[Accessibility] Localized braille (Was: Gnopernicus and ISO-Latin2 characters)

Samuel Thibault samuel.thibault at ens-lyon.org
Thu Aug 25 18:27:06 PDT 2005


BTW,

Remus, I bounced you a proposition from Erkki Kolehmainen about having
localized braille patterns included in the Unicode Common Locale Data
Repository (CLDR [1]), because I'm not sure whether you are subscribed
to brltty at mielke.cc or accessibility at a11y.org.

I've added quite a lot of Ccs. Sorry for such broadcasting, but I think
the issue is important. Maybe a mailing list could be setup at a11y.org
for people interested in the discussion.

Brass, brltty, gnopernicus, libbraille, suse blinux, etc. are all
software that need to translate text into braille patterns. For now,
each of them have their own (more or less complete) algorithms and
tables for various encodings, languages and countries.

Erkki proposed to have at least those tables collected in CLDR. This
seems quite nice since CLDR people are rather good at handling such
data. I listened again to the record of the FSG meeting in Hawaii: this
very issue was raised, but no solution had emerged. Erkki now proposes
one.

But more than that, it would be useful to have a single library using
these tables, that every software would be able to use. Because
elaborating braille is _not_ an easy task at all :)

The experimental gnome-braille software from Bill is a bit similar
to such library. In a few words (please correct me if I'm wrong), it
is able to turn utf-8 text into braille dots and display them via
libbraille or on braille mon. It takes into account the limited width of
the actual display, and lets the application control how it is scrolled.

Maybe this is a good start, I don't know. Libbraille already uses it in
his experimental unicode translator.

There are of course issues. And they need to be discussed, because else
people will probably not use gnome-braille or whatever library that
could get developped, and they will eventually rather develop their own
algorithms, which is just duplicated work.

Some examples of issues that I personally see are that it uses
libgobject and libglib, while screen readers tend to be as small as
possible, for embedded devices or installation images ; the features
that gnome-braille proposes also seem a bit mixed: it proposes braille
translation, display width management and braille output, all in one,
while I would have rather seen 3 separate libraries.

I guess that for instance Brass/brltty/suse blinux would rather be
interested in a very simple library, with no libgobject/libglib
dependency, which just provides localized braille translation (actually,
roughly what gnome-braille's braille-encoder.h and braille-table*.h
declares). It could be seen as a braille equivalent to the mb*towc*(),
iconv(), setlocale() etc. functions, so I'm not sure whether this should
remain in the gnome project. Erkki, maybe you would have more precise
opinion on this?

Gnopernicus could then be interested in a complementary library that
takes care of screen width and scrolling.

And eventually, for applications (or even gnopernicus, I don't know),
facilities to connect that to actual output (braille monitor / BrlAPI /
libbraille) could be useful indeed.

Well, that was just to give a first opinion. This really needs discussed
somehow. Probably not using all those mailing lists but some new list,
though.

Regards,
Samuel
[1] http://www.unicode.org/cldr




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