mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-03 07:21:14 -05:00
488 lines
14 KiB
C++
488 lines
14 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
|
|
// Copyright (C) 2016 F4EXB //
|
|
// written by Edouard Griffiths //
|
|
// //
|
|
// Integer half-band FIR based interpolator and decimator //
|
|
// This is the double buffer variant //
|
|
// //
|
|
// 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 INCLUDE_INTHALFBANDFILTER_DB_H
|
|
#define INCLUDE_INTHALFBANDFILTER_DB_H
|
|
|
|
#include <stdint.h>
|
|
#include "dsp/dsptypes.h"
|
|
#include "dsp/hbfiltertraits.h"
|
|
#include "util/export.h"
|
|
|
|
template<uint32_t HBFilterOrder>
|
|
class SDRANGEL_API IntHalfbandFilterDB {
|
|
public:
|
|
IntHalfbandFilterDB();
|
|
|
|
// downsample by 2, return center part of original spectrum
|
|
bool workDecimateCenter(Sample* sample)
|
|
{
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sample->real(), (FixReal) sample->imag());
|
|
|
|
switch(m_state)
|
|
{
|
|
case 0:
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 1;
|
|
// tell caller we don't have a new sample
|
|
return false;
|
|
|
|
default:
|
|
// save result
|
|
doFIR(sample);
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 0;
|
|
|
|
// tell caller we have a new sample
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// upsample by 2, return center part of original spectrum - double buffer variant
|
|
bool workInterpolateCenter(Sample* sampleIn, Sample *SampleOut)
|
|
{
|
|
switch(m_state)
|
|
{
|
|
case 0:
|
|
// insert sample into ring-buffer
|
|
storeSample(0, 0);
|
|
// save result
|
|
doFIR(SampleOut);
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 1;
|
|
// tell caller we didn't consume the sample
|
|
return false;
|
|
|
|
default:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
|
|
// save result
|
|
doFIR(SampleOut);
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 0;
|
|
// tell caller we consumed the sample
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool workDecimateCenter(qint32 *x, qint32 *y)
|
|
{
|
|
// insert sample into ring-buffer
|
|
storeSample(*x, *y);
|
|
|
|
switch(m_state)
|
|
{
|
|
case 0:
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// 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
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 0;
|
|
// tell caller we have a new sample
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// downsample by 2, return lower half of original spectrum
|
|
bool workDecimateLowerHalf(Sample* sample)
|
|
{
|
|
switch(m_state)
|
|
{
|
|
case 0:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) -sample->imag(), (FixReal) sample->real());
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 1;
|
|
// tell caller we don't have a new sample
|
|
return false;
|
|
|
|
case 1:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) -sample->real(), (FixReal) -sample->imag());
|
|
// save result
|
|
doFIR(sample);
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 2;
|
|
// tell caller we have a new sample
|
|
return true;
|
|
|
|
case 2:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sample->imag(), (FixReal) -sample->real());
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 3;
|
|
// tell caller we don't have a new sample
|
|
return false;
|
|
|
|
default:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sample->real(), (FixReal) sample->imag());
|
|
// save result
|
|
doFIR(sample);
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 0;
|
|
// tell caller we have a new sample
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// upsample by 2, from lower half of original spectrum - double buffer variant
|
|
bool workInterpolateLowerHalf(Sample* sampleIn, Sample *sampleOut)
|
|
{
|
|
Sample s;
|
|
|
|
switch(m_state)
|
|
{
|
|
case 0:
|
|
// insert sample into ring-buffer
|
|
storeSample(0, 0);
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(s.imag());
|
|
sampleOut->setImag(-s.real());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 1;
|
|
|
|
// tell caller we didn't consume the sample
|
|
return false;
|
|
|
|
case 1:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(-s.real());
|
|
sampleOut->setImag(-s.imag());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 2;
|
|
|
|
// tell caller we consumed the sample
|
|
return true;
|
|
|
|
case 2:
|
|
// insert sample into ring-buffer
|
|
storeSample(0, 0);
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(-s.imag());
|
|
sampleOut->setImag(s.real());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 3;
|
|
|
|
// tell caller we didn't consume the sample
|
|
return false;
|
|
|
|
default:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(s.real());
|
|
sampleOut->setImag(s.imag());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 0;
|
|
|
|
// tell caller we consumed the sample
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// downsample by 2, return upper half of original spectrum
|
|
bool workDecimateUpperHalf(Sample* sample)
|
|
{
|
|
switch(m_state)
|
|
{
|
|
case 0:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sample->imag(), (FixReal) -sample->real());
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 1;
|
|
// tell caller we don't have a new sample
|
|
return false;
|
|
|
|
case 1:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) -sample->real(), (FixReal) -sample->imag());
|
|
// save result
|
|
doFIR(sample);
