Glo Side-loaded fonts decay

[ShellShock]

Yes if you rename it as *.kepub.epub it will be treated as a kepub and italics will work for "broken" fonts like Kobo Nickel. You do not need to change any meta data in the epub, just rename it. I think there is a Calibre plug-in which does this too.

But kepubs are displayed with a title bar that takes up too much space, in my opinion, so I do not use kepubs.

I agree "optimal" is just a weazel word, rather than admit there is a bug.

[DNSB]

Originally Posted by roger64

Thanks for your comments.

I have a question: If I rename the epub as kepub and tweak some metadata, will it work properly at last?

Interesting statement from Kobo:



optimal seems to have a strange meaning in Canada...

Do they expect customers to believe that kepubs are an enhanced sort of epub, and, for this reason, they keep some artificial hurdles specially for epubs... ?

The italics displaying as bold issue does not seem to be an issue when using the kepub (ACCESS?) rendering engine. There are other issues with differences between how the two rendering engines work. The majority of the hurdles for epubs seem to be common to any device using the Adobe Reader Mobile code. The hurdles for kepub files are unique to Kobo.

The rendering engine for kepubs is enhanced in several ways with support for quite a few EPUB3 directives. Try displaying Hebrew, Arabic, Japanese, etc. as an .epub and on as a .kepub.epub. Take a wild guess as to which one you will want to use.

There is a Calibre add-on to allow automating the tweaking of epubs and saving them on the Kobo as .kepub.epub. It addresses some of the issues such as cover images but does not add the <span id="kobo.x.x">tags used to track each paragraph in a file nor does it address the stylesheet changes needed to compensate for differences between the rendering engines.

The freebie Great Expectations kepub file from my Glo looks rather different when renamed as .epub and viewed on the Glo or copied to my laptop and viewed using ADE.

As for the font issue, I've found a font that supports the characters I need and has a nice weight and use that for pretty much all my reading. My only other need was a monospaced font on hand for special purposes such as computer output display. Now, that is a font that I feel should have been supplied by Kobo. I feel no real need to have my ebooks look like ransom notes. I've been there and read that during the early days of the Macintosh when there seemed to a competition to see how many fonts you could use in a single page letter. Then there was writing programs in PostScript to display text in a spiral on the page for those who wanted to be really different. Don Lancaster had much to answer for.

Regards,
David

[DNSB]

Originally Posted by roger64

The fonts are the one I downloaded from official site. I did not modify anything inside. I just changed the suffix according to Kobo requests. Here is a joint example of one, initially perfectly good and which turned sour.

I think this problem could be repeated. Try it, wait some days, and try it again.

What official site did you download those fonts from? The only official fonts are part of the Kobo firmware and I am unaware of a download site for them.

As for the fonts in the .zip file you supplied, they are not going to work on a Kobo even when copied into the fonts folder in the root of the internal storage. Please check the information in the modified fonts sticky about font naming. Your Linux Libertine font shows a font family name of the Linux Libertine O and that MUST be the first part of the font file name.

If you change the font file names as follows:

  old name                              new name
LinLibertine_RI.otf             Linux Libertine O-Italic.otf
LinLibertine-Bold.otf           Linux Libertine O-Bold.otf
LinLibertine_BoldItalic.otf     Linux Libertine O-BoldItalic.otf
LinLibertine-Regular.otf        Linux Libertine O-Regular.otf

then you have a hope of getting this font to work for you. If the font file names are not correct, your Kobo will select a font for you.

My font tester files worked after the files were renamed, copied into the fonts directory and the ereader power cycled (pinhole reset works as well).

Personally I find the font too lightweight for comfortable long term reading but à chacun son goût.

Regards,
David

[davidfor]

Originally Posted by DNSB

There is a Calibre add-on to allow automating the tweaking of epubs and saving them on the Kobo as .kepub.epub. It addresses some of the issues such as cover images but does not add the <span id="kobo.x.x">tags used to track each paragraph in a file nor does it address the stylesheet changes needed to compensate for differences between the rendering engines.

The extended plugin does add the span and ids. The tracking doesn't work in all books, as it seems a javascript and extra stylesheet is needed. These weren't included due to copyright, but I think they found a way around this.

