Gap 11: A/B reference track — /reference-analyze LUFS/dBTP/centroid + RefCompareModal A/B listen (5 test, 174 passed)

app/api/v1/audio.py

@@ -485,6 +485,90 @@ async def list_user_files(req: MyFilesRequest, current_user: dict = Depends(get_
     user_files.sort(key=lambda x: x["created_at"], reverse=True)
     return user_files
 
+class ReferenceAnalyzeRequest(BaseModel):
+    path: Optional[str] = None      # local path (media/browse server mode)
+    file_id: Optional[str] = None   # uploaded/processed file id
+
+def _spectral_centroid_hz(audio, sr):
+    """Tone proxy: mean spectral centroid (Hz) over 1 s windows.
+    Mono downmix + decimate to ~8 kHz (bounded cost). 0.0 for silence."""
+    import numpy as np
+    from scipy.signal import resample_poly
+    x = audio
+    if x.ndim > 1:
+        x = np.mean(x, axis=0)
+    if x.size == 0 or not np.any(x):
+        return 0.0
+    g = max(1, int(round(sr / 8000.0)))
+    x = resample_poly(x, 1, g)
+    sr8 = float(sr) / g
+    win = int(round(1.0 * sr8))
+    if win < 64 or x.size < win:
+        return 0.0
+    hann = np.hanning(win)
+    freqs = np.fft.rfftfreq(win, 1.0 / sr8)
+    cents = []
+    step = win // 2
+    for i in range(0, x.size - win, step):
+        mag = np.abs(np.fft.rfft(x[i:i + win] * hann))
+        msum = float(mag.sum())
+        if msum > 1e-9:
+            cents.append(float((freqs * mag).sum() / msum))
+    if not cents:
+        return 0.0
+    return float(np.mean(cents))
+
+@router.post("/reference-analyze")
+async def analyze_reference(req: ReferenceAnalyzeRequest, current_user: Optional[dict] = Depends(get_optional_user)):
+    """Gap 11: A/B reference track - analyze LUFS/dBTP/centroid of a
+    reference file (local path from media/browse, or uploaded file_id),
+    return compare metrics + playback url for the A/B toggle."""
+    import numpy as np
+    import soundfile as sf
+    from urllib.parse import quote
+    from app.core import loudness
+    path = ""
+    url = ""
+    if req.file_id:
+        path = _resolve_storage_path(req.file_id)
+        if not path:
+            raise HTTPException(status_code=404, detail="File not found")
+        url = "/api/v1/audio/download/%s" % _safe_file_id(req.file_id)
+    elif req.path:
+        path = os.path.normpath(req.path)
+        if not os.path.isfile(path):
+            raise HTTPException(status_code=404, detail="Khong tim thay file")
+        ext = os.path.splitext(path)[1].lower().lstrip(".")
+        if ext not in ALLOWED_AUDIO_EXTENSIONS:
+            raise HTTPException(status_code=400, detail="Dinh dang khong ho tro: %s" % ext)
+        url = "/api/v1/media/file?path=" + quote(path)
+    else:
+        raise HTTPException(status_code=400, detail="Can path hoac file_id")
+    try:
+        info = sf.info(path)
+        if info.samplerate and info.frames / info.samplerate > 900:
+            raise HTTPException(status_code=413, detail="File qua dai (>15 phut)")
+        data, sr = sf.read(path, dtype="float32", always_2d=True)
+    except HTTPException:
+        raise
+    except Exception as e:
+        raise HTTPException(status_code=400, detail="Khong doc duoc audio: %s" % e)
+    audio = np.asarray(data.T, dtype=np.float64)  # (ch, n)
+    lufs = loudness.integrated_lufs(audio, sr)
+    tp = loudness.true_peak_db(audio, sr)
+    centroid = await asyncio.to_thread(_spectral_centroid_hz, audio, sr)
+    dur = float(info.frames / max(1, info.samplerate or 1))
+    return {
+        "filename": os.path.basename(path),
+        "duration": round(dur, 2),
+        "sample_rate": int(info.samplerate or 0),
+        "channels": int(info.channels or 0),
+        "lufs": round(lufs, 2) if np.isfinite(lufs) else None,
+        "true_peak_db": round(tp, 2) if np.isfinite(tp) else None,
+        "centroid_hz": round(centroid, 0) if centroid > 0 else None,
+        "url": url,
+    }
+
 @router.delete("/my-files/{file_id}")
 async def delete_user_file(file_id: str, current_user: dict = Depends(get_current_user)):
     user_id = current_user["user_id"]