two examples of `marsyas `

marsyas_example.cpp

#include <string>
#include "marsyas/MarSystemManager.h"
#include "marsyas/SoundFileSource.h"
#include "marsyas/SoundFileSink.h"
#include "marsyas/Series.h"

using namespace std;
using namespace Marsyas;

void
sfplay(string inSfName = "sample.mp3",string outSfName = "sample.wav"){

    MarSystemManager mng;

    // Create a series Composite
    MarSystem* series = mng.create("Series", "series");
    series->addMarSystem(mng.create("SoundFileSource", "src"));
    series->addMarSystem(mng.create("SoundFileSink", "dest"));

    // only update controls from Composite level
    series->updctrl("mrs_natural/inSamples", 64);
    series->updctrl("SoundFileSource/src/mrs_string/filename", inSfName);
    series->updctrl("SoundFileSink/dest/mrs_string/filename", outSfName);

    while (series->getctrl("SoundFileSource/src/mrs_bool/hasData")->to<mrs_bool>())
    {
        series->tick();
    }
    delete series;
}

void //extract Spectral centroid
extract_centroid_feature(string sfName)
{
    cout << "Centroid Feature Extraction for: " << sfName << endl;
    MarSystemManager mng;

    // Create a series Composite 
    MarSystem* series = mng.create("Series", "series");
    series->addMarSystem(mng.create("SoundFileSource", "src"));

    // hamming window -> complex spectrum -> power spectrum 
    series->addMarSystem(mng.create("Windowing", "hamming"));
    series->addMarSystem(mng.create("Spectrum", "spk"));
    series->addMarSystem(mng.create("PowerSpectrum", "pspk"));
    series->updctrl("PowerSpectrum/pspk/mrs_string/spectrumType", "power");
    series->addMarSystem(mng.create("Centroid", "centroid"));

    // only update controls from Composite level 
    mrs_natural inSamples = 4096;
    series->updctrl("mrs_natural/inSamples", inSamples);
    series->updctrl("SoundFileSource/src/mrs_string/filename", sfName);

    mrs_real srate = series->getctrl("SoundFileSource/src/mrs_real/osrate")->to<mrs_real>();
    mrs_natural size = series->getctrl("SoundFileSource/src/mrs_natural/size")->to<mrs_natural>();
    realvec in(series->getctrl("mrs_natural/inObservations")->to<mrs_natural>(), 
            series->getctrl("mrs_natural/inSamples")->to<mrs_natural>());
    realvec out(series->getctrl("mrs_natural/onObservations")->to<mrs_natural>(), 
            series->getctrl("mrs_natural/onSamples")->to<mrs_natural>());

    int count = 0;
    while (series->getctrl("SoundFileSource/src/mrs_bool/hasData")->to<mrs_bool>())
    {
        series->process(in,out);
        cout << "centroid = " << out(0,0) << endl;
        count ++;
    }
    //in_Count * in_Samples == channel * Sample_Rate * Seconds
    cout << "in count: " << count << endl;
    cout << "in sample rate: " << inSamples << endl;
    cout << count << "*" << inSamples << "=" << count * inSamples <<endl;

    cout << "size: " << size << endl;
    cout << "sample rate: " << srate << endl;
    int channel_count = 2;
    cout << "time: " << channel_count * size/srate << endl;
}

int main(int argc, const char **argv){
    string sound_file = "sample.mp3",
    out_file = "sample.wav";
    sfplay(sound_file, out_file);
    extract_centroid_feature(sound_file);
}