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@8:1fa224c83cfa, 2017-02-18 (annotated)

Committer:
shorie
Date:
Sat Feb 18 01:05:19 2017 +0000
Revision:
8:1fa224c83cfa
Parent:
2:fbdf03b330ae 
Fixed mistake of visibility in the limitterlinatan.h

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 2:fbdf03b330ae 10 amakusa::OSCSinCos::OSCSinCos( float freq, int Fs, int block_size )
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 2:fbdf03b330ae 15 this->bs = block_size;
shorie 0:058daa59980d 16 }
shorie 0:058daa59980d 17
shorie 2:fbdf03b330ae 18 void amakusa::OSCSinCos::run( float *s, float *c)
shorie 0:058daa59980d 19 {
shorie 2:fbdf03b330ae 20
shorie 2:fbdf03b330ae 21 for ( int i=0; i<this->bs; i++ )
shorie 0:058daa59980d 22 {
shorie 0:058daa59980d 23 // to make the expression simple
shorie 0:058daa59980d 24 float phase = this->deltaPhase * ( i+ this->phaseInSample );
shorie 0:058daa59980d 25
shorie 2:fbdf03b330ae 26 // normal sind cosine
shorie 0:058daa59980d 27 s[i] = std::sin( phase );
shorie 0:058daa59980d 28 // skip cosine if c is NULL
shorie 0:058daa59980d 29 if ( c != NULL )
shorie 0:058daa59980d 30 c[i] = std::cos( phase );
shorie 2:fbdf03b330ae 31
shorie 2:fbdf03b330ae 32
shorie 0:058daa59980d 33 }
shorie 0:058daa59980d 34 // update the internal phase
shorie 2:fbdf03b330ae 35 this->phaseInSample += this->bs;
shorie 0:058daa59980d 36 // truncate the phase
shorie 0:058daa59980d 37 while ( this->phaseInSample >= this->sampleFreq )
shorie 0:058daa59980d 38 this->phaseInSample -= this->sampleFreq;
shorie 0:058daa59980d 39 }
shorie 0:058daa59980d 40
shorie 0:058daa59980d 41
shorie 0:058daa59980d 42 void amakusa::OSCSinCos::setFrequency( float freq )
shorie 0:058daa59980d 43 {
shorie 0:058daa59980d 44 // convert frequency to the update phase per sample.
shorie 0:058daa59980d 45 this->deltaPhase = 2 * M_PI * freq / this->sampleFreq;
shorie 0:058daa59980d 46 }
shorie 0:058daa59980d 47
shorie 0:058daa59980d 48 // put the phase into the range [0, 2pi)
shorie 0:058daa59980d 49 void amakusa::OSCSinCos::setPhase( float phase )
shorie 0:058daa59980d 50 {
shorie 0:058daa59980d 51 // convert phisical phase to the phase in sample.
shorie 0:058daa59980d 52 this->phaseInSample = phase * this->sampleFreq / ( 2 * M_PI );
shorie 0:058daa59980d 53
shorie 0:058daa59980d 54 // truncate phase in to [0,2pi)
shorie 0:058daa59980d 55 while ( this->phaseInSample < 0 )
shorie 0:058daa59980d 56 this->phaseInSample += this->sampleFreq;
shorie 0:058daa59980d 57 while ( this->phaseInSample >= this->sampleFreq )
shorie 0:058daa59980d 58 this->phaseInSample -= this->sampleFreq;
shorie 0:058daa59980d 59 }
shorie 0:058daa59980d 60
shorie 0:058daa59980d 61 float amakusa::OSCSinCos::getFrequency()
shorie 0:058daa59980d 62 {
shorie 0:058daa59980d 63 // convert sample
shorie 0:058daa59980d 64 return this->deltaPhase * this->sampleFreq / ( 2 * M_PI );
shorie 0:058daa59980d 65 }
shorie 0:058daa59980d 66 /**
shorie 0:058daa59980d 67 * \brief get the internal phase
shorie 0:058daa59980d 68 * \returns Phase in radian
shorie 0:058daa59980d 69 */
shorie 0:058daa59980d 70 float amakusa::OSCSinCos::getPhase()
shorie 0:058daa59980d 71 {
shorie 0:058daa59980d 72 return this->phaseInSample * 2 * M_PI / this->sampleFreq;
shorie 0:058daa59980d 73 }