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Code cleanup: removed the old real FFT code not used since at least 2009.

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I confirmed that the currently used real FFT code in RealFFTf.cpp is faster
than the old one with a quick benchmark that calls PowerSpectrum() on 4-minute
audio file, with different sizes of computation windows:

Window_size: 256 method: new FFT time_s: 0.393
Window_size: 256 method: old FFT time_s: 1.065
Window_size: 1024 method: new FFT time_s: 0.38
Window_size: 1024 method: old FFT time_s: 0.958
Window_size: 4096 method: new FFT time_s: 0.413
Window_size: 4096 method: old FFT time_s: 1.084
Window_size: 16384 method: new FFT time_s: 0.518
Window_size: 16384 method: old FFT time_s: 1.338
Window_size: 65536 method: new FFT time_s: 0.655
Window_size: 65536 method: old FFT time_s: 1.524
Window_size: 262144 method: new FFT time_s: 0.735
Window_size: 262144 method: old FFT time_s: 1.873
This commit is contained in:
Raphaël Marinier
2016-06-25 16:23:56 +02:00
parent cf79f91da0
commit 6ac68db5be
10 changed files with 8 additions and 210 deletions
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17
src/FreqWindow.cpp
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@@ -1255,11 +1255,7 @@ bool SpectrumAnalyst::Calculate(Algorithm alg, int windowFunc,
case EnhancedAutocorrelation:
// Take FFT
#ifdef EXPERIMENTAL_USE_REALFFTF
RealFFT(mWindowSize, in, out, out2);
#else
FFT(mWindowSize, false, in, NULL, out, out2);
#endif
// Compute power
for (int i = 0; i < mWindowSize; i++)
in[i] = (out[i] * out[i]) + (out2[i] * out2[i]);
@@ -1277,11 +1273,7 @@ bool SpectrumAnalyst::Calculate(Algorithm alg, int windowFunc,
in[i] = pow(in[i], 1.0f / 3.0f);
}
// Take FFT
#ifdef EXPERIMENTAL_USE_REALFFTF
RealFFT(mWindowSize, in, out, out2);
#else
FFT(mWindowSize, false, in, NULL, out, out2);
#endif
// Take real part of result
for (int i = 0; i < half; i++)
@@ -1289,12 +1281,7 @@ bool SpectrumAnalyst::Calculate(Algorithm alg, int windowFunc,
break;
case Cepstrum:
#ifdef EXPERIMENTAL_USE_REALFFTF
RealFFT(mWindowSize, in, out, out2);
#else
FFT(mWindowSize, false, in, NULL, out, out2);
#endif
// Compute log power
// Set a sane lower limit assuming maximum time amplitude of 1.0
{
@@ -1309,11 +1296,7 @@ bool SpectrumAnalyst::Calculate(Algorithm alg, int windowFunc,
in[i] = log(power);
}
// Take IFFT
#ifdef EXPERIMENTAL_USE_REALFFTF
InverseRealFFT(mWindowSize, in, NULL, out);
#else
FFT(mWindowSize, true, in, NULL, out, out2);
#endif
// Take real part of result
for (int i = 0; i < half; i++)