Language metadata in ePub files

HarryT · 06-22-2010, 09:47 AM

Hi Kovid,

I don't know if you've noticed the matter in the Apple forum, but an issue has arisen with Calibre-generated ePub files in the new versions of the "iBooks" bookreader for iPad and iPhone. iBooks has a language-specific dictionary, and all ePub files generated by Calibre appear to contain a "dc:language" metadata value of "UND", resulting in an inability to use the dictionary. Editing the metadata value to "EN" makes the dictionary work.

Three questions:

1. Can Calibre generate a default language metadata value of "EN" rather than "UND"?

2. Would it be possible to edit this value in Calibre's "Edit Metadata" screen?

3. When Calibre converts a Mobipocket file containing a valid language metadata value, even then it still produces the "UND" value in the ePub. Would it be possible to correctly import this value from the Mobipocket file?

I would enter this on the project tracker, but unfortunately it doesn't seem to want to let me log on at present.

Thanks!

kovidgoyal · 06-22-2010, 09:50 AM

1. Possibly, I'll look at it

2. It's on the todo list

3. Can you attach a sample mobi file showing this behavior

HarryT · 06-22-2010, 09:58 AM

Thanks. I'll upload a Mobi and ePub file showing the issue when I get home from work in a couple of hours.

GRiker · 06-22-2010, 10:37 AM

Kovid, I have a provisional patch in place for the iPad driver, we need to discuss.

G

HarryT · 06-22-2010, 11:22 AM

Hi Kovid,

Attached is a Mobi file, and the resulting ePub file created from it by Calibre.

The OPF file used to generate the Mobi file (using MobiPocket Creator) contains the element "<dc:Language>en-gb</dc:Language>".

The ePub file created by Calibre contains "<dc:language>UND</dc:language>

Hope this example helps.

GRiker · 06-22-2010, 01:37 PM

After discussion with Kovid, I've modified the iDevice driver in 0.7.5 so that it forces a value of <dc:language>en</dc:language> into the epub's metadata. This is a temporary solution for iDevices until calibre has proper language support and we know more about international iDevices.

G

kovidgoyal · 06-22-2010, 01:39 PM

There's actually nothing wrong with the conversion system as you can verify by converting the book using the command line ebook-convert.

However, I'm guessing you used the GUI to convert. Since the GUI does not store language information, it is passing UND to the conversion system. I'[ve changed that to have it pass instead the language you have set the calibre interface to, which should be a reasonable interim solution.

foghat · 06-22-2010, 01:45 PM

Quote:

Originally Posted by GRiker

After discussion with Kovid, I've modified the iDevice driver in 0.7.5 so that it forces a value of <dc:language>en</dc:language> into the epub's metadata. This is a temporary solution for iDevices until calibre has proper language support and we know more about international iDevices.

G

Super! Any idea when 0.7.5 will be available for download? I assume we will have to regenerate the epubs? Or will this 'forcing' of the value <dc:language>en</dc:language> be something that happens in the background somehow?

Thanks.

GRiker · 06-22-2010, 02:10 PM

Foghat, it happens when you send an epub to the iPad, metadata is dynamically rewritten.

G

HarryT · 06-22-2010, 02:15 PM

Quote:

Originally Posted by kovidgoyal

There's actually nothing wrong with the conversion system as you can verify by converting the book using the command line ebook-convert.

However, I'm guessing you used the GUI to convert. Since the GUI does not store language information, it is passing UND to the conversion system. I'[ve changed that to have it pass instead the language you have set the calibre interface to, which should be a reasonable interim solution.

Yes, I do indeed use the GUI. Thanks for the fix - that sounds like a good compromise.

foghat · 06-22-2010, 02:46 PM

Quote:

Originally Posted by GRiker

Foghat, it happens when you send an epub to the iPad, metadata is dynamically rewritten.

G

Okay, I don't have an ipad - are you saying Calibre can send directly to the ipad without itunes?

Either way, I am thinking about ibooks on the iphone - and having to sync through Itunes to get the epub on the iphone.

