Move normalization from ValueMap to FFT class.

2 files changed, 8 insertions, 4 deletions

diff --git a/src/fft.cpp b/src/fft.cpp
index 8f94986..2802346 100644
--- a/src/fft.cpp
+++ b/src/fft.cpp
@@ -104,6 +104,11 @@ FFT::Compute(const ComplexWindow& input)
                 (void *) this->out_,
                 lhl * sizeof(fftw_complex));
 
+    /* fftw does not normalize; divide by the window size */
+    for (auto& v : output) {
+        v /= (double)output.size();
+    }
+
     return output;
 }
 
@@ -231,4 +236,4 @@ FFT::Crop(const RealWindow& input, double rate, double fmin, double fmax)
 
     /* return corresponding subvector */
     return RealWindow(input.begin() + i_fmin, input.begin() + i_fmax);
-}
\ No newline at end of file
+}
diff --git a/src/value-map.cpp b/src/value-map.cpp
index 2627ed3..51e3944 100644
--- a/src/value-map.cpp
+++ b/src/value-map.cpp
@@ -49,7 +49,7 @@ RealWindow LinearValueMap::Map(const RealWindow &input)
     RealWindow output(n);
 
     for (unsigned int i = 0; i < n; i ++) {
-        output[i] = std::clamp<double>(input[i] / n, this->lower_, this->upper_);
+        output[i] = std::clamp<double>(input[i], this->lower_, this->upper_);
         output[i] = (output[i] - this->lower_) / (this->upper_ - this->lower_);
     }
 
@@ -67,7 +67,7 @@ RealWindow DecibelValueMap::Map(const RealWindow &input)
     RealWindow output(n);
 
     for (unsigned int i = 0; i < n; i ++) {
-        output[i] = 20.0 * std::log10(input[i] / n);
+        output[i] = 20.0 * std::log10(input[i]);
         output[i] = std::clamp<double>(output[i], this->lower_, this->upper_);
         output[i] = (output[i] - this->lower_) / (this->upper_ - this->lower_);
     }
@@ -79,4 +79,3 @@ std::string DecibelValueMap::GetUnit() const
 {
     return "dB" + unit_;
 }
-