[Conversion Output] KePub Output Plugin

[SylChamber]

Originally Posted by SylChamber

I just upgraded from 4.2 to 4.3, and again, the KePub* plugins disappeared and won't install. This is annoying. I've never had those problems before, and I've been using Calibre and the Kobo/KePub plugins for years.

This time, I restarted calibre in debug mode so I could post a bug report (I know, I should have done that on the first time). It's available in the menu on the Preferences button > Restart in debug mode.

Then I went to the Plugins section in the preferences to download and reinstall the KePub Output plugin.

This time, no error occured! And all the missing extensions magically reappeared.

As a user I'm relieved, but as a developer myself, I'm frustrated that I can't help debug this. There are no errors in the log, of course.

[theducks]

You may have had a ISP buffered older version of the PI, wich was no longer compatible wit updated Calibre. (Then there is Windows updates where other things just stop functioning until you reboot. to wit: Search the internet PI would 'not' until I rebooted )

[davidfor]

Originally Posted by SylChamber

This time, I restarted calibre in debug mode so I could post a bug report (I know, I should have done that on the first time). It's available in the menu on the Preferences button > Restart in debug mode.

Then I went to the Plugins section in the preferences to download and reinstall the KePub Output plugin.

This time, no error occured! And all the missing extensions magically reappeared.

As a user I'm relieved, but as a developer myself, I'm frustrated that I can't help debug this. There are no errors in the log, of course.

Not as frustrated as we are. This has been happening for several years. The driver disappears or an error is shown. Restarting calibre, or reinstalling the driver and everything is OK. No sign in either case of why.

[JSWolf]

Sly, I think you might be better to use the KoboTouchExtended driver to send KePub to your Kobo.

[koboyedi]

Just one issue on kobo forma: graphics (e.g. cover pages) seem more compressed/distorted when using the plugin, expecially fonts that appear as graphics (e.g. title page right after the cover page). Is there a way to modify the compression level?

[jgoguen]

Originally Posted by koboyedi

Just one issue on kobo forma: graphics (e.g. cover pages) seem more compressed/distorted when using the plugin, expecially fonts that appear as graphics (e.g. title page right after the cover page). Is there a way to modify the compression level?

That's really interesting, this plugin doesnt do anything with graphics. That's entirely delegated to calibre. I'm not sure where to change this, but when you first start calibre for the very first time you're asked to choose a device type. If you chose an older Kobo it may be that calibre is now applying too much compression based on the older device details. I always recommend choosing "General" so no compression or modification is done. But unfortunately I'm not sure where to check or change that

[davidfor]

I'm embarrassed to say that I did not read the thread title properly. I assumed this was in the KoboTouchExtended driver thread. The points I originally mad mostly valid, and I'll leave them. I'll add the only other thing I can think of after them.

Originally Posted by koboyedi

Just one issue on kobo forma: graphics (e.g. cover pages) seem more compressed/distorted when using the plugin, expecially fonts that appear as graphics (e.g. title page right after the cover page). Is there a way to modify the compression level?

When do they look bad? In the book or when displayed as the cover image?

if it is the latter, you might want to try the options to send the cover. The driver generates the cover images directly from the covers in calibre and puts them on the device. Someone who cares about these images did some work last year to improve the quality.

If it is when reading, you need to check the actual code that is wrapping the image. Calibre will update the cover image in the book when sending it to the device. But, it needs to be able to find it, and it doesn't update the code that displays the cover. This means that if you had a low resolution cover in the book, and found a high resolution cover, it might not have been updated or the display options won't be optimal. Both of these can be fixed with the Polish books tool, the Modify ePub plugin, a conversion or using the editor.

Also, it could be the renderer. Epubs and kepubs use different renderers. They give different results when you see the image. The KoboTouchExtended driver doesn't actually touch the covers in the book. The only change it makes is to make sure the device can find the cover when it tries to generate the cover image.


Edit: This is where the output plugin stuff starts.


What output profile do you have? This is on the "Page setup" page of the conversion. The output profile sets the maximum size for images in the converted book. Anything larger will be scaled down. Anything smaller will not be changed. Don't use the Kobo profiles. I recommend using the "Tablet" option. That won't resize the images and will let the device handle them when you are reading. These are the only options that I can think of that affect the quality of the cover. You can change this each time you do a conversion, or via the preferences. That sets the defaults for new conversions.

As you are doing a conversion, the page should be setup correctly for the image size. Personally, for the cover options on the "KEPUB Output" page, I make sure the "No SVG cover" is unselected and select the "Preserve cover aspect ratio". To me those options will work best on my different readers.

[jxall]

After happily using this plugin to convert hundreds of files, I'm having trouble with just one file.

If I convert this ebook (it's a large epub) the resulting kepub causes my Clara HD to freeze for 26 minutes on the 'Processing content' screen, and when the processing finally finishes the ebook won't open. When I tap on the ebook (to open it) I only get a blank screen for three minutes, and then the device auto-reboots.

Please note that if I put on the Kobo the original epub or the kepub produced using Kepubify 3.0 they both work flawlessly: very fast processing time and smooth opening/navigation of the ebook.

The problematic epub is a Bible (50 MB file - Thousands of pages, chapters, footnotes, pictures, maps, etc.)

[jgoguen]

It's likely there's a difference in how we generate our Kobo markup. I'm working on some changes, but with life the way it is for me I can't promise how long that'll take. In the meantime I'd suggest using Kepubify on the large files. If you save them with the .kepub extension you can import them into calibre as KePub format, and if you use the extended driver and set kepub as a higher priority format it's smart enough to not attempt to convert a KePub file again.

[jxall]

Understood, thanks!

Also worth mentioning that I had converted other similar ebooks (50-55 MB - thousands of pages, etc.) using KTE + Kepub Output and they didn't give me the same problem.

Originally Posted by jgoguen

I'd suggest using Kepubify on the large files. If you save them with the .kepub extension you can import them into calibre as KePub format, and if you use the extended driver and set kepub as a higher priority format it's smart enough to not attempt to convert a KePub file again.

That's exactly what I did as a workaround and it works.

[jgoguen]

New version just uploaded, introducing Python 3 compatibility. This version loads in both the released Python2 calibre and the beta Python 3 calibre. It should even function, but it's possible there's code paths not fully exercised.

[jgoguen]

New new version just uploaded, fixing an issue with logging on Windows for non-ASCII characters.

Someone tell Microsoft the 1990s called, they want their non-Unicode nonsense back.

[Youki]

Hello.
Thank you very much for this plugin I have been using for many years.
I have just installed the last version and since I have been unable to convert into kepub. Any idea? Thank you

[bansheeat]

Hello, I am using Calibre 4.15 on Windows 10 64bit and the Kepub Output Plugin 3.2.3 gives me an Error. Also the KoboTouchExtended Driver is not working. I have 2 E Book Readers Kobo Aura HD one with Firmware 3.19.5761 and one with Firmware 4.15.xxxx.
I include the Logfile

[carpegodi]

With the new version of kepub in/out. I cannot convert epubs in kepubs and I can´t open single kepub-files in calibre any longer. Please help and have a look into your software.