/////////////////////////////////////////////////////////////////////////////////// // 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; } }