According to page 5 of [RFC5645](https://tools.ietf.org/html/bcp47#page-1-5),
variant subtags must have 5 to 8 characters. A 9-character subtag is
sytactically ill-formed and should be rejected by conforming parsers.
Technically, BCP47 does not allow the use of unregistered variant subtags.
For `fonkirsh`, I’ve filed a
[language variant subtag registration request](https://mailarchive.ietf.org/arch/msg/ietf-languages/1IrLl3n4wJ4Fr1xXV34QquJn8Bc)
with the IETF. If IETF rejects my request, we could probably add
Kirshenbaum to Unicode’s registry for [RFC6497](https://tools.ietf.org/html/rfc6497).
Not sure what to do about the other non-registered variants. If they’re
commonly used, it might be an option to register them as well, but
they seem to be even more exotic than Kirshenbaum, and we wouldn’t to
bloat the BCP47 registry too much. If espeak-ng really wants to handle these
alphabets, it would probably make sense to use BCP47 private-use extensions,
such as `x-fonzsamp`. According to IETF BCP47, private-use subtags can have
up to (but not more than) 8 characters, so I’m shortening these too.
This reverts commit 0f55204522.
This breaks using voice files like mb-de5-en. It could also use
named values for the stress rules (e.g. 'first-syllable').
Keyword stressRule in voices.c handles setting langopts->stress_rule.
tr_languages.c still contains the setting for some languages that don't have a language file yet.
Contributes to:
Issue #218, https://github.com/espeak-ng/espeak-ng/issues/218
Contributes to:
Issue #218, https://github.com/espeak-ng/espeak-ng/issues/218
Changes:
language files have a new keyword letterVowel. It can be a latin alphabet from a-z or a hex value (used by bulgarian).
Errors in parsing the values are only reported, nothing is done about them.
About testing:
I haven't noticed any differences in the output audio with letterVowel set or unset in any tested language. The code seems to work and the correct bits seem to be set, but I don't know how to confirm from the final audio.
TODO:
1. Write better documentation in docs/voices.md
2. The code uses new_translator. Should it use translator instead?
Reece H. Dunn