this repo has no description
spectral whitening
+83
-2
+14
src/cqtdata.c
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src/cqtdata.c
···
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// Array of kernels, one per CQT bin
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CqtKernel cqtKernels[CQT_BINS];
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// Spectral whitening data
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float cqtBinAverages[CQT_BINS];
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float cqtWhitenedData[CQT_BINS];
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void CQT_Init(void)
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{
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// Zero all data arrays
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// Zero kernel pointers
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memset(cqtKernels, 0, sizeof(cqtKernels));
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// Initialize spectral whitening arrays
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memset(cqtBinAverages, 0, sizeof(cqtBinAverages));
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memset(cqtWhitenedData, 0, sizeof(cqtWhitenedData));
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// Start with small initial averages to avoid divide-by-zero
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for (int i = 0; i < CQT_BINS; i++)
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{
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cqtBinAverages[i] = CQT_WHITENING_FLOOR;
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}
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}
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void CQT_Cleanup(void)
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src/cqtdata.h
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src/cqtdata.h
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#define CQT_BASS_Q_MAX 17.0f // Full Q achieved at 80+ Hz
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#define CQT_TREBLE_Q_FACTOR 11.0f // Smoother for high frequencies
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// Spectral whitening toggle (set to 0 to disable)
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#define CQT_SPECTRAL_WHITENING_ENABLED 1
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// Spectral whitening parameters
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#define CQT_WHITENING_DECAY 0.99f // Running average decay (0.98-0.995 for 1-2 second adaptation)
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#define CQT_WHITENING_FLOOR 0.001f // Minimum average to prevent divide-by-zero
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// Raw CQT magnitude data
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extern float cqtData[CQT_BINS];
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···
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// Enable flag (tied to fftEnabled initially)
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extern bool cqtEnabled;
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// Spectral whitening data
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extern float cqtBinAverages[CQT_BINS]; // Long-term running averages per bin
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extern float cqtWhitenedData[CQT_BINS]; // Whitened CQT data
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// Sparse kernel storage structures
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typedef struct {
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src/ext/cqt.c
+58
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src/ext/cqt.c
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}
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#endif
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// Apply smoothing
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// Apply spectral whitening if enabled
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#if CQT_SPECTRAL_WHITENING_ENABLED
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for (int i = 0; i < CQT_BINS; i++)
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{
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// Update running average for this bin
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cqtBinAverages[i] = cqtBinAverages[i] * CQT_WHITENING_DECAY +
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cqtData[i] * (1.0f - CQT_WHITENING_DECAY);
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// Ensure average doesn't go below floor
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if (cqtBinAverages[i] < CQT_WHITENING_FLOOR)
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cqtBinAverages[i] = CQT_WHITENING_FLOOR;
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// Apply whitening by dividing by the average
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cqtWhitenedData[i] = cqtData[i] / cqtBinAverages[i];
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// Check for NaN or Inf
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if (!isfinite(cqtWhitenedData[i]))
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cqtWhitenedData[i] = 0.0f;
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}
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// Apply smoothing to whitened data
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for (int i = 0; i < CQT_BINS; i++)
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{
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cqtSmoothingData[i] = cqtSmoothingData[i] * CQT_SMOOTHING_FACTOR +
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cqtWhitenedData[i] * (1.0f - CQT_SMOOTHING_FACTOR);
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}
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#else
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// Apply smoothing to raw data (spectral whitening disabled)
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for (int i = 0; i < CQT_BINS; i++)
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{
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cqtSmoothingData[i] = cqtSmoothingData[i] * CQT_SMOOTHING_FACTOR +
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cqtData[i] * (1.0f - CQT_SMOOTHING_FACTOR);
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}
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#endif
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// Find peak for normalization
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float currentPeak = 0.0f;
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// Apply CQT kernels
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CQT_ApplyKernels(fftReal, fftImag);
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// Apply smoothing
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// Apply spectral whitening if enabled
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#if CQT_SPECTRAL_WHITENING_ENABLED
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for (int i = 0; i < CQT_BINS; i++)
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{
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// Update running average for this bin
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cqtBinAverages[i] = cqtBinAverages[i] * CQT_WHITENING_DECAY +
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cqtData[i] * (1.0f - CQT_WHITENING_DECAY);
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// Ensure average doesn't go below floor
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if (cqtBinAverages[i] < CQT_WHITENING_FLOOR)
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cqtBinAverages[i] = CQT_WHITENING_FLOOR;
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// Apply whitening by dividing by the average
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cqtWhitenedData[i] = cqtData[i] / cqtBinAverages[i];
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// Check for NaN or Inf
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if (!isfinite(cqtWhitenedData[i]))
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cqtWhitenedData[i] = 0.0f;
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}
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// Apply smoothing to whitened data
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for (int i = 0; i < CQT_BINS; i++)
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{
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cqtSmoothingData[i] = cqtSmoothingData[i] * CQT_SMOOTHING_FACTOR +
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cqtWhitenedData[i] * (1.0f - CQT_SMOOTHING_FACTOR);
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}
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#else
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// Apply smoothing to raw data (spectral whitening disabled)
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for (int i = 0; i < CQT_BINS; i++)
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{
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cqtSmoothingData[i] = cqtSmoothingData[i] * CQT_SMOOTHING_FACTOR +
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cqtData[i] * (1.0f - CQT_SMOOTHING_FACTOR);
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}
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#endif
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// Find peak for normalization
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float currentPeak = 0.0f;