
problems to compile them without disturbing the installed dynamic
libburn. (Installing libburn.so from source will probably need an
Ubuntu expert.)

If libburn is ok - which i assume - then one would again have to
inspect the source code of Brasero for the way how it uses libburn.
Possibly one will have to insert the libburn call which enables
the SCSI log. This will require recompilation of Brasero which
might become an adventure on its own.

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I am now subscribed to this Ubuntu bug report 656297.
You may also contact me via <email address hidden> .

Have a nice day :)

Thomas