[Libburn] Re: Condensed list of problems with libburn

[scdbackup at gmx.net]

Hi,

an update to the condensed problem list :

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I revoke my complaint about setting speed.
The conversion factor for consumer x-speed to libburn speed
seems to be 176 to 176.5 rather than 150.

176.0 does not work on my LG, but with a little add-on it does :
  k_speed= 10*176+50;
  burn_drive_set_speed(drive,k_speed,k_speed);
sets the drive to 10x speed.


The failure to use 4x speed with the "4x-12x" CD-RW media is not
peculiar to libburn but shared by cdrecord. So it's the LG drive
which insists in its own opinion about healthy speed.
The LITE-ON allows me to write 4x to the "4x-12x" media via libburn.
It also uses "4x" media at speed 4 and at speed 2. I even broke
out some old "2x" media. (The burner has no support for speed 1.)


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My complaint about burn_drive_get_write_speed from drive has to be
weakened :

I do get the correct settings for the inserted media,
if i run my program twice. First i get 4234 for any
media and on second inquiry i get
on LG GSA-4082B :
  4234  for "52x"    CD-R  (24x which is max for the burner)
  1764  for "4x-12x" CD-RW (10x which is max for the burner)
   706  for "4x"     CD-RW (4x)
   706  for "2x"     CD-RW (4x, burner is unable to burn 2x,
                                   cdrecord refuses to burn those,
                                   libburn uses 4x speed, CD verifies with MD5)

On LITE-ON LTR-48125S i get 8448 with the first run and afterwards:
  8448  for "52x"    CD-R  (48x, which is max for the burner)
  2112  for "4x-12x" CD-RW (12x)
   704  for "4x"     CD-RW (4x)
   352  for "2x"     CD-RW (2x)
(so this drive shows a neat factor of 176)

I then searched for workarounds within a single program run.

Wrong result with :

 (load manually) - init+scan - grab - release - grab

 init+scan(loading) - grab - release - grab

 init+scan(loading) - finish - init+scan - grab - release - grab


Correct result with:

 (load manually) - init+scan - finish - init+scan - grab - release - grab

 init+scan(loading) - grab - release - grab - release - finish - init+scan - grab - release - grab

(Maybe one can still economize on grab-release cycles)

It would be worthwile to reduce that latter startup procedure to
 init+scan(loading) - grab 
(Currently this yields wrong media type and wrong speed.)

In libburn.h i read:
"   If is possible to 'restart' the library by shutting it down and
    re-initializing it, though there is no good reason to do that."
Well, looks like i found such a reason (plus a typo).
 

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Have a nice day :)

Thomas