Floating point to integer decimator optimization using the even/odd algorithm

This commit is contained in:
f4exb 2018-04-29 22:56:34 +02:00
parent 1213ad2a71
commit 48cc6df8a7
4 changed files with 258 additions and 25 deletions

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@ -130,6 +130,8 @@ set(sdrbase_HEADERS
dsp/inthalfbandfilterdbf.h
dsp/inthalfbandfiltereo1.h
dsp/inthalfbandfiltereo1i.h
dsp/inthalfbandfiltereo2.h
dsp/inthalfbandfiltereof.h
dsp/inthalfbandfilterst.h
dsp/inthalfbandfiltersti.h
dsp/kissfft.h

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@ -32,7 +32,7 @@ void DecimatorsFI::decimate1(SampleVector::iterator* it, const float* buf, qint3
void DecimatorsFI::decimate2_cen(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double intbuf[2];
float intbuf[2];
for (int pos = 0; pos < nbIAndQ - 3; pos += 4)
{
@ -54,7 +54,7 @@ void DecimatorsFI::decimate2_cen(SampleVector::iterator* it, const float* buf, q
void DecimatorsFI::decimate2_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal, yimag;
float xreal, yimag;
for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
{
@ -74,7 +74,7 @@ void DecimatorsFI::decimate2_inf(SampleVector::iterator* it, const float* buf, q
void DecimatorsFI::decimate2_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal, yimag;
float xreal, yimag;
for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
{
@ -94,7 +94,7 @@ void DecimatorsFI::decimate2_sup(SampleVector::iterator* it, const float* buf, q
void DecimatorsFI::decimate4_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal, yimag;
float xreal, yimag;
for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
{
@ -116,7 +116,7 @@ void DecimatorsFI::decimate4_sup(SampleVector::iterator* it, const float* buf, q
// Inf (LSB):
// x y x y x y x y / x -> 0,-3,-4,7 / y -> 1,2,-5,-6
// [ rotate: 0, 1, -3, 2, -4, -5, 7, -6]
double xreal, yimag;
float xreal, yimag;
for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
{
@ -132,7 +132,7 @@ void DecimatorsFI::decimate4_sup(SampleVector::iterator* it, const float* buf, q
void DecimatorsFI::decimate8_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal[2], yimag[2];
float xreal[2], yimag[2];
for (int pos = 0; pos < nbIAndQ - 15; pos += 8)
{
@ -154,7 +154,7 @@ void DecimatorsFI::decimate8_inf(SampleVector::iterator* it, const float* buf, q
void DecimatorsFI::decimate8_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal[2], yimag[2];
float xreal[2], yimag[2];
for (int pos = 0; pos < nbIAndQ - 15; pos += 8)
{
@ -178,7 +178,7 @@ void DecimatorsFI::decimate16_inf(SampleVector::iterator* it, const float* buf,
{
// Offset tuning: 4x downsample and rotate, then
// downsample 4x more. [ rotate: 0, 1, -3, 2, -4, -5, 7, -6]
double xreal[4], yimag[4];
float xreal[4], yimag[4];
for (int pos = 0; pos < nbIAndQ - 31; )
{
@ -205,7 +205,7 @@ void DecimatorsFI::decimate16_sup(SampleVector::iterator* it, const float* buf,
{
// Offset tuning: 4x downsample and rotate, then
// downsample 4x more. [ rotate: 1, 0, -2, 3, -5, -4, 6, -7]
double xreal[4], yimag[4];
float xreal[4], yimag[4];
for (int pos = 0; pos < nbIAndQ - 31; )
{
@ -230,7 +230,7 @@ void DecimatorsFI::decimate16_sup(SampleVector::iterator* it, const float* buf,
void DecimatorsFI::decimate32_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal[8], yimag[8];
float xreal[8], yimag[8];
for (int pos = 0; pos < nbIAndQ - 63; )
{
@ -260,7 +260,7 @@ void DecimatorsFI::decimate32_inf(SampleVector::iterator* it, const float* buf,
void DecimatorsFI::decimate32_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal[8], yimag[8];
float xreal[8], yimag[8];
for (int pos = 0; pos < nbIAndQ - 63; )
{
@ -290,7 +290,7 @@ void DecimatorsFI::decimate32_sup(SampleVector::iterator* it, const float* buf,
void DecimatorsFI::decimate64_inf(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal[16], yimag[16];
float xreal[16], yimag[16];
for (int pos = 0; pos < nbIAndQ - 127; )
{
@ -329,7 +329,7 @@ void DecimatorsFI::decimate64_inf(SampleVector::iterator* it, const float* buf,
void DecimatorsFI::decimate64_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double xreal[16], yimag[16];
float xreal[16], yimag[16];
for (int pos = 0; pos < nbIAndQ - 127; )
{
@ -368,7 +368,7 @@ void DecimatorsFI::decimate64_sup(SampleVector::iterator* it, const float* buf,
void DecimatorsFI::decimate4_cen(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double intbuf[4];
float intbuf[4];
for (int pos = 0; pos < nbIAndQ - 7; pos += 8)
{
@ -402,7 +402,7 @@ void DecimatorsFI::decimate4_cen(SampleVector::iterator* it, const float* buf, q
void DecimatorsFI::decimate8_cen(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double intbuf[8];
float intbuf[8];
for (int pos = 0; pos < nbIAndQ - 15; pos += 16)
{
@ -461,7 +461,7 @@ void DecimatorsFI::decimate8_cen(SampleVector::iterator* it, const float* buf, q
void DecimatorsFI::decimate16_cen(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double intbuf[16];
float intbuf[16];
for (int pos = 0; pos < nbIAndQ - 31; pos += 32)
{
@ -569,7 +569,7 @@ void DecimatorsFI::decimate16_cen(SampleVector::iterator* it, const float* buf,
void DecimatorsFI::decimate32_cen(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double intbuf[32];
float intbuf[32];
for (int pos = 0; pos < nbIAndQ - 63; pos += 64)
{
@ -774,7 +774,7 @@ void DecimatorsFI::decimate32_cen(SampleVector::iterator* it, const float* buf,
void DecimatorsFI::decimate64_cen(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ)
{
double intbuf[64];
float intbuf[64];
for (int pos = 0; pos < nbIAndQ - 127; pos += 128)
{