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 2;
|
|
// tell caller we have a new sample
|
|
return true;
|
|
|
|
case 2:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) -sample->imag(), (FixReal) sample->real());
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 3;
|
|
// tell caller we don't have a new sample
|
|
return false;
|
|
|
|
default:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sample->real(), (FixReal) sample->imag());
|
|
// save result
|
|
doFIR(sample);
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
// next state
|
|
m_state = 0;
|
|
// tell caller we have a new sample
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// upsample by 2, move original spectrum to upper half - double buffer variant
|
|
bool workInterpolateUpperHalf(Sample* sampleIn, Sample *sampleOut)
|
|
{
|
|
Sample s;
|
|
|
|
switch(m_state)
|
|
{
|
|
case 0:
|
|
// insert sample into ring-buffer
|
|
storeSample(0, 0);
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(-s.imag());
|
|
sampleOut->setImag(s.real());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 1;
|
|
|
|
// tell caller we didn't consume the sample
|
|
return false;
|
|
|
|
case 1:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(-s.real());
|
|
sampleOut->setImag(-s.imag());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 2;
|
|
|
|
// tell caller we consumed the sample
|
|
return true;
|
|
|
|
case 2:
|
|
// insert sample into ring-buffer
|
|
storeSample(0, 0);
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(s.imag());
|
|
sampleOut->setImag(-s.real());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 3;
|
|
|
|
// tell caller we didn't consume the sample
|
|
return false;
|
|
|
|
default:
|
|
// insert sample into ring-buffer
|
|
storeSample((FixReal) sampleIn->real(), (FixReal) sampleIn->imag());
|
|
|
|
// save result
|
|
doFIR(&s);
|
|
sampleOut->setReal(s.real());
|
|
sampleOut->setImag(s.imag());
|
|
|
|
// advance write-pointer
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
// next state
|
|
m_state = 0;
|
|
|
|
// tell caller we consumed the sample
|
|
return true;
|
|
}
|
|
}
|
|
|
|
void myDecimate(const Sample* sample1, Sample* sample2)
|
|
{
|
|
storeSample((FixReal) sample1->real(), (FixReal) sample1->imag());
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
storeSample((FixReal) sample2->real(), (FixReal) sample2->imag());
|
|
doFIR(sample2);
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
}
|
|
|
|
void myDecimate(qint32 x1, qint32 y1, qint32 *x2, qint32 *y2)
|
|
{
|
|
storeSample(x1, y1);
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
|
|
storeSample(*x2, *y2);
|
|
doFIR(x2, y2);
|
|
m_ptr = (m_ptr + 1) % m_size;
|
|
}
|
|
|
|
protected:
|
|
qint32 m_samplesDB[2*(HBFIRFilterTraits<HBFilterOrder>::hbOrder - 1)][2]; // double buffer technique
|
|
int m_ptr;
|
|
int m_size;
|
|
int m_state;
|
|
|
|
void storeSample(const FixReal& sampleI, const FixReal& sampleQ)
|
|
{
|
|
m_samplesDB[m_ptr][0] = sampleI;
|
|
m_samplesDB[m_ptr][1] = sampleQ;
|
|
m_samplesDB[m_ptr + m_size][0] = sampleI;
|
|
m_samplesDB[m_ptr + m_size][1] = sampleQ;
|
|
}
|
|
|
|
void storeSample(qint32 x, qint32 y)
|
|
{
|
|
m_samplesDB[m_ptr][0] = x;
|
|
m_samplesDB[m_ptr][1] = y;
|
|
m_samplesDB[m_ptr + m_size][0] = x;
|
|
m_samplesDB[m_ptr + m_size][1] = y;
|
|
}
|
|
|
|
void doFIR(Sample* sample)
|
|
{
|
|
int a = m_ptr + m_size; // tip pointer
|
|
int b = m_ptr + 1; // tail pointer
|
|
qint32 iAcc = 0;
|
|
qint32 qAcc = 0;
|
|
|
|
for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
|
|
{
|
|
iAcc += (m_samplesDB[a][0] + m_samplesDB[b][0]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
|
|
qAcc += (m_samplesDB[a][1] + m_samplesDB[b][1]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
|
|
a -= 2;
|
|
b += 2;
|
|
}
|
|
|
|
iAcc += ((qint32)m_samplesDB[b-1][0]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
|
|
qAcc += ((qint32)m_samplesDB[b-1][1]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
|
|
|
|
sample->setReal(iAcc >> HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
|
|
sample->setImag(qAcc >> HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
|
|
}
|
|
|
|
void doFIR(qint32 *x, qint32 *y)
|
|
{
|
|
int a = m_ptr + m_size; // tip pointer
|
|
int b = m_ptr + 1; // tail pointer
|
|
qint32 iAcc = 0;
|
|
qint32 qAcc = 0;
|
|
|
|
for (int i = 0; i < HBFIRFilterTraits<HBFilterOrder>::hbOrder / 4; i++)
|
|
{
|
|
iAcc += (m_samplesDB[a][0] + m_samplesDB[b][0]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
|
|
qAcc += (m_samplesDB[a][1] + m_samplesDB[b][1]) * HBFIRFilterTraits<HBFilterOrder>::hbCoeffs[i];
|
|
a -= 2;
|
|
b += 2;
|
|
}
|
|
|
|
iAcc += ((qint32)m_samplesDB[b-1][0]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
|
|
qAcc += ((qint32)m_samplesDB[b-1][1]) << (HBFIRFilterTraits<HBFilterOrder>::hbShift - 1);
|
|
|
|
*x = iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1); // HB_SHIFT incorrect do not loose the gained bit
|
|
*y = qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
|
|
}
|
|
};
|
|
|
|
template<uint32_t HBFilterOrder>
|
|
IntHalfbandFilterDB<HBFilterOrder>::IntHalfbandFilterDB()
|
|
{
|
|
m_size = HBFIRFilterTraits<HBFilterOrder>::hbOrder - 1;
|
|
|
|
for (int i = 0; i < m_size; i++)
|
|
{
|
|
m_samplesDB[i][0] = 0;
|
|
m_samplesDB[i][1] = 0;
|
|
}
|
|
|
|
m_ptr = 0;
|
|
m_state = 0;
|
|
}
|
|
|
|
#endif // INCLUDE_INTHALFBANDFILTER_DB_H
|