Kobo and Footnotes. Again.

[John F]

Originally Posted by Quoth

The DX (and later DXG) was one of Amazon's biggest failures. ...

Be that as it may, the Bezo's quote seems to counter your previous post.

Originally Posted by Quoth

... The Sony, Kindle, Kobo etc never advertised till recently for anything other than straight novels. ...

I Bezo's statement as advertising it for things other then novels.
and I don't consider 2009 as recent (at least in the timespan of eink ereaders).

[Quoth]

Originally Posted by John F

I Bezo's statement as advertising it for things other then novels.

A PR statement that was a lie. Not a regular advert. In fact it only really managed English language novels.
Nor was it marked as a regular ereader like the K2 and k3 (same time as DX and DXG).
But your speciality is nitpicking.

[John F]

Originally Posted by Quoth

...
But your speciality is nitpicking.

Vs your specialty of mixing opinion, facts, and info dumps?

[mramosch]

Originally Posted by DNSB

In playing with audio on my Sage, if I had Bluetooth on and a audio device connected, I could play an audio file in a .kepub.epub file if the format was supported.

Hi Dave,

I am still hoping that you can point me to some epub that plays embedded Audio on your KOBO device, as you confirmed above.

I would really like to cross check it with a new Clara BW because I have tried many different audio formats and bit rates without success.

I also correctly applied the media-type (audio/mpeg or audio/mp4) to the item declaration in the manifest, and all scenarios and tests I conducted were behaving correctly in all apps I’ve tried on iOS including Apple books which usually is very picky in terms of missing manifest declarations. Even the KOBO app on iOS accepted all file formats and manifest declarations…

The embedded audio element appears on the KOBO device in the form of an error message which usually means that the embedded audio player element works but the file format cannot be handled by the reader app.

I tried all mp3 files that are flawlessly played back by the .mp3z hack and also formats that are recommended for SMIL MediaOverlays in the KOBO specs.

So I am really curious what the file format of the files you managed
to play back on your device was.


Maybe you could spare a little time and find those books you successfully played audio with.


Thanks!

— — —

[mramosch]

Originally Posted by Quoth

Even the Android eink are extremely limited. You can run some players on my Android eink and some Android apps. Compatibility is poor and performance OK to abysmal even if it does work.

Hi Quoth,

I was wondering whether you had the chance and time to try the BookFusion app on one of your Android devices?

I would just be curious whether their Android version runs audio MediaOverlays as smoothly as their iOS version does.

If you don’t have an epub with a audio MO at hand I can send you one or point you to one online.

From the moment you open up a chapter that has an audio dub available you should see a play button in the bottom left corner that will start/stop your playback. A long press on the text will open a little context menu that also gives you a start button for starting from the phrase you long pressed on.

Don’t mind the highlighting of the text while reading along, I don’t care about that, just wanna know whether audio works.

I could also send you a file that would show you whether JS interactivity works in case you are not into coding yourself.

[Quoth]

I've spent decades programming. I've retired from that to take up a different occupation. Everything from embedded systems, cross platform desktop (Java) and complex server side programming with Cold Fusion, Oracle DB, Javascript for client side and others.

[mramosch]

Originally Posted by Quoth

I've spent decades programming. I've retired from that to take up a different occupation. Everything from embedded systems, cross platform desktop (Java) and complex server side programming with Cold Fusion, Oracle DB, Javascript for client side and others.

Well, that doesn’t really answer my question whether you already had the time to open some interactive epub in the BookFusion app on your Android device…

…unless you consider opening a book as ‘programming’ :-)

— — —

[PeterT]

Why don 't you just post some sample books and provide guides as to what should happen.

[Quoth]

Originally Posted by mramosch

Well, that doesn’t really answer my question whether you already had the time to open some interactive epub in the BookFusion app on your Android device…

Originally Posted by mramosch

I could also send you a file that would show you whether JS interactivity works in case you are not into coding yourself.

I neglected to say I have tested many ebook app on Androids from 4.x to 13. I'm not interested in testing Bookfusion.

Also I'm not interested in interactive or multimedia content that's supposed to be an ebook.
I also haven't listened to audio books for years, I prefer either to read, or listen to music or watch moving pictures with sound. I've used interactive multimedia encyclopedias and have some. All went out of business due to wikipedia, which in contrast has almost no audio / video / interactive (and all of it is optional, so doesn't interrupt reading).
I once had a company producing interactive media, with artists, musicians, programmers, animators etc.

I like my ebooks to be simple easy to use reflowable (i.e. any size screen, font, linespacing) simply taking sequential text and images that might be in a paper book. I've even reformated a couple of ebooks that used two columns for two letters (which hardly works on paper!) and made the letters chrologically sequential, which was easier to read and works better on paper or ebook.

