Calibre warns that MIME type application/font-sfnt is wrong for .ttf font

[Peter Danckwerts]

Calibre 6.20, MacOS 13.4

This is a very minor thing but Calibre warns that MIME type application/font-sfnt is wrong for .ttf fonts but ePubcheck likes application/font-sfnt and not the alternatives. I believe that either is supposed to be acceptable.

[Kovid Goyal (kovid)]

Except that historically, application/font-sfnt didnt exist and I am
sure there are renderers out there that wont recognize it. calibre
prefers to produce code that *actually works* on real renderers, unlike
epubcheck.

[Peter Danckwerts (peterdanckwerts)]

Very sensible, although I’ve tried all and they all seem to work in Kindle and not in Apple Books!

> On 13 Jun 2023, at 12:52, Kovid Goyal <email address hidden> wrote:
>
> Except that historically, application/font-sfnt didnt exist and I am
> sure there are renderers out there that wont recognize it. calibre
> prefers to produce code that *actually works* on real renderers, unlike
> epubcheck.
>
>
> ** Changed in: calibre
> Status: New => Won't Fix
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/2023646
>
> Title:
> Calibre warns that MIME type application/font-sfnt is wrong for .ttf
> font
>
> Status in calibre:
> Won't Fix
>
> Bug description:
> Calibre 6.20, MacOS 13.4
>
> This is a very minor thing but Calibre warns that MIME type
> application/font-sfnt is wrong for .ttf fonts but ePubcheck likes
> application/font-sfnt and not the alternatives. I believe that either
> is supposed to be acceptable.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/calibre/+bug/2023646/+subscriptions
>

[Kovid Goyal (kovid)]

What doesnt work in Apple Books? You mean the actual epub file doesnt
work or apples publishig process rejects it?

[Peter Danckwerts (peterdanckwerts)]

The Apple Book works but it ignores the .ttf font, while happily accepting the .otf one. (On the other hand, the font works in Kindle but the footnotes appear in the text area as well as in pop-ups (as they do in Calibre)! I think the file is a bit of a mess, having been converted from LaTeX using tex4ebook. I’m sure I’ll get to the bottom of it eventually.) The .ttf font issue is a pain because it has a very specific editorial function, whereas the .otf font has only an aesthetic function. Apple’s Digital Book Essentials uses an example with media-type="application/x-font-ttf" so I’ve switched back to that, to no avail.

> On 13 Jun 2023, at 13:24, Kovid Goyal <email address hidden> wrote:
>
> What doesnt work in Apple Books? You mean the actual epub file doesnt
> work or apples publishig process rejects it?
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/2023646
>
> Title:
> Calibre warns that MIME type application/font-sfnt is wrong for .ttf
> font
>
> Status in calibre:
> Won't Fix
>
> Bug description:
> Calibre 6.20, MacOS 13.4
>
> This is a very minor thing but Calibre warns that MIME type
> application/font-sfnt is wrong for .ttf fonts but ePubcheck likes
> application/font-sfnt and not the alternatives. I believe that either
> is supposed to be acceptable.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/calibre/+bug/2023646/+subscriptions
>