PDB to PMLZ File type plugin

[pdurrant]

Originally Posted by KevinH

If I am reading the latest version of erdr2pml.py correctly, the metadata is not actually drm'd, it just looks like it. The metadata has actually just been XOR'd with a table that is actually present before any decrypting or unshuffling.

So, FWIW it may be possible to read the metadata without actually decrypting an an ereader pdb.

That would be an good work around, and generally useful - fix the PDB metadata reader to also read the metadata in an encrypted PDB. Hmm...

[kovidgoyal]

There are plugins to read metadata from archive files as well. They look for well known ebook types inside the archive and read the metadata from them. If that's not working, please file a bug report, witha test case and I'll take a look.

Originally Posted by pdurrant

I've just been looking at the built-in file type plug-ins, and I can see that for most of them reading the metadata from the original file will work.

But what about your Archive Extract Filetype plug-in? Doesn't it have the same problem that my plug-in has - no meta data extracted from the file?

(goes to check)
Yes, it does - If I put a (non-DRMed) Mobipocket file into a zip archive and import it, it imports as a PRC format file, and can be viewed in the viewer, but no metadata has been read for it.

Should I raise an enhancement request for this? Of can you think of a work-around?

[pdurrant]

Originally Posted by pdurrant

That would be an good work around, and generally useful - fix the PDB metadata reader to also read the metadata in an encrypted PDB. Hmm...

Unfortunately, the first section of the eReader file containing indexes to all other interesting sections, including the metadata section and the section used an an xor table is encrypted. So a metadata reader for encrypted PDB files would still need the name and number key to the file, and would need, in a small way, to de-drm the file. I think this would be sufficient to make it a circumvention tool according to the DMCA, and so couldn't be an official part of Calibre.

I don't currently see a way that I can get this to work so long as Metadata is read before the file type plugins are called.

But I'm hoping that those more familiar with Calibre do see a way around this.

[pdurrant]

Originally Posted by kovidgoyal

If that's not working, please file a bug report, witha test case and I'll take a look.

Reported as bug #4958, sample zipped Mobipocket file attached.