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。

Diff: oscsincos.cpp

Revision:
0:058daa59980d
Child:
2:fbdf03b330ae
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/oscsincos.cpp	Sun Dec 11 21:04:06 2016 +0000
@@ -0,0 +1,68 @@
+#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;
+}