Kobalt: an alternative reader app for Kobo devices

[fogice]

Originally Posted by MrSilverstrike

The battery currently only shows when you bring up the menu

Ah, OK. I also noticed that the font size for the clock and the battery percentage are different sizes.

[JSWolf]

Originally Posted by mrmikey

And bionic reading is off, I've tried turning it on, reloading the book and then turning it off, same result.

Bionic reading is a sham. It doesn't work, It just makes it harder to read. If you have a plugin for bionic reading, uninstall it.

As for your capitalization problem, take the ePub that exhibits this problem and use the ScrambleEbook plugin with calibre to scramble the eBook. Then try it on your Kobo and if it still has the same problem, attach it here.

[JSWolf]

Originally Posted by MrSilverstrike

It's surprisingly easy to accidentally turn on bionic reading in Calibre

Where is this option in calibre to turn on bionic reading? I've never seen it.

[Apollyon202]

There’s no evidence that bionic fonts make reading faster. The same applies to KOReader’s perception expander. Although if it creates a positive placebo effect and makes a lad read more, then it’s a win.

[fogice]

Originally Posted by JSWolf

Where is this option in calibre to turn on bionic reading? I've never seen it.

I think he meant to say "in Kobalt", because it does exist there.

[jackie_w]

@MrSilverstrike,

Well, this is off to a promising start. I've installed it on an old AuraOne running the latest fw 4.38.23828. Some feedback after a short time using it...

• Problem. Any CSS style which contains font-family:sans-serif doesn't appear to display as sans-serif. At first I thought the same was true of CSS font-family:monospace but I did get that to work OK by selecting Publisher default in the [Aa] menu. Unfortunately it didn't also fix the sans-serif problem. Any ideas?
  
• Suggestion. The option to set a default font for serif is fairly standard in most apps but very few seem to offer the option to additionally set a default sans-serif font and a default monospace font. KOReader is the only app I've used which does have this feature. Might this be a future possibility?
  
• Problem. After setting the brightness level it seems to reset itself down to 5% within a very short time. Is there an option to choose the length of time before this happens?
  
• Suggestion. When using GUI options which need to page through a long list (e.g. TOC Chapters), once you arrive at the last page then, to get back to the first page you have to reverse-page all the way back again. Nickel cycles around from last page to first (or first to last) in one step. I've appreciated this a lot over the years.
  
• On the plus side, I'm pleased to say that font-variant:small-caps and pseudo-selectors ::first-letter and ::first-line seem to work very well in standard epubs.
  
• I like how you've only changed the reading app and left Nickel to handle the main GUI (booklists etc.)

[mrmikey]

Where is this option in calibre to turn on bionic reading? I've never seen it

Neither have I, and I was looking big time.

[DNSB]

Originally Posted by mrmikey

Neither have I, and I was looking big time.

If you have the EBook Metaguider (intellireading) plugin installed, it give you an option to enable bionic reading for ePub/kepub files. The KoboTouch - Metaguide Driver (intellireading) gives you the option of adding the bionic reading bolding to a ePub as it is being transferred to your Kobo ereader.

My personal recommendation is to uninstall those plugins as no repeatable tests have shown any benefit and most people consider the bolding to be an objectionable distraction.

[Lukusaukko]

Is there a manual install? It looks like it needs a Chromium-based browser, but there isn't one installed on my system, and I'm unlikely to install one just for this.

EDIT: never mind, found the instructions on Github.

[JSWolf]

Originally Posted by MrSilverstrike

It's surprisingly easy to accidentally turn on bionic reading in Calibre

If you meant Kobalt, then please do everyone a favor and remove the code for bionic reading. Thanks.

[Dal Bhat]

Using either Kobalt or the native reader on my pretty new Clara BW, I find that the number of pages per book is really inflated. At least compared to how many pages are reported by Calibre for the same file.

For example, the page count for a book in Calibre is 364. In Kobalt it is 856. In the Kobo reader it is 1006.

The reading is fine; but the page counts are weird. Is this addressable?

[Sirtel]

Originally Posted by Dal Bhat

Using either Kobalt or the native reader on my pretty new Clara BW, I find that the number of pages per book is really inflated. At least compared to how many pages are reported by Calibre for the same file.

For example, the page count for a book in Calibre is 364. In Kobalt it is 856. In the Kobo reader it is 1006.

The reading is fine; but the page counts are weird. Is this addressable?

Do you read kepubs? Kepubs use one screen=one page. Epubs use the Adobe system. And Calibre uses its own system. It's best not to take any page count too seriously.

[DNSB]

My personal opinion on page counts for reflowable ebooks is that they exist purely to tickle my sense of humour. If you stick to one counting method, you can get an approximate idea of the length of a book compared to another book but that is about all they are useful for. Word counts are more consistent.

The issue is how the page counts are calculated.

Kobo kepubs for example use 1 page per screen which means that font size, margins, line height, etc. change the page count.

Adobe's synthetic page count algorithm is based on the compressed size of the ePub and is generated by determining a compressed byte length of each resource which is referenced in the spine, subtracting any known encryption overhead (IV (initialization vector) size for instance). It is then assumed that there is a page for each 1024 bytes in each resource, rounding up to the nearest whole number of pages for each resource. This has some sensitivity to the zip storage compression levels. However it does have the advantage that is is not affected by font size, margins, etc. though you will get pages that take 3 or more screens to display and other pages that take less than a screen to display. The results if you run into one of those rare ePubs that use Base64 encoded images are unuseful.

Other systems such as the one used by calibre use their own algorithm to calculate the number of pages.

You will also run into books that use either Adobe's old page-map or the ePub3 page-list which tie an ePub to the pages in a specific physical book. Somewhat useful but you need to realize that almost every physical edition has a different page count depending on the book's physical dimensions (hard cover, trade paperback, MMPB, etc.), font size, line spacing, margins, etc. I've run into several hardcover textbooks where the page numbers differ between the same edition but different printing years due to layout changes, error corrections and whatever else the publisher/printer has done.

[MrSilverstrike]

Thank you for the feedback everyone, I'm hard at work at sorting out the issues everyone has been reporting here and on GitHub.

I specifically appreciate the very precise feedback by jackie_w; all of your remarks are being addressed. Publisher fonts will fall back correctly and I enjoyed the UX suggestion, this should all be present in beta 3 when it releases later this week.

I've also made serious performance improvements, especially on newer devices where faster high quality refreshes are now used for the UI. That means less flickering!

About bionic reading: it is getting renamed to "Bold reading" because apparently there's a trademark situation I don't want to get in trouble with. I generally agree that it doesn't really help (I don't personally care for it!) yet it's been a surprisingly popular request!

Stay tuned for the next beta...

RE: page numbers; couldn't have said it better than DNSB here! It's a super inconsistent system because it basically depends on how books are laid out in print or digitally and as such those tend to vary.

[PeterT]

Installed on my Libra H2O. I will admit to being impressed. One mi ir suggestion, any chance of the UI following the Kobo's Beta Features Large Print Mode / Font Scale settings? Especially for the menu of options displayed at the bottom (Chapters / Text / Layout etc)

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