I wasn't giving more of an explanation because I didn't want to offend and explaining more takes time. I made it clear before that personally I'm not interested in what you are trying to do, and also there is no mass market. It's a niche. Novels and text books come from writers and experts who can barely use wordprocessing properly. Creating an "enhanced title" needs a production / artistic team, like the multimedia titles on CD thirty years ago. Doing the combo text and audio, popups etc is better in an app frameworks and sold in Playstore and Apple store, not distributed as an ebook and hoping the user gets a compatible app. Just because the latest specs for a format have some cool feature doesn't make it the best format to use.

[mramosch]

Just for your information! (2025)

As the discussion here strays pretty far from the original post I’ve forked
a continuation for the original topic at

https://www.mobileread.com/forums/sh...65#post4487365

.

[mramosch]

Originally Posted by jackie_w

I had a look at your sample epub3. I don't think there is anything wrong with the way you've coded your footnotes/endnotes.

The problem is with your NAV/NCX. Kobos (at least for kepubs) are very picky about TOCs. If you stick to the golden rule for NAV/NCX your Kobo reading life will run more smoothly, i.e. make sure that there is a one-to-one relationship between HTML files in the epub and TOC entries in the NAV/NCX.
…
…
…
I've attached an edited version of your sample epub3. Use your normal method of transforming it to kepub and you should see that all the footnotes/endnotes now pop-up as expected.

Originally Posted by enuddleyarbl

I checked your modified file out and every single footnote/endnote worked correctly! Not only did they display in a popup, the popups also ended when they were supposed to (many times, when I got a popup before, the footnote just continued on for some random amount of text (possibly to chapter breaks).

I'm going to have to figure out what to do to change my standard editing process.

Thanks! I'm going to add your information to my issue report on Kobo's github page:

https://github.com/kobolabs/epub-spec/issues/59

In order to learn more about the KOBO footnote/endnote problems I checked the original and Jackie_w’s edited version myself.


I am on a Clara BW with firmware 4.41.23145 (637199291b, 10/29/24)
and it does NOT work entirely correctly.


What does NOT work:

The upstream-references to the footnotes/endnotes DO show a pop-up with the correct text of the respective footnote/endnote, however the backlink from the footnote/endnote back to the reference in the text does ALSO (unexpectedly IMHO) open up a pop-up with a string starting at the exact location where the upstream-link is positioned in the text BUT not stopping until it reaches the next upstream-link in the text.

In case of the last upstream-link (or when there is only one single footnote/endnote in the chapter) the string in the pop-up will continue until the end of the chapter.

The erroneous string will swallow footnotes (or even collectively all endnotes positioned at the end of the chapter - like in your ‘footnotes_at_chapter_end.xhtml’ example) until it reaches the next upstream reference (or end-of-chapter/file).


What DOES work:

The ONLY place where (almost*) everything really works as expected is when you have your endnotes in a different file/chapter like in your ‘footnotes_as_endnotes.xhtml’ example. Here the upstream-links point and navigate correctly to the ‘endnotes.xhtml’ file and the backlinks do NOT force-show a pop-up but go rather straight back to the correct position in the ‘footnotes_as_endnotes.xhtml’ file.

(almost*) -> because the navigation menu opens automatically when linking cross-file, so you have to tap first to get rid of it in order to view the whole page of endnotes.

The only difference in the format of your cross-file upstream-links and back-links is that, instead of pointing to the target id only (#id), they have the file name preceding them (file_name.xhtml#id).

So I added preceding file names to your ‘footnotes_at_chapter_end.xhtml’ backlinks but it didn’t change anything in their wrong behavior, still showing the pop-up with string continuing until reaching the next upstream-link or end-of-chapter/file.


What’s the problem?

The reason that the back-links do not work correctly is because they are positioned within a paragraph.

From some other bug report on the ‘allegedly abandoned’ KOBO GitHub page we know that KOBO suggests a hack, where they want us to insert <div></div> pairs in front of every paragraph with a reference to a footnote and then backlink to the <div> from the actual footnote/endnote.

But that is very problematic for many reasons!

Besides cluttering up the file with dummy elements there is also the problem when your reference is somewhere at the end of a paragraph and therefore probably not on the same page than the start of the paragraph anymore. The backlink will navigate you back to the <div> and not to the place of the actual reference.

Another problem is that when having two or more references per paragraph you need two or more <div></div> pairs but in this case the device causes havoc again and does not work as expected. Although this solution DOES work in their iOS app.

The only hack to solve THIS problem is to put the two <div></div> pairs at the beginning of the paragraph in reversed order, first the pair for the second reference and then the one for the first reference.

But this gets ugly pretty soon so I refrained from figuring out how even more references per paragraph would turn out…



— — —

[mramosch]

.
Can anyone confirm whether this bug was introduced in a newer firmware and actually did work on older devices like Jackie mentioned back in 2023, or if it was just an oversight on his part and it actually didn’t work back then eigther.

