mirror of
https://github.com/jankae/LibreVNA.git
synced 2026-04-09 08:23:41 +00:00
Move DFT/TDR calculation into dedicated thread, limit update rate
This commit is contained in:
Jan Käberich
parent
fd786c4176
commit
8e47d14192
5 changed files with 299 additions and 148 deletions
|
|
@ -19,9 +19,22 @@ TDR::TDR()
|
|||
stepResponse = true;
|
||||
mode = Mode::Lowpass;
|
||||
|
||||
destructing = false;
|
||||
thread = new TDRThread(*this);
|
||||
thread->start(TDRThread::Priority::LowestPriority);
|
||||
|
||||
connect(&window, &WindowFunction::changed, this, &TDR::updateTDR);
|
||||
}
|
||||
|
||||
TDR::~TDR()
|
||||
{
|
||||
// tell thread to exit
|
||||
destructing = true;
|
||||
semphr.release();
|
||||
thread->wait();
|
||||
delete thread;
|
||||
}
|
||||
|
||||
TraceMath::DataType TDR::outputType(TraceMath::DataType inputType)
|
||||
{
|
||||
if(inputType == DataType::Frequency) {
|
||||
|
|
@ -190,85 +203,8 @@ void TDR::inputSamplesChanged(unsigned int begin, unsigned int end)
|
|||
// not the end, do nothing
|
||||
return;
|
||||
}
|
||||
vector<complex<double>> frequencyDomain;
|
||||
auto stepSize = (input->rData().back().x - input->rData().front().x) / (input->rData().size() - 1);
|
||||
if(mode == Mode::Lowpass) {
|
||||
if(stepResponse) {
|
||||
auto steps = input->rData().size();
|
||||
auto firstStep = input->rData().front().x;
|
||||
// frequency points need to be evenly spaced all the way to DC
|
||||
if(firstStep == 0) {
|
||||
// zero as first step would result in infinite number of points, skip and start with second
|
||||
firstStep = input->rData()[1].x;
|
||||
steps--;
|
||||
}
|
||||
if(firstStep * steps != input->rData().back().x) {
|
||||
// data is not available with correct frequency spacing, calculate required steps
|
||||
steps = input->rData().back().x / firstStep;
|
||||
stepSize = firstStep;
|
||||
}
|
||||
frequencyDomain.resize(2 * steps + 1);
|
||||
// copy frequencies, use the flipped conjugate for negative part
|
||||
for(unsigned int i = 1;i<=steps;i++) {
|
||||
auto S = input->getInterpolatedSample(stepSize * i).y;
|
||||
frequencyDomain[steps - i] = conj(S);
|
||||
frequencyDomain[steps + i] = S;
|
||||
}
|
||||
if(automaticDC) {
|
||||
// use simple extrapolation from lowest two points to extract DC value
|
||||
auto abs_DC = 2.0 * abs(frequencyDomain[steps + 1]) - abs(frequencyDomain[steps + 2]);
|
||||
auto phase_DC = 2.0 * arg(frequencyDomain[steps + 1]) - arg(frequencyDomain[steps + 2]);
|
||||
frequencyDomain[steps] = polar(abs_DC, phase_DC);
|
||||
} else {
|
||||
frequencyDomain[steps] = manualDC;
|
||||
}
|
||||
} else {
|
||||
auto steps = input->rData().size();
|
||||
unsigned int offset = 0;
|
||||
if(input->rData().front().x == 0) {
|
||||
// DC measurement is inaccurate, skip
|
||||
steps--;
|
||||
offset++;
|
||||
}
|
||||
// no step response required, can use frequency values as they are. No extra extrapolated DC value here -> 2 values less than with step response
|
||||
frequencyDomain.resize(2 * steps - 1);
|
||||
frequencyDomain[steps - 1] = input->rData()[offset].y;
|
||||
for(unsigned int i = 1;i<steps;i++) {
|
||||
auto S = input->rData()[i + offset].y;
|
||||
frequencyDomain[steps - i - 1] = conj(S);
|
||||
frequencyDomain[steps + i - 1] = S;
|
||||
}
|
||||
}
|
||||
} else {
|
||||
// bandpass mode
|
||||
// Can use input data directly, no need to extend with complex conjugate
|
||||
frequencyDomain.resize(input->rData().size());
|
||||
for(unsigned int i=0;i<input->rData().size();i++) {
|
||||
frequencyDomain[i] = input->rData()[i].y;
|
||||
}
|
||||
}
|
||||
|
||||
window.apply(frequencyDomain);
|
||||
Fft::shift(frequencyDomain, true);
|
||||
|
||||
auto fft_bins = frequencyDomain.size();
|
||||
const double fs = 1.0 / (stepSize * fft_bins);
|
||||
|
||||
Fft::transform(frequencyDomain, true);
|
||||
|
||||
data.clear();
|
||||
data.resize(fft_bins);
|
||||
|
||||
for(unsigned int i = 0;i<fft_bins;i++) {
|
||||
data[i].x = fs * i;
|
||||
data[i].y = frequencyDomain[i] / (double) fft_bins;
|
||||
}
|
||||
if(stepResponse && mode == Mode::Lowpass) {
|
||||
updateStepResponse(true);
|
||||
} else {
|
||||
updateStepResponse(false);
|
||||
}
|
||||
