Hidden metadata? Category mismatch between Calibre and iBooks on iPhone

usedtowork · 01-31-2011, 10:58 AM

My Calibre library of about 50 books currently has no Tags, Category, Genre or Subject fields, as indicated in the left pane in Calibre (where it says "Tags [0]", "Subject [0]" etc.). However when I look at the books in iBooks on my iPhone and sort by Category, I see a number of the books have categories attached, including some very strange ones (like Cannery Row being listed under "French literature"). See pics for details:

I would have thought iBooks categories would be built from Tags/Category/Genre/Subject but it appears they're coming from some (possibly hidden) metadata in the books. Is there a way in Calibre I can view and edit all the metadata in a book, and not just the few fields that are available under the Edit Metadata dialog box?

Manichean · 01-31-2011, 11:07 AM

How did you get the books onto the iPhone? Normally, Calibre should update the metadata on export from the library (send to device or save to disk), and there are no hidden metadata fields (that I know of), so Calibre should've set the books' metadata accordingly. It can't do that, however, if you've copied them directly out of the library folder. In that case, you'd have to re-transfer them to your iPhone.

GRiker · 01-31-2011, 01:08 PM

IIRC, the metadata in the OPF file (where the genre comes from) is only updated if a tag is present or a plugboard transform has been applied. With no tags/plugboards, calibre makes no changes to the OPF file, so whatever metadata is the original source file remains intact.

(Assuming you're using 'Connect to iTunes' to send the file.)

G

usedtowork · 01-31-2011, 05:09 PM

Quote:

Originally Posted by Manichean

How did you get the books onto the iPhone?

I simply drag the file into Calibre, convert to EPUB, then Send To Device.

Quote:

Originally Posted by GRiker

IIRC, the metadata in the OPF file (where the genre comes from) is only updated if a tag is present or a plugboard transform has been applied. With no tags/plugboards, calibre makes no changes to the OPF file, so whatever metadata is the original source file remains intact.

It's possible the metadata is already baked into the source files, if that's the case is it possible to examine/remove it with Calibre?

GRiker · 02-01-2011, 11:29 AM

What's your objective? If you want to control how the books are categorized when sent to the iDevice, review the Metadata Mapping and Plugboard Transformations section of the Calibre + Apple iDevices: Start here sticky. You'll see an example of using a custom column as the Genre/Category when sending to iTunes/iBooks.

G

usedtowork · 02-01-2011, 06:02 PM

Quote:

Originally Posted by GRiker

What's your objective?

I'd be happy to just strip out all tags from any book, then manually add the fields I'm interested in (title and author) through the Calibre interface.

I took a look at that plugboard thing but as I say, these books seem to have no metadata that could be used as Categories in iBooks, and yet they're showing up with categories, sometimes very strange ones. Maybe an iBooks bug?

I'll try overriding the genre tag with "" or equivalent using the plugboards, but if anyone can recommend a tool (commercial or otherwise) that merely lets me examine and edit all the metadata in an EPUB document, I'd certainly appreciate it.

usedtowork · 02-01-2011, 07:12 PM

Update: I found that by deleting all the books from my device, deleting all the metadata.opf files in my collection and re-uploading all my books, all my books are now showing as having no Category in iBooks as expected. I think a change to iBooks, Calibre or maybe both must have happened in the past 6 months as books that were previously "Uncategorized" now have no category at all.

So if metadata's got you down, try cleaning it with Sigil first, but if that fails delete the metadata.opf files and you should be able to scrub your books clean.

itimpi · 02-02-2011, 12:50 AM

Not sure why deleting the metadata.opf file should have any effect. That file is just a backup copy of what is in the calibre database.

However deleting the books from iBooks (and iTunes) and re-sending them could well have an effect. The iDevice integration has evolved over the last few months to improve the mapping of metadata onto iTunes fields.

DoctorOhh · 02-02-2011, 04:57 AM

Quote:

Originally Posted by usedtowork

So if metadata's got you down, try cleaning it with Sigil first, but if that fails delete the metadata.opf files and you should be able to scrub your books clean.

As itimpi said these files are essentially a backup of what is in your calibre database and were created and are used as a backup of your database one book at a time. if your metadata.db file ever disappears these files will help you restore the database. Deleting these files in the short term won't hurt but they won't help either.

01-31-2011, 10:58 AM	#1
usedtowork Junior Member Posts: 5 Karma: 10 Join Date: Jan 2011 Device: iPhone	Hidden metadata? Category mismatch between Calibre and iBooks on iPhone My Calibre library of about 50 books currently has no Tags, Category, Genre or Subject fields, as indicated in the left pane in Calibre (where it says "Tags [0]", "Subject [0]" etc.). However when I look at the books in iBooks on my iPhone and sort by Category, I see a number of the books have categories attached, including some very strange ones (like Cannery Row being listed under "French literature"). See pics for details: I would have thought iBooks categories would be built from Tags/Category/Genre/Subject but it appears they're coming from some (possibly hidden) metadata in the books. Is there a way in Calibre I can view and edit all the metadata in a book, and not just the few fields that are available under the Edit Metadata dialog box?

01-31-2011, 01:08 PM	#3
GRiker Comparer of the Ephemeris Posts: 1,496 Karma: 424697 Join Date: Mar 2009 Device: iPad	IIRC, the metadata in the OPF file (where the genre comes from) is only updated if a tag is present or a plugboard transform has been applied. With no tags/plugboards, calibre makes no changes to the OPF file, so whatever metadata is the original source file remains intact. (Assuming you're using 'Connect to iTunes' to send the file.) G Last edited by GRiker; 01-31-2011 at 01:51 PM.

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01-31-2011, 11:07 AM	#2
Manichean Wizard Posts: 3,130 Karma: 91256 Join Date: Feb 2008 Location: Germany Device: Cybook Gen3	How did you get the books onto the iPhone? Normally, Calibre should update the metadata on export from the library (send to device or save to disk), and there are no hidden metadata fields (that I know of), so Calibre should've set the books' metadata accordingly. It can't do that, however, if you've copied them directly out of the library folder. In that case, you'd have to re-transfer them to your iPhone.

02-01-2011, 11:29 AM	#5
GRiker Comparer of the Ephemeris Posts: 1,496 Karma: 424697 Join Date: Mar 2009 Device: iPad	What's your objective? If you want to control how the books are categorized when sent to the iDevice, review the Metadata Mapping and Plugboard Transformations section of the Calibre + Apple iDevices: Start here sticky. You'll see an example of using a custom column as the Genre/Category when sending to iTunes/iBooks. G

02-01-2011, 07:12 PM	#7
usedtowork Junior Member Posts: 5 Karma: 10 Join Date: Jan 2011 Device: iPhone	Update: I found that by deleting all the books from my device, deleting all the metadata.opf files in my collection and re-uploading all my books, all my books are now showing as having no Category in iBooks as expected. I think a change to iBooks, Calibre or maybe both must have happened in the past 6 months as books that were previously "Uncategorized" now have no category at all. So if metadata's got you down, try cleaning it with Sigil first, but if that fails delete the metadata.opf files and you should be able to scrub your books clean.

02-02-2011, 12:50 AM	#8
itimpi Wizard Posts: 4,552 Karma: 950151 Join Date: Nov 2008 Device: Sony PRS-950, iphone/ipad (Marvin/iBooks/QuickReader)	Not sure why deleting the metadata.opf file should have any effect. That file is just a backup copy of what is in the calibre database. However deleting the books from iBooks (and iTunes) and re-sending them could well have an effect. The iDevice integration has evolved over the last few months to improve the mapping of metadata onto iTunes fields.