audio_analysis.h

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#ifndef AUDIO_ANALYSIS_H
#define AUDIO_ANALYSIS_H
 
#define INIT_PRISM(M)                   \
  M.setWindowSize(SAMPLES);             \
  M.setSampleRate(SAMPLING_FREQUENCY);  \
  M.setSpectrogram(&fftHistory);
 
#include <math.h>
#include <Arduino.h>
#include <Fast4ier.h>
#include <complex>
#include "AudioPrism.h"
#include "nanolux_types.h"
#include "nanolux_util.h"
 

class AudioAnalysis {
public:
  AudioAnalysis();
 
  /* ============== Public Interface ============== */

  void processAudioFrame(int);

  float* getVReal();       

  float* getVReal(float);  

  float getPeak();

  float getVolume();

  int getMaxDelta();

  float* getDeltas();

  int* getSalientFreqs();

  float getCentroid();

  bool getPercussionPresence();

  float getNoisiness();

  float* getFiveBandSplit(int len);

  void resetCache();
 
private:
  /* ============== Result Cache ============== */
  float volume            = 0;            // Volume level
  float peak              = 0;            // Peak frequency in Hz
  int   maxDelt           = 0;            // Maximum delta between FFT bins
  int   salFreqs[3]       = {0,0,0};      // Salient frequencies
  float centroid          = 0;            // Centroid frequency
  bool  percussionPresent = false;        // Percussion presence flag
  float noisiness         = 0;            // Noisiness level
  float fbs[5]            = {0,0,0,0,0};  // Five-band split values
 
  /* ============== Internal Buffers ============== */
  complex fftBuffer[SAMPLES];   // Buffer for FFT samples
  float   vReal[SAMPLES];       // Raw real FFT values
  float   smoothVReal[SAMPLES]; // Smoothed FFT values
  float   delt[SAMPLES];        // Delta FFT values
 
  /* ============== AudioPrism Modules ============== */
  Spectrogram              fftHistory;         // Spectrogram history
  MeanAmplitude            volumeModule;       // Volume analysis module
  MajorPeaks               peaksModule;        // Peaks detection module
  DeltaAmplitudes          deltaModule;        // Delta amplitudes detection module
  SalientFreqs             salientModule;      // Salient frequencies detection module
  Centroid                 centroidModule;     // Centroid frequency detection module
  PercussionDetection      percussionModule;   // Percussion detection module
  Noisiness                noisinessModule;    // Noisiness detection module
 
  /* ============== Flags ============== */
  bool vRealSmoothed     = false;   // Flag for vReal smoothing
  bool peakUpdated       = false;   // Flag for peak value update
  bool volumeUpdated     = false;   // Flag for volume update
  bool maxDeltaUpdated   = false;   // Flag for max delta update
  bool deltasUpdated     = false;   // Flag for delta values update
  bool salientsUpdated   = false;   // Flag for salient frequencies update
  bool centroidUpdated   = false;   // Flag for centroid frequency update
  bool percussionUpdated = false;   // Flag for percussion detection update
  bool noisinessUpdated  = false;   // Flag for noisiness level update
  bool fbsUpdated        = false;   // Flag for five-band split update
 
  /* ============== Helper Functions ============== */

  void sample_audio();

  void compute_FFT();

  void noise_gate(int);

  void vReal_smoothing(float);

  void update_peak();

  void update_volume();

  void update_max_delta();

  void update_deltas();

  void update_salient_freqs();

  void update_centroid();

  void update_percussion_detection();

  void update_noisiness();

  void update_five_band_split(int);
};

extern AudioAnalysis audioAnalysis;
 
#endif