mirror of
https://github.com/f4exb/sdrangel.git
synced 2025-10-31 04:50:29 -04:00
111 lines
4.0 KiB
C++
111 lines
4.0 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
|
|
// Copyright (C) 2015-2017 F4EXB //
|
|
// written by Edouard Griffiths //
|
|
// //
|
|
// 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/>. //
|
|
///////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include <QDebug>
|
|
#include <dsp/devicesamplesource.h>
|
|
|
|
DeviceSampleSource::DeviceSampleSource() :
|
|
m_guiMessageQueue(0)
|
|
{
|
|
connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
|
|
}
|
|
|
|
DeviceSampleSource::~DeviceSampleSource()
|
|
{
|
|
}
|
|
|
|
void DeviceSampleSource::handleInputMessages()
|
|
{
|
|
Message* message;
|
|
|
|
while ((message = m_inputMessageQueue.pop()) != 0)
|
|
{
|
|
if (handleMessage(*message))
|
|
{
|
|
delete message;
|
|
}
|
|
}
|
|
}
|
|
|
|
qint64 DeviceSampleSource::calculateDeviceCenterFrequency(
|
|
quint64 centerFrequency,
|
|
qint64 transverterDeltaFrequency,
|
|
int log2Decim,
|
|
fcPos_t fcPos,
|
|
quint32 devSampleRate,
|
|
bool transverterMode)
|
|
{
|
|
qint64 deviceCenterFrequency = centerFrequency;
|
|
deviceCenterFrequency -= transverterMode ? transverterDeltaFrequency : 0;
|
|
deviceCenterFrequency = deviceCenterFrequency < 0 ? 0 : deviceCenterFrequency;
|
|
qint64 f_img = deviceCenterFrequency;
|
|
|
|
deviceCenterFrequency -= calculateFrequencyShift(log2Decim, fcPos, devSampleRate);
|
|
f_img -= 2*calculateFrequencyShift(log2Decim, fcPos, devSampleRate);
|
|
|
|
qDebug() << "DeviceSampleSource::calculateDeviceCenterFrequency:"
|
|
<< " desired center freq: " << centerFrequency << " Hz"
|
|
<< " device center freq: " << deviceCenterFrequency << " Hz"
|
|
<< " device sample rate: " << devSampleRate << "S/s"
|
|
<< " Actual sample rate: " << devSampleRate/(1<<log2Decim) << "S/s"
|
|
<< " center freq position code: " << fcPos
|
|
<< " image frequency: " << f_img << "Hz";
|
|
|
|
return deviceCenterFrequency;
|
|
}
|
|
|
|
/**
|
|
* log2Decim = 0: no shift
|
|
*
|
|
* n = log2Decim <= 2: fc = +/- 1/2^(n-1)
|
|
* center
|
|
* | ^ |
|
|
* | inf | sup |
|
|
* ^ ^
|
|
*
|
|
* n = log2Decim > 2: fc = +/- 1/2^n
|
|
* center
|
|
* | ^ |
|
|
* | |inf| | |sup| |
|
|
* ^ ^
|
|
*/
|
|
qint32 DeviceSampleSource::calculateFrequencyShift(
|
|
int log2Decim,
|
|
fcPos_t fcPos,
|
|
quint32 devSampleRate)
|
|
{
|
|
if (log2Decim == 0) { // no shift at all
|
|
return 0;
|
|
} else if (log2Decim < 3) {
|
|
if (fcPos == FC_POS_INFRA) { // shift in the square next to center frequency
|
|
return -(devSampleRate / (1<<(log2Decim+1)));
|
|
} else if (fcPos == FC_POS_SUPRA) {
|
|
return devSampleRate / (1<<(log2Decim+1));
|
|
} else {
|
|
return 0;
|
|
}
|
|
} else {
|
|
if (fcPos == FC_POS_INFRA) { // shift centered in the square next to center frequency
|
|
return -(devSampleRate / (1<<(log2Decim)));
|
|
} else if (fcPos == FC_POS_SUPRA) {
|
|
return devSampleRate / (1<<(log2Decim));
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
}
|