Initial standalone vox TTS server extracted from the ttstoy bot cog

Self-contained HTTP service with engine, data, start script, systemd unit,
and documentation. Runs independently of the Discord bot on its fixed port.

vox_engine.py

@@ -0,0 +1,104 @@
+"""
+Bundled VOX engine for ttstoy.
+Based on VOXGen by wphillips (https://github.com/wphillips/VOXGen)
+Black Mesa / Half-Life VOX announcer text-to-speech via word-level WAV concatenation.
+"""
+import os
+import wave
+import struct
+from pathlib import Path
+from typing import List, Optional
+
+_BASE_DIR = Path(__file__).resolve().parent
+
+VOX_PACKS = {
+    "vox": _BASE_DIR / "vox_words",
+    "vox2": _BASE_DIR / "vox2_words",
+}
+
+
+def get_available_packs() -> List[str]:
+    """Return list of installed VOX packs."""
+    return [name for name, p in VOX_PACKS.items() if p.exists()]
+
+
+def get_available_words(pack: str = "vox") -> List[str]:
+    """Return sorted list of available words for a VOX pack."""
+    pack_dir = VOX_PACKS.get(pack)
+    if not pack_dir or not pack_dir.exists():
+        return []
+    return sorted(
+        p.stem for p in pack_dir.glob("*.wav")
+        if not p.stem.startswith("00_") and not p.stem.startswith("_")
+    )
+
+
+def generate_vox(text: str, output_path: str, pack: str = "vox") -> List[str]:
+    """
+    Generate VOX audio from text by concatenating word WAV files.
+
+    Args:
+        text: Input sentence (words separated by spaces).
+        output_path: Path to write the output WAV/MP3 file.
+        pack: Which VOX pack to use ("vox" or "vox2").
+
+    Returns:
+        List of words that were actually found and used.
+
+    Raises:
+        RuntimeError: If no words matched or pack not found.
+    """
+    pack_dir = VOX_PACKS.get(pack)
+    if not pack_dir or not pack_dir.exists():
+        raise RuntimeError(f"VOX pack '{pack}' not found at {pack_dir}")
+
+    words = text.lower().split()
+    accepted = []
+    splice = bytes()
+
+    sample_rate = 11025
+    sample_width = 1
+    channels = 1
+
+    for word in words:
+        wav_path = pack_dir / f"{word}.wav"
+        if not wav_path.exists():
+            continue
+
+        with wave.open(str(wav_path), 'rb') as snd:
+            sample_rate = snd.getframerate()
+            sample_width = snd.getsampwidth()
+            channels = snd.getnchannels()
+            splice += snd.readframes(snd.getnframes())
+            accepted.append(word)
+
+    if not accepted:
+        raise RuntimeError(
+            f"No matching VOX words found. Available words include: "
+            f"{', '.join(get_available_words(pack)[:20])}..."
+        )
+
+    # Write intermediate WAV
+    wav_out = output_path.rsplit('.', 1)[0] + '_tmp.wav'
+    with wave.open(wav_out, 'wb') as out:
+        out.setnchannels(channels)
+        out.setsampwidth(sample_width)
+        out.setframerate(sample_rate)
+        out.writeframes(splice)
+
+    # Convert to MP3 using ffmpeg for consistency with the rest of ttstoy
+    import subprocess
+    cmd = [
+        "ffmpeg", "-y", "-i", wav_out,
+        "-ac", "1", "-ar", "32000", "-b:a", "128k",
+        output_path,
+    ]
+    subprocess.run(cmd, check=True, capture_output=True, text=True)
+
+    # Clean up temp WAV
+    try:
+        os.remove(wav_out)
+    except OSError:
+        pass
+
+    return accepted