Re: Is there a way to know what speed are avilable using cdrecord or wodim?

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

> Is there a way to tell how many different speeds are supported
> by the combination of the current driver and the disc in it?
> [...] Again I only have cdrecord / wodim [...]

Your mileage may vary.

Option -atip tells ID codes of CD models and sometimes it
tells two speed related lines.

E.g. a CD-RW labeled "4x-12x"

  $ cdrecord dev=/dev/sr0 -atip
  ...
    ATIP start of lead in:  -11635 (97:26/65)
    ATIP start of lead out: 359849 (79:59/74)
    1T speed low:  4 1T speed high: 10
    2T speed low:  4 2T speed high:  0 (reserved val  6)
  ...

or a CD-RW labeled "4x"

    ATIP start of lead in:  -11078 (97:34/22)
    ATIP start of lead out: 336075 (74:43/00)
    1T speed low:  0 (reserved val  0) 1T speed high:  4
    2T speed low:  0 (reserved val  5) 2T speed high:  0 (reserved val 12)

A CD-R labeld "52x" does not produce speed lines, but only

    ATIP start of lead in:  -11559 (97:27/66)
    ATIP start of lead out: 359846 (79:59/71)

(cdrskin says
    1T speed low:  24 1T speed high: 40
 Probably it got this info from the newer SCSI command GET PERFORMANCE
 rather than by old READ TOC/PMA/ATIP. The reply of GET PERFORMANCE
 is influenced by media and drive. The info in ATIP is only influenced
 by the media.)


The "lead in"+"lead out" time codes (e.g. "97:27/66" + "79:59/71")
characterize the manufacturer and the CD model. The numbers can be
found in the Internet. I collected some in
  http://www.libburnia-project.org/browser/libburn/trunk/doc/mediainfo.txt

It identifies the "52x" media as
  97 26 66  79 59 71  702.83MB CMC 52X

The "4x-12x" is listed as
  97 26 65  79 59 74  702.83MB Melody(CMC) 10X 

The "4x" is old enough to fall victim to rumors (the 32x entry is wrong):
  97 34 22  74 43 00  656.40MB Mitsubishi N/A 1-4X 
  97 34 22  74 43 00  74 32x "Mitsubishi Chemical Corporation"
  97 34 22  74 43 00  MCC
  97 34 22  74 43 00  Mitsubishi CD-RW 1-4X 656.40MB


You may use that list or start an own database of media.
Examine ewly bought media for these codes. Register new codes with
the speed values which you read with your own eyes from the media
imprints.

If you find some which are not in my list, i would appreciate
to learn about them. (Alternative vendors of known media are
of fewer interest, but such info is still welcome.)


Have a nice day :)

Thomas