feat: true RMS dBFS level measurement for LevelMeterFab via getFloatTimeDomainData

DeepDrftPublic.Client/Controls/AudioPlayerBar/LevelMeterFab.razor.cs

@@ -11,12 +11,12 @@ public partial class LevelMeterFab : ComponentBase, IAsyncDisposable
 
     [Parameter] public EventCallback OnClick { get; set; }
 
-    // Calibration window (PLAN-level-meter-fill.md §2). These four constants are the
-    // spec contract: floor/ceiling define the dB window, and the linear map places
-    // -12 dB at 60% fill (green/yellow) and -4.5 dB at 85% (yellow/orange) to match
-    // the SVG gradient stops. The attack/release coefficients are by-ear tuning values.
-    private const double FloorDb = -70.0;            // fill = 0%; lowered to match FFT peak values (AnalyserNode.getFloatFrequencyData returns peaks, not RMS — typical loud dance tracks cluster ~-40 to -60 dB)
-    private const double CeilingDb = -10.0;          // fill = 100%; lowered to match FFT peak ceiling (loud dance FFT peaks land around -10 dB, far below 0 dB RMS full-scale)
+    // Calibration window for true RMS dBFS (AnalyserNode.getFloatTimeDomainData).
+    // Floor/ceiling define the dB window; the linear map across this 57 dB range places
+    // a steady dance track (~-14 dBFS) at ~81% fill (upper yellow) and a hot drop
+    // (~-6 dBFS) at ~95% (deep orange). Attack/release coefficients are by-ear tuning values.
+    private const double FloorDb = -60.0;            // fill = 0%; below this is near-silence (true RMS dBFS)
+    private const double CeilingDb = -3.0;           // fill = 100%; hot peaks on commercial masters (true RMS dBFS)
     private const double SilenceFloorDb = -80.0;     // matches the analyzer's normalization window
 
     private const double AttackCoefficient = 0.5;    // fast rise toward a louder reading
@@ -91,7 +91,7 @@ public partial class LevelMeterFab : ComponentBase, IAsyncDisposable
         _isAnimating = true;
         _smoothedDb = SilenceFloorDb;
         _fillPercent = 0;
-        await AudioInterop.StartSpectrumAnimationAsync(_playerId, _instanceId, OnLevelData);
+        await AudioInterop.StartLevelAnimationAsync(_playerId, _instanceId, OnLevelData);
     }
 
     private async Task StopAnimation()
@@ -99,7 +99,7 @@ public partial class LevelMeterFab : ComponentBase, IAsyncDisposable
         if (!_isAnimating || string.IsNullOrEmpty(_playerId)) return;
 
         _isAnimating = false;
-        await AudioInterop.StopSpectrumAnimationAsync(_playerId, _instanceId);
+        await AudioInterop.StopLevelAnimationAsync(_playerId, _instanceId);
 
         // Drop the column to empty so only the dim silhouette remains.
         if (_fillPercent != 0)
@@ -110,23 +110,16 @@ public partial class LevelMeterFab : ComponentBase, IAsyncDisposable
         _smoothedDb = SilenceFloorDb;
     }
 
-    private Task OnLevelData(double[] buckets)
+    private Task OnLevelData(double db)
     {
-        if (buckets.Length == 0) return Task.CompletedTask;
-
-        // Peak reads more responsively than mean for a "hot signal" indicator.
-        var peak = 0.0;
-        foreach (var bucket in buckets)
-        {
-            if (bucket > peak) peak = bucket;
-        }
-
-        // Inverse of SpectrumAnalyzer's normalization: value = (clampedDb + 80) / 80.
-        var instantDb = peak * 80.0 - 80.0;
+        // db is true RMS dBFS from getFloatTimeDomainData; -Infinity on silence.
+        var instantDb = double.IsNegativeInfinity(db) || double.IsNaN(db)
+            ? SilenceFloorDb
+            : Math.Max(db, SilenceFloorDb);
 
         // Attack-fast / release-slow envelope so the column doesn't strobe at 30fps.
-        var coefficient = instantDb > _smoothedDb ? AttackCoefficient : ReleaseCoefficient;
-        _smoothedDb += (instantDb - _smoothedDb) * coefficient;
+        var coeff = instantDb > _smoothedDb ? AttackCoefficient : ReleaseCoefficient;
+        _smoothedDb += (instantDb - _smoothedDb) * coeff;
 
         // Linear map of smoothed dB onto a 0-100 fill across the [floor, ceiling] window.
         var next = Math.Clamp((_smoothedDb - FloorDb) / (CeilingDb - FloorDb) * 100.0, 0.0, 100.0);

DeepDrftPublic.Client/Services/AudioInteropService.cs

@@ -243,6 +243,35 @@ public class AudioInteropService : IAsyncDisposable
         return await InvokeJsAsync<AudioOperationResult>("DeepDrftAudio.stopSpectrumAnimation", playerId, callbackId);
     }
 
+    public async Task<AudioOperationResult> StartLevelAnimationAsync(string playerId, string callbackId, Func<double, Task> callback)
+    {
+        try
+        {
+            var callbackWrapper = new LevelCallback { OnData = callback };
+            var dotNetObjectRef = DotNetObjectReference.Create(callbackWrapper);
+            _callbacks[playerId + "_level_" + callbackId] = dotNetObjectRef;
+
+            return await _jsRuntime.InvokeAsync<AudioOperationResult>(
+                "DeepDrftAudio.startLevelAnimation",
+                playerId, callbackId, dotNetObjectRef, "OnLevelDataCallback");
+        }
+        catch (Exception ex)
+        {
+            return new AudioOperationResult { Success = false, Error = ex.Message };
+        }
+    }
+
+    public async Task<AudioOperationResult> StopLevelAnimationAsync(string playerId, string callbackId)
+    {
+        var key = playerId + "_level_" + callbackId;
+        if (_callbacks.TryGetValue(key, out var callback))
+        {
+            callback?.Dispose();
+            _callbacks.Remove(key);
+        }
+        return await InvokeJsAsync<AudioOperationResult>("DeepDrftAudio.stopLevelAnimation", playerId, callbackId);
+    }
+
     public async Task<AudioOperationResult> DisposePlayerAsync(string playerId)
     {
         CleanupPlayerCallbacks(playerId);
@@ -341,6 +370,18 @@ public class SpectrumCallback
     }
 }
 
+public class LevelCallback
+{
+    public Func<double, Task>? OnData { get; set; }
+
+    [JSInvokable]
+    public async Task OnLevelDataCallback(double db)
+    {
+        if (OnData != null)
+            await OnData(db);
+    }
+}
+
 public class AudioOperationResult
 {
     public bool Success { get; set; }