#5916: Add gaincontrol files

sflphone-common/src/audio/gaincontrol.cpp

+#include <math.h>
+#include <limits.h>
+#include <fstream>
+#include <iostream>
+
+#include "global.h"
+#include "gaincontrol.h"
+
+#define SFL_GAIN_ATTACK_RELEASE_TIME 10
+
+#define SFL_GAIN_LIMITER_RATIO 0.1
+#define SFL_GAIN_LIMITER_THRESHOLD 0.6
+
+GainControl::GainControl(double sr) : averager(sr, SFL_GAIN_ATTACK_RELEASE_TIME)
+				    , limiter(SFL_GAIN_LIMITER_RATIO, SFL_GAIN_LIMITER_THRESHOLD) {}
+
+GainControl::~GainControl() {}
+
+std::fstream tmpRms("testrms.raw", std::fstream::out);
+
+void GainControl::process(SFLDataFormat *inBuf, SFLDataFormat *outBuf, int bufLength) 
+{
+    double rms, rmsAvg, in, out;
+
+    for(int i = 0; i < bufLength; i++) {
+	in = (double)inBuf[i] / (double)SHRT_MAX;
+        rms = detector.getRms(in);
+        rmsAvg = sqrt(averager.getAverage(rms));
+        
+	tmpRms.write(reinterpret_cast<char *>(&rmsAvg), sizeof(double));
+
+        out = limiter.limit(in);
+        outBuf[i] = (short)(out * (double)SHRT_MAX);
+    }
+}
+
+GainControl::RmsDetection::RmsDetection() {}
+
+double GainControl::RmsDetection::getRms(double in) 
+{
+    return in * in;
+}
+
+GainControl::DetectionAverage::DetectionAverage(double sr, double t) : 
+			g(0.0), teta(t), samplingRate(sr), previous_y(0.0) 
+{
+    g = exp(-1.0 / (samplingRate * (teta / 1000.0)));        
+
+    std::cout << "GainControl: g: " << g << ", teta: " << teta << std::endl;
+}
+
+double GainControl::DetectionAverage::getAverage(double in)
+{
+    previous_y = ((1.0 - g) * in) + (g * previous_y);
+
+    return previous_y;
+}
+
+GainControl::Limiter::Limiter(double r, double thresh) : ratio(r), threshold(thresh)
+{
+    std::cout << "GainControl: limiter threshold: " << threshold << std::endl;
+}
+
+double GainControl::Limiter::limit(double in)
+{
+    double out;
+
+    out = (in > threshold ? (ratio * (in - threshold)) + threshold :
+    in < -threshold ? (ratio * (in + threshold)) - threshold : in);
+
+    return out;
+}

sflphone-common/src/audio/gaincontrol.h

+#ifndef GAINCONTROL_H
+#define GAINCONTROL_H
+
+#include "global.h"
+
+#define SFL_GAIN_BUFFER_LENGTH 160
+
+class GainControl {
+
+public:
+    GainControl(double);
+    ~GainControl(void);
+
+    void process(SFLDataFormat *, SFLDataFormat *, int);
+
+private:
+
+    class RmsDetection {
+    public:
+	/**
+	 * Constructor for this class
+         */
+	RmsDetection(void);
+
+        /**
+	 * Get rms value
+	 */
+        double getRms(double);
+    
+    };
+
+    class DetectionAverage {
+    public:
+        /**
+         * Constructor for this class
+         */
+	DetectionAverage(double, double);
+        
+        /**
+	 * Process average
+	 */
+        double getAverage(double);
+
+    private:
+        /**
+         * Average factor
+         */
+	double g;
+
+        /**
+         * Attack and release ramp time (in ms)
+         */
+	double teta;
+
+        /**
+	 * Samplig rate
+	 */
+        double samplingRate;
+
+        /**
+	 * Previous gain (first order memory)
+         */
+        double previous_y;
+    };
+
+    class Limiter {
+    public:
+    	Limiter(double, double);
+
+        double limit(double);
+
+    private:
+	double ratio;
+	double threshold;
+    };
+
+    RmsDetection detector;
+
+    DetectionAverage averager;
+
+    Limiter limiter;
+};
+
+#endif // GAINCONTROL_H