Initial commit

espeak_phonemizer/__init__.py

@@ -0,0 +1,139 @@
+import ctypes
+import re
+import typing
+
+
+class Phonemizer:
+    """Use ctypes and libespeak-ng to get IPA phonemes from text"""
+
+    SEEK_SET = 0
+
+    EE_OK = 0
+
+    AUDIO_OUTPUT_SYNCHRONOUS = 0x02
+    espeakPHONEMES_IPA = 0x02
+    espeakCHARS_AUTO = 0
+    espeakPHONEMES = 0x100
+
+    LANG_SWITCH_FLAG = re.compile(r"\([^)]+\)")
+
+    DEFAULT_CLAUSE_BREAKERS = {",", ";", ":", ".", "!", "?"}
+
+    STRESS_PATTERN = re.compile(r"[ˈˌ]")
+
+    def __init__(
+        self,
+        default_voice: typing.Optional[str] = None,
+        clause_breakers: typing.Optional[typing.Collection[str]] = None,
+    ):
+        self.current_voice: typing.Optional[str] = None
+        self.default_voice = default_voice
+        self.clause_breakers = clause_breakers or Phonemizer.DEFAULT_CLAUSE_BREAKERS
+
+        self.libc: typing.Any = None
+        self.lib_espeak: typing.Any = None
+
+    def phonemize(
+        self,
+        text: str,
+        voice: typing.Optional[str] = None,
+        keep_clause_breakers: bool = False,
+        phoneme_separator: typing.Optional[str] = None,
+        word_separator: str = " ",
+        punctuation_separator: str = "",
+        keep_language_flags: bool = False,
+        no_stress: bool = False,
+    ) -> str:
+        """Return IPA string for text"""
+        self._maybe_init()
+
+        voice = voice or self.default_voice
+
+        if (voice is not None) and (voice != self.current_voice):
+            self.current_voice = voice
+            voice_bytes = voice.encode("utf-8")
+            result = self.lib_espeak.espeak_SetVoiceByName(voice_bytes)
+            assert result == Phonemizer.EE_OK, f"Failed to set voice to {voice}"
+
+        missing_breakers = []
+        if keep_clause_breakers and self.clause_breakers:
+            missing_breakers = [c for c in text if c in self.clause_breakers]
+
+        # Create in-memory file for phoneme trace.
+        # espeak_TextToPhonemes segfaults no matter what I do, so this is the back.
+        phonemes_buffer = ctypes.c_char_p()
+        phonemes_size = ctypes.c_size_t()
+        phonemes_file = self.libc.open_memstream(
+            ctypes.byref(phonemes_buffer), ctypes.byref(phonemes_size)
+        )
+
+        try:
+            phoneme_flags = Phonemizer.espeakPHONEMES_IPA
+            if phoneme_separator:
+                phoneme_flags = phoneme_flags | (ord(phoneme_separator) << 8)
+
+            self.lib_espeak.espeak_SetPhonemeTrace(phoneme_flags, phonemes_file)
+
+            identifier = ctypes.c_uint()
+            user_data = ctypes.c_void_p()
+            text_bytes = text.encode("utf-8")
+            self.lib_espeak.espeak_Synth(
+                text_bytes,
+                0,  # buflength
+                0,  # position
+                0,  # position_type
+                0,  # end_position
+                Phonemizer.espeakCHARS_AUTO | Phonemizer.espeakPHONEMES,
+                identifier,
+                user_data,
+            )
+            self.libc.fflush(phonemes_file)
+
+            phoneme_lines = ctypes.string_at(phonemes_buffer).decode().splitlines()
+
+            if not keep_language_flags:
+                # Remove language switching flags, e.g. (en)
+                phoneme_lines = [
+                    Phonemizer.LANG_SWITCH_FLAG.sub("", line) for line in phoneme_lines
+                ]
+
+            # Re-insert clause breakers
+            if missing_breakers:
+                # pylint: disable=consider-using-enumerate
+                for line_idx in range(len(phoneme_lines)):
+                    if line_idx < len(missing_breakers):
+                        phoneme_lines[line_idx] += (
+                            word_separator + missing_breakers[line_idx]
+                        )
+
+            phonemes_str = word_separator.join(line.strip() for line in phoneme_lines)
+
+            if no_stress:
+                # Remove primary/secondary stress markers
+                phonemes_str = Phonemizer.STRESS_PATTERN.sub("", phonemes_str)
+
+            # Clean up multiple phoneme separators
+            if phoneme_separator:
+                phonemes_str = re.sub(
+                    "[" + re.escape(phoneme_separator) + "]+",
+                    phoneme_separator,
+                    phonemes_str,
+                )
+
+            return phonemes_str
+        finally:
+            self.libc.fclose(phonemes_file)
+
+    def _maybe_init(self):
+        if self.libc and self.lib_espeak:
+            # Already initialize
+            return
+
+        self.libc = ctypes.cdll.LoadLibrary("libc.so.6")
+        self.libc.open_memstream.restype = ctypes.POINTER(ctypes.c_char)
+
+        self.lib_espeak = ctypes.cdll.LoadLibrary("libespeak-ng.so")
+        sample_rate = self.lib_espeak.espeak_Initialize(
+            Phonemizer.AUDIO_OUTPUT_SYNCHRONOUS, 0, None, 0
+        )
+        assert sample_rate > 0, "Failed to initialize libespeak-ng"