VE7UWU/sdrangel
1
0
Fork 0
mirror of https://github.com/f4exb/sdrangel.git synced 2024-11-26 01:39:05 -05:00
Code Issues Projects Releases Wiki Activity

IntHalfbandFilterDB: Optimized versions of workInterpolateCenter and myInterpolate

Browse Source
This commit is contained in:
f4exb 2017-04-26 00:22:27 +02:00
parent 6b3bdef3a7
commit 822fff3aac
1 changed files with 100 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

100
sdrbase/dsp/inthalfbandfilterdb.h
View File

@ -91,6 +91,41 @@ public:
}
}
/** Optimized upsampler by 2 not calculating FIR with inserted null samples */
bool workInterpolateCenterOptimized(Sample* sampleIn, Sample *SampleOut)
{
switch(m_state)
{
case 0:
// return the middle peak
SampleOut->setReal(m_samplesDB[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0]);
SampleOut->setImag(m_samplesDB[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1]);
m_state = 1; // next state
return false; // tell caller we didn't consume the sample
default:
// calculate with non null samples
doInterpolateFIR(SampleOut);
// insert sample into ring double buffer
m_samplesDB[m_ptr][0] = sampleIn->real();
m_samplesDB[m_ptr][1] = sampleIn->imag();
m_samplesDB[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = sampleIn->real();
m_samplesDB[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][1] = sampleIn->imag();
// advance pointer
if (m_ptr < (HBFIRFilterTraits<HBFilterOrder>::hbOrder/2) - 1) {
m_ptr++;
} else {
m_ptr = 0;
}
m_state = 0; // next state
return true; // tell caller we consumed the sample
}
}
bool workDecimateCenter(qint32 *x, qint32 *y)
{
// insert sample into ring-buffer
@ -424,6 +459,29 @@ public:
advancePointer();
}
void myInterpolateOptimized(qint32 *x1, qint32 *y1, qint32 *x2, qint32 *y2)
{
// insert sample into ring double buffer
m_samplesDB[m_ptr][0] = *x1;
m_samplesDB[m_ptr][1] = *y1;
m_samplesDB[m_ptr + HBFIRFilterTraits<HBFilterOrder>::hbOrder/2][0] = *x1;
m_samplesDB[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_samplesDB[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][0];
*y1 = m_samplesDB[m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder/4) - 1][1];
// second sample calculated with the filter
doInterpolateFIR(x2, y2);
}
protected:
qint32 m_samplesDB[2*(HBFIRFilterTraits<HBFilterOrder>::hbOrder - 1)][2]; // double buffer technique
int m_ptr;
@ -494,6 +552,48 @@ protected:
*x = iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1); // HB_SHIFT incorrect do not loose the gained bit
*y = qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
}
void doInterpolateFIR(Sample* sample)
{
qint16 a = m_ptr;
qint16 b = m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder / 2) - 1;
// go through samples in buffer
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++;
b--;
}
sample->setReal(iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1));
sample->setImag(qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1));
}
void doInterpolateFIR(qint32 *x, qint32 *y)
{
qint16 a = m_ptr;
qint16 b = m_ptr + (HBFIRFilterTraits<HBFilterOrder>::hbOrder / 2) - 1;
// go through samples in buffer
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++;
b--;
}
*x = iAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
*y = qAcc >> (HBFIRFilterTraits<HBFilterOrder>::hbShift -1);
}
};
template<uint32_t HBFilterOrder>