feat: true RMS dBFS level measurement for LevelMeterFab via getFloatTimeDomainData

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; }