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@ -17,7 +17,7 @@
#ifndef SDRBASE_DSP_DECIMATORSFI_H_
#define SDRBASE_DSP_DECIMATORSFI_H_
#include "dsp/inthalfbandfilterdbf.h"
#include "dsp/inthalfbandfiltereof.h"
#include "export.h"
#define DECIMATORSFI_HB_FILTER_ORDER 64
@ -46,12 +46,12 @@ public:
void decimate64_sup(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ);
void decimate64_cen(SampleVector::iterator* it, const float* buf, qint32 nbIAndQ);
IntHalfbandFilterDBF<double, float, DECIMATORSFI_HB_FILTER_ORDER> m_decimator2; // 1st stages
IntHalfbandFilterDBF<double, float, DECIMATORSFI_HB_FILTER_ORDER> m_decimator4; // 2nd stages
IntHalfbandFilterDBF<double, float, DECIMATORSFI_HB_FILTER_ORDER> m_decimator8; // 3rd stages
IntHalfbandFilterDBF<double, float, DECIMATORSFI_HB_FILTER_ORDER> m_decimator16; // 4th stages
IntHalfbandFilterDBF<double, float, DECIMATORSFI_HB_FILTER_ORDER> m_decimator32; // 5th stages
IntHalfbandFilterDBF<double, float, DECIMATORSFI_HB_FILTER_ORDER> m_decimator64; // 6th stages
IntHalfbandFilterEOF<DECIMATORSFI_HB_FILTER_ORDER> m_decimator2; // 1st stages
IntHalfbandFilterEOF<DECIMATORSFI_HB_FILTER_ORDER> m_decimator4; // 2nd stages
IntHalfbandFilterEOF<DECIMATORSFI_HB_FILTER_ORDER> m_decimator8; // 3rd stages
IntHalfbandFilterEOF<DECIMATORSFI_HB_FILTER_ORDER> m_decimator16; // 4th stages
IntHalfbandFilterEOF<DECIMATORSFI_HB_FILTER_ORDER> m_decimator32; // 5th stages
IntHalfbandFilterEOF<DECIMATORSFI_HB_FILTER_ORDER> m_decimator64; // 6th stages
};