emit outputSamplesChanged(0, data.size());
|
||||
// trigger calculation in thread
|
||||
semphr.release();
|
||||
success();
|
||||
} else {
|
||||
// not enough input data
|
||||
|
|
@ -295,3 +231,105 @@ TDR::Mode TDR::getMode() const
|
|||
{
|
||||
return mode;
|
||||
}
|
||||
|
||||
TDRThread::TDRThread(TDR &tdr)
|
||||
: tdr(tdr)
|
||||
{
|
||||
|
||||
}
|
||||
|
||||
void TDRThread::run()
|
||||
{
|
||||
qDebug() << "TDR thread starting";
|
||||
while(1) {
|
||||
tdr.semphr.acquire();
|
||||
// clear possible additional semaphores
|
||||
tdr.semphr.tryAcquire(tdr.semphr.available());
|
||||
if(tdr.destructing) {
|
||||
// TDR object about to be deleted, exit thread
|
||||
qDebug() << "TDR thread exiting";
|
||||
return;
|
||||
}
|
||||
qDebug() << "TDR thread calculating";
|
||||
// perform calculation
|
||||
vector<complex<double>> frequencyDomain;
|
||||
auto stepSize = (tdr.input->rData().back().x - tdr.input->rData().front().x) / (tdr.input->rData().size() - 1);
|
||||
if(tdr.mode == TDR::Mode::Lowpass) {
|
||||
if(tdr.stepResponse) {
|
||||
auto steps = tdr.input->rData().size();
|
||||
auto firstStep = tdr.input->rData().front().x;
|
||||
// frequency points need to be evenly spaced all the way to DC
|
||||
if(firstStep == 0) {
|
||||
// zero as first step would result in infinite number of points, skip and start with second
|
||||
firstStep = tdr.input->rData()[1].x;
|
||||
steps--;
|
||||
}
|
||||
if(firstStep * steps != tdr.input->rData().back().x) {
|
||||
// data is not available with correct frequency spacing, calculate required steps
|
||||
steps = tdr.input->rData().back().x / firstStep;
|
||||
stepSize = firstStep;
|
||||
}
|
||||
frequencyDomain.resize(2 * steps + 1);
|
||||
// copy frequencies, use the flipped conjugate for negative part
|
||||
for(unsigned int i = 1;i<=steps;i++) {
|
||||
auto S = tdr.input->getInterpolatedSample(stepSize * i).y;
|
||||
frequencyDomain[steps - i] = conj(S);
|
||||
frequencyDomain[steps + i] = S;
|
||||
}
|
||||
if(tdr.automaticDC) {
|
||||
// use simple extrapolation from lowest two points to extract DC value
|
||||
auto abs_DC = 2.0 * abs(frequencyDomain[steps + 1]) - abs(frequencyDomain[steps + 2]);
|
||||
auto phase_DC = 2.0 * arg(frequencyDomain[steps + 1]) - arg(frequencyDomain[steps + 2]);
|
||||
frequencyDomain[steps] = polar(abs_DC, phase_DC);
|
||||
} else {
|
||||
frequencyDomain[steps] = tdr.manualDC;
|
||||
}
|
||||
} else {
|
||||
auto steps = tdr.input->rData().size();
|
||||
unsigned int offset = 0;
|
||||
if(tdr.input->rData().front().x == 0) {
|
||||
// DC measurement is inaccurate, skip
|
||||
steps--;
|
||||
offset++;
|
||||
}
|
||||
// no step response required, can use frequency values as they are. No extra extrapolated DC value here -> 2 values less than with step response
|
||||
frequencyDomain.resize(2 * steps - 1);
|
||||
frequencyDomain[steps - 1] = tdr.input->rData()[offset].y;
|
||||
for(unsigned int i = 1;i<steps;i++) {
|
||||
auto S = tdr.input->rData()[i + offset].y;
|
||||
frequencyDomain[steps - i - 1] = conj(S);
|
||||
frequencyDomain[steps + i - 1] = S;
|
||||
}
|
||||
}
|
||||
} else {
|
||||
// bandpass mode
|
||||
// Can use input data directly, no need to extend with complex conjugate
|
||||
frequencyDomain.resize(tdr.input->rData().size());
|
||||
for(unsigned int i=0;i<tdr.input->rData().size();i++) {
|
||||
frequencyDomain[i] = tdr.input->rData()[i].y;
|
||||
}
|
||||
}
|
||||
|
||||
tdr.window.apply(frequencyDomain);
|
||||
Fft::shift(frequencyDomain, true);
|
||||
|
||||
auto fft_bins = frequencyDomain.size();
|
||||
const double fs = 1.0 / (stepSize * fft_bins);
|
||||
|
||||
Fft::transform(frequencyDomain, true);
|
||||
|
||||
tdr.data.clear();
|
||||
tdr.data.resize(fft_bins);
|
||||
|
||||
for(unsigned int i = 0;i<fft_bins;i++) {
|
||||
tdr.data[i].x = fs * i;
|
||||
tdr.data[i].y = frequencyDomain[i] / (double) fft_bins;
|
||||
}
|
||||
if(tdr.stepResponse && tdr.mode == TDR::Mode::Lowpass) {
|
||||
tdr.updateStepResponse(true);
|
||||
} else {
|
||||
tdr.updateStepResponse(false);
|
||||
}
|
||||
emit tdr.outputSamplesChanged(0, tdr.data.size());
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue