sdrangel/plugins/samplesource/audioinput/audioinputthread.cpp

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
// written by Christian Daniel                                                   //
// Copyright (C) 2020 Jon Beniston, M7RCE                                        //
//                                                                               //
// 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 <stdio.h>
#include <errno.h>
#include <chrono>
#include <thread>

#include "dsp/samplesinkfifo.h"
#include "audio/audiofifo.h"

#include "audioinputthread.h"

AudioInputThread::AudioInputThread(SampleSinkFifo* sampleFifo, AudioFifo *fifo, QObject* parent) :
    QThread(parent),
    m_fifo(fifo),
    m_running(false),
    m_log2Decim(0),
    m_iqMapping(AudioInputSettings::IQMapping::L),
    m_convertBuffer(m_convBufSamples),
    m_sampleFifo(sampleFifo)
{
    start();
}

AudioInputThread::~AudioInputThread()
{
}

void AudioInputThread::startWork()
{
    m_startWaitMutex.lock();

    start();

    while(!m_running)
    {
        m_startWaiter.wait(&m_startWaitMutex, 100);
    }

    m_startWaitMutex.unlock();
}

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

void AudioInputThread::run()
{
    m_running = true;
    qDebug("AudioInputThread::run: start running loop");

    while (m_running)
    {
        workIQ(m_convBufSamples);
    }

    qDebug("AudioInputThread::run: running loop stopped");
    m_running = false;
}

void AudioInputThread::workIQ(unsigned int samples)
{
    // Most of the time, this returns 0, because of the low sample rate.
    // Could be more efficient in this case to have blocking wait?
    uint32_t nbRead = m_fifo->read((unsigned char *) m_buf, samples);

    // Map between left and right audio channels and IQ channels
    if (m_iqMapping == AudioInputSettings::IQMapping::L)
    {
        for (uint32_t i = 0; i < nbRead; i++)
            m_buf[i*2+1] = 0;
    }
    else if (m_iqMapping == AudioInputSettings::IQMapping::R)
    {
        for (uint32_t i = 0; i < nbRead; i++)
        {
            m_buf[i*2] = m_buf[i*2+1];
            m_buf[i*2+1] = 0;
        }
    }
    else if (m_iqMapping == AudioInputSettings::IQMapping::LR)
    {
        for (uint32_t i = 0; i < nbRead; i++)
        {
            qint16 t = m_buf[i*2];
            m_buf[i*2] = m_buf[i*2+1];
            m_buf[i*2+1] = t;
        }
    }

    SampleVector::iterator it = m_convertBuffer.begin();

    switch (m_log2Decim)
    {
    case 0:
        m_decimatorsIQ.decimate1(&it, m_buf, 2*nbRead);
        break;
    case 1:
        m_decimatorsIQ.decimate2_cen(&it, m_buf, 2*nbRead);
        break;
    case 2:
        m_decimatorsIQ.decimate4_cen(&it, m_buf, 2*nbRead);
        break;
    case 3:
        m_decimatorsIQ.decimate8_cen(&it, m_buf, 2*nbRead);
        break;
    case 4:
        m_decimatorsIQ.decimate16_cen(&it, m_buf, 2*nbRead);
        break;
    case 5:
        m_decimatorsIQ.decimate32_cen(&it, m_buf, 2*nbRead);
        break;
    case 6:
        m_decimatorsIQ.decimate64_cen(&it, m_buf, 2*nbRead);
        break;
    default:
        break;
    }

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