Quote:
Originally Posted by DNSB
@enuddleyarbl: Please note that the key for font encryption is very often the dc:identifier found in content.opf and anything that modifies it will disable font decryption. And yes. a calibre conversion can and will break the ability to decrypt fonts. One of the reasons I prefer to use KindleUnpack to generate epubs from a KF8/azw3 file....
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There's definitely a difference between the dc:identifier lines from the AZW3 brought into Calibre and those from that same file run through KindleUnpack.
The KU version of a book:
Code:
<dc:identifier>mobi-asin:B0030P1W9A</dc:identifier>
<dc:identifier>isbn:9780307575357</dc:identifier>
<dc:identifier>calibre:461</dc:identifier>
<dc:identifier>uuid:9280af86-82f9-4a3d-8087-e2091a2bcecb</dc:identifier>
<dc:identifier id="uid">3359571780</dc:identifier>
<dc:identifier>urn:uuid:f886b17f-3a7d-4826-8ad7-fcfe0c38f40a</dc:identifier>
The Calibre AZW3 version:
Code:
<dc:identifier id="calibre_id" opf:scheme="calibre">9280af86-82f9-4a3d-8087-e2091a2bcecb</dc:identifier>
...
<dc:identifier opf:scheme="ISBN">9780307575357</dc:identifier>
<dc:identifier opf:scheme="MOBI-ASIN">B0030P1W9A</dc:identifier>
The Calibre EPUB2 version:
Code:
<dc:identifier id="uuid_id" opf:scheme="uuid">urn:uuid:9280af86-82f9-4a3d-8087-e2091a2bcecb</dc:identifier>
...
<dc:identifier opf:scheme="calibre">9280af86-82f9-4a3d-8087-e2091a2bcecb</dc:identifier>
<dc:identifier opf:scheme="MOBI-ASIN">B0030P1W9A</dc:identifier>
<dc:identifier opf:scheme="ISBN">9780307575357</dc:identifier>
And, the Calibre editor EPUB2 > EPUB3 version:
Code:
<dc:identifier id="uuid_id">uuid:9280af86-82f9-4a3d-8087-e2091a2bcecb</dc:identifier>
...
<dc:identifier>calibre:9280af86-82f9-4a3d-8087-e2091a2bcecb</dc:identifier>
<dc:identifier>MOBI-ASIN:B0030P1W9A</dc:identifier>
<dc:identifier>ISBN:9780307575357</dc:identifier>
The AZW3, EPUB2 and EPUB3 versions are mostly the same (cosmetic changes). The KU version adds that calibre one, the id="uid" one and the urn one. Interesting. I'm assuming the missing urn one is the key.
EDIT1: it's odd, then, that the book seems fine as an AZW3 and EPUB2. But, as an EPUB3, with the same dc:identifiers, it fails. /EDIT1.
EDIT2: I guess, from your first link, the dc:identifiers have to be exactly the same, and, possibly, in the same order. /EDIT2.
Of course, at my Joe-Bag-O-Donuts level, I just assumed Calibre could convert anything it opened and I wouldn't have to pay attention to whether or not the book contained fonts.
I guess I'll go back to stripping all the font stuff out of the books when I play with them. Since I use my Kobo's fonts instead of the Publisher Defaults, I should be fine.