[Libburn] Re: Condensed list of problems with libburn

[Tiago Cogumbreiro]

Keep in mind that the CD speed is affected by the inserted media. For
example, if you insert a CD-RW the drive will show the max write speed
of a CD-RW whereas if you insert a CD-R or leave it empty it will show
the max speed of write-once medium.

On 12/26/05, scdbackup at gmx.net <scdbackup at gmx.net> wrote:
> Hi,
>
> an update to the condensed problem list :
>
> ------------------------------------------------------------------
>
> 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.)
>
>
> ------------------------------------------------------------------
>
> 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).
>