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superg / redumper

Low level CD dumper utility
GNU General Public License v3.0
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Redumper does not detect the PVD on a UDF disc. #128

Open maxz opened 3 months ago

maxz commented 3 months ago

I have a UDF disc which has empty Volume Recognition Sequences (BEA01 and NSR02). Redumper therefore cannot find the Primary Volume Descriptor (PVD) and does not return any information contained in it. DiscImageCreator correctly finds it.

I would wish for Redumper to at least return the Volume Identifier in the log file. The timestamp RecordingDateandTime would probably also be useful to record.

You have to go via one of the Anchor Volume Descriptor Pointers (AVDP) to find the proper PVD.

First check whether the Volume Recognition Sequences contain the PVD. If they do, use it. If they do not:

  1. Locate an AVDP (it will be at two of the three sectors 256, N - 256 or N) (see [1], page 23)
  2. Validate the AVDP and use the provided extent to find the volume descriptor sequence and the PVD contained therein. (additionally see [2], section 7 Basic types)
  3. Validate the PVD and at least return the Volume Identifier in the log file.

You can also use [3] for a quick overview, but be aware that it contains some errors.

This request is remotely related to #113, but all the features I'm writing about are already in the first version of the UDF specification.

[1] Universal Disk Format Specification, Revision 2.60 [2] ECMA-167 [3] https://wiki.osdev.org/UDF

Logs Pandora German (Redumper).zip Pandora German (DiscImageCreator).zip

maxz commented 3 months ago

Also related to #45.