diff options
| -rw-r--r-- | Alc/effects/fshifter.cpp | 2 | ||||
| -rw-r--r-- | Alc/effects/pshifter.cpp | 4 | ||||
| -rw-r--r-- | common/alcomplex.cpp | 58 | ||||
| -rw-r--r-- | common/alcomplex.h | 18 |
4 files changed, 41 insertions, 41 deletions
diff --git a/Alc/effects/fshifter.cpp b/Alc/effects/fshifter.cpp index 496a767d..0bbcc859 100644 --- a/Alc/effects/fshifter.cpp +++ b/Alc/effects/fshifter.cpp @@ -171,7 +171,7 @@ void FshifterState::process(const ALsizei samplesToDo, const FloatBufferLine *RE } /* Processing signal by Discrete Hilbert Transform (analytical signal). */ - complex_hilbert(mAnalytic, HIL_SIZE); + complex_hilbert(mAnalytic); /* Windowing and add to output accumulator */ for(k = 0;k < HIL_SIZE;k++) diff --git a/Alc/effects/pshifter.cpp b/Alc/effects/pshifter.cpp index f1865830..619bde34 100644 --- a/Alc/effects/pshifter.cpp +++ b/Alc/effects/pshifter.cpp @@ -230,7 +230,7 @@ void PshifterState::process(const ALsizei samplesToDo, const FloatBufferLine *RE /* ANALYSIS */ /* Apply FFT to FFTbuffer data */ - complex_fft(mFFTbuffer, STFT_SIZE, -1.0); + complex_fft(mFFTbuffer, -1.0); /* Analyze the obtained data. Since the real FFT is symmetric, only * STFT_HALF_SIZE+1 samples are needed. @@ -302,7 +302,7 @@ void PshifterState::process(const ALsizei samplesToDo, const FloatBufferLine *RE mFFTbuffer[k] = complex_d{}; /* Apply iFFT to buffer data */ - complex_fft(mFFTbuffer, STFT_SIZE, 1.0); + complex_fft(mFFTbuffer, 1.0); /* Windowing and add to output */ for(ALsizei k{0};k < STFT_SIZE;k++) diff --git a/common/alcomplex.cpp b/common/alcomplex.cpp index ace1b43f..9074cf5f 100644 --- a/common/alcomplex.cpp +++ b/common/alcomplex.cpp @@ -4,6 +4,7 @@ #include "alcomplex.h" #include <cmath> +#include <algorithm> namespace { @@ -11,13 +12,14 @@ constexpr double Pi{3.141592653589793238462643383279502884}; } // namespace -void complex_fft(std::complex<double> *FFTBuffer, int FFTSize, double Sign) +void complex_fft(const al::span<std::complex<double>> buffer, const double sign) { + const size_t fftsize{buffer.size()}; /* Bit-reversal permutation applied to a sequence of FFTSize items */ - for(int i{1};i < FFTSize-1;i++) + for(size_t i{1u};i < fftsize-1;i++) { - int j{0}; - for(int mask{1};mask < FFTSize;mask <<= 1) + size_t j{0u}; + for(size_t mask{1u};mask < fftsize;mask <<= 1) { if((i&mask) != 0) j++; @@ -26,25 +28,25 @@ void complex_fft(std::complex<double> *FFTBuffer, int FFTSize, double Sign) j >>= 1; if(i < j) - std::swap(FFTBuffer[i], FFTBuffer[j]); + std::swap(buffer[i], buffer[j]); } /* Iterative form of Danielson–Lanczos lemma */ - int step{2}; - for(int i{1};i < FFTSize;i<<=1, step<<=1) + size_t step{2u}; + for(size_t i{1u};i < fftsize;i<<=1, step<<=1) { - int step2{step >> 1}; + const size_t step2{step >> 1}; double arg{Pi / step2}; - std::complex<double> w{std::cos(arg), std::sin(arg)*Sign}; + std::complex<double> w{std::cos(arg), std::sin(arg)*sign}; std::complex<double> u{1.0, 0.0}; - for(int j{0};j < step2;j++) + for(size_t j{0};j < step2;j++) { - for(int k{j};k < FFTSize;k+=step) + for(size_t k{j};k < fftsize;k+=step) { - std::complex<double> temp{FFTBuffer[k+step2] * u}; - FFTBuffer[k+step2] = FFTBuffer[k] - temp; - FFTBuffer[k] += temp; + std::complex<double> temp{buffer[k+step2] * u}; + buffer[k+step2] = buffer[k] - temp; + buffer[k] += temp; } u *= w; @@ -52,25 +54,23 @@ void complex_fft(std::complex<double> *FFTBuffer, int FFTSize, double Sign) } } -void complex_hilbert(std::complex<double> *Buffer, int size) +void complex_hilbert(const al::span<std::complex<double>> buffer) { - const double inverse_size = 1.0/static_cast<double>(size); + std::for_each(buffer.begin(), buffer.end(), [](std::complex<double> &c) { c.imag(0.0); }); - for(int i{0};i < size;i++) - Buffer[i].imag(0.0); + complex_fft(buffer, 1.0); - complex_fft(Buffer, size, 1.0); + const double inverse_size = 1.0/static_cast<double>(buffer.size()); + auto bufiter = buffer.begin(); + const auto halfiter = bufiter + (buffer.size()>>1); - int todo{size>>1}; - int i{0}; + *bufiter *= inverse_size; ++bufiter; + bufiter = std::transform(bufiter, halfiter, bufiter, + [inverse_size](const std::complex<double> &c) -> std::complex<double> + { return c * (2.0*inverse_size); }); + *bufiter *= inverse_size; ++bufiter; - Buffer[i++] *= inverse_size; - while(i < todo) - Buffer[i++] *= 2.0*inverse_size; - Buffer[i++] *= inverse_size; + std::fill(bufiter, buffer.end(), std::complex<double>{}); - for(;i < size;i++) - Buffer[i] = std::complex<double>{}; - - complex_fft(Buffer, size, -1.0); + complex_fft(buffer, -1.0); } diff --git a/common/alcomplex.h b/common/alcomplex.h index 554886c4..f224cce2 100644 --- a/common/alcomplex.h +++ b/common/alcomplex.h @@ -3,22 +3,22 @@ #include <complex> +#include "alspan.h" + /** * Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is - * FFT and 1 is iFFT (inverse). Fills FFTBuffer[0...FFTSize-1] with the - * Discrete Fourier Transform (DFT) of the time domain data stored in - * FFTBuffer[0...FFTSize-1]. FFTBuffer is an array of complex numbers, FFTSize - * MUST BE power of two. + * FFT and 1 is iFFT (inverse). Fills the buffer with the Discrete Fourier + * Transform (DFT) of the time domain data stored in the buffer. The buffer is + * an array of complex numbers, and MUST BE power of two. */ -void complex_fft(std::complex<double> *FFTBuffer, int FFTSize, double Sign); +void complex_fft(const al::span<std::complex<double>> buffer, const double sign); /** * Calculate the complex helical sequence (discrete-time analytical signal) of * the given input using the discrete Hilbert transform (In-place algorithm). - * Fills Buffer[0...size-1] with the discrete-time analytical signal stored in - * Buffer[0...size-1]. Buffer is an array of complex numbers, size MUST BE - * power of two. + * Fills the buffer with the discrete-time analytical signal stored in the + * buffer. The buffer is an array of complex numbers and MUST BE power of two. */ -void complex_hilbert(std::complex<double> *Buffer, int size); +void complex_hilbert(const al::span<std::complex<double>> buffer); #endif /* ALCOMPLEX_H */ |