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Re: Check / verify and test quality of burned CD/DVD's



On Thu 15 July 2004 16:50, Ashish Rangole wrote:
> I usually calculate the md5sum of the iso image before
> writing it to the disc. After successful write I use
> readcd to read the iso image back, calculate its md5sum
> and compare.

But that doesn't give you any quality information does it? And that 
was what you were asking about?

From the readcd manpage:

       -c2scan
              Scans  the  whole  CD or the range specified by the
              sectors=range for C2 errors. C2 errors  are  errors
              that  are  uncorrectable  after the second stage of
              the 24/28 + 28/32 Reed Solomon correction system at
              audio  level  (2352 bytes sector size). If an audio
              CD has C2 errors, interpolation is needed  to  hide
              the  errors.  If  a  data  CD  has C2 errors, these
              errors are in most cases corrected by  the  ECC/EDC
              code  that makes 2352 bytes out of 2048 data bytes.
              The ECC/EDC code should be able  to  correct  about
              100 C2 error bytes per sector.

              If  you  find  C2 errors you may want to reduce the
              speed using the speed= option as C2 errors may be a
              result of dynamic unbalance on the medium.

If it finds a lot of C2 errors, quality is low, if not, quality is 
high.

Unless I misunderstood your question...

Lourens
-- 
GPG public key: http://home.student.utwente.nl/l.e.veen/lourens.key



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