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spectrogram: Simplify a bit

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Mike Walters
2016-06-04 14:44:13 +01:00
parent 1e9c96b9b9
commit 1d33e70a1f
1 changed files with 3 additions and 5 deletions
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8
spectrogramplot.cpp
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@@ -138,8 +138,7 @@ void SpectrogramPlot::getLine(float *dest, off_t sample)
return;
for (int i = 0; i < fftSize; i++) {
buffer[i].real(buffer[i].real() * window[i]);
buffer[i].imag(buffer[i].imag() * window[i]);
buffer[i] *= window[i];
}
fft->process(buffer.get(), buffer.get());
@@ -147,9 +146,8 @@ void SpectrogramPlot::getLine(float *dest, off_t sample)
// Start from the middle of the FFTW array and wrap
// to rearrange the data
int k = (i + fftSize / 2) & (fftSize - 1);
float re = buffer[k].real();
float im = buffer[k].imag();
float mag = sqrt(re * re + im * im) / fftSize;
auto s = buffer[k] / (float)fftSize;
float mag = sqrt(s.real() * s.real() + s.imag() * s.imag());
float magdb = 10 * log2f(mag) / log2f(10);
*dest = magdb;
dest++;