Re: DSIG and other issues

On Tue, May 20, 2014 at 3:33 PM, Levantovsky, Vladimir <
Vladimir.Levantovsky@monotype.com> wrote:

>  Folks,
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> I am traveling this week and won't be able to join the telcon tomorrow, we
> will resume next week.
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> One issue that was discussed recently at the MPEG font list about DSIG is
> the reliance of some of the Windows  applications on DSIG presence to
> distinguish OT fonts from TTF, and by extension, to use this distinction to
> enable the OpenType layout features. It is not clear whether only certain
> applications are affected, or any that use the underlying Win API, but this
> is something we may need to investigate because of the WOFF2 spec
> recommendation to remove DSIG because it will be compromised by
> pre-processing and reconstruction steps. What we may consider instead (or
> in addition to) is to remove the DSIG table while encoding a font and
> recreate a dummy DSIG (if the original font had it) to preserve font
> compatibility with Win API. Let's give it a time to discuss it at the next
> telcon (on May 28).
>

Most interesting.  Would you happen to know what Windows applications (or
underlying APIs) rely on the presence of the DSIG table?

Specifically, I am eager to know if browsers (such as Chrome, Firefox,
Internet Explorer) would be impacted.

In quickly testing with Chrome M36 + the Google Fonts directory + a few
complex scripts (Devanagari, Khmer) + WOFF 2.0, the OpenType functionality
appears to work (at least to my untrained eye).  Would we expect it to not
work?

Reconstructing the DSIG table is an interesting idea.  Perhaps (if the
impact is limited), the respective Windows browsers (or WOFF 2.0 consuming
applications) could take this on?

>
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> Thank you,
>
> Vlad
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