Revision as of 00:09, 3 May 2023

Our group's final project is a orthographic conversion tool from IPA to Tibetan Script of Japhug based on lexd and twol of apertium.

Note: in order to display Tibetan glyphs correctly, you should download and install this font.

Project Description

Currently, compared to IPA, Tibetan Script-based orthography is more accepted among Japhug speakers. Therefore, we developed the orthographic conversion tool to make our transducer/translator more accessible for the Japhug community.

Transcription Scheme

Our orthographic conversion is based on the orthography proposed by Guillaume Jacques, from A Grammar of Japhug(2021) p.105 to p.106

Main differences from Standard Tibetan script

This transcription aims to minimize ambiguity, maximizing one-to-one map from sounds to orthography. Because the phonology of Japhug is richer than Standard Tibetan, in order to reduce ambiguity, this transcription uses some archaic Tibetan letters and some Tibetan letters for Sanskrit. For example, the archaic Tibetan diacritic ྀ represents vowel /ɯ/, and the letter ཊ that used to represent Sanskrit sound /ʈ/ represents /tʂ/ in this transcription.

Since vowel /ɤ/ is more common than /a/ in Japhug, we use /ɤ/ as the base vowel of each syllabus(a.k.a akshara) instead of /a/ in Standard Tibetan. On the other hand, we use the long vowel diacritic ཱ to represent /a/.

Japhug consonants can be prenasalized. In this transcription, we use letter འ to represent prenasalization. For example, "znde" should be transcribed as "འསྡེ".

There are no distinguish between palatal and alveo-palatal in standard Tibetan. We emailed Jacques, and he suggested us use velar+j to represent palatals, while keep alveo-palatals the same as standard Tibetan, because velar+i/j is very rare in Japhug. For example, palatal consonant "c" is transcribed as "ཀྱ", and its alveo-palatal counterpart "tɕ" is "ཅ"

Table

The following table tells about the details of the transcription for consonants. Colored entries are consonants not in Standard Tibetan:

The following table is the scheme for vowel transcription. Colored entries are those different or new to Standard Tibetan:

When a vowel is not preceded by any consonants, use འ with the corresponding vowel mark. For example, "andi" is transcribed as "འཱ༌འདི".

Because y is extremely uncommon in Japhug, we choose to represent it in the same way as u.

Implementation Method

We built a mini-transducer based on apertium to implement IPA to Tibetan Script transcriber. Specifically, we hard coded the rules for transcription in lexd and twol files. Moreover, because there are ambiguation in transcribing consonant clusters, we also used an xfst file to deal with that kind of ambiguation.

Currently, we have about 8 lexicon categories with about 170 lexicon entires in the lexd file, 5 twol rules and 48 disambiguation rules in the xfst file.

Installation

You can install the orthographical convertor from our Japhug language transducer.

After clone the transducer and make it, you can use the following command to do transcription:

apertium -d . jya_Latn-jya_Tibt

For example, to transcribe a full Japhug sentence:

echo "tɤrʑaβ nɯ pjɤrɤɕphɤt" | apertium -d . jya_Latn-jya_Tibt

You'll expect to get

ཏ༌རྮཱབ༌ ནྀ༌ པྱ༌ར༌ཤྥཏ།

Evaluation

Since there are not many existing texts of Japhug in this transcription, we'll just list some transcription pairs here. Every syllabus follows the Tibetan script convention that the vowel lies in either the first or second consonant.

kɯɕɯŋgɯ tɕe, nɤki, lɯlu ci pjɤtu, tɕendɤre βʑɯ ci pjɤtu -> ཀྀ༌ཤྀ༌འགྀ༌ ཅེ༌ ན༌ཀི༌ ལྀ༌ལུ༌ ཀྱི༌ པྱ༌ཏུ༌ ཅེ༌འད༌རེ༌ བཞྀ༌ ཀྱི༌ པྱ༌ཏུ།

lɯlu nɯ kɯ nɤkinɯ, βʑɯ ri tundze ɕti -> ལྀ༌ལུ༌ ནྀ༌ ཀྀ༌ ན༌ཀི༌ནྀ༌ བཞྀ༌ རི༌ ཏུ༌འཛེ༌ ཤྟི།

