Restrict FFT_Magnitude and FFT_MajorPeak detection to the set freq range

Victoare · Mar 19, 2024 · e2c10d0 · e2c10d0
1 parent 84b322f
commit e2c10d0
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Showing 5 changed files with 16 additions and 18 deletions.
diff --git a/source/WledSRServer/Audio/AudioProcessor/FFT/FFTransform.cs b/source/WledSRServer/Audio/AudioProcessor/FFT/FFTransform.cs
@@ -7,9 +7,6 @@ internal class FFTData : Context
         public double[] Values { get; set; } = Array.Empty<double>();
         public double[] Frequencies { get; set; } = Array.Empty<double>();
 
-        public double PeakValue { get; set; }
-        public double PeakFrequency { get; set; }
-
         public int[] GetIndexesByFreq(double freqLow, double freqHigh)
             => Frequencies.Select((freq, idx) => new { freq, idx })
                           .Where(f => f.freq >= freqLow && f.freq <= freqHigh)
@@ -50,20 +47,10 @@ public override bool Process()
             var complexData = FftSharp.FFT.Forward(values);
             var positiveOnly = true; // using only half of the spectrum
 
-            _fft.Values = FftSharp.FFT.Magnitude(complexData, positiveOnly); // WLED based on Magnitude (Scaling appliend in bucketizer)
+            _fft.Values = FftSharp.FFT.Magnitude(complexData, positiveOnly);  // WLED based on Magnitude (Scaling appliend in bucketizer)
             // _fft.Values = FftSharp.FFT.Power(complexData, positiveOnly);     // value[i] = 20 * Math.Log10(value[i])
-
             _fft.Frequencies = FftSharp.FFT.FrequencyScale(_fft.Values.Length, _sampleRate, positiveOnly);
 
-            for (int i = 0; i < _fft.Values.Length; i++)
-            {
-                if (_fft.Values[i] > _fft.PeakValue)
-                {
-                    _fft.PeakValue = _fft.Values[i];
-                    _fft.PeakFrequency = _fft.Frequencies[i];
-                }
-            }
-
             return true;
         }
     }

diff --git a/source/WledSRServer/Audio/AudioProcessor/FFTBuckets/Bucketizer.cs b/source/WledSRServer/Audio/AudioProcessor/FFTBuckets/Bucketizer.cs
@@ -69,6 +69,11 @@ public override bool Process()
         {
             // Debug.WriteLine($"FreqBands: {string.Join(";", _fft.Frequencies.Select(f => f.ToString()))}");
 
+            var freqIndexes = _fft.GetIndexesByFreq(_freqPoints[0], _freqPoints[_freqPoints.Length - 1]);
+            var peakIndex = freqIndexes.MaxBy(idx => _fft.Values[idx]);
+            _buckets.PeakValue = _fft.Values[peakIndex];
+            _buckets.PeakFrequency = _fft.Frequencies[peakIndex];
+
             for (var bucket = 0; bucket < _bucketCount; bucket++)
             {
                 var values = _fft.GetValuesByFreq(_freqPoints[bucket], _freqPoints[bucket + 1]);

diff --git a/source/WledSRServer/Audio/AudioProcessor/FFTBuckets/FFTBucketData.cs b/source/WledSRServer/Audio/AudioProcessor/FFTBuckets/FFTBucketData.cs
@@ -1,4 +1,6 @@
-namespace WledSRServer.Audio.AudioProcessor.FFTBuckets
+using FftSharp;
+
+namespace WledSRServer.Audio.AudioProcessor.FFTBuckets
 {
     internal class FFTBucketData : Context
     {
@@ -12,5 +14,8 @@ public struct Bucket
         }
 
         public Bucket[] Values { get; set; } = Array.Empty<Bucket>();
+
+        public double PeakValue { get; set; }
+        public double PeakFrequency { get; set; }
     }
 }
diff --git a/source/WledSRServer/Audio/AudioProcessor/Packet/SetPacket.cs b/source/WledSRServer/Audio/AudioProcessor/Packet/SetPacket.cs
@@ -43,8 +43,8 @@ public override bool Process()
             _packet.SampleSmth = raw;
             _packet.SamplePeak = (byte)(_beat.Detected ? 1 : 0);
 
-            _packet.FFT_Magnitude = (float)_fft.PeakValue;
-            _packet.FFT_MajorPeak = (float)_fft.PeakFrequency;
+            _packet.FFT_Magnitude = (float)_buckets.PeakValue;
+            _packet.FFT_MajorPeak = (float)_buckets.PeakFrequency;
 
             return true;
         }

diff --git a/source/WledSRServer/UserControls/BeatDetectorGraph.cs b/source/WledSRServer/UserControls/BeatDetectorGraph.cs
@@ -42,7 +42,8 @@ protected override void OnPaint(PaintEventArgs e)
 
             var indexes = fft.GetIndexesByFreq(dispFreqMin, dispFreqMax);
 
-            var scaleFFTValue = new Func<double, float>(v => this.Height - (float)(v / fft.PeakValue * this.Height));
+            var fftMaxValue = fft.Values.Max();
+            var scaleFFTValue = new Func<double, float>(v => this.Height - (float)(v / fftMaxValue * this.Height));
 
             //e.Graphics.Clear(Color.FromKnownColor(KnownColor.Control));
             if (beat.Detected)