Install Windows CUDA runtime for STT

python/local_stt_worker.py

@@ -1,7 +1,11 @@
 import base64
+import glob
 import json
 import os
+from pathlib import Path
+import site
 import sys
+import sysconfig
 import tempfile
 import traceback
 import wave
@@ -44,6 +48,71 @@ def resolve_device() -> str:
     return "cpu"
 
 
+def configure_windows_cuda_runtime() -> None:
+    if os.name != "nt":
+        return
+
+    candidate_dirs: list[str] = []
+
+    for key in ("CUDA_PATH", "CUDA_HOME"):
+        value = os.environ.get(key)
+        if value:
+            candidate_dirs.append(os.path.join(value, "bin"))
+
+    for key, value in os.environ.items():
+        if key.startswith("CUDA_PATH_V") and value:
+            candidate_dirs.append(os.path.join(value, "bin"))
+
+    candidate_dirs.extend(
+        sorted(glob.glob(r"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v*\bin"), reverse=True)
+    )
+
+    site_roots: list[str] = []
+    try:
+        site_roots.extend(site.getsitepackages())
+    except Exception:
+        pass
+
+    try:
+        site_roots.append(site.getusersitepackages())
+    except Exception:
+        pass
+
+    for key in ("purelib", "platlib"):
+        value = sysconfig.get_paths().get(key)
+        if value:
+            site_roots.append(value)
+
+    for root in site_roots:
+        nvidia_root = Path(root) / "nvidia"
+        if not nvidia_root.is_dir():
+            continue
+
+        for pattern in ("**/cublas64_12.dll", "**/cudnn*.dll", "**/cudart64*.dll"):
+            for dll_path in nvidia_root.glob(pattern):
+                candidate_dirs.append(str(dll_path.parent))
+
+    unique_dirs: list[str] = []
+    for candidate in candidate_dirs:
+        normalized = os.path.normpath(candidate)
+        if not os.path.isdir(normalized):
+            continue
+        if normalized in unique_dirs:
+            continue
+        unique_dirs.append(normalized)
+
+    for directory in unique_dirs:
+        try:
+            os.add_dll_directory(directory)
+        except (AttributeError, FileNotFoundError, OSError):
+            pass
+
+    if unique_dirs:
+        existing_path = os.environ.get("PATH", "")
+        os.environ["PATH"] = os.pathsep.join(unique_dirs + [existing_path])
+        log(f"configured CUDA DLL search paths: {', '.join(unique_dirs)}")
+
+
 def resolve_compute_type(device: str) -> str:
     raw = os.environ.get("LOCAL_STT_COMPUTE_TYPE", "auto").strip().lower()
     if raw and raw != "auto":
@@ -55,6 +124,7 @@ def resolve_compute_type(device: str) -> str:
 
 class SttWorker:
     def __init__(self) -> None:
+        configure_windows_cuda_runtime()
         from faster_whisper import WhisperModel
 
         self.model_name = os.environ.get("LOCAL_STT_MODEL", "tiny").strip() or "tiny"