A Calibre library with only kepub

[Regard_39]

Hi,
My library has 2000 books. Only 180 are converted via Calibre to kepub.
My 3 children and I each use a Kobo and therefore the Calibre conversion to take advantage of kepub. My wife uses a Kindle.
Recently I struggled to convert a kepub. A Calibre error was preventing me from doing so. Kepubify did not have this problem and got me out of it.

I'm wondering if I should change my entire database and start with a library that has been fully converted to kepub using kepubify.
- the transfer would be much faster and without errors.
- the size would be divided by two?

A) Is there anything I haven't seen?

B) But I don't know if Calibre will be able to process the kepubs and send them to the kindle in mobi format.

C) I prefer to ask the following question: My current library is very rich with tags, series, collections and ratings. Is all this info kept after kepubify conversion?

Here is how I see the procedure:
- streamline my library by deleting the 180 existing kepubs
- launch the batch conversion with kepubify
- delete all epubs

No one seems to manage their library with only kepub. Something seems to escape me... maybe I didn't search enough on the forum

[JSWolf]

Your best solution is to keep all of your eBooks in ePub. You can convert the ones you want to KF8 for your wife's Kindle. You can use the KoboTouchExtended driver to convert your ePub to KePub on the fly when you send them to one of the Kobos.

There's no need to keep KePub in the library. That's why the driver does the conversion on the fly.

[compurandom]

If the KoboTouchExtended driver has problems converting a epub to kepub on the fly, it is a probably a bug and you should report it in the thread for the KoboTouchExtended driver. For convenience until the bug is fixed, you might want to convert it with Kepubify and import the additional format into the same book in calibre.

When transferring small batches of books (assuming it works), generally the on the fly conversion is pretty fast. However, when transferring large numbers of epubs all at once, it can be time consuming. If you do this often, it might be worth converting a significant number of books to kepub (or maybe just large ones), but otherwise, there's not a lot of point, and it's easier to just let the driver do it on the fly.

Calibre is pretty smart, and when multiple book formats are available, it will choose the best one for the device.

[Sirtel]

Originally Posted by JSWolf

Your best solution is to keep all of your eBooks in ePub. You can convert the ones you want to KF8 for your wife's Kindle. You can use the KoboTouchExtended driver to convert your ePub to KePub on the fly when you send them to one of the Kobos.

There's no need to keep KePub in the library. That's why the driver does the conversion on the fly.

Yeah, that's what I do for my Kobos. I've never pre-converted anything, that would waste space. The extended driver does a superb job on the fly and I won't have any kepubs taking space in my library.

As I edit all my books (as in the files, not only metadata), it would be pointless for me to keep my books as kepubs.

[Katsunami]

Originally Posted by Regard_39

I'm wondering if I should change my entire database and start with a library that has been fully converted to kepub using kepubify.

Wrong approach. The best-known format right now is EPUB2; you can basically convert TO it from everything, and FROM it into everything.

Therefore having every book as EPUB2 (base format) + the format you need at the moment is the best approach. My entire library is EPUB2. When I put stuff onto my (old) Kindle from 2012 I convert those books to AZW3, for Kobo I have then auto-converted to KEPUB by the KoboTouchExtended driver, and if I'd ever get a newer Kindle, those books would either convert to AZW3 or KFX.

At some point I remove all the non-EPUB versions from the library, but I never remove the EPUB2 version.

(Same with Music: I have everything in FLAC, but the music for use on my phone is converted to Opus. If I'd use a device somewhere that can only do MP3, I convert the FLAC to that. And if FLAC, as a lossless format, falls out of fashion down the line, I can convert from FLAC into the new de facto default lossless format.)

[davidfor]

Originally Posted by Regard_39

Hi,
My library has 2000 books. Only 180 are converted via Calibre to kepub.
My 3 children and I each use a Kobo and therefore the Calibre conversion to take advantage of kepub. My wife uses a Kindle.
Recently I struggled to convert a kepub. A Calibre error was preventing me from doing so. Kepubify did not have this problem and got me out of it.

As @compurandom said, if there is an error in the conversion report it and we will try to fix it.

I'm wondering if I should change my entire database and start with a library that has been fully converted to kepub using kepubify.
- the transfer would be much faster and without errors.
- the size would be divided by two?

A) Is there anything I haven't seen?

There is no real reason not to do it. A valid kepub is a valid epub. If you want to read it somewhere that only handles epubs, you just change the extension. The difference is extra spans which will have no effect on the formatting. Or if they do, you know that the epub reader you are using should not be used.

B) But I don't know if Calibre will be able to process the kepubs and send them to the kindle in mobi format.

So long as you have the Kepub input plugin installed, calibre can convert from kepub to any other format that it can convert epubs to.

C) I prefer to ask the following question: My current library is very rich with tags, series, collections and ratings. Is all this info kept after kepubify conversion?

If you run kepubify against the epub and put the kepub back in the library as another format for the book, you will not lose anything. You do need to have the Kepub Metadata Reader and Writer plugins installed. These are needed for calibre to update or read the metadata in kepubs.

Here is how I see the procedure:
- streamline my library by deleting the 180 existing kepubs
- launch the batch conversion with kepubify
- delete all epubs

No one seems to manage their library with only kepub. Something seems to escape me... maybe I didn't search enough on the forum

It isn't done because only Kobo ereaders support kepubs. And apart from Kindles, everything else will work with epubs. It makes things simpler if you are using multiple devices or apps to have the epub. And while kepubs are really just epubs with some extra spans, some people think that means they are not real books. About the only thing you can't do with an kepub in calibre is edit it. The calibre editor only allows epubs or AZW3. But, working around that is not very hard.

