Does editing metadata affect the EPUB itself?

Cactus Chef · 05-03-2020, 10:20 AM

I've got a roughly 200-book collection in Calibre at the moment, mostly cobbled from a mix of Amazon and Kobo books. The vast majority of them are missing metadata like the ISBN or other useful info due to the import method. I'd like to go through and fix them using Calibre's "download metadata" feature, however I'm concerned that doing so will:

Cause all of the books to fall out-of-sync with how they appear on my Kobo
Modify the EPUBs themselves and force me to re-sync my entire collection over to all my backup devices

I did a test on one of my ebooks, and after downloading new metadata (keeping the original cover), I didn't see the EPUB itself being modified, I only saw a change to the metadata.opf in the same directory. If so, that's fine. If not (i.e. the EPUB also gets edited), that's not a deal-breaker, I'll just need to hold off on doing this for awhile until I'm confident I've got some good backups of my library in its "pre-normalization" state.

Can anyone confirm?

Thank-you in advance!

theducks · 05-03-2020, 12:04 PM

Downloading / Editing Metadata in the Library (view) mainly affects the DB (entry).
It will also cause metadata.opf ( a backup of the data) to update in the Titles folder. Same goes for cover changes.

IF... you change either the Title or Author, the book moves to a new location within the file system.

If that is all you do. The actual book files do not change INTERNALLY. The file name may change if you change the TITLE

It takes extra action to force a Library copy to update internally.
OTOH if you SEND... (again) those get updated on the fly

free file sync only sends updated files to your backup target, and it is fairly quick if you have bandwidth.

davidfor · 05-03-2020, 10:31 PM

@Cactus Chef: In most cases, updating the metadata in your library shouldn't affect the connection to the books on the Kobo devices. And the KoboTouch driver can update the metadata in the database on the device to match what is in the calibre library.

The main issue would be if you need to resend the book to the device, and change the metadata that is used to construct the file name on the device . If the file name or path change, the device will see it as a separate book. The default save template uses the title and author, but, you could be using something else.

05-03-2020, 10:20 AM	#1
Cactus Chef Fanatic Posts: 574 Karma: 7058832 Join Date: Apr 2019 Location: East Coast, United States Device: Kobo Sage, Kobo Clara HD, Galaxy Tab S5e, Kindle 4th Gen	Does editing metadata affect the EPUB itself? I've got a roughly 200-book collection in Calibre at the moment, mostly cobbled from a mix of Amazon and Kobo books. The vast majority of them are missing metadata like the ISBN or other useful info due to the import method. I'd like to go through and fix them using Calibre's "download metadata" feature, however I'm concerned that doing so will: Cause all of the books to fall out-of-sync with how they appear on my Kobo Modify the EPUBs themselves and force me to re-sync my entire collection over to all my backup devices I did a test on one of my ebooks, and after downloading new metadata (keeping the original cover), I didn't see the EPUB itself being modified, I only saw a change to the metadata.opf in the same directory. If so, that's fine. If not (i.e. the EPUB also gets edited), that's not a deal-breaker, I'll just need to hold off on doing this for awhile until I'm confident I've got some good backups of my library in its "pre-normalization" state. Can anyone confirm? Thank-you in advance!

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05-03-2020, 12:04 PM	#2
theducks Well trained by Cats Posts: 31,056 Karma: 60358908 Join Date: Aug 2009 Location: The Central Coast of California Device: Kobo Libra2,Kobo Aura2v1, K4NT(Fixed: New Bat.), Galaxy Tab A	Downloading / Editing Metadata in the Library (view) mainly affects the DB (entry). It will also cause metadata.opf ( a backup of the data) to update in the Titles folder. Same goes for cover changes. IF... you change either the Title or Author, the book moves to a new location within the file system. If that is all you do. The actual book files do not change INTERNALLY. The file name may change if you change the TITLE It takes extra action to force a Library copy to update internally. OTOH if you SEND... (again) those get updated on the fly free file sync only sends updated files to your backup target, and it is fairly quick if you have bandwidth.

05-03-2020, 10:31 PM	#3
davidfor Grand Sorcerer Posts: 24,905 Karma: 47303824 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	@Cactus Chef: In most cases, updating the metadata in your library shouldn't affect the connection to the books on the Kobo devices. And the KoboTouch driver can update the metadata in the database on the device to match what is in the calibre library. The main issue would be if you need to resend the book to the device, and change the metadata that is used to construct the file name on the device . If the file name or path change, the device will see it as a separate book. The default save template uses the title and author, but, you could be using something else.

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