[HarfBuzz] Any comments on ISO OFFS (ISO 14496-22 & ISO 9541-4)

[mpsuzuki at hiroshima-u.ac.jp]

Hi

Recently, ISO MPEG-4 committie is going to replace their
"standard" font format by OpenType, because existing PFR
(by Bitstream) is not easy to produce a digital contents
including internationalized text in non-Latin script.
I heard that OpenType specification v1.4 is approved as
ISO 14496-22, as it is.

Although the new standard ISO 14496-22 is only for
coding of multimedia data around moving pictures,
the committie for ISO 9541 will approve same standard as
new standard font format ISO 9541-4 (I remember, at
present, ISO standard font format is only PS Type1 -
in ISO 9541-1). So, I think, ISO 9541-4 will be the
first standardization of TrueType graphic language :-).

Do HarfBuzz developers have any comment on the standardization?

--

I think, from the viewpoint of "standard", OpenType
specification itself is insufficient to layout Unicode text.
For example, the detailed procedure (which layout feature
should be applied 1st, which is 2nd, ...) to layout Devanagari
script is not described in OpenType font format. It is
described in Microsoft's "Script-specific Development"
document, but it is dependent with Uniscribe, and revised
by Microsoft's VOLT community.

So, I'm afraid, the approving OpenType font format v1.4
itself does not support to implement portable OpenType
renderer. More detailed specification is required, even
if it's just another approval of Microsoft implementation.
(there can be a nightmare: a MPEG-4 video player including
Uniscribe can show closed caption correctly, but others
cannot. Oops)

Regards,
mpsuzuki