sdrangel/sdrbase/dsp/devicesamplesink.cpp

145 wiersze
5.6 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2016-2019 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 //
// (at your option) any later version. //
// //
// 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/devicesamplesink.h"
DeviceSampleSink::DeviceSampleSink() :
m_sampleSourceFifo(1<<19),
m_guiMessageQueue(0)
{
connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
}
DeviceSampleSink::~DeviceSampleSink()
{
}
void DeviceSampleSink::handleInputMessages()
{
Message* message;
while ((message = m_inputMessageQueue.pop()) != 0)
{
if (handleMessage(*message))
{
delete message;
}
}
}
qint64 DeviceSampleSink::calculateDeviceCenterFrequency(
quint64 centerFrequency,
qint64 transverterDeltaFrequency,
int log2Interp,
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(log2Interp, fcPos, devSampleRate);
f_img -= 2*calculateFrequencyShift(log2Interp, fcPos, devSampleRate);
qDebug() << "DeviceSampleSink::calculateDeviceCenterFrequency:"
<< " desired center freq: " << centerFrequency << " Hz"
<< " device center freq: " << deviceCenterFrequency << " Hz"
<< " device sample rate: " << devSampleRate << "S/s"
<< " Actual sample rate: " << devSampleRate/(1<<log2Interp) << "S/s"
<< " center freq position code: " << fcPos
<< " image frequency: " << f_img << "Hz";
return deviceCenterFrequency;
}
qint64 DeviceSampleSink::calculateCenterFrequency(
quint64 deviceCenterFrequency,
qint64 transverterDeltaFrequency,
int log2Interp,
fcPos_t fcPos,
quint32 devSampleRate,
bool transverterMode)
{
qint64 centerFrequency = deviceCenterFrequency;
centerFrequency += calculateFrequencyShift(log2Interp, fcPos, devSampleRate);
centerFrequency += transverterMode ? transverterDeltaFrequency : 0;
centerFrequency = centerFrequency < 0 ? 0 : centerFrequency;
qDebug() << "DeviceSampleSink::calculateCenterFrequency:"
<< " desired center freq: " << centerFrequency << " Hz"
<< " device center freq: " << deviceCenterFrequency << " Hz"
<< " device sample rate: " << devSampleRate << "S/s"
<< " Actual sample rate: " << devSampleRate/(1<<log2Interp) << "S/s"
<< " center freq position code: " << fcPos;
return centerFrequency;
}
/**
* log2Interp = 0: no shift
*
* log2Interp = 1: middle of side band (inf or sup: 1/2)
* ^ | ^
* | inf | inf | sup | sup |
*
* log2Interp = 2: middle of far side half side band (inf, inf or sup, sup: 1/2 + 1/4)
* ^ | ^
* | inf | inf | sup | sup |
*
* log2Interp = 3: inf, inf, sup or sup, sup, inf: 1/2 + 1/4 - 1/8 = 5/8
* log2Interp = 4: inf, inf, sup, inf or sup, sup, inf, sup: 1/2 + 1/4 - 1/8 + 1/16 = 11/16
* log2Interp = 5: inf, inf, sup, inf, sup or sup, sup, inf, sup, inf: 1/2 + 1/4 - 1/8 + 1/16 - 1/32 = 21/32
* log2Interp = 6: inf, sup, inf, sup, inf, sup or sup, inf, sup, inf, sup, inf: 1/2 - 1/4 + 1/8 -1/16 + 1/32 - 1/64 = 21/64
*
*/
qint32 DeviceSampleSink::calculateFrequencyShift(
int log2Interp,
fcPos_t fcPos,
quint32 devSampleRate)
{
if (fcPos == FC_POS_CENTER) {
return 0;
}
int sign = fcPos == FC_POS_INFRA ? -1 : 1;
int halfSampleRate = devSampleRate / 2; // fractions are relative to sideband thus based on half the sample rate
if (log2Interp == 0) {
return 0;
} else if (log2Interp == 1) {
return sign * (halfSampleRate / 2);
} else if (log2Interp == 2) {
return sign * ((halfSampleRate * 3) / 4);
} else if (log2Interp == 3) {
return sign * ((halfSampleRate * 5) / 8);
} else if (log2Interp == 4) {
return sign * ((halfSampleRate * 11) / 16);
} else if (log2Interp == 5) {
return sign * ((halfSampleRate * 21) / 32);
} else if (log2Interp == 6) {
return sign * ((halfSampleRate * 21) / 64);
} else {
return 0;
}
}