AudioFFT provides real-to-complex/complex-to-real FFT routines.
Features:
- Real-complex FFT and complex-real inverse FFT for power-of-2-sized real data.
- Uniform interface to different FFT implementations (currently Ooura, FFTW3 and Apple Accelerate).
- Complex data is handled in "split-complex" format, i.e. there are separate arrays for the real and imaginary parts which can be useful for SIMD optimizations (split-complex arrays have to be of length (size/2+1) representing bins from DC to Nyquist frequency).
- Output is "ready to use" (all scaling etc. is already handled internally).
- No allocations/deallocations after the initialization which makes it usable for real-time audio applications (that's what I wrote it for and using it).
How to use it in your project:
- Add the .h and .cpp file to your project - that's all.
- To get extra speed, you can link FFTW3 to your project and define AUDIOFFT_FFTW3 (however, please check whether your project suits the according license).
- To get the best speed on Apple platforms, you can link the Apple Accelerate framework to your project and define AUDIOFFT_APPLE_ACCELERATE (however, please check whether your project suits the according license).
Remarks:
- AudioFFT is not intended to be the fastest FFT, but to be a fast-enough FFT suitable for most audio applications.
- AudioFFT uses the quite liberal MIT license.
Example usage:
void Example()
{
const size_t fftSize = 1024;
std::vector<float> input(fftSize, 0.0f);
std::vector<float> output(fftSize);
fft.
fft(input.data(), re.data(), im.data());
fft.
ifft(output.data(), re.data(), im.data());
}
Performs 1D FFTs.
Definition AudioFFT.h:106
void init(size_t size)
Initializes the FFT object.
Definition AudioFFT.cpp:984
void fft(const float *data, float *re, float *im)
Performs the forward FFT.
Definition AudioFFT.cpp:990
void ifft(float *data, const float *re, const float *im)
Performs the inverse FFT.
Definition AudioFFT.cpp:992
static size_t ComplexSize(size_t size)
Calculates the necessary size of the real/imaginary complex arrays.
Definition AudioFFT.cpp:994
1.12.0