/* * Chromaprint -- Audio fingerprinting toolkit * Copyright (C) 2010 Lukas Lalinsky * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 * USA */ #include "utils.h" #include "fft_lib_fftw3.h" using namespace std; using namespace Chromaprint; FFTLib::FFTLib(int frame_size, double *window) : m_window(window), m_frame_size(frame_size) { m_input = (double *)fftw_malloc(sizeof(double) * frame_size); m_output = (double *)fftw_malloc(sizeof(double) * frame_size); m_plan = fftw_plan_r2r_1d(frame_size, m_input, m_output, FFTW_R2HC, FFTW_ESTIMATE); } FFTLib::~FFTLib() { fftw_destroy_plan(m_plan); fftw_free(m_input); fftw_free(m_output); } void FFTLib::ComputeFrame(CombinedBuffer::Iterator input, double *output) { ApplyWindow(input, m_window, m_input, m_frame_size, 1.0); fftw_execute(m_plan); double *in_ptr = m_output; double *rev_in_ptr = m_output + m_frame_size - 1; output[0] = in_ptr[0] * in_ptr[0]; output[m_frame_size / 2] = in_ptr[m_frame_size / 2] * in_ptr[m_frame_size / 2]; in_ptr += 1; output += 1; for (int i = 1; i < m_frame_size / 2; i++) { *output++ = in_ptr[0] * in_ptr[0] + rev_in_ptr[0] * rev_in_ptr[0]; in_ptr++; rev_in_ptr--; } }