feat: Arabic diacritization via text2tashkeel (rawi); drop vendored libtashkeel

Replace the vendored libtashkeel with text2tashkeel for all Arabic tashkeel. The
default model is rawi-ensemble, which restores hamza and the dagger alef in addition
to the standard marks — so it fixes inconsistently-spelled input that libtashkeel's
15-class scheme left as-is (e.g. bare 'ا' -> 'أ').

- remove phoonnx/thirdparty/tashkeel/ (vendored libtashkeel + its 4.8 MB onnx).
- BasePhonemizer: a lazy text2tashkeel diacritizer; add_diacritics(text, lang,
  model=None) routes Arabic to it.
- config: a generic 'diacritizer_model' key (default rawi-ensemble) on VoiceConfig
  and SynthesisConfig, round-tripped through config and threaded through voice.py —
  named generically so future languages that need a diacritizer model reuse it.
- the [ar] extra requires text2tashkeel; a clear ImportError is raised if missing.

Config and Arabic phonemizer tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: JarbasAl

phoonnx/config.py

@@ -125,6 +125,8 @@ class VoiceConfig:
     noise_scale: float = DEFAULT_NOISE_SCALE
     noise_w_scale: float = DEFAULT_NOISE_W_SCALE
     add_diacritics: bool = None # arabic and hebrew
+    # diacritizer model name (for languages that need one — e.g. Arabic uses text2tashkeel models like "rawi-ensemble")
+    diacritizer_model: str = "rawi-ensemble"
 
     # tokenization settings
     tokenizer: Optional[TTSTokenizer] = None
@@ -256,6 +258,7 @@ def from_dict(config: dict[str, Any],  # phoonnx/piper/coqui/mimic3
         phoneme_type = phoneme_type or config.get("phoneme_type")
         alphabet = alphabet or config.get("alphabet")
         diacritics = False
+        ar_diacritizer_model = "rawi-ensemble"
 
         if VoiceConfig.is_phoonnx(config):
             engine = engine or config.get("engine") or Engine.PHOONNX
@@ -264,6 +267,7 @@ def from_dict(config: dict[str, Any],  # phoonnx/piper/coqui/mimic3
             phoneme_type = phoneme_type or config.get("phoneme_type", PhonemeType.ESPEAK)
             alphabet = alphabet or Alphabet(config.get("alphabet", "ipa"))
             diacritics = config.get("inference", {}).get("add_diacritics", True)
+            ar_diacritizer_model = config.get("inference", {}).get("diacritizer_model", "rawi-ensemble")
 
             # Preserve the model's own special tokens when present (a native
             # config may use any pad/blank/bos/eos); fall back to phoonnx defaults.
@@ -394,6 +398,7 @@ def from_dict(config: dict[str, Any],  # phoonnx/piper/coqui/mimic3
             length_scale=inference.get("length_scale", DEFAULT_LENGTH_SCALE),
             noise_w_scale=inference.get("noise_w", DEFAULT_NOISE_W_SCALE),
             add_diacritics=diacritics,
+            diacritizer_model=ar_diacritizer_model,
             lang_code=lang_code,
             alphabet=Alphabet(alphabet) if isinstance(alphabet, str) else alphabet,
             engine=Engine(engine) if isinstance(engine, str) else engine,
@@ -443,6 +448,7 @@ def to_native_dict(self) -> Dict[str, Any]:
             "lang_id_map": dict(self.lang_id_map or {}),
             "phonemizer_model": self.phonemizer_model,
             "add_diacritics": self.add_diacritics,
+            "diacritizer_model": self.diacritizer_model,
             "inference": {
                 "noise_scale": self.noise_scale,
                 "length_scale": self.length_scale,
@@ -490,6 +496,9 @@ class SynthesisConfig:
     """for arabic and hebrew models"""
     add_diacritics: bool = True
 
+    # diacritizer model name (for languages that need one — e.g. Arabic uses text2tashkeel models like "rawi-ensemble")
+    diacritizer_model: str = "rawi-ensemble"
+
     # Engine-specific per-call params (d_factor, p_factor, e_factor, …)
     extra_params: Dict[str, Any] = field(default_factory=dict)
 

phoonnx/phonemizers/base.py

@@ -9,7 +9,6 @@
 from phoonnx.config import Alphabet
 from phoonnx.util import normalize, match_lang
 from phoonnx.thirdparty.phonikud import PhonikudDiacritizer
-from phoonnx.thirdparty.tashkeel import TashkeelDiacritizer
 
 # list of (substring, terminator, end_of_sentence) tuples.
 TextChunks = List[Tuple[str, str, bool]]
@@ -21,25 +20,40 @@
 
 class BasePhonemizer(metaclass=abc.ABCMeta):
     def __init__(self, alphabet: Alphabet = Alphabet.UNICODE,
-                 taskeen_threshold: Optional[float] = 0.8):
+                 diacritizer_model: str = "rawi-ensemble"):
         super().__init__()
         self.alphabet = alphabet
 
-        self.taskeen_threshold = taskeen_threshold  # arabic only
-        self._tashkeel: Optional[TashkeelDiacritizer] = None
+        # diacritizer model name, for languages that need one. Arabic uses
+        # text2tashkeel; the default "rawi-ensemble" restores hamza and the dagger
+        # alef in addition to the standard marks.
+        self.diacritizer_model = diacritizer_model
         self._phonikud: Optional[PhonikudDiacritizer] = None # hebrew only
+        self._tashkeel: dict = {}  # model name -> text2tashkeel Diacritizer
 
     @property
     def phonikud(self) -> PhonikudDiacritizer:
         if self._phonikud is None:
             self._phonikud = PhonikudDiacritizer()
         return self._phonikud
 
-    @property
-    def tashkeel(self) -> TashkeelDiacritizer:
-        if self._tashkeel is None:
-            self._tashkeel = TashkeelDiacritizer()
-        return self._tashkeel
+    def tashkeel(self, model: Optional[str] = None):
+        """Lazily build (and cache) the text2tashkeel Diacritizer used for Arabic.
+
+        text2tashkeel is a dependency of the ``[ar]`` extra; it restores hamza and the
+        dagger alef in addition to the standard marks. Install with
+        ``pip install phoonnx[ar]`` (or ``pip install text2tashkeel``)."""
+        model = model or self.diacritizer_model
+        if model not in self._tashkeel:
+            try:
+                from text2tashkeel import Diacritizer
+            except ImportError as e:
+                raise ImportError(
+                    "Arabic diacritization requires the text2tashkeel package: "
+                    "pip install phoonnx[ar]  (or pip install text2tashkeel)"
+                ) from e
+            self._tashkeel[model] = Diacritizer(model)
+        return self._tashkeel[model]
 
     @abc.abstractmethod
     def phonemize_string(self, text: str, lang: str) -> str:
@@ -48,11 +62,12 @@ def phonemize_string(self, text: str, lang: str) -> str:
     def phonemize_to_list(self, text: str, lang: str) -> List[str]:
         return list(self.phonemize_string(text, lang))
 
-    def add_diacritics(self, text: str, lang: str) -> str:
+    def add_diacritics(self, text: str, lang: str,
+                       model: Optional[str] = None) -> str:
         if lang.startswith("he"):
             return self.phonikud.diacritize(text)
         elif lang.startswith("ar"):
-            return self.tashkeel.diacritize(text, self.taskeen_threshold)
+            return self.tashkeel(model).diacritize(text)
         return text
 
     def phonemize(self, text: str, lang: str) -> PhonemizedChunks: