Calibre Metadata Editing

[Tushar Mehta]

Metadata editing in Calibre does not change the metadata at file level.
It seems that the editing remains at level of Calibre library level.
This means:
After editing the metadata in Calibre, if the epub file is copied at some other place and re loaded in Calibre, the file turns out to be devoid of any edited changes in metadata.

This characteristic is not mentioned anywhere in documentation.

It would be highly desirable if the edited data remains permanently remains embedded in file or Calibre gives option for either way.

- Tushar Mehta.

[VydorScope]

No, that is not correct. At least when I look in the actual EPUB file it out puts I can see the meta data in the file.

[Turtle91]

The OP is correct. The meta data is not updated to the ePub unless the user does something to incorporate it...it is not automatic.
You either need to select Save to Disk, or use the new book polishing to update metadata.

I have to admit I haven't used the new book polishing yet, so I'm not sure if that has the option of being done automatically??

[VydorScope]

All I know is I see this:

  <metadata xmlns:calibre="http://calibre.kovidgoyal.net/2009/metadata" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:opf="http://www.idpf.org/2007/opf" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <dc:publisher>Vincent Trigili</dc:publisher>
    <dc:language>en</dc:language>
    <dc:creator opf:file-as="Trigili, Vincent" opf:role="aut">Vincent Trigili</dc:creator>
    <dc:title>The First Quartet</dc:title>
    <meta content="cover" name="cover" />
    <dc:date>2013-04-25T04:00:00+00:00</dc:date>
    <dc:identifier id="uuid_id" opf:scheme="uuid">160df120-4549-4348-8680-b49d2d1fa6f0</dc:identifier>
    <dc:identifier opf:scheme="calibre">160df120-4549-4348-8680-b49d2d1fa6f0</dc:identifier>
    <dc:date opf:event="modification">2013-04-28</dc:date>
  </metadata>

And other stuff like it in the EPUB that I did not put there, and Calibre did. So I disagree that Calibre does not add meta data to the files. Publisher, language, etc. I ONLY set that in Calibre.

[Dr. Drib]

This thread by the OP has been moved to the calibre forum, since it has nothing whatsoever to do with the Writing Forum.


Don
(Moderator)

[theducks]

<dc:date opf:event="modification">2013-04-28</dc:date>

This line says you did something on 4/28 that modified the original book of

<dc:date>2013-04-25T04:00:00+00:00</dc:date>

Modify EPUB PI might do this, Quality Check PI: Fix might do this.
Copying a Book BACK from a device might

[VydorScope]

Yeah, I was in Sigil cleaning out tags that Calibre put in And re-running Flight check. I only grab that section cause i did not keep the pre-clean file which had Calibre specifci tags in it that were label "Calibre". The point is I only, ONLY, put that meta data in Calibre, no place else. The Flight could not add those fields because Sigil and Flight check did not know that data. ONLY Calibre did.

[Adoby]

Most changes to metadata in calibre are only written to metadata.db.

When books are saved to device or to a folder outside calibre, the metadata in the book is written to the book, to the extent that the file format has support for the metadata. Polish, conversions and some plugins to update the books also cause metadata to be written to the books.

You can easily confirm this by changing some metadata for a book (other than title and authors) and check that the book has not been changed.

There are numerous warnings about not looking up the skirts of calibre, including sticky threads. You are NOT supposed to directly access books inside the calibre library, unless you know what you are doing and why. If you don't know about the "lazy update" of metadata then you obviously shouldn't peek inside the calibre library file structure.

The reason for the lazy updates is (I assume) that it makes calibre MUCH faster, both when it comes to searches based on metadata and when it comes to changing the metadata.

But it also makes it possible to corrupt the calibre library if you makes changes to the books stored in the calibre library, without using calibre.

[DoctorOhh]

Originally Posted by Tushar Mehta

Metadata editing in Calibre does not change the metadata at file level. It seems that the editing remains at level of Calibre library level.

This is true.

Originally Posted by Tushar Mehta

This means:
After editing the metadata in Calibre, if the epub file is copied at some other place and re loaded in Calibre, the file turns out to be devoid of any edited changes in metadata.

The problem here is you used the OS file manager to copy the epub from the calibre library. Calibre provides multiple ways to export epubs from the library. Every one of these methods will update the metadata as the ePub is exported. Ways to export include Save to disk, Send to device, email, and the Content server.

Originally Posted by Tushar Mehta

It would be highly desirable if the edited data remains permanently remains embedded in file or Calibre gives option for either way.

If you use calibre to control your books you don't ever have to worry about it. When you start using other programs to manipulate the books you run into problems. You can embed the metadata into the ePub while it is in the library by using either the Polish Books feature or the Modify ePub plugin.

[BetterRed]

This issue seems to arise very frequently, perhaps more any other "common" issue.

Now that Polish exists I wonder of a preference could be added to do a 'quiet' Polish on a book's ePUB and/or AZW3 immediately after metadata updates.

By 'quiet' I mean no dialogue, use whatever was used last time Polish was used stand-alone, or give Polish a configuration option to set up default settings for 'quiet' polishing.

BR