rtlsdrthread.cpp

Go to the documentation of this file.

// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
// written by Christian Daniel                                                   //
//                                                                               //
// 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 <stdio.h>
#include <errno.h>
#include "rtlsdrthread.h"

#include "dsp/samplesinkfifo.h"

#define FCD_BLOCKSIZE 16384

RTLSDRThread::RTLSDRThread(rtlsdr_dev_t* dev, SampleSinkFifo* sampleFifo, QObject* parent) :
    QThread(parent),
    m_running(false),
    m_dev(dev),
    m_convertBuffer(FCD_BLOCKSIZE),
    m_sampleFifo(sampleFifo),
    m_samplerate(288000),
    m_log2Decim(4),
    m_fcPos(0)
{
}

RTLSDRThread::~RTLSDRThread()
{
    stopWork();
}

void RTLSDRThread::startWork()
{
    m_startWaitMutex.lock();
    start();
    while(!m_running)
        m_startWaiter.wait(&m_startWaitMutex, 100);
    m_startWaitMutex.unlock();
}

void RTLSDRThread::stopWork()
{
    m_running = false;
    wait();
}

void RTLSDRThread::setSamplerate(int samplerate)
{
    m_samplerate = samplerate;
}

void RTLSDRThread::setLog2Decimation(unsigned int log2_decim)
{
    m_log2Decim = log2_decim;
}

void RTLSDRThread::setFcPos(int fcPos)
{
    m_fcPos = fcPos;
}

void RTLSDRThread::run()
{
    int res;

    m_running = true;
    m_startWaiter.wakeAll();

    while(m_running) {
        if((res = rtlsdr_read_async(m_dev, &RTLSDRThread::callbackHelper, this, 32, FCD_BLOCKSIZE)) < 0) {
            qCritical("RTLSDRThread: async error: %s", strerror(errno));
            break;
        }
    }

    m_running = false;
}

//  Decimate according to specified log2 (ex: log2=4 => decim=16)
void RTLSDRThread::callback(const quint8* buf, qint32 len)
{
    SampleVector::iterator it = m_convertBuffer.begin();

    if (m_log2Decim == 0)
    {
        m_decimators.decimate1(&it, buf, len);
    }
    else
    {
        if (m_fcPos == 0) // Infradyne
        {
            switch (m_log2Decim)
            {
            case 1:
                m_decimators.decimate2_inf(&it, buf, len);
                break;
            case 2:
                m_decimators.decimate4_inf(&it, buf, len);
                break;
            case 3:
                m_decimators.decimate8_inf(&it, buf, len);
                break;
            case 4:
                m_decimators.decimate16_inf(&it, buf, len);
                break;
            case 5:
                m_decimators.decimate32_inf(&it, buf, len);
                break;
            case 6:
                m_decimators.decimate64_inf(&it, buf, len);
                break;
            default:
                break;
            }
        }
        else if (m_fcPos == 1) // Supradyne
        {
            switch (m_log2Decim)
            {
            case 1:
                m_decimators.decimate2_sup(&it, buf, len);
                break;
            case 2:
                m_decimators.decimate4_sup(&it, buf, len);
                break;
            case 3:
                m_decimators.decimate8_sup(&it, buf, len);
                break;
            case 4:
                m_decimators.decimate16_sup(&it, buf, len);
                break;
            case 5:
                m_decimators.decimate32_sup(&it, buf, len);
                break;
            case 6:
                m_decimators.decimate64_sup(&it, buf, len);
                break;
            default:
                break;
            }
        }
        else // Centered
        {
            switch (m_log2Decim)
            {
            case 1:
                m_decimators.decimate2_cen(&it, buf, len);
                break;
            case 2:
                m_decimators.decimate4_cen(&it, buf, len);
                break;
            case 3:
                m_decimators.decimate8_cen(&it, buf, len);
                break;
            case 4:
                m_decimators.decimate16_cen(&it, buf, len);
                break;
            case 5:
                m_decimators.decimate32_cen(&it, buf, len);
                break;
            case 6:
                m_decimators.decimate64_cen(&it, buf, len);
                break;
            default:
                break;
            }
        }
    }

    m_sampleFifo->write(m_convertBuffer.begin(), it);

    if(!m_running)
        rtlsdr_cancel_async(m_dev);
}

void RTLSDRThread::callbackHelper(unsigned char* buf, uint32_t len, void* ctx)
{
    RTLSDRThread* thread = (RTLSDRThread*)ctx;
    thread->callback(buf, len);
}