/////////////////////////////////////////////////////////////////////////////////// // 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 // // // // 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 . // /////////////////////////////////////////////////////////////////////////////////// #include #include #include "rtlsdrthread.h" #include "dsp/samplefifo.h" #define BLOCKSIZE 16384 RTLSDRThread::RTLSDRThread(rtlsdr_dev_t* dev, SampleFifo* sampleFifo, QObject* parent) : QThread(parent), m_running(false), m_dev(dev), m_convertBuffer(BLOCKSIZE), m_sampleFifo(sampleFifo), m_samplerate(288000) { } 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::run() { int res; m_running = true; m_startWaiter.wakeAll(); while(m_running) { if((res = rtlsdr_read_async(m_dev, &RTLSDRThread::callbackHelper, this, 32, BLOCKSIZE)) < 0) { qCritical("RTLSDRThread: async error: %s", strerror(errno)); break; } } m_running = false; } void RTLSDRThread::decimate2(SampleVector::iterator* it, const quint8* buf, qint32 len) { qint16 xreal, yimag; for (int pos = 0; pos < len - 7; pos += 8) { xreal = buf[pos+0] - buf[pos+3]; yimag = buf[pos+1] + buf[pos+2] - 255; Sample s( xreal << 3, yimag << 3 ); **it = s; (*it)++; xreal = buf[pos+7] - buf[pos+4]; yimag = 255 - buf[pos+5] - buf[pos+6]; Sample t( xreal << 3, yimag << 3 ); **it = t; (*it)++; } } void RTLSDRThread::decimate4(SampleVector::iterator* it, const quint8* buf, qint32 len) { qint16 xreal, yimag; for (int pos = 0; pos < len - 7; pos += 8) { xreal = buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]; yimag = buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]; Sample s( xreal << 3, yimag << 3 ); **it = s; (*it)++; } } void RTLSDRThread::decimate8(SampleVector::iterator* it, const quint8* buf, qint32 len) { qint16 xreal, yimag; for (int pos = 0; pos < len - 15; pos += 8) { xreal = buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]; yimag = buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]; Sample s1( xreal << 3, yimag << 3 ); pos += 8; xreal = buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]; yimag = buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]; Sample s2( xreal << 3, yimag << 3 ); m_decimator2.myDecimate(&s1, &s2); **it = s2; (*it)++; } } void RTLSDRThread::decimate16(SampleVector::iterator* it, const quint8* buf, qint32 len) { // Offset tuning: 4x downsample and rotate, then // downsample 4x more. [ rotate: 0, 1, -3, 2, -4, -5, 7, -6] qint16 xreal[4], yimag[4]; for (int pos = 0; pos < len - 31; ) { for (int i = 0; i < 4; i++) { xreal[i] = (buf[pos+0] - buf[pos+3] + buf[pos+7] - buf[pos+4]) << 4; yimag[i] = (buf[pos+1] - buf[pos+5] + buf[pos+2] - buf[pos+6]) << 4; pos += 8; } Sample s1( xreal[0], yimag[0] ); Sample s2( xreal[1], yimag[1] ); Sample s3( xreal[2], yimag[2] ); Sample s4( xreal[3], yimag[3] ); m_decimator2.myDecimate(&s1, &s2); m_decimator2.myDecimate(&s3, &s4); m_decimator4.myDecimate(&s2, &s4); **it = s4; (*it)++; } } // Decimate everything by 16x, except 288kHz by 4x // and 1152kHz, 2048kHz by 8x void RTLSDRThread::callback(const quint8* buf, qint32 len) { SampleVector::iterator it = m_convertBuffer.begin(); if (m_samplerate < 800000) decimate4(&it, buf, len); else if ((m_samplerate == 1152000)||(m_samplerate == 2048000)) decimate8(&it, buf, len); else decimate16(&it, buf, len); 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); }