Converting AZW3 to Epub

[Lyn2012]

After converting an AZW3 to Epub, the main text is changed from black to red, can anybody suggest why this should happen and how to prevent it? I used Sigil to change the colour back to black but am totally at a loss as to why it happened at all.

Also, both before and after editing the Epub, I am unable to open the book on my Kobo Aura HD with the error message "This document couldn't be opened, there might be a problem with the file". The Aura says "Processing" and gets to 6% before going straight to the Home page.

After changing the coloured text with Sigil I checked the Epub with both FlightCrew and Epubcheck with no errors showing so I am at a loss about this as well. I have previously done this conversion successfully on many occasions and don't know why this should be any different.

Using Calibre version 2.3.0 (also tried 1.8.0) on a Mac running Mountain Lion.

Any help would be much appreciated.

[BetterRed]

@Lyn2012 - is it something your Conversion->Look and Feel Extra CSS settings

BR

[theducks]

Check that you don't have an overly large image.
Recently my PEz would open and shortly close.
Turned out it was 1100x 900 size images (thank you Apple, et al for HiRes images) it the top of each chapter and scene break.

[Lyn2012]

Originally Posted by BetterRed

@Lyn2012 - is it something your Conversion->Look and Feel Extra CSS settings

BR

A good suggestion, thank you. I checked the output settings and realised that I had changed it from Paperwhite to Tablet, (as recommended in another thread on MR), and thought this might be the problem to at least the colour issue. However, on testing after resetting output options, quitting and restarting Calibre, the text has still changed to red. Kobo being unable to open the book remains the same as well.

[Lyn2012]

Originally Posted by theducks

Check that you don't have an overly large image.
Recently my PEz would open and shortly close.
Turned out it was 1100x 900 size images (thank you Apple, et al for HiRes images) it the top of each chapter and scene break.

Another good suggestion. Having checked all 69 jpegs the largest are 427 x 600, 336 x 625 and 604 x 910. I'm assuming these should be fine on a reader with a screen of 1440 x 1080.

Thanks for the suggestion though.

[BetterRed]

@Lyn2012 - the calibre book editor can edit both AZW3 and EPUB; it also has a feature called CSS Live, see ==>> The Live CSS panel

It's helped me identify a couple of long standing 'oddities', maybe you can spot where the Red ink comes from. You may need to adjust Edit->Preferences->Integration with calibre->Ask which format to edit...

BR

[theducks]

Originally Posted by Lyn2012

Another good suggestion. Having checked all 69 jpegs the largest are 427 x 600, 336 x 625 and 604 x 910. I'm assuming these should be fine on a reader with a screen of 1440 x 1080.

Thanks for the suggestion though.

Calibre Book editor has an image tool that can resize. If you ever need to

With that screen.. not likely

[JSWolf]

Don't convert AZW3 (KF8) to ePub. Use the KindleUnpack plugin to shift the KF8 code to ePub. Then use Calibre's Edit book to check the code and fix any errors found. Once it's error free, you'll have an ePub that matches the AZW3 as close as possible. There won't be any changes in the code except for what you have to do to fix any errors. There will be some errors as AZW3 is not 100% the same as ePub but it's close enough and it's not hard to fix things.

[Agama]

Originally Posted by JSWolf

Don't convert AZW3 (KF8) to ePub. Use the KindleUnpack plugin to shift the KF8 code to ePub.

Thanks JSWolf that's a useful option that I hadn't spotted. I've now fixed a few commercial ePubs with errors in their CSS. Is there a corresponding ePub to AZW3 plugin?

[JSWolf]

Originally Posted by Agama

Thanks JSWolf that's a useful option that I hadn't spotted. I've now fixed a few commercial ePubs with errors in their CSS. Is there a corresponding ePub to AZW3 plugin?

The best way to do that for commercial AZW3 is to use KindleGen to generate the combo Mobi/AZW3. If you want to split them out so you have a separate Mobi & AZW3, use the KindleGen plugin for that too. There is also the standalone version of KindleUnpack you can also find on MR that doesn't need Calibre.

[Lyn2012]

I've followed JSWolf's suggestions and used KindleUnpack to convert AZW3 to ePub and then used the Calibre editor (thanks also to BetterRed) to check and edit the ePub. The red text problem is solved but the Aura HD still refuses to open the file giving the same error message: "This document couldn't be opened, there might be a problem with the file". The Aura says "Processing" and gets to 6% before going straight to the Home page.

[JSWolf]

Originally Posted by Lyn2012

I've followed JSWolf's suggestions and used KindleUnpack to convert AZW3 to ePub and then used the Calibre editor (thanks also to BetterRed) to check and edit the ePub. The red text problem is solved but the Aura HD still refuses to open the file giving the same error message: "This document couldn't be opened, there might be a problem with the file". The Aura says "Processing" and gets to 6% before going straight to the Home page.

That is odd. I've never had a problem using KindleUnpack to go from AZW3 > ePub. I use epubcheck 3.0.1 to check for any technical errors, fix them and then the ePub is valid. But one thing I do is all the extra meta tags in the OPF that are leftover from the AZW3 I do delete them. Maybe the Kobo doesn't like them if you've left them in.

[davidfor]

Originally Posted by Lyn2012

I've followed JSWolf's suggestions and used KindleUnpack to convert AZW3 to ePub and then used the Calibre editor (thanks also to BetterRed) to check and edit the ePub. The red text problem is solved but the Aura HD still refuses to open the file giving the same error message: "This document couldn't be opened, there might be a problem with the file". The Aura says "Processing" and gets to 6% before going straight to the Home page.

How many books did you add to the device? What you are seeing with the processing screen is probably right if you only add one book. It always starts at about 6% and if you add a few books, it will show more steps during the processing.

Have you done a check in the calibre editor for errors? The likely problem is that there is a mismatch between the ToC and the actual files or the spine or manifest and the other files. The processing of the files the Kobo devices does checks these are valid, but doesn't necessarily check that what they point to exists. I would hope it does this for the spine and manifest, but I know it doesn't check the destinations for the toc.ncx.

[Lyn2012]

It's completely stumped me. There are no tags present and the book passed all checks (epubcheck 3.0.1, FlightCrew and Calibre) but still won't load properly. I have added, converted and sent to device hundreds of books in exactly the same way without a problem. Looking at the coding it makes me wonder if the book is designed primarily for tablets and something in it doesn't work with e-readers.

I added only the one book to the device, and yes (davidfor), you are correct i that the percent does often jump straight from a low percentage (6%) to the Home screen. However, the book won't open, it just errors when I try.

There were no Tags when I checked the metadata but the only 'error' that showed when running the Calibre editor check wasn't an error as such, just a comment that I could remove the metadata comment if I liked. I removed this comment, let the editor do it for me, saved and tried to load onto the device again (after deleting the previous version from the device). Unfortunately, the result was the same and the book still wouldn't open on the device.

[davidfor]

I think to get any further we would need to see the book. I assume it is copyrighted. Is a preview available somewhere?