Remove distinction between Coeff and Sample types; they are always the same floating point type.

Filter.cc

@@ -208,23 +208,23 @@ void DownsampleFilter::process(const SampleVector& samples_in,
         // the FIR coefficient table. This is a bitch.
 
         // Estimate number of output samples we can produce in this run.
-        Coeff p = m_pos_frac;
+        Sample p = m_pos_frac;
-        Coeff pstep = m_downsample;
+        Sample pstep = m_downsample;
         unsigned int n_out = int(2 + n / pstep);
 
         samples_out.resize(n_out);
 
         // Produce output samples.
         unsigned int i = 0;
-        Coeff pf = p;
+        Sample pf = p;
         unsigned int pi = int(pf);
         while (pi < n) {
-            Coeff k1 = pf - pi;
+            Sample k1 = pf - pi;
-            Coeff k0 = 1 - k1;
+            Sample k0 = 1 - k1;
 
             Sample y = 0;
             for (unsigned int j = 0; j <= order; j++) {
-                Coeff  k = m_coeff[j] * k0 + m_coeff[j+1] * k1;
+                Sample k = m_coeff[j] * k0 + m_coeff[j+1] * k1;
                 Sample s = (j <= pi) ? samples_in[pi-j] : m_state[order+pi-j];
                 y += k * s;
             }
@@ -278,8 +278,8 @@ void LowPassFilterRC::process(const SampleVector& samples_in,
      * Discrete domain:
      *   H(z) = (1 - exp(-1/timeconst)) / (1 - exp(-1/timeconst) / z)a
      */
-    Coeff a1 = - exp(-1/m_timeconst);;
+    Sample a1 = - exp(-1/m_timeconst);;
-    Coeff b0 = 1 + a1;
+    Sample b0 = 1 + a1;
 
     unsigned int n = samples_in.size();
     samples_out.resize(n);
@@ -298,8 +298,8 @@ void LowPassFilterRC::process(const SampleVector& samples_in,
 // Process samples in-place.
 void LowPassFilterRC::processInPlace(SampleVector& samples)
 {
-    Coeff a1 = - exp(-1/m_timeconst);;
+    Sample a1 = - exp(-1/m_timeconst);;
-    Coeff b0 = 1 + a1;
+    Sample b0 = 1 + a1;
 
     unsigned int n = samples.size();
 

Filter.h

@@ -85,8 +85,8 @@ private:
     double          m_downsample;
     unsigned int    m_downsample_int;
     unsigned int    m_pos_int;
-    Coeff           m_pos_frac;
+    Sample          m_pos_frac;
-    CoeffVector     m_coeff;
+    SampleVector    m_coeff;
     SampleVector    m_state;
 };
 
@@ -132,7 +132,7 @@ public:
     void process(const SampleVector& samples_in, SampleVector& samples_out);
 
 private:
-    Coeff   b0, a1, a2, a3, a4;
+    Sample  b0, a1, a2, a3, a4;
     Sample  y1, y2, y3, y4;
 };
 
@@ -157,7 +157,7 @@ public:
     void processInPlace(SampleVector& samples);
 
 private:
-    Coeff  b0, b1, b2, a1, a2;
+    Sample b0, b1, b2, a1, a2;
     Sample x1, x2, y1, y2;
 };
 

FmDecode.cc

@@ -96,12 +96,12 @@ PilotPhaseLock::PilotPhaseLock(double freq, double bandwidth, double minsignal)
     m_lock_delay = int(10.0 / bandwidth);
     m_lock_cnt   = 0;
 
-    // Create 2nd order filter for IQ representation of phase error
+    // Create 2nd order filter for I/Q representation of phase error.
-    // with both poles at z = exp(-2.5 * bandwidth * 2*PI).
+    // Filter has both poles at z = exp(-2.5 * bandwidth * 2*PI).
     double t = exp(-2.5 * bandwidth * 2.0 * M_PI);
-    m_iqfilter_a1 = -2.0 * t;
+    m_phasor_a1 = -2.0 * t;
-    m_iqfilter_a2 = t * t;
+    m_phasor_a2 = t * t;
-    m_iqfilter_b0 = m_iqfilter_a1 + m_iqfilter_a2;
+    m_phasor_b0 = m_phasor_a1 + m_phasor_a2;
 