[DNSB]

Originally Posted by davidfor

The extended plugin does add the span and ids. The tracking doesn't work in all books, as it seems a javascript and extra stylesheet is needed. These weren't included due to copyright, but I think they found a way around this.

I'll have to give it a try again. It was a while back when I last tried it and I didn't really see any benefits for my reading style in using .kepub. It'll be worth trying again since I am somewhat involved in a project to convert some ebooks for use on the Kobo ereaders.

Regards,
David

[roger64]

@DNSB

Thanks for your help. I did two mistakes while renaming four files which is indeed not very brilliant... Now it's OK.

But, if each ebook dealer requested like Kobo to use special naming conventions for fonts, what a mess! As a new Kobo user, I am still very surprised by these - ... - requirements.

Chacun son goût, of course. I like reading with Linux Libertine and dislike to read with over-weighted fonts. I understand very well that others make other choices.

When I was speaking about "official" source for Linux Libertine, I only thought about their own site, not about Kobo. I should have precised it. I meant to say that it was not any kind of custom-built subset font, western languages only for example, or something like that. It was the REAL thing, straight from the horse's mouth.

Thanks again.

[taming]

Originally Posted by roger64

But, if each ebook dealer requested like Kobo to use special naming conventions for fonts, what a mess! As a new Kobo user, I am still very surprised by these - ... - requirements.

Anytime I copy a font from my Windows font folder onto the device it works (assuming I have all the variants). It always seemed to me that Kobo's naming conventions were pretty ordinary.

[DNSB]

Originally Posted by roger64

@DNSB

Thanks for your help. I did two mistakes while renaming four files which is indeed not very brilliant... Now it's OK.

But, if each ebook dealer requested like Kobo to use special naming conventions for fonts, what a mess! As a new Kobo user, I am still very surprised by these - ... - requirements.

The explanation from one Kobo developer was that QT does not allow easy instrospection of font files. Rather than spending the developer time on working around this issue, they went with a simple naming convention where the font family name is followed the font style/weight.

Given that this is a restriction only when adding your own fonts to a Kobo ereader, it does not strike me as overly onerous.

And I do like Linux Libertine for it's glyph support. I prefer the weight of Charis SIL for reading but at least another font to choose when you get tired of seeing diacriticals rendered as blank boxes.

Regards,
David

[roger64]

Originally Posted by DNSB

Given that this is a restriction only when adding your own fonts to a Kobo ereader, it does not strike me as overly onerous.

I agree with you that the Kobo naming convention is not overly onerous when you add, once in a lifetime, a side-loaded font to your Kobo. Alas, it's not the only restriction. It also apply for embedded fonts.

Forgive me for this. I will give you an 'onerous' example. You'll understand then better why I am a little sensitive about this question...

After publishing on MR two months ago a batch of 45 EPUB (it was a v2 of my 2012 work) I realized later that if I wished them to be displayed as intended on Kobo ebook readers, I had better rename and/or tweak all of my embedded fonts...

As it's usual for embedded fonts, it was of course not complete fonts but small subsets of the main ones. In each book I embedded the same four fonts: a special font for dropcaps (Linux Libertine Display), another one for smallcaps, a Regular and Italic one.

While the ADE rendering engine copes well with all these fonts and manages to display them precisely, Kobo's chokes on them. The only way I found to display my books as intended on Kobo is using PDF (I also publish each book on 6 and 9,7 inches PDF).

Here is the link to these books (in French).

I still struggle with this and would appreciate any help.

[DNSB]

Originally Posted by roger64

I agree with you that the Kobo naming convention is not overly onerous when you add, once in a lifetime, a side-loaded font to your Kobo. Alas, it's not the only restriction. It also apply for embedded fonts.

Forgive me for this. I will give you an 'onerous' example. You'll understand then better why I am a little sensitive about this question...

After publishing on MR two months ago a batch of 45 EPUB (it was a v2 of my 2012 work) I realized later that if I wished them to be displayed as intended on Kobo ebook readers, I had better rename and/or tweak all of my embedded fonts...

As it's usual for embedded fonts, it was of course not complete fonts but small subsets of the main ones. In each book I embedded the same four fonts: a special font for dropcaps (Linux Libertine Display), another one for smallcaps, a Regular and Italic one.

While the ADE rendering engine copes well with all these fonts and manages to display them precisely, Kobo's chokes on them. The only way I found to display my books as intended on Kobo is using PDF (I also publish each book on 6 and 9,7 inches PDF).

