[Conversion Output] KFX Output

[skinnybirch]

I'm not able to convert the ePUB BasisBibel: Die Komfortable (scrambled file attached) to KFX in Calibre. No issues with other ePUB files. It times out after 15 minutes/at 67% in Kindle Previewer without an error message when both "Enable conversion timeout" and "Show full Kindle Previewer conversion logs" are checked in KFX Output. Calibre and all plugins are up to date.

Thank you for your help!

[HowlerX]

Originally Posted by jhowell

I had some time to test this and I can confirm that this is the case.

In order to get Assistive Reader to work with sideloaded books they must be created with CDETYPE=EBOK which mimics a book purchased or borrowed from Amazon. See the Usage section in the first post of this thread for instructions on how to do that when converting to KFX format.

Yes, I can confirm this now. I thought that was the case at first. So I tried both scenarios, EBOK and PDOC of the same novel. I believe my problem arose because I didn't delete the PDOC version properly, I just overwrote the PDOC kfx with the EBOK kfx and I couldn't get Assistive Reader working. Deleting and then uploading the EBOK kfx version fixes the problem. Thanks for all your efforts.
--Howler

[jhowell]

Originally Posted by skinnybirch

I'm not able to convert the ePUB BasisBibel: Die Komfortable (scrambled file attached) to KFX in Calibre. No issues with other ePUB files. It times out after 15 minutes/at 67% in Kindle Previewer without an error message when both "Enable conversion timeout" and "Show full Kindle Previewer conversion logs" are checked in KFX Output. Calibre and all plugins are up to date.

Disable the conversion timeout and try it again. Very large books like that one can take several hours to convert.

If that does not work you can break up the book into smaller pieces using the EpubSplit plugin and then convert each one individually.


Added: I was able to convert the scrambled EPUB to KFX on my PC. It took almost six hours to complete.

[PeterT]

Many bibles are problematic to calibre (and eReaders).

[skinnybirch]

Originally Posted by jhowell

Disable the conversion timeout and try it again. Very large books like that one can take several hours to convert.

[...]

Added: I was able to convert the scrambled EPUB to KFX on my PC. It took almost six hours to complete.

Oops, I had no idea a conversion could take that long! I set it to run overnight, and the log showed a runtime of 6 hours and 45 minutes. Thank you so much.

[jhowell]

Version 2.18.0 - 12 Oct 2025

Detect Kindle Previewer versions up to 3.98.0.

Remove special handling for Hebrew (he) and Persian (fa) languages when Kindle Previewer version 3.98.0 or later is installed since those languages are now supported by Amazon. (Kindle firmware 5.18.5 or later is required for proper handling of the resulting books.)

[oldmoto]

my kindle colorsoft 5.18.5.0.1 can't dedrm ,is kfx-zip,how can I do

[jhowell]

Originally Posted by oldmoto

my kindle colorsoft 5.18.5.0.1 can't dedrm ,is kfx-zip,how can I do

You currently cannot remove DRM from a book downloaded to a non-Scribe Kindle running firmware 5.18.5 or later. For other options see the thread Dealing with Kindle ebooks in calibre.

[JSWolf]

Originally Posted by oldmoto

my kindle colorsoft 5.18.5.0.1 can't dedrm ,is kfx-zip,how can I do

And even if you jailbreak, it's possible you cannot rollback to an older firmware.

[rzsolti]

Hi, i have come across an issue.
If I set to create ebok instead of a pdoc in the settings-conversion-output, it doesn't apply, when calibre auto converts a book.

[jhowell]

Originally Posted by rzsolti

Hi, i have come across an issue.
If I set to create ebok instead of a pdoc in the settings-conversion-output, it doesn't apply, when calibre auto converts a book.

Conversion by calibre can be tricky. When you change a default conversion option it does not apply to any books that have been previously converted. Those books retain the same conversion options that were in effect the last time they were converted. So if any of the books you are sending have converted previously, including conversion when previously sent, the option to produce a book or personal document that was in effect at that time will continue to be used for those books.

See the section How options are set/saved for conversion in the calibre documentation for more details including how to discard the saved conversion options and revert to the current default settings.

[tomsem]

Originally Posted by rzsolti

Hi, i have come across an issue.
If I set to create ebok instead of a pdoc in the settings-conversion-output, it doesn't apply, when calibre auto converts a book.

That option is only for MOBI and has no effect in my experience. Maybe it does something for Mobi 7 but that's not read by any Kindles since Kindle 2/DX. You need to choose Enable Sharing option to generate PDOC (Document) instead of EBOK (Book), or better, convert to AZW3 (again with Enable Sharing) or KFX, where PDOC is default.

MOBI is roughly twice the size of AZW3 because it contains the legacy mobi format as well as mobi 8.

[jhowell]

Originally Posted by tomsem

That option is only for MOBI and has no effect in my experience.

Since the question was posted in this thread I assume that it was in regard to producing KFX format.

For conversion to KFX the type of file produced is controlled by the option "Create book (EBOK) instead of personal document (PDOC)" in the KFX Output tab of the conversion dialog. The default for future conversions can be set in the KFX Output tab under Preferences, Output options.

[rzsolti]

Originally Posted by jhowell

it does not apply to any books that have been previously converted.

I get that.

Let me rephrase the issue: in the settings menu (conversion, output) i have set the option to create ebok, instead of pdoc. Than, also set, that when calibre sends a book to my kindle, it must be in kfx.
The issue is, that even fresh converts are showing up as documents.
If I manually convert a book (chose the convert action from zhe toolbar), and select the kfx output, and open the ffy convert settings in that dialogue, the ebok option is not enabled. Once enabled, it works like a charm.

So, it seems to me, that the actual conversion process does not respect the preference set in the main settings dialogue, only the one, set in a conversion dialogue

[jhowell]

Originally Posted by rzsolti

Let me rephrase the issue: in the settings menu (conversion, output) i have set the option to create ebok, instead of pdoc. Than, also set, that when calibre sends a book to my kindle, it must be in kfx.

OK.

Originally Posted by rzsolti

The issue is, that even fresh converts are showing up as documents.

That does not happen when I try it on a book freshly added to calibre.

Originally Posted by rzsolti

If I manually convert a book (chose the convert action from zhe toolbar), and select the kfx output, and open the ffy convert settings in that dialogue, the ebok option is not enabled. Once enabled, it works like a charm.

If the setting does not match the current default then that indicates the book in question was converted sometime previously and the conversion settings for that book were locked in at that time. You can press the "Restore defaults" button at the bottom of the conversion dialog to discard the settings from prior conversions.

Originally Posted by rzsolti

So, it seems to me, that the actual conversion process does not respect the preference set in the main settings dialogue, only the one, set in a conversion dialogue

It only respects the default preference if that particular book has never been previously converted.