* Real FFT wraper for Apple's Accelerate Framework * and STFT implementation making use of Apple's Accelerate Framework (pkmFFT) * * Created by Parag K. Mital - http://pkmital.com * Contact: parag@pkmital.com * * Copyright 2011 Parag K. Mital. All rights reserved. * * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documentation * files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, * copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following * conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. * * Additional resources: * http://developer.apple.com/library/ios/#documentation/Accelerate/Reference/vDSPRef/Reference/reference.html * http://developer.apple.com/library/ios/#documentation/Performance/Conceptual/vDSP_Programming_Guide/SampleCode/SampleCode.html * http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework * http://stackoverflow.com/questions/1964955/audio-file-fft-in-an-os-x-environment * * * This code is a very simple interface for Accelerate's fft/ifft code. * It was built out of hacking Maximilian (Mick Grierson and Chris Kiefer) and * the above mentioned resources for performing a windowed FFT which could * be used underneath of an STFT implementation * * FFT Usage: * * // be sure to either use malloc or __attribute__ ((aligned (16)) * float *sample_data = (float *) malloc (sizeof(float) * 4096); * float *allocated_magnitude_buffer = (float *) malloc (sizeof(float) * 2048); * float *allocated_phase_buffer = (float *) malloc (sizeof(float) * 2048); * * pkmFFT *fft; * fft = new pkmFFT(4096); * fft.forward(0, sample_data, allocated_magnitude_buffer, allocated_phase_buffer); * fft.inverse(0, sample_data, allocated_magnitude_buffer, allocated_phase_buffer); * delete fft; * * * STFT Usage: * // be sure to either use malloc or __attribute__ ((aligned (16)) * size_t buffer_size = 4096; * float *sample_data = (float *) malloc (sizeof(float) * buffer_size); * pkm::Mat magnitude_matrix, phase_matrix; * * pkmSTFT *stft; * stft = new pkmSTFT(512); * stft.STFT(sample_data, buffer_size, magnitude_matrix, phase_matrix); * fft.ISTFT(sample_data, buffer_size, magnitude_matrix, phase_matrix); * delete stft;