* 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: [email protected]
*
* 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;