Testing a subset

[roger64]

Hi

I've found a commercial book which uses a subset of four Liberation Serif fonts. Calibre do not display them correctly, while it's OK for ADE 1.73, Azardi, Prince.

I downloaded from FontSquirrel a new set of Liberation Serif fonts, installed them on the EPUB and using the Editor made a subset out of them. Everything is now displayed OK but the question remains as to why Calibre choked on the original subset.

In the original EPUB, I also found some minor mistakes (you said commercial? ) like using as a font-family name LiberationSerif instead of the inside coded "Liberation Serif ", a wrong Mime-type in the content.opf file.

Question: Is there a way to analyze technically a subset as to learn what happened there? I extracted the original subsets from the EPUB and uploaded them here on MR. As you can see, two of the four fonts are nearly empty (in fact the book does not use Bold and BoldItalic fonts at all). Is this the reason?

[kovidgoyal]

I assume you mean the editor's preview panel did not display the font? As is noted in the preview panel when you start the editor, it will not display fonts if the name inside the font does not match the name in the @font-face rule exactly.

If you run check book, it will warn you of this problem and even allow you to auto-fix it.

[roger64]

Originally Posted by kovidgoyal

I assume you mean the editor's preview panel did not display the font?

Thanks for your reply. I am sorry I was not clear: the Calibre viewer did not display properly the book using this original subsets (uploaded above). So, to try to understand:

1. - I used the Editor but it failed to repair anything even if I was warned about a "dummy" font.
2. - The only solution I found was to change totally the fonts and create new subsets.

[kovidgoyal]

Attach a complete example in that case, not just the fonts.

[roger64]

OK Here it is attached.

As it's a commercial ebook, I've just included two text html files from the original book. As far as Liberation Serif is concerned, ADE 1.73 gives a good display while the calibre viewer gives a faulty one.

I did not try to repair or touch anything else (fonts, stylesheets, whatever) with the Editor. The Editor reports about "dummy" fonts which seem to be the Bold and BoldItalic Liberation Serif fonts here included.

[kovidgoyal]

As I said in my previous post, the font names in the font and in the font-face rules do not match. For example:

@font-face {
font-family: LiberationSerif;
font-style: normal;
font-weight: normal;
src: url(../Fonts/LiberationSerif-Regular.ttf);
}

Note the missing space between Liberation and Serif. And then there is the use of family name Dummy for other variants of Liberation Serif. That is what is causing the problem for the viewer. The viewer cannot handle multiple font face rules referring to the same actual font family with different family-names (and this is due to a limitation of Qt, which cannot be helped).

Either delete those two embedded fonts or fix the @fontface rules to use the font-family name "Dummy" which will make the file render fine in the viewer.

[roger64]

Thanks for your explanation.