initial commit

src/dsp/SpectrumAnalyzer.h

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+#pragma once
+
+#include "core/Types.h"
+#include "dsp/FFTProcessor.h"
+#include "dsp/WindowFunctions.h"
+#include <deque>
+#include <vector>
+
+namespace baudline {
+
+// Manages the DSP pipeline: accumulation with overlap, windowing, FFT,
+// averaging, and waterfall history.
+//
+// Supports three modes:
+//   - Mono real   (numChannels=1, isIQ=false): 1 real FFT  → 1 spectrum
+//   - Multi-ch real (numChannels>1, isIQ=false): N real FFTs → N spectra
+//   - I/Q complex (isIQ=true):                 1 complex FFT → 1 spectrum
+class SpectrumAnalyzer {
+public:
+    SpectrumAnalyzer();
+
+    void configure(const AnalyzerSettings& settings);
+    const AnalyzerSettings& settings() const { return settings_; }
+
+    // Feed raw interleaved audio samples.
+    // `frames` = number of sample frames (1 frame = inputChannels() samples).
+    void pushSamples(const float* data, size_t frames);
+
+    // Returns true if a new spectrum line is available since last call.
+    bool hasNewSpectrum() const { return newSpectrumReady_; }
+
+    // Number of independent spectra (1 for mono/IQ, numChannels for multi-ch).
+    int numSpectra() const { return static_cast<int>(channelSpectra_.size()); }
+
+    // Per-channel spectra (dB magnitudes).
+    const std::vector<float>& channelSpectrum(int ch) const { return channelSpectra_[ch]; }
+
+    // Convenience: first channel spectrum (backward compat / primary).
+    const std::vector<float>& currentSpectrum() const { return channelSpectra_[0]; }
+
+    // All channel spectra.
+    const std::vector<std::vector<float>>& allSpectra() const { return channelSpectra_; }
+
+    // Number of output bins (per channel).
+    int spectrumSize() const { return fft_.spectrumSize(); }
+
+    // Peak detection on a given channel.
+    std::pair<int, float> findPeak(int ch = 0) const;
+
+    // Get frequency for a given bin index.
+    double binToFreq(int bin) const;
+
+    void clearHistory();
+
+    // Waterfall history for a given channel (most recent = back).
+    const std::deque<std::vector<float>>& waterfallHistory(int ch = 0) const {
+        return channelWaterfalls_[ch];
+    }
+
+private:
+    void processBlock();
+
+    AnalyzerSettings    settings_;
+    FFTProcessor        fft_;
+    std::vector<float>  window_;
+    float               windowGain_ = 1.0f;
+
+    // Accumulation buffer (interleaved, length = fftSize * inputChannels)
+    std::vector<float>  accumBuf_;
+    size_t              accumPos_ = 0;
+    size_t              hopSize_  = 0;
+
+    // Per-channel averaging
+    std::vector<std::vector<float>> avgAccum_;
+    int                             avgCount_ = 0;
+
+    // Per-channel output
+    std::vector<std::vector<float>>                channelSpectra_;
+    std::vector<std::deque<std::vector<float>>>     channelWaterfalls_;
+    bool                                            newSpectrumReady_ = false;
+};
+
+} // namespace baudline