Move normalization from ValueMap to FFT class.

1 files changed, 6 insertions, 1 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
+}