Page number mapping in EPUBs?

[epubmystery]

I recently sent an EPUB from Calibre to my Kindle via email, and the book had page number support out of the box (both on the Kindle, and on the app on Android). It wasn't something that Calibre did; I verified by uploading to Kindle straight from my phone, and the page numbers were still there.

However, I'm not seeing this with every EPUB. I've compared 2 EPUBS (one which had out of the box page number support and which doesn't) and I've been unable to figure out what exactly it is in the EPUB that provides this support. I've compared the `toc.ncx` and `content.opf` files, but haven't seen anything that would indicate page numbers. Any ideas?

Happy to upload both EPUBs here, but not sure what the forum rules are around that.

[Turtle91]

Did the ones with page counts have a "page-map" file in the ePub??

[epubmystery]

Originally Posted by Turtle91

Did the ones with page counts have a "page-map" file in the ePub??

Nope, no "page-map" files either. The only thing I've seen is `<div class="mbppagebreak" id="calibre_pb_4"></div>` on the content files. But these content files are split by chapter, so it doesn't seem like this would say anything about page numbers.

[Turtle91]

I would suggest using a “Borkify” plugin to scramble the words of the ePubs, then post it here. I know Sigil has that plugin and I’m 98.7% sure Calibre does too. That way we can take a look under the hood.

[JSWolf]

Originally Posted by Turtle91

I would suggest using a “Borkify” plugin to scramble the words of the ePubs, then post it here. I know Sigil has that plugin and I’m 98.7% sure Calibre does too. That way we can take a look under the hood.

The calibre plugin to scramble eBooks is ScrambleEbook.

[epubmystery]

Apologies for the delay, and thank you for the replies! I've used ScrambleEbook, hopefully there's something in the EPUBs that can point us in the right direction.

Can't upload stuff directly here, so you can find the scrambled EPUBs here: https://limewire.com/d/mAlQW#QJXYwWnRQ3

Thanks!

[KevinH]

These are both epub2 epubs with no page maps and no page section in the ncx.

There are no real page numbers indexed in either book. There are calibre mpagebreaks in at least one of them. So if they were based on real page numbers in a valid printed edition then you could create a real page map if you so desired.

But I think you are confusing real page numbering maps with e-reader/calibre generated fake page numbers. Many e-readers, calibre included, can generate "pages" based on fixed word or letter counts to help people see reading progress but that are not at all related to real page numbers in a published edition of the book.

I thought you somehow had either an ADE pagemap.xml, or an ncx page section or a nav pagelist (if it was an epub3) that specifies the exact page breaks that match a specific published printed edition. These are actually used for academic citations. But rare in general fiction.

[epubmystery]

Many e-readers, calibre included, can generate "pages" based on fixed word or letter counts to help people see reading progress but that are not at all related to real page numbers in a published edition of the book.

Thanks for taking a look!

So it sounds like the Kindle is somehow generating these "page" numbers. I've never seen that before, but it would make sense.

I'm not sure how to investigate the conversion between the EPUB and KFX so I guess that's that. It would be nice to figure out what exactly tells the Kindle to generate page numbers for one EPUB but not the other.

[Turtle91]

I don’t play with Kindle much, but other apps have options that can be set for each book, not just the entire app???

[KevinH]

Fwiw, Kindles used to keep their page maps as separate files (.apnx) that is not part of the epub.

KindleUnpack has the ability to create an adobe pagemap.xml file from a separate apnx file associated with kindle files in .kf8 format.

I have no idea how the KFX file format stores page numbers. Perhaps jhowell knows. He created the kfx to epub output converter that calibre uses.

[jhowell]

Originally Posted by KevinH

I have no idea how the KFX file format stores page numbers. Perhaps jhowell knows. He created the kfx to epub output converter that calibre uses.

In KFX format page numbers are stored internally as part of the book navigation data along with the table of contents and guide data, instead of in a separate file.

Originally Posted by epubmystery

Apologies for the delay, and thank you for the replies! I've used ScrambleEbook, hopefully there's something in the EPUBs that can point us in the right direction.

I used the send-to-kindle web page to send both of the "page numbers" and "no page numbers" book samples you provided and neither results in page numbers being present in the resulting book on my Kindle device. It is possible that whatever content makes page numbers appear for you may have been stripped out in the scrambling process.

[epubmystery]

I used the send-to-kindle web page to send both of the "page numbers" and "no page numbers" book samples you provided and neither results in page numbers being present in the resulting book on my Kindle device.

Interesting. I just double checked, and I was able to get page numbers working by both:

1. using the send-to-kindle web page, and
2. uploading to the kindle app from my android phone (you can do this by downloading the epub and "sharing" with the kindle app)

I confirmed that page numbers show up both on the Kindle device and the Kindle app on Android. I wonder if I'm in some A/B test by Amazon