Request for comment about current packet writing software product

keiji_katata at post.pioneer.co.jp keiji_katata at post.pioneer.co.jp
Thu Nov 28 04:56:08 PST 2002


* From the T10 Reflector (t10 at t10.org), posted by:
* keiji_katata at post.pioneer.co.jp
*

Hello all and Chigita san,

  Today, we held Mt.Fuji5 DRM-DM sub working group meeting to discuss Type
  1 error level criteria. In the meeting, within device venders, Type 1
  error level and Type 2 error level criteria are defined. We can achieve
  an agreement of technical possibility for actual compatible
  implementation on DVD-RW media/device.

  In the meeting, some members consider necessity to turn on/off of DRT-DM
  feature. Their comment is that if DRT-DM caused problem with current
  packet writing software, turn on/off command or mode parameter is needed.
  So I would like to ask to all software venders that there is possibility
  of problem between current packet writing software for DVD-RW media and
  DRT-DM, or not. All (e.g. UDF 1.5 packet writing) software are subjects.
  And I would like to request to all software venders to attend to the next
  SWG meeting at 12/4 Pioneer PAX building.

  DRT-DM feature works as follows:
  1.  Device certifies packets (sectors / ECC block) on C/DVD-RW at Read
  command and remembers in its memory. If PER bit of Read Write Mode
  parameter is set to 1 and device found defective packet, device reports
  RECOVERD ERROR at the end of the Read command. If PER bit is set to 0,
  device terminates Read command without CHECK CONDITION.

  2.  Regardless PER bit setting, device reports RECOVERD ERROR at the end
  of a Write command if the write address was issued to the defective
  packet that is found at Read command.

  3.  Packet writing software performs defect management if necessary.
  For more detail, please refer to DRT-DM.PPT in
   ftp.avc-pioneer.com/Mtfuji5/Proposal/Aug02/Pioneer/DRT/DM.zip

  Currently, there is no method to turn off this feature in my proposal.
  Because current possible problem of packet writing on DVD-RW is that two
  specific packets have high possibility to be un-readable due to too many
  write cycles. Those packets are for Volume Integrity Descriptor and Space
  Bitmap.
  "RECOVERD ERROR" at the end of Write command does not stop writing the
  actual data onto the disc. So Volume Integrity Descriptor or Space Bitmap
  is written on the disc correctly. But packet writing software can get
  message from device to show the end of life of media for end user.
  Without this message, the disc should be failed to mount at the next
  insertion due to read error of Volume Integrity Descriptor or Space
  Bitmap.

  The concerning point of members is that if drive reported "RECOVERD
  ERROR" at the Write command for directory entry or file data writing,
  what will happen.
  1.  "RECOVERD ERROR" is ignored. Then writing file is continued. So
  directory entry or file data writing is completed with no problem.
  2.  Warning is displayed. Then writing file is continued. So directory
  entry or file data writing is completed with no problem.
  3.  Directory entry or file data writing is terminated immediately as
  incomplete state. But recovering software (like scandisk.exe) can recover
  the incomplete state.
  4.  Directory entry or file data writing is terminated immediately as
  incomplete state. All file in the directory or the file should be lost.
  5.  Packet writing software may cause inconceivably difficult situation.

  Please let me know if your packet writing software has any serious
  trouble by "RECOVERD ERROR" at Write command. No comment is treated as no
  problem on your products.

  Best regards,

  Keiji Katata
  PIONEER CORP.





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