     // Create loop filter to stabilize the loop.
     // Zero at z = exp(-0.2 * bandwidth * 2*PI), 
@@ -113,10 +113,10 @@ PilotPhaseLock::PilotPhaseLock(double freq, double bandwidth, double minsignal)
     m_freq  = freq * 2.0 * M_PI;
     m_phase = 0;
 
-    m_iqfilter_i1 = 0;
+    m_phasor_i1 = 0;
-    m_iqfilter_i2 = 0;
+    m_phasor_i2 = 0;
-    m_iqfilter_q1 = 0;
+    m_phasor_q1 = 0;
-    m_iqfilter_q2 = 0;
+    m_phasor_q2 = 0;
 }
 
 
@@ -141,16 +141,16 @@ void PilotPhaseLock::process(const SampleVector& samples_in,
         Sample phasor_q = psin * x;
 
         // Run IQ phase error through low-pass filter.
-        phasor_i = m_iqfilter_b0 * phasor_i
+        phasor_i = m_phasor_b0 * phasor_i
-                   - m_iqfilter_a1 * m_iqfilter_i1
+                   - m_phasor_a1 * m_phasor_i1
-                   - m_iqfilter_a2 * m_iqfilter_i2;
+                   - m_phasor_a2 * m_phasor_i2;
-        phasor_q = m_iqfilter_b0 * phasor_q
+        phasor_q = m_phasor_b0 * phasor_q
-                   - m_iqfilter_a1 * m_iqfilter_q1
+                   - m_phasor_a1 * m_phasor_q1
-                   - m_iqfilter_a2 * m_iqfilter_q2;
+                   - m_phasor_a2 * m_phasor_q2;
-        m_iqfilter_i2 = m_iqfilter_i1;
+        m_phasor_i2 = m_phasor_i1;
-        m_iqfilter_i1 = phasor_i;
+        m_phasor_i1 = phasor_i;
-        m_iqfilter_q2 = m_iqfilter_q1;
+        m_phasor_q2 = m_phasor_q1;
-        m_iqfilter_q1 = phasor_q;
+        m_phasor_q1 = phasor_q;
 
         // Convert I/Q ratio to estimate of phase error.
         Sample phase_err;

FmDecode.h

@@ -26,7 +26,7 @@ public:
     void process(const IQSampleVector& samples_in, SampleVector& samples_out);
 
 private:
-    const Coeff m_freq_scale_factor;
+    const Sample m_freq_scale_factor;
     IQSample     m_last_sample;
 };
 
@@ -56,10 +56,10 @@ public:
     }
 
 private:
-    Coeff   m_minfreq, m_maxfreq;
+    Sample  m_minfreq, m_maxfreq;
-    Coeff   m_iqfilter_b0, m_iqfilter_a1, m_iqfilter_a2;
+    Sample  m_phasor_b0, m_phasor_a1, m_phasor_a2;
-    Coeff   m_loopfilter_b0, m_loopfilter_b1;
+    Sample  m_phasor_i1, m_phasor_i2, m_phasor_q1, m_phasor_q2;
-    Sample  m_iqfilter_i1, m_iqfilter_i2, m_iqfilter_q1, m_iqfilter_q2;
+    Sample  m_loopfilter_b0, m_loopfilter_b1;
     Sample  m_loopfilter_x1;
     Sample  m_freq, m_phase;
     Sample  m_minsignal;

SoftFM.h

@@ -10,12 +10,10 @@ typedef std::vector<IQSample> IQSampleVector;
 typedef double Sample;
 typedef std::vector<Sample> SampleVector;
 
-typedef double Coeff;
-typedef std::vector<Coeff> CoeffVector;
-
 
 /** Compute mean and RMS over a sample vector. */
-inline void samples_mean_rms(const SampleVector& samples, double& mean, double& rms)
+inline void samples_mean_rms(const SampleVector& samples,
+                             double& mean, double& rms)
 {
     Sample vsum = 0;
     Sample vsumsq = 0;