Opus Fonts directory for Calibre -> External CSS

[fiery]

For those interesting in epub Fonts usage, the public Fonts directory of Cybook Opus is in fact /mnt/fat/Fonts/. The internal Fonts folder is "/mnt/app/res/fonts". You can find them in the system/.fonts-cache-1 text file.

So after a lot of reading and testing I successfully used the Liberation fonts (available in Calibre) in my epub files. Most importantly, I was even able to embed these fonts in the epub files so ADE could show Cyrillic letters instead of ???. You can read this thread if you need a portable epub file with embedded fonts: https://www.mobileread.com/forums/showthread.php?t=61587

However, if you want to use the Liberation fonts only on your device, first copy all fonts from "C:\Program Files\Calibre2\resources\fonts\liberation" to your Cybook Opus Fonts folder. Then edit the stylesheet.css file (or enter the following text at Calibre -> Look & Feel -> External CSS field):
----------------
stylesheet.css - insert the following text after the first line
----------------
@font-face {
font-style: italic;
font-family: 'Liberation', serif, sans-serif;
font-weight: normal;
src: url(res:///mnt/fat/Fonts/LiberationSerif-Italic.ttf);
}
@font-face {
font-style: normal;
font-family: 'Liberation', serif, sans-serif;
font-weight: normal;
src: url(res:///mnt/fat/Fonts/LiberationSerif-Regular.ttf);
}
@font-face {
font-style: italic;
font-family: 'Liberation', serif, sans-serif;
font-weight: bold;
src: url(res:///mnt/fat/Fonts/LiberationSerif-BoldItalic.ttf);
}
@font-face {
font-style: normal;
font-family: 'Liberation', serif, sans-serif;
font-weight: bold;
src: url(res:///mnt/fat/Fonts/LiberationSerif-Bold.ttf);
}

[EowynCarter]

I know some will be intersted by these infos

[elmargol]

Thank you

[Godzil]

I really don't understand what allow you to use external fonts like here instead of embedding them in your ePub file ?

Using external file dissallow to make them portable around devices without adding fonts too on them. (nor allow you to distribute your file on the net without asking people to use the font you force) and the ePub will neither be portable with other device like Sony's one

[Jellby]

The only reason would be making the epub file a bit smaller.

[elmargol]

font-family: 'Liberation', serif, sans-serif;
If you don't have Liberation it is going to use serif... if you don't have serif it is going to use sans-serif... no problem at all

[Godzil]

Sorry, but I know CSS, but using external font file is a really bad idea. Using a specific font for a file, is to get a good formated document, and using fall back always led to unexpected results.

And making the file smaller is not a real problem. ePub file are zipped, and there is now a lot of memory on all devices, so the gain of 100ko is not a real problem.

[LoganK]

Originally Posted by Godzil

Sorry, but I know CSS, but using external font file is a really bad idea. Using a specific font for a file, is to get a good formated document, and using fall back always led to unexpected results.

I actually came here hoping the title was correct: external fonts and external CSS. That's what we really want as readers.

(Writers/publishers probably want to embed both.)

[JSWolf]

It this an Opus only public fonts directory or is it an ADE public fonts directory?

Fiery, how did you figure out what the public fonts directory is?

[wallcraft]

Originally Posted by JSWolf

It this an Opus only public fonts directory or is it an ADE public fonts directory?

It is Opus only (a part of mobile ADE, but customized by each vendor). The same approach works on Sonys (ePub custom Fonts on 700, 505, 300, 600) and Hanlins ( Fonts and Epub - What works on Sony, Works for Pocket Pro too!). All that differs between the Cybooks, Sonys and Hanlins is the location of the user provided font directory (e.g. SD card vs internal memory) and how it is named in the src: line.

[fiery]

Originally Posted by JSWolf

It this an Opus only public fonts directory or is it an ADE public fonts directory?

Fiery, how did you figure out what the public fonts directory is?

This is a Cybook Opus specific location for the Fonts folder available on the internal (not SD) memory of the Opus. All fonts and their locations could be read in the system/.fonts.cache-1 file. I attached mine if someone wants to look at it.

It seems that all devices use different locations for their public Fonts folders.

[fiery]

I found several posts how to use external fonts on Sony devices, but there was no instructions for the Opus users. So, this thread is for the Opus users who want to use external fonts (I slightly edited my initial post for more clarity).

The main advantage of external fonts is that you can produce your epub files simply by pasting some css definitions in Calibre. There is no need to edit epubs afterward.

The advantage of embedded fonts is that ADE, Opus and some other devices will use them instead of the default fonts. The disadvantage is more file editing and copying of fonts in each epub file. If you want to embed fonts after Calibre conversion you can read this thread: https://www.mobileread.com/forums/showthread.php?t=61587

[Rizla]

To clarify for future readers, put the external fonts in a new folder called Fonts in the Cybook root folder of its internal memory.

Then reference the fonts using the css code stated above.

Then finally, and this is what got me, when in a book, choose options and fonts, then choose your new font from the list (it should be there). The font will change. This is actually really nice and much nicer than how it's done on a Sony.

If the font doesn't change, its because the epub is referencing other fonts internally.