[Bug 1458230] Re: libburn imposing 0.2x BD-R burn (5-6 hours)

[Thomas Schmitt]

Hi,

everything points towards Defect Management which seems to
be extremely slow with the given drive and BD-R media.
It normally slows down writing by a factor of 2 or 3 but not
by 10 or 20.

So the option  stream_recording=on  of cdrskin and xorrecord
is worth a try with the next BD-R you burn.

There remains the question why the BD-R written by your
xorrecord run is formatted despite you did not use option
blank=format_if_needed.

-----------------------------------------------------------
Reasoning:

> cdrtools [...] proceeded at a reasonable speed

cdrecord does not format the BD-R and thus no Defect Management
is employed while writing.

> growisofs [...] at the cost of five to six hours' burning

growisofs always formats, uses no stream recording, and thus
always employs Defect Management.

> I think the xorriso run did format the disc.

It should not have done it with the arguments you showed.
Whatever, there is still the option stream_recording=on
which should compensate for the speed effect of formatting.
(... and make formatting more or less senseless.)

> I've just tried a DVD-RW 2x, in the drive.  Performance seemed consistent
> with my experience with my DVD writers, and I calculated it as proceeding
> about twice as quickly as the problem BD-Rs.

2x DVD = 2.7 MB/s. That's plausible in comparison to the
1 MB/s you measure with BD-R.

So most probably the hardware connection is not to blame.


> libisoburn [1.3.2] is rather stale,

It's ok for the purpose.
Anyway, libburn is the one which operates the drive.
The BD stuff did not change much since many years.


> disc06 burnt with xorrecord (xorrecord -v dev=/dev/sr0 speed=26970k
> fs=8m -multi --grow_overwriteable_iso blank=as_needed padsize=300k
> disc06.iso):

It does not report BD spare area which i would expect if
it is formatted. But the announced size is smaller than the
unformatted size.

Can you show the output of the growisofs written BD-R or the
one which you wrote with cdrskin option blank=format_if_needed ?

Please also run with the xorriso-written BD-R

  xorriso -outdev /dev/sr0 -list_formats

and show the output.


> The only interesting result, from dvd+rw-mediainfo on that disc, is that
> Speed Descriptor#n is 00/12219391 c.f. 00/11826175 on the cdrskin and
> xorriso burns I reported earlier.  (I've no idea what that means and,
> hence, the compass of "interesting" might be minimal.

Speed descriptors are the way how the drive tells the burn
program the speeds offered with the loaded medium.
Theoretically a speed descriptor could be valid only for
a part of the medium (with other speed on the rest). Therefore
the speed descriptors tell the end address of their valid
block range. In practice all ranges end at the medium end.
Further the drive decides on its own how fast it really burns.

The xorriso-written BD-R reports a range up to 11826175 blocks
which is the end address of default size formatted BD-R.
The cdrecord-written BD-R reports 12219391 which is the end
of an unformatted BD-R.
See also output of dvd+rw-mediainfo on a blank BD-R:
> READ FORMAT CAPACITIES:
>  unformatted:           12219392*2048=25025314816
>  00h(3000):             11826176*2048=24220008448


(Just how did the xorriso-written BD-R get formatted ... ?)

----------------------------------------------------------------

Have a nice day :)

Thomas

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Title:
  libburn imposing 0.2x BD-R burn (5-6 hours)

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