110 lines
2.4 KiB
C++
110 lines
2.4 KiB
C++
/*
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* bitvis
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* Copyright (C) Bob 2012
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*
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* bitvis is free software: you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* bitvis is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <math.h>
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#include <stdlib.h> //TODO: REMOVE
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#include <string.h>
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#include "fft.h"
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#include "util/timeutils.h"
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#include "util/log.h"
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Cfft::Cfft()
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{
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m_inbuf = NULL;
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m_inbufpos = 0;
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m_fftin = NULL;
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m_outbuf = NULL;
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m_window = NULL;
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m_bufsize = 0;
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m_plan = NULL;
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}
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Cfft::~Cfft()
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{
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Free();
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}
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void Cfft::Allocate(unsigned int size)
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{
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if (size != m_bufsize)
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{
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Free();
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m_bufsize = size;
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m_inbuf = new float[m_bufsize];
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m_fftin = (float*)fftw_malloc(m_bufsize * sizeof(float));
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m_outbuf = (fftwf_complex*)fftw_malloc(m_bufsize * sizeof(fftwf_complex));
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m_window = new float[m_bufsize];
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//create a hamming window
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for (unsigned int i = 0; i < m_bufsize; i++)
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m_window[i] = 0.54f - 0.46f * cosf(2.0f * M_PI * i / (m_bufsize - 1.0f));
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Log("Building fft plan");
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int64_t start = GetTimeUs();
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m_plan = fftwf_plan_dft_r2c_1d(m_bufsize, m_fftin, m_outbuf, FFTW_MEASURE);
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Log("Built fft plan in %.0f ms", (double)(GetTimeUs() - start) / 1000.0f);
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}
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}
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void Cfft::Free()
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{
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delete[] m_inbuf;
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fftw_free(m_fftin);
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fftw_free(m_outbuf);
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delete[] m_window;
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m_inbuf = NULL;
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m_inbufpos = 0;
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m_fftin = NULL;
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m_outbuf = NULL;
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m_window = NULL;
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m_bufsize = 0;
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if (m_plan)
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{
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fftwf_destroy_plan(m_plan);
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m_plan = NULL;
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}
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}
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void Cfft::ApplyWindow()
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{
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float* in = m_inbuf + m_inbufpos;
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float* inend = m_inbuf + m_bufsize;
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float* out = m_fftin;
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float* window = m_window;
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while (in != inend)
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*(out++) = *(in++) * *(window++);
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in = m_inbuf;
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inend = m_inbuf + m_inbufpos;
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while (in != inend)
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*(out++) = *(in++) * *(window++);
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}
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void Cfft::AddSample(float sample)
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{
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m_inbuf[m_inbufpos] = sample;
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m_inbufpos++;
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if (m_inbufpos == m_bufsize)
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m_inbufpos = 0;
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}
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