JSWolf · 06-22-2010, 02:49 PM

Quote:

Originally Posted by kovidgoyal

There's actually nothing wrong with the conversion system as you can verify by converting the book using the command line ebook-convert.

However, I'm guessing you used the GUI to convert. Since the GUI does not store language information, it is passing UND to the conversion system. I'[ve changed that to have it pass instead the language you have set the calibre interface to, which should be a reasonable interim solution.

Can we have a setting in ebook-convert to force the language identifier to be forced to be English in case the original eBook is wrong or undefined?

kovidgoyal · 06-22-2010, 02:56 PM

--language

kjk · 06-22-2010, 02:57 PM

Quote:

Originally Posted by foghat

Okay, I don't have an ipad - are you saying Calibre can send directly to the ipad without itunes?

https://www.mobileread.com/forums/showthread.php?t=85856

You have to have iTunes running, but you don't have to deal with iTunes, if that makes sense.

foghat · 06-22-2010, 08:01 PM

^ So, do you know if this should work with an iphone/ibooks? "I get a Cannot Send: No device is connected".

06-22-2010, 09:47 AM	#1
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	Language metadata in ePub files Hi Kovid, I don't know if you've noticed the matter in the Apple forum, but an issue has arisen with Calibre-generated ePub files in the new versions of the "iBooks" bookreader for iPad and iPhone. iBooks has a language-specific dictionary, and all ePub files generated by Calibre appear to contain a "dc:language" metadata value of "UND", resulting in an inability to use the dictionary. Editing the metadata value to "EN" makes the dictionary work. Three questions: 1. Can Calibre generate a default language metadata value of "EN" rather than "UND"? 2. Would it be possible to edit this value in Calibre's "Edit Metadata" screen? 3. When Calibre converts a Mobipocket file containing a valid language metadata value, even then it still produces the "UND" value in the ePub. Would it be possible to correctly import this value from the Mobipocket file? I would enter this on the project tracker, but unfortunately it doesn't seem to want to let me log on at present. Thanks!

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06-22-2010, 09:50 AM	#2
kovidgoyal creator of calibre Posts: 43,842 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	1. Possibly, I'll look at it 2. It's on the todo list 3. Can you attach a sample mobi file showing this behavior

06-22-2010, 09:58 AM	#3
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	Thanks. I'll upload a Mobi and ePub file showing the issue when I get home from work in a couple of hours.

06-22-2010, 10:37 AM	#4
GRiker Comparer of the Ephemeris Posts: 1,496 Karma: 424697 Join Date: Mar 2009 Device: iPad	Kovid, I have a provisional patch in place for the iPad driver, we need to discuss. G

06-22-2010, 01:37 PM	#6
GRiker Comparer of the Ephemeris Posts: 1,496 Karma: 424697 Join Date: Mar 2009 Device: iPad	After discussion with Kovid, I've modified the iDevice driver in 0.7.5 so that it forces a value of <dc:language>en</dc:language> into the epub's metadata. This is a temporary solution for iDevices until calibre has proper language support and we know more about international iDevices. G

06-22-2010, 01:39 PM	#7
kovidgoyal creator of calibre Posts: 43,842 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	There's actually nothing wrong with the conversion system as you can verify by converting the book using the command line ebook-convert. However, I'm guessing you used the GUI to convert. Since the GUI does not store language information, it is passing UND to the conversion system. I'[ve changed that to have it pass instead the language you have set the calibre interface to, which should be a reasonable interim solution.

06-22-2010, 02:10 PM	#9
GRiker Comparer of the Ephemeris Posts: 1,496 Karma: 424697 Join Date: Mar 2009 Device: iPad	Foghat, it happens when you send an epub to the iPad, metadata is dynamically rewritten. G

06-22-2010, 02:56 PM	#13
kovidgoyal creator of calibre Posts: 43,842 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	--language

06-22-2010, 08:01 PM	#15
foghat Evangelist Posts: 464 Karma: 1006520 Join Date: Mar 2010 Location: Alberta, Canada Device: Kindle PW3	^ So, do you know if this should work with an iphone/ibooks? "I get a Cannot Send: No device is connected".

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