[jackie_w]

Originally Posted by mramosch

.
Can anyone confirm whether this bug was introduced in a newer firmware and actually did work on older devices like Jackie mentioned back in 2023, or if it was just an oversight on his part and it actually didn’t work back then eigther.

Firstly, I'm a she, not a he.

I can't be sure but I suspect the back-link has always worked this way, i.e. gives an unwanted pop-up on the back-link if the original text and the footnote are in the same file. It may be that most people (including me ) never noticed because either:

• they usually only read the pop-up text and rarely press the [See more] button to see the actual fully styled footnote/endnote.
• they *do* press [See more] but don't press the back-link to go back because if the scrubber pane is opened (or already open) at the bottom of the screen it has a [Back to page n] button which they press instead.

I don't think there's any way to guarantee that pop-up footnotes/endnotes work "perfectly" for any definition of "perfect". All you can do is give yourself the best chance of them working "well enough". I don't know whether non-Kobo ereaders are more foolproof or whether every brand has it's own arcane "rules".

Other Kobo quirks I've seen are:

• Pop-ups may not work if your id="..." attributes contain characters other than [a-z][0-9], i.e. avoid dots, hyphens, underscores.
• If your Endnotes page also includes a chapter sub-heading before each group of endnotes for that chapter, don't be surprised if the pop-up text for the last endnote of a chapter also appends the text of the chapter sub-heading following it.

[mramosch]

.

Originally Posted by jackie_w

Firstly, I'm a she, not a he.

Sorry for that but your profile says ‘Grand Sorcerer’ and not ‘Grand Witch’ ;-)

Originally Posted by jackie_w

I don't think there's any way to guarantee that pop-up footnotes/endnotes work "perfectly" for any definition of "perfect". All you can do is give yourself the best chance of them working "well enough". I don't know whether non-Kobo ereaders are more foolproof or whether every brand has it's own arcane "rules".

All links, note-refs, footnotes, endnotes do work perfectly on every other device (beside KOBO devices) or app I have tested so far.

The problem starts because KOBO’s implementation of footnotes is based on some assumptions (that you can read about in the second post of the GitHub issue#32 by bdugas) and the subsequent hack they have to apply in order to get out of their own trap.

https://github.com/kobolabs/epub-spec/issues/32


But the main problem that I encountered is that KOBO under certain circumstances shows different behavior for ‘exactly’ identically formatted backlinks with regards to the pop-up appearing (or not).

But after several days of trying to get to the bottom of the problem I found the bug and I am now able to also create 100% ‘perfect’ backlinks even without inserting KOBO’s recommended <div> dummy element hack in front of the paragraph the link is in.

There is only one thing that I can’t check that could still be a potential source for a failing backlink, and that is the scenario where the ‘working’ file I have produced is virginly loaded onto a new device that hadn’t had another (non-working) version of the same file loaded before.

My assumption is that KOBO does some indexing and caching of footnotes, note-refs and backlinks that somehow survives even if a file is deleted and a new version with a different file name is loaded onto the same device. Maybe the cached data is bound to some meta data that is the same in the old and the new file.

I haven’t had the time yet to test this with the provided ‘MySampleBook’ from this thread but I will attach another book that had the same issues to this post and maybe you could check whether the 5 footnotes in the first chapter of the book (Estrofa primera) do work correctly.

Forward links with pop-up and backlinks without pop-ups!

If this works even on a fresh install of the book, you can then try to load the non-working version of the same book which I have attached to post #2 in the forked out thread.

The forked out thread deals with the inconsistency of behavior for multiple occurrences of ‘exactly’ identically formatted backlinks which was originally not part of the backlink bug of this thread, but is an extended variation of it. Here the link to the forked thread:

https://www.mobileread.com/forums/sh...65#post4487365

At the very end of this post you can read what the wrong behavior of the backlinks is actually doing wrong.

On my Clara BW I get a 100% consistent (correct/incorrect) behavior of the respective (working/erroneous) file, but of course I had several incorrect versions loaded first and maybe they messed up the alleged indexing/caching of the KOBO.

So there is a slight chance that my working version only works because there was a non-working version on the device before, so please:

• load the working version first onto your device and check for correct backlinks and only then load and test the non-working version.

If they both behave according to my description then we do have 100% workaround for the backlink bug.

Hope to hear from you soon!


Bye for now.


—

Bye the way, mind!

On my device I have to tap the backlinks on the very top of the anchor text (when they are shown on subsequent lines). Tapping below (roughly) the middle of the text will trigger the link of the following line.

And if the size of the font is relatively small sometimes you can’t even trigger some of the backlinks because the previous and following links are overlapping from above and below and render the link in the middle inaccessible.

Another bug in KOBO kepub files only…


—

[John F]

Originally Posted by mramosch

.


Sorry for that but your profile says ‘Grand Sorcerer’ and not ‘Grand Witch’ ;-)
...

Doing a quick google, men can witches. Maybe Sorceress?