Re: [Bug-xorriso] To Thomas Schmitt: how to go on, xorriso is installed

[Thomas Schmitt]

Hi,

some remarks about your draft.txt :

> But xfburn only can produce finalized media (which makes xfburn quite
> useless for CD-RW media, at least for the W part of them).
> Therefore stream recording should not be used for CD-R or CD-RW media.

The statement about finalized media and CD-RW is not related to the
problem of Stream Recording on CD media.
I would move it out of that text paragraph.

Instead you could insert something like

  Stream recording is of benefit only with DVD-RAM, BD-RE, and formatted
  BD-R media. [Therefore stream recording should not be used for CD-R or
  CD-RW media.]

and then in a separate paragraph:

  xfburn only writes a single session and then finalizes the medium.
  So it is not the best tool for my goal to archive photos in multiple
  sessions on the same medium.

The "W" in CD-RW means that it can be blanked. Elsewise, if not formatted,
they behave like CD-R.


> It would be a problem if one of the buffers runs empty.

In the previous century it was indeed a problem. Nowadays the drives
can continue after a pause in the write stream. Only audiophiles would
complain about microseconds of delay in CD playback.


> There is a bug in the underlying library libburn which will be fixed
> in the coming version 1.5.2.

You should add that libburn 1.5.2 will ask the drive whether it is willing
to do stream recording and will believe a positive answer only for DVD-RAM,
BR-R, and BD-RE.
Then it is clearer what bug there was. (And yes, the decision to do it
only with those three media types is made now.)


> The other Matshita DVD-RAM products (from the T400 and T410 computers,
> namely DVD-RAM UJ862A revision SB04 and DVD-RAM UJ892 revision SB01)
> which I have tested, tell the software that they can’t do stream
> recording, but xfburn tells them to do so despite of that,
> because the specification states, that the hardware shall gracefully
> do without stream recording even if told to do so although it can’t.
> Then writing goes wrong and the blank renders unusable in my case!

This is wrong. The specs say that the drive may refuse if it did not
announce to be able.
It was the fault of libburn not to ask the drive in advance.

So how about this:

  The other Matshita DVD-RAM products (from the T400 and T410 computers,
  namely DVD-RAM UJ862A revision SB04 and DVD-RAM UJ892 revision SB01)
  which I have tested, would tell the software that they can’t do stream
  recording, if they were asked about it.
  But xfburn tells libburn to use stream recording and libburn did not
  ask the drive in advance.
  So writing goes wrong and the blank renders unusable in my case!

  The excuse of libburn's developer is that all his drives tolerate
  stream recording on CD. Even the one which says it would not.
  So the problem was not noticed for nearly 10 years.


> [...] xfburn [...]
> being unable to reasonably treat rewritable media (i.e. -RW media)

I think it has a blank media job. Lower left corner of the greeting
screen: "Blank Disc" "Prepare the rewritable disc for a new burn".
More special treatment is not possible with CD-RW (except formatting,
which yields smaller capacity and clonking drive).


> Thomas Schmitt will write a technical article for debian on our experiments

That's not decided yet. Fixing libburn seems more worthwhile and more
feasible. But currently Debian is in "full freeze" for upcomming
release 10 "Buster".
Before Debian 10.0 is out, nothing will be possible about Xfburn or
libburn. (Unless they manage to crash the system.)


> During the many mail exchanges we also found out that xfburn can only create
> finalized CDs. [...]
> One has to use the command line program xorriso for this purpose.

Afaik, Brasero and K3B can do multi-session. (Begin by looking for
"Import" options when your appendable CD-R is inserted in the drive.)

On the command line, growisofs and the combination of mkisofs and cdrecord
can do multi-session. growisofs emulates thhis on overwritable media,
but cdrecord does it only on sequential media.

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But:

I think that too much talk about multi-session and xorriso would devalue
the answer to the actual problem about which you asked.

I would end it after

  "Then writing goes wrong and the blank renders unusable in my case!"

and only add as last statement:

  "The Stream Recording flaw in xfburn will automatically be fixed once
   a newer corrected version of libburn is available and installed."


I would also omit the text between (and including):

  "The ability to stream-record can be determined by software:"

and

   "See Thomas Schmitts technical report."

(Nobody needs to care where libburn learns about the drive's
 announcements.)

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Have a nice day :)

Thomas