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@ -0,0 +1,231 @@
///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2018 F4EXB //
// written by Edouard Griffiths //
// //
// Integer half-band FIR based interpolator and decimator //
// This is the even/odd double buffer variant. Really useful only when SIMD is //
// used //
// //
// This program is free software; you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation as version 3 of the License, or //
// //
// This program 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 General Public License V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#ifndef SDRBASE_DSP_INTHALFBANDFILTEREOF_H_
#define SDRBASE_DSP_INTHALFBANDFILTEREOF_H_
#include <stdint.h>
#include <cstdlib>
#include "dsp/dsptypes.h"
#include "dsp/hbfiltertraits.h"
#include "export.h"
template<uint32_t HBFilterOrder>
class SDRBASE_API IntHalfbandFilterEOF {
public:
IntHalfbandFilterEOF();
bool workDecimateCenter(float *x, float *y)
{
// insert sample into ring-buffer
storeSample(*x, *y);
switch(m_state)
{
case 0:
// advance write-pointer
advancePointer();
// next state
m_state = 1;
// tell caller we don't have a new sample
return false;
default:
// save result
doFIR(x, y);
// advance write-pointer
advancePointer();
// next state
m_state = 0;
// tell caller we have a new sample
return true;
}
}
void myDecimate(float x1, float y1, float *x2, float *y2)
{
storeSample(x1, y1);
advancePointer();
storeSample(*x2, *y2);
doFIR(x2, y2);
advancePointer();
}
/** Simple zero stuffing and filter */
void myInterpolateZeroStuffing(float *x1, float *y1, float *x2, float *y2)
{
storeSample(*x1, *y1);
doFIR(x1, y1);
advancePointer();
storeSample(0, 0);
doFIR(x2, y2);
advancePointer();
}
/** Optimized upsampler by 2 not calculating FIR with inserted null samples */
void myInterpolate(float *x1, float *y1, float *x2, float *y2)
{
// insert sample into ring double buffer
m_samples[m_ptr][0] = *x1;
m_samples[m_ptr][1] = *y1;
m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = *x1;
m_samples[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = *y1;
// advance pointer
if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
m_ptr++;
} else {
m_ptr = 0;
}
// first output sample calculated with the middle peak
*x1 = m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0];
*y1 = m_samples[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1];
// second sample calculated with the filter
doInterpolateFIR(x2, y2);
}
protected:
double m_even[2][HBFIRFilterTraits<HBFilterOrder>::hbOrder]; // double buffer technique
double m_odd[2][HBFIRFilterTraits<HBFilterOrder>::hbOrder]; // double buffer technique
double m_samples[HBFIRFilterTraits<HBFilterOrder>::hbOrder][2]; // double buffer technique
int m_ptr;
int m_size;
int m_state;
void storeSample(float x, float y)
{
if ((m_ptr % 2) == 0)
{
m_even[0][m_ptr/2] = x;
m_even[1][m_ptr/2] = y;
m_even[0][m_ptr/2 + m_size] = x;
m_even[1][m_ptr/2 + m_size] = y;
}
else
{
m_odd[0][m_ptr/2] = x;
m_odd[1][m_ptr/2] = y;
m_odd[0][m_ptr/2 + m_size] = x;
m_odd[1][m_ptr/2 + m_size] = y;
}
}
void advancePointer()
{
m_ptr = m_ptr + 1 < 2*m_size ? m_ptr + 1: 0;
}
void doFIR(float *x, float *y)
{
double iAcc = 0;
double qAcc = 0;
//#if defined(USE_SSE4_1) && !defined(NO_DSP_SIMD)
// IntHalfbandFilterEO1Intrisics<HBFilterOrder>::work(
// m_ptr,
// m_even,
// m_odd,
// iAcc,
// qAcc
// );
//#else
int a = m_ptr/2 + m_size; // tip pointer
int b = m_ptr/2 + 1; // tail pointer
for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
{
if ((m_ptr % 2) == 0)
{
iAcc += (m_even[0][a] + m_even[0][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffsF[i];
qAcc += (m_even[1][a] + m_even[1][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffsF[i];
}
else
{
iAcc += (m_odd[0][a] + m_odd[0][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffsF[i];
qAcc += (m_odd[1][a] + m_odd[1][b]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffsF[i];
}
a -= 1;
b += 1;
}
//#endif
if ((m_ptr % 2) == 0)
{
iAcc += m_odd[0][m_ptr/2 + m_size/2] * 0.5f;
qAcc += m_odd[1][m_ptr/2 + m_size/2] * 0.5f;
}
else
{
iAcc += m_even[0][m_ptr/2 + m_size/2 + 1] * 0.5f;
qAcc += m_even[1][m_ptr/2 + m_size/2 + 1] * 0.5f;
}
*x = iAcc; // HB_SHIFT incorrect do not loose the gained bit
*y = qAcc;
}
void doInterpolateFIR(float *x, float *y)
{
qint32 iAcc = 0;
qint32 qAcc = 0;
qint16 a = m_ptr;
qint16 b = m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder / 2) - 1;
// go through samples in buffer
for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
{
iAcc += (m_samples[a][0] + m_samples[b][0]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffsF[i];
qAcc += (m_samples[a][1] + m_samples[b][1]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffsF[i];
a++;
b--;
}
*x = iAcc * SDR_RX_SCALED;
*y = qAcc * SDR_RX_SCALED;
}
};
template<uint32_t HBFilterOrder>
IntHalfbandFilterEOF<HBFilterOrder>::IntHalfbandFilterEOF()
{
m_size = HBFIRFilterTraits<HBFilterOrder>::hbOrder/2;
for (int i = 0; i < 2*m_size; i++)
{
m_even[0][i] = 0.0f;
m_even[1][i] = 0.0f;
m_odd[0][i] = 0.0f;
m_odd[1][i] = 0.0f;
m_samples[i][0] = 0.0f;
m_samples[i][1] = 0.0f;
}
m_ptr = 0;
m_state = 0;
}
#endif /* SDRBASE_DSP_INTHALFBANDFILTEREOF_H_ */