Here is the link to these books (in French).

I still struggle with this and would appreciate any help.

Even more fun when I renamed the font files and changed the @font-face to match. See the link for what happened (hope it works, if not, it's in the serious issues with kepubs thread. This was with ADE on a PC.

https://www.mobileread.com/forums/sho...9&postcount=60

I've attached the slightly modified version to this message.

I'm going to do a bit more fiddling with the styles to see if I can get it to be readable on a Kobo -- the way the chapter titles look like they're dripping is not quite the effect I think either of us would want.

Regards,
David

[DNSB]

Originally Posted by roger64;2507164
As it's usual for embedded fonts, it was of course not complete fonts but small subsets of the main ones. In each book I embedded the same four fonts: a special font for dropcaps (Linux Libertine Display), another one for smallcaps, a Regular and Italic one.

While the ADE rendering engine copes well with all these fonts and manages to display them precisely, Kobo's chokes on them. The only way I found to display my books as intended on Kobo is using PDF (I also publish each book on 6 and 9,7 inches PDF).

Here is [URL="https://www.mobileread.com/forums/showpost.php?p=2446592&postcount=219"

the link to these books[/URL] (in French).

I still struggle with this and would appreciate any help.

I went through the Monsieur Mars and Madame Venus book and made a few more changes. I also removed the embedded fonts while I did some of the cleanup. Without the small caps font, I tried resizing the font to 75% which while not the prettiest does work but ran into an old issue with ADE when I attempted to use the text-transform:uppercase style so retyping the lower case would not be necessary. With ADE and Reader Mobile on a Kobo, that text-transform does not work. Renaming the book to .kepub.epub and using the ACCESS NetFront renderer, it does work. I've attached copies of both to this message.

Regards,
David

[guma]

Originally Posted by taming

I think they are saying that when a user cobbles together an epub or gets it from non-kobo sources and then sideloads it onto the device, where it will go through either the Adobe or the Kobo renderer, they cannot guarantee that the fonts will perform as well as a book that has been coded to spec.

At least around here KOBO readers are advertised as 'open' devices. Thus side-loading books from other sources than KOBO should not be considered some sort of hack which they can simply ignore but is a standard use case. As far as I can see, the font display problems mentioned here are not caused by bad epub code anyway.

[taming]

No, it seems to be caused by non-standard (or at least different than when a publisher does it) embedded fonts. Or non-standard (at least from Kobo's POV) font specifications in user added fonts.

EDIT: I am going to try to say this in a nice way, but I am struggling. Kobo may be an open device, but that does not, to me, mean that anything ending in .epub is guaranteed to work on it.

[DNSB]

Originally Posted by guma

At least around here KOBO readers are advertised as 'open' devices. Thus side-loading books from other sources than KOBO should not be considered some sort of hack which they can simply ignore but is a standard use case. As far as I can see, the font display problems mentioned here are not caused by bad epub code anyway.

Some issues are caused by embedded fonts, some are caused by sideloaded fonts but the majority (in my opinion) are caused by css style code that is poorly written. Some of those code issues are caused by the differences between the renderers used on various devices -- it works on a Sony but not on a Nook or a Kobo type of problem. Kobo suffers here because they are supporting two renderers. The Adobe Reader Mobile seems to be close factory stock as most of the issues that show up using ADE on my computer are also issues on my Kobo reader. As to the state of the ACCESS NetFront BookReader, I haven't seen it elsewhere so it's hard to comment on just what changes other than adding the DRM code have been made by/for Kobo.

Regards,
David

[DNSB]

Originally Posted by taming

No, it seems to be caused by non-standard (or at least different than when a publisher does it) embedded fonts. Or non-standard (at least from Kobo's POV) font specifications in user added fonts.

EDIT: I am going to try to say this in a nice way, but I am struggling. Kobo may be an open device, but that does not, to me, mean that anything ending in .epub is guaranteed to work on it.

Considering most sites where CSS code is discussed still have disclaimers such as "this works with IE 8 or higher, Firefox 4+, Safari 5+" on almost every bit of sample code, there are no guarantees that any css is going to work on any given renderer. You learn what works for most devices and what is an invitation to a world of complaints.

Regards,
David