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@0:058daa59980d, 2016-12-11 (annotated)

Committer:
shorie
Date:
Sun Dec 11 21:04:06 2016 +0000
Revision:
0:058daa59980d
Child:
2:fbdf03b330ae
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Who changed what in which revision?

UserRevisionLine numberNew contents of line
shorie 0:058daa59980d 1 #include <cstdlib>
shorie 0:058daa59980d 2 #include <cmath>
shorie 0:058daa59980d 3
shorie 0:058daa59980d 4 #include "amakusa.h"
shorie 0:058daa59980d 5
shorie 0:058daa59980d 6 #ifndef M_PI
shorie 0:058daa59980d 7 #define M_PI 3.141592653589793F
shorie 0:058daa59980d 8 #endif
shorie 0:058daa59980d 9
shorie 0:058daa59980d 10 amakusa::OSCSinCos::OSCSinCos( float freq, int Fs )
shorie 0:058daa59980d 11 {
shorie 0:058daa59980d 12 this->sampleFreq = Fs;
shorie 0:058daa59980d 13 this->setFrequency( freq );
shorie 0:058daa59980d 14 this->setPhase( 0.0 ); // must call after setFrequenc()
shorie 0:058daa59980d 15 }
shorie 0:058daa59980d 16
shorie 0:058daa59980d 17 void amakusa::OSCSinCos::run( float *s, float *c , int count )
shorie 0:058daa59980d 18 {
shorie 0:058daa59980d 19 for ( int i=0; i<count; i++ )
shorie 0:058daa59980d 20 {
shorie 0:058daa59980d 21 // to make the expression simple
shorie 0:058daa59980d 22 float phase = this->deltaPhase * ( i+ this->phaseInSample );
shorie 0:058daa59980d 23
shorie 0:058daa59980d 24 s[i] = std::sin( phase );
shorie 0:058daa59980d 25 // skip cosine if c is NULL
shorie 0:058daa59980d 26 if ( c != NULL )
shorie 0:058daa59980d 27 c[i] = std::cos( phase );
shorie 0:058daa59980d 28 }
shorie 0:058daa59980d 29 // update the internal phase
shorie 0:058daa59980d 30 this->phaseInSample += count;
shorie 0:058daa59980d 31 // truncate the phase
shorie 0:058daa59980d 32 while ( this->phaseInSample >= this->sampleFreq )
shorie 0:058daa59980d 33 this->phaseInSample -= this->sampleFreq;
shorie 0:058daa59980d 34 }
shorie 0:058daa59980d 35
shorie 0:058daa59980d 36
shorie 0:058daa59980d 37 void amakusa::OSCSinCos::setFrequency( float freq )
shorie 0:058daa59980d 38 {
shorie 0:058daa59980d 39 // convert frequency to the update phase per sample.
shorie 0:058daa59980d 40 this->deltaPhase = 2 * M_PI * freq / this->sampleFreq;
shorie 0:058daa59980d 41 }
shorie 0:058daa59980d 42
shorie 0:058daa59980d 43 // put the phase into the range [0, 2pi)
shorie 0:058daa59980d 44 void amakusa::OSCSinCos::setPhase( float phase )
shorie 0:058daa59980d 45 {
shorie 0:058daa59980d 46 // convert phisical phase to the phase in sample.
shorie 0:058daa59980d 47 this->phaseInSample = phase * this->sampleFreq / ( 2 * M_PI );
shorie 0:058daa59980d 48
shorie 0:058daa59980d 49 // truncate phase in to [0,2pi)
shorie 0:058daa59980d 50 while ( this->phaseInSample < 0 )
shorie 0:058daa59980d 51 this->phaseInSample += this->sampleFreq;
shorie 0:058daa59980d 52 while ( this->phaseInSample >= this->sampleFreq )
shorie 0:058daa59980d 53 this->phaseInSample -= this->sampleFreq;
shorie 0:058daa59980d 54 }
shorie 0:058daa59980d 55
shorie 0:058daa59980d 56 float amakusa::OSCSinCos::getFrequency()
shorie 0:058daa59980d 57 {
shorie 0:058daa59980d 58 // convert sample
shorie 0:058daa59980d 59 return this->deltaPhase * this->sampleFreq / ( 2 * M_PI );
shorie 0:058daa59980d 60 }
shorie 0:058daa59980d 61 /**
shorie 0:058daa59980d 62 * \brief get the internal phase
shorie 0:058daa59980d 63 * \returns Phase in radian
shorie 0:058daa59980d 64 */
shorie 0:058daa59980d 65 float amakusa::OSCSinCos::getPhase()
shorie 0:058daa59980d 66 {
shorie 0:058daa59980d 67 return this->phaseInSample * 2 * M_PI / this->sampleFreq;
shorie 0:058daa59980d 68 }