Personally, I don't think it is worth it. If there are multiple Kobo's being connected to the library, then converting in a batch and storing the kepub will work. And be quicker when you send it to the device. I don't think the space saved is worth worrying about.

[salamanderjuice]

Originally Posted by Katsunami

Wrong approach. The best-known format right now is EPUB2; you can basically convert TO it from everything, and FROM it into everything.

Therefore having every book as EPUB2 (base format) + the format you need at the moment is the best approach. My entire library is EPUB2. When I put stuff onto my (old) Kindle from 2012 I convert those books to AZW3, for Kobo I have then auto-converted to KEPUB by the KoboTouchExtended driver, and if I'd ever get a newer Kindle, those books would either convert to AZW3 or KFX.

At some point I remove all the non-EPUB versions from the library, but I never remove the EPUB2 version.

(Same with Music: I have everything in FLAC, but the music for use on my phone is converted to Opus. If I'd use a device somewhere that can only do MP3, I convert the FLAC to that. And if FLAC, as a lossless format, falls out of fashion down the line, I can convert from FLAC into the new de facto default lossless format.)

EPUB 2 is absolutely NOT the best format. EPUB 3 is a thing and it does offer benefits over 2 even for English books. If you have an Epub 3 and it works on your devices just leave it like that. It's best to just keep books in the original format that you have that supports the most features and works with your tools.

[ZodWallop]

Originally Posted by salamanderjuice

EPUB 2 is absolutely NOT the best format. EPUB 3 is a thing and it does offer benefits over 2 even for English books. If you have an Epub 3 and it works on your devices just leave it like that. It's best to just keep books in the original format that you have that supports the most features and works with your tools.

To be fair, he said 'best-known format', not 'best format'.

[Katsunami]

Originally Posted by salamanderjuice

EPUB 2 is absolutely NOT the best format. EPUB 3 is a thing and it does offer benefits over 2 even for English books. If you have an Epub 3 and it works on your devices just leave it like that. It's best to just keep books in the original format that you have that supports the most features and works with your tools.

Originally Posted by ZodWallop

To be fair, he said 'best-known format', not 'best format'.

Indeed. There may be benefits to EPUB3; at some point, I may convert my entire library to EPUB3. I don't know yet. It is just that EPUB2 is (nowadays) an old format, which has been in use like forever (I never had an EPUB1 book, for example), so I don't see it disappearing soon. EPUB2 will be supported for a LONG time to come, just like (for example) jpg, mp3, and FLAC. Some formats have just become the 'de facto standard' and it's impossible to NOT support them in your application. I think EPUB2 is one of them, and that's the reason why my entire library is EPUB2.

[salamanderjuice]

My point is don't bother converting anything unless you know you'll need it. It's just bad advice IMO to say convert everything to Epub 2 and store it that way. Ebook conversion tools are not perfect, features are easily lost (e.g. converting any AZW3 manga to Epub 2 will essentially break it). IMO just keep the best format you got originally unless it's like DRM locked KFX then keep the next best.

[DNSB]

In my experience, converting epub2 to epub3 offers very little unless you are also planning on editing the epub3 to make use of it's new features. The few times I've needed to do that conversion has been due to a requirement for accessibility features.

For those conversions, I am very thankful for KevinH and his ePub3-itizer and Access-Aide plugins for Sigil which did much of the work for me. Add in much gratitude for Strahinja Val Marković, John Schember, Kevin Hendricks and Doug Massay for their work on Sigil and Kovid Goyal for his work on calibre's ebook-editor.

[Regard_39]

I have to digest this avalanche of information. I realized that my idea was dead end. Also, it seemed to me that by looking at the contents of the folder of each ebook, the metadata.opf file was shared by the epub and the kepub.

I wonder though why the kepub file generated by kobotouchextended does not go into a temporary file. Shouldn't on the fly behave like this? So you have to delete the kepub manually once it is transferred to the e-reader. Maybe there is a setting to delete it automatically.
And do you leave your kepubs or do you delete them?

I did not report the error and unfortunately I could not find on which Kobo e-reader and which ebook I had this failure. Mea culpa.

In fact I discovered by chance kepubify far from home and it helped me a lot. I secretly hoped to find a way to combine the speed performance of kepubify and still enjoy Calibre. Wrong way it seems.
I still have a lot to learn and I thank you all

[JSWolf]

Originally Posted by Katsunami

Indeed. There may be benefits to EPUB3; at some point, I may convert my entire library to EPUB3. I don't know yet. It is just that EPUB2 is (nowadays) an old format, which has been in use like forever (I never had an EPUB1 book, for example), so I don't see it disappearing soon. EPUB2 will be supported for a LONG time to come, just like (for example) jpg, mp3, and FLAC. Some formats have just become the 'de facto standard' and it's impossible to NOT support them in your application. I think EPUB2 is one of them, and that's the reason why my entire library is EPUB2.

The precursor to ePub 2 is the now defunct MS LIT format.

[JSWolf]

Originally Posted by DNSB

In my experience, converting epub2 to epub3 offers very little unless you are also planning on editing the epub3 to make use of it's new features. The few times I've needed to do that conversion has been due to a requirement for accessibility features.

For those conversions, I am very thankful for KevinH and his ePub3-itizer and Access-Aide plugins for Sigil which did much of the work for me. Add in much gratitude for Strahinja Val Marković, John Schember, Kevin Hendricks and Doug Massay for their work on Sigil and Kovid Goyal for his work on calibre's ebook-editor.

Very well said!

[JSWolf]

I do keep the original ePub be it ePub 2 or 3.