seiichi horie / amakusa

Basic Audio Signal Processing Library

Dependents:   unzen_sample_nucleo_f746 skeleton_unzen_nucleo_f746 ifmag_noise_canceller synthesizer_f746

オーディオ信号処理用のライブラリです。

mbed-dspのフィルタ群向けに作ったクラス・ラッパーのほか、以下のクラスを用意しています。

  • ヒステリシス
  • sin/cosオシレータ
  • リミッター

クラスは全て名前空間amakusaに含まれます。

oscsincos.cpp

Committer:
shorie
Date:
2016-12-11
Revision:
0:058daa59980d
Child:
2:fbdf03b330ae

File content as of revision 0:058daa59980d:

#include <cstdlib>
#include <cmath>

#include "amakusa.h"

#ifndef M_PI
#define M_PI  3.141592653589793F
#endif

amakusa::OSCSinCos::OSCSinCos( float freq, int Fs )
{
        this->sampleFreq = Fs;
        this->setFrequency( freq );
        this->setPhase( 0.0 );      // must call after setFrequenc()
}

void amakusa::OSCSinCos::run( float *s, float *c , int count )
{
    for ( int i=0; i<count; i++ )
    {
            // to make the expression simple
        float phase = this->deltaPhase * ( i+ this->phaseInSample );
        
        s[i] = std::sin( phase );
            // skip cosine if c is NULL
        if ( c != NULL )
            c[i] = std::cos( phase );
    }
        // update the internal phase
    this->phaseInSample += count;
        // truncate the phase
    while ( this->phaseInSample >= this->sampleFreq )
        this->phaseInSample -= this->sampleFreq;
}


void amakusa::OSCSinCos::setFrequency( float freq )
{
        // convert frequency to the update phase per sample.
    this->deltaPhase = 2 * M_PI * freq / this->sampleFreq;
}

    // put the phase into the range [0, 2pi)
void amakusa::OSCSinCos::setPhase( float phase )
{
        // convert phisical phase to the phase in sample.
    this->phaseInSample = phase  * this->sampleFreq / ( 2 * M_PI );
    
        // truncate phase in to [0,2pi)
    while ( this->phaseInSample < 0 )
        this->phaseInSample += this->sampleFreq;
    while ( this->phaseInSample >= this->sampleFreq )
        this->phaseInSample -= this->sampleFreq;
}

float amakusa::OSCSinCos::getFrequency()
{
        // convert sample
    return this->deltaPhase * this->sampleFreq / ( 2 * M_PI );
}
            /**
            * \brief get the internal phase
            * \returns Phase in radian
            */
float amakusa::OSCSinCos::getPhase()
{
    return this->phaseInSample * 2 * M_PI / this->sampleFreq;
}