[#3507] Add downsampling decimation filter

sflphone-common/src/audio/delaydetection.cpp

@@ -40,13 +40,13 @@ FirFilter::FirFilter(std::vector<double> ir) : _impulseResponse(ir),
 
 FirFilter::~FirFilter() {}
 
-int FirFilter::getOutputSample(int inputSample) 
+float FirFilter::getOutputSample(float inputSample) 
 {
-  _delayLine[_count] = (double)inputSample;
+  _taps[_count] = inputSample;
   double result = 0.0;
   int index = _count;
   for(int i = 0; i < _length; i++) {
-    result = result + _impulseResponse[i] * _delayLine[index--];
+    result = result + _impulseResponse[i] * _taps[index--];
     if(index < 0)
       index = _length-1;
   }
@@ -54,17 +54,28 @@ int FirFilter::getOutputSample(int inputSample)
   if(_count >= _length)
     _count = 0;
 
-  return (int)result;
+  return result;
 }
 
 
-DelayDetection::DelayDetection(){}
+DelayDetection::DelayDetection(std::vector<double> ir) : _decimationFilter(ir) {}
 
 DelayDetection::~DelayDetection(){}
 
 void DelayDetection::reset() {}
 
-void DelayDetection::putData(SFLDataFormat *inputData, int nbBytes) {}
+void DelayDetection::putData(SFLDataFormat *inputData, int nbBytes) 
+{
+  int nbSamples = nbBytes/sizeof(SFLDataFormat);
+  
+  float tmp[nbSamples];
+
+  float down[nbSamples];
+
+  convertInt16ToFloat32(inputData, tmp, nbSamples);
+
+  downsampleData(tmp, down, nbSamples, 8);
+}
 
 int DelayDetection::getData(SFLDataFormat *outputData) { return 0; }
 
@@ -120,6 +131,7 @@ void DelayDetection::crossCorrelate(double *ref, double *seg, double *res, short
     ++i;
   }
 }
+
 double DelayDetection::correlate(double *sig1, double *sig2, short size) {
 
   short s = size;
@@ -130,3 +142,33 @@ double DelayDetection::correlate(double *sig1, double *sig2, short size) {
 
   return ac;
 }
+
+
+void DelayDetection::convertInt16ToFloat32(SFLDataFormat *input, float *output, int nbSamples) {
+
+    // factor is 1/(2^15), used to rescale the short int range to the
+    // [-1.0 - 1.0] float range.
+#define S2F_FACTOR .000030517578125f;
+  int len = nbSamples;
+
+  while(len) {
+    len--;
+    output[len] = (float)input[len] * S2F_FACTOR;
+  }
+}
+
+
+
+void DelayDetection::downsampleData(float *input, float *output, int nbSamples, int factor) {
+
+  
+    float tmp[nbSamples];
+
+    for(int i = 0; i < nbSamples; i++) {
+        tmp[i] = _decimationFilter.getOutputSample(input[i]);
+    }
+
+    for(int i = 0; i < nbSamples; i+=factor) {
+        output[i] = tmp[i];
+    }
+}

sflphone-common/src/audio/delaydetection.h

@@ -40,6 +40,9 @@
 // Segment length in ms for correlation
 #define MAX_DELAY 150
 
+// Size of internal buffers in samples
+#define DELAY_BUFF_SIZE 150*8000/1000 
+
 #define MAXFILTERSIZE 100
 
 class FirFilter {
@@ -56,6 +59,11 @@ class FirFilter {
    */
   ~FirFilter();
   
+  /**
+   * Perform filtering on one sample
+   */
+  float getOutputSample(float inputSample);
+
 
  private:
 
@@ -72,17 +80,12 @@ class FirFilter {
   /**
    * Circular buffer
    */
-  double _delayLine[MAXFILTERSIZE];
+  double _taps[MAXFILTERSIZE];
 
   /**
    * Counter
    */
   int _count;
-
-  /**
-   * Perform filtering on one sample
-   */
-  int getOutputSample(int inputSample);
   
 };
 
@@ -91,7 +94,7 @@ class DelayDetection : public Algorithm {
 
  public:
 
-    DelayDetection();
+    DelayDetection(std::vector<double> ir);
 
     ~DelayDetection();
 
@@ -119,6 +122,10 @@ class DelayDetection : public Algorithm {
      */
     double correlate(double *sig1, double *sig2, short size);
 
+    void convertInt16ToFloat32(SFLDataFormat *input, float *ouput, int nbSamples);
+
+    void downsampleData(float *input, float *output, int nbSamples, int factor);
+
     /**
      * Segment size in samples for correlation
      */
@@ -129,6 +136,22 @@ class DelayDetection : public Algorithm {
      */
     short _correlationSize;
 
+    float _spkrReference[DELAY_BUFF_SIZE];
+
+    float _capturedData[DELAY_BUFF_SIZE];
+
+    float _spkrReferenceDown[DELAY_BUFF_SIZE];
+
+    float _captureDataDown[DELAY_BUFF_SIZE];
+
+    float _spkrReferenceFilter[DELAY_BUFF_SIZE];
+
+    float _captureDataFilter[DELAY_BUFF_SIZE];
+
+    //     int myints[] = {16,2,77,29};
+    // vector<int> fifth (myints, myints + sizeof(myints) / sizeof(int) );
+
+    FirFilter _decimationFilter;
 
  public: