Initial commit (forked from jamiepine/voicebox)

backend/utils/platform_detect.py

@@ -0,0 +1,88 @@
+"""
+Platform detection for backend selection.
+"""
+
+import platform
+import subprocess
+from functools import lru_cache
+from typing import Literal
+
+
+def is_apple_silicon() -> bool:
+    """
+    Check if running on Apple Silicon (arm64 macOS).
+
+    Returns:
+        True if on Apple Silicon, False otherwise
+    """
+    return platform.system() == "Darwin" and platform.machine() == "arm64"
+
+
+@lru_cache(maxsize=1)
+def is_amd_gpu_windows() -> bool:
+    """
+    Check if the primary GPU on Windows is an AMD Radeon card.
+
+    Uses WMI to query Win32_VideoController, with a fallback to
+    torch.cuda.get_device_name(0) if WMI is unavailable.  This is
+    useful for deciding whether the ROCm backend is appropriate.
+
+    Result is cached since it shells out to PowerShell and the GPU
+    does not change at runtime — safe to call from the health path.
+
+    Returns:
+        True if an AMD GPU is detected on Windows, False otherwise.
+    """
+    if platform.system() != "Windows":
+        return False
+
+    # Primary method: WMI query for AMD adapters
+    try:
+        result = subprocess.run(
+            [
+                "powershell",
+                "-Command",
+                "Get-CimInstance Win32_VideoController | "
+                "Where-Object {$_.AdapterCompatibility -like '*AMD*'} | "
+                "Measure-Object | Select-Object -ExpandProperty Count",
+            ],
+            capture_output=True,
+            text=True,
+            check=True,
+        )
+        if int(result.stdout.strip()) > 0:
+            return True
+    except Exception:
+        pass
+
+    # Fallback: torch.cuda.get_device_name(0) (works for ROCm/HIP too)
+    try:
+        import torch
+
+        if torch.cuda.is_available():
+            name = torch.cuda.get_device_name(0)
+            if "Radeon" in name or "AMD" in name:
+                return True
+    except Exception:
+        pass
+
+    return False
+
+
+def get_backend_type() -> Literal["mlx", "pytorch"]:
+    """
+    Detect the best backend for the current platform.
+
+    Returns:
+        "mlx" on Apple Silicon (if MLX is available and functional), "pytorch" otherwise
+    """
+    if is_apple_silicon():
+        try:
+            import mlx.core  # noqa: F401 — triggers native lib loading
+            return "mlx"
+        except (ImportError, OSError, RuntimeError):
+            # MLX not installed, or native libraries failed to load inside a
+            # PyInstaller bundle (OSError on missing .dylib / .metallib).
+            # Fall through to PyTorch.
+            return "pytorch"
+    return "pytorch"