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/*
* This file is part of AtracDEnc.
*
* AtracDEnc 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.
*
* AtracDEnc 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 AtracDEnc; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#pragma once
#include <string.h>
#include "../config.h"
template<class TPCM, int nIn>
class TQmf {
static const float TapHalf[24];
float QmfWindow[48];
TPCM PcmBuffer[nIn + 46];
float PcmBufferMerge[nIn + 46];
float DelayBuff[46];
public:
TQmf() {
const int sz = sizeof(QmfWindow)/sizeof(QmfWindow[0]);
for (size_t i = 0 ; i < sz/2; i++) {
QmfWindow[i] = QmfWindow[ sz - 1 - i] = TapHalf[i] * 2.0;
}
for (size_t i = 0; i < sizeof(PcmBuffer)/sizeof(PcmBuffer[0]); i++) {
PcmBuffer[i] = 0;
PcmBufferMerge[i] = 0;
}
}
void Analysis(TPCM* in, float* lower, float* upper) {
float temp;
for (size_t i = 0; i < 46; i++)
PcmBuffer[i] = PcmBuffer[nIn + i];
for (size_t i = 0; i < nIn; i++)
PcmBuffer[46+i] = in[i];
for (size_t j = 0; j < nIn; j+=2) {
lower[j/2] = upper[j/2] = 0.0;
for (size_t i = 0; i < 24; i++) {
lower[j/2] += QmfWindow[2*i] * PcmBuffer[48-1+j-(2*i)];
upper[j/2] += QmfWindow[(2*i)+1] * PcmBuffer[48-1+j-(2*i)-1];
}
temp = upper[j/2];
upper[j/2] = lower[j/2] - upper[j/2];
lower[j/2] += temp;
}
}
void Synthesis(TPCM* out, float* lower, float* upper) {
memcpy(&PcmBufferMerge[0], &DelayBuff[0], 46*sizeof(float));
float* newPart = &PcmBufferMerge[46];
for (int i = 0; i < nIn; i+=4) {
newPart[i+0] = lower[i/2] + upper[i/2];
newPart[i+1] = lower[i/2] - upper[i/2];
newPart[i+2] = lower[i/2 + 1] + upper[i/2 + 1];
newPart[i+3] = lower[i/2 + 1] - upper[i/2 + 1];
}
float* winP = &PcmBufferMerge[0];
for (size_t j = nIn/2; j != 0; j--) {
float s1 = 0;
float s2 = 0;
for (size_t i = 0; i < 48; i+=2) {
s1 += winP[i] * QmfWindow[i];
s2 += winP[i+1] * QmfWindow[i+1];
}
out[0] = s2;
out[1] = s1;
winP += 2;
out += 2;
}
memcpy(&DelayBuff[0], &PcmBufferMerge[nIn], 46*sizeof(float));
}
};
template<class TPCM, int nIn>
const float TQmf<TPCM, nIn>::TapHalf[24] = {
-0.00001461907, -0.00009205479, -0.000056157569, 0.00030117269,
0.0002422519, -0.00085293897, -0.0005205574, 0.0020340169,
0.00078333891, -0.0042153862, -0.00075614988, 0.0078402944,
-0.000061169922, -0.01344162, 0.0024626821, 0.021736089,
-0.007801671, -0.034090221, 0.01880949, 0.054326009,
-0.043596379, -0.099384367, 0.13207909, 0.46424159
};
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