βʑɯ chondɤre nɤki, kumpɣɤtɕɯ nɯ kɯ βzaŋsa tonɯpandʑi -> བཞྀ༌ ཁྱོ༌འད༌རེ༌ ན༌ཀི༌ ཀུ༌འཔྺ༌ཅྀ༌ ནྀ༌ ཀྀ༌ བཟཱ༌འསཱ༌ ཏོ༌ནྀ༌པཱ༌འཇི།

tɕe βzaŋsa tonɯpandʑi tɕe, wuma pjɤkɤmɯmindʑici -> ཅེ༌ བཟཱ༌འསཱ༌ ཏོ༌ནྀ༌པཱ༌འཇི༌ ཅེ༌ བུ༹༌མཱ༌ པྱ༌ཀ༌མྀ༌མི༌འཇི༌ཀྱི།

maka cici ŋotɕu jɤarɯrindʑi ʑo tɯtɯrca ntsɯ juɕendʑi pjɤŋu -> མཱ༌ཀཱ༌ ཀྱི༌ཀྱི༌ ངོ༌ཅུ༌ ཡ༌འཱ༌རྀ༌རི༌འཇི༌ ཞོ༌ ཏྀ༌ཏྀ༌རྐྱཱ༌ འཙྀ༌ ཡུ༌ཤེ༌འཇི༌ པྱ༌ངུ།

kɤndza ci tu nɤ pjɯnɯkrondʑi -> ཀ༌འཛཱ༌ ཀྱི༌ ཏུ༌ ན༌ པྱྀ༌ནྀ༌ཀྲོ༌འཇི།

nɯ mɤʑɯ kɯmtɕhɯ kɯfse tɤtu nɤ, tɯɣrɤz ɲɯnɤɣrondʑi nɯ ra pjɤŋgrɤl -> ནྀ༌ མ༌ཞྀ༌ ཀྀ༌འཆྀ༌ ཀྀ༌ཕ༹སེ༌ ཏ༌ཏུ༌ ན༌ ཏྀ༌ཝྲཟ༌ ཉྀ༌ན༌ཝྲོ༌འཇི༌ ནྀ༌ རཱ༌ པྱ༌འགྲལ།

tɕhi kɤcha tukɤpjɤl kowa ntsɯ tuβzundʑi pjɤŋu tɕe -> ཆི༌ ཀ༌ཁྱཱ༌ ཏུ༌ཀ༌པྱལ༌ ཀོ༌བཱ༹༌ འཙྀ༌ ཏུ༌བཟུ༌འཇི༌ པྱ༌ངུ༌ ཅེ།

lɯlu nɯ kɯ βʑɯ ɯɕa tɕi pjɤrga, pɣɤtɕɯ ɯɕa tɕi pjɤrga ɕti tɕe -> ལྀ༌ལུ༌ ནྀ༌ ཀྀ༌ བཞྀ༌ འྀ༌ཤཱ༌ ཅི༌ པྱ༌རྒཱ༌ པྺ༌ཅྀ༌ འྀ༌ཤཱ༌ ཅི༌ པྱ༌རྒཱ༌ ཤྟི༌ ཅེ།

tɕe nɯ maʁ nɤ tɕe, βʑɯ nɯ kɯ wuma kɤrɤfsoʁ pjɤcha tɕe -> ཅེ༌ ནྀ༌ མཱག༌ ན༌ ཅེ༌ བཞྀ༌ ནྀ༌ ཀྀ༌ བུ༹༌མཱ༌ ཀ༌ར༌ཕ༹སོག༌ པྱ༌ཁྱཱ༌ ཅེ།

tɕendɤre ci nɯ ra nɯtɯscit, tɕheme nɯ ɯtɯmpɕɤr -> ཅེ༌འད༌རེ༌ ཀྱི༌ ནྀ༌ རཱ༌ ནྀ༌ཏྀ༌སྐྱིཏ༌ ཆེ༌མེ༌ ནྀ༌ འྀ༌ཏྀ༌འཔྴར།

Future Improvements

For some Japhug expressions with multiple consonants between vowels, there still exists ambiguity. For example, the word "paχɕi" (apple) can be transcribed as either "པཱ༌ཧ༹ཤི" when treating the consonant χ as the first consonant of the second syllabus, or "པཱག༌ཤི" if treating χ as the last consonant of the first syllabus.

External Resources

Japhug Grammar resources

Japhug Transducer

Tibetan Font