マイク入力をリアルタイムでサウンドスペクトログラムする

ofApp.cpp

#include "ofApp.h"
#include "FFT.h"


#define SAMPLING_RATE 44100
//--------------------------------------------------------------
void ofApp::setup(){
    
    ofSetFrameRate(60);
    
    fbo.allocate(BUF_FRAME, BUFSIZE, GL_RGB);
    fbo_raw.allocate(ofGetWidth(), ofGetHeight());
    fbo_fft.allocate(ofGetWidth(), ofGetHeight());
    
	int bufferSize = BUFSIZE;
	soundStream.listDevices();
	soundStream.setup(this,  // self callback
										0,     // no output
										1,     // 1 input ( mono input )
										SAMPLING_RATE, // sampling rate[Hz]
										bufferSize, // buffer size
										4);    // number of buffer size.

    for( int i = 0; i < BUF_FRAME; i++ ){
        for( int j = 0; j < BUFSIZE; j++){
            buf_spectrogram[i][j] = 0;
        }
    }
    
    gui.setup();
    gui.add(gain.set("Gain", 0.5, 0.01, 5.0));
}

//--------------------------------------------------------------
void ofApp::update(){
    fbo.begin();
    ofClear(0);
    {
        // Draw Sound Spectrogram
        int pos_start_x = 0;
        int pos_start_y = BUFSIZE-1;
        glBegin(GL_POINTS);
        for( int i = 0; i < BUF_FRAME; i++ ){
            for( int j = 0; j < BUFSIZE; j++){
                ofSetColor(255,255,255, 255*buf_spectrogram[i][j]*gain);
                glVertex2f(pos_start_x+i, pos_start_y-j);
            }
        }
        glEnd();
    }
    fbo.end();
    
    fbo_raw.begin();
     ofClear(0);
    ofBeginShape();
    for(int i = 0; i < BUFSIZE; i++ ){
        ofVertex(ofGetWidth()*(i/(float)BUFSIZE),
                 ofGetHeight()/2 + sound[i]*100);
    }
    ofEndShape();
    fbo_raw.end();
    
    fbo_fft.begin();
     ofClear(0);
    ofBeginShape();
    for( int i = 0; i < BUFSIZE; i++ ){
        ofVertex(ofGetWidth()*(i/(float)BUFSIZE)*2,
                 ofGetHeight()- power[i]-100);
    }
    ofEndShape();
    
    ofDrawBitmapString("freq[Hz]", 10, ofGetHeight()-100+20);
    for( int i = 0; i < BUFSIZE/2; i++ ){
        if( i%10 == 0 ){
            ofDrawBitmapString(
                               ofToString(i*(int)myfft.getFreqStep(SAMPLING_RATE, BUFSIZE)),
                               2*ofGetWidth()*(i/(float)BUFSIZE), ofGetHeight()-100+10);
        }
        if( i%10 == 0 ){
            ofLine(ofGetWidth()*(i/(float)BUFSIZE)*2,
                   ofGetHeight()-100+10,
                   ofGetWidth()*(i/(float)BUFSIZE)*2,
                   ofGetHeight()-100-10);
        }
        
    }
    fbo_fft.end();
}

//--------------------------------------------------------------
void ofApp::draw(){
    ofBackground(0);
	ofSetColor(255);
	ofDrawBitmapString(ofToString(ofGetFrameRate()), ofGetWidth()-100,10);
	
	ofNoFill();
	ofSetLineWidth(1.0);
    
    // Draw Sound Spectrogram
    fbo.draw(0,0, ofGetWidth(), ofGetHeight());
    
    // Draw Realtime FFT
    fbo_fft.draw(0,0);
    
    // Draw RawData
    fbo_raw.draw(0,0);
   
    
    ofDrawBitmapString(ofToString(spectrogram.size()), 20,20);
    gui.draw();

}

void ofApp::keyPressed(int key)
{
    if( key == 's' ){
        ofPixels pixels;
        fbo.readToPixels(pixels);
        ofSaveImage(pixels, "output.jpg", OF_IMAGE_QUALITY_BEST);
    }
}

//--------------------------------------------------------------
void ofApp::audioIn(float * input, int bufferSize, int nChannels){

	//lets go through each sample and calculate the root mean square which is a rough way to calculate volume
	for (int i = 0; i < bufferSize; i++){
		sound[i] = input[i];
	}

  float avg_power = 0.0f;
  myfft.powerSpectrum(0,
                      (int)BUFSIZE/2,
                      sound,
                      BUFSIZE,
                      &magnitude[0],
                      &phase[0],
                      &power[0],
                      &avg_power);
    
    for( int i = 511-1; i >= 0; i-- ){
        for( int j = 0; j < BUFSIZE; j++ ){
            buf_spectrogram[i+1][j] = buf_spectrogram[i][j];
        }
    }

    
    for( int j = 0; j < BUFSIZE; j++ ){
        buf_spectrogram[0][j] = log10(power[j]);
    }
   


}

ofApp.h

#pragma once

#include "ofMain.h"
#include "ofxGui.h"
#include "FFT.h"

#define BUF_FRAME 512
#define BUFSIZE 512// 2^11

class ofApp : public ofBaseApp{
    
    public:
    void setup();
    void update();
    void draw();
    void keyPressed(int key);
    
    void audioIn(float *input, int bufferSize, int nChannels);
    ofSoundStream soundStream;
    
    float sound[BUFSIZE];
    
    fft	myfft;
    float magnitude[BUFSIZE];  // 振幅
    float phase[BUFSIZE];      //
    float power[BUFSIZE];      // 振幅×振幅
    vector<vector<float>> spectrogram;
    float buf_spectrogram[BUF_FRAME][BUFSIZE];
    double db_min;
    
    ofxPanel gui;
    ofParameter<float>gain;
    ofFbo fbo;
    ofFbo fbo_raw;
    ofFbo fbo_fft;
};