Create new SDR output abstraction and port Soapy

1 files changed, 994 insertions, 0 deletions

diff --git a/src/output/UHD.cpp b/src/output/UHD.cpp
new file mode 100644
index 0000000..4942f3f
--- /dev/null
+++ b/src/output/UHD.cpp
@@ -0,0 +1,994 @@
+/*
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Her Majesty the
+   Queen in Right of Canada (Communications Research Center Canada)
+
+   Copyright (C) 2017
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://opendigitalradio.org
+ */
+/*
+   This file is part of ODR-DabMod.
+
+   ODR-DabMod 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, either version 3 of the
+   License, or (at your option) any later version.
+
+   ODR-DabMod 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 for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with ODR-DabMod.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "OutputUHD.h"
+
+#ifdef HAVE_OUTPUT_UHD
+
+#include "PcDebug.h"
+#include "Log.h"
+#include "RemoteControl.h"
+#include "Utils.h"
+
+#include <boost/thread/future.hpp>
+
+#include <uhd/utils/msg.hpp>
+
+#include <cmath>
+#include <iostream>
+#include <assert.h>
+#include <stdexcept>
+#include <stdio.h>
+#include <time.h>
+#include <errno.h>
+#include <unistd.h>
+#include <pthread.h>
+
+using namespace std;
+
+// Maximum number of frames that can wait in frames
+static const size_t FRAMES_MAX_SIZE = 8;
+
+typedef std::complex<float> complexf;
+
+std::string stringtrim(const std::string &s)
+{
+    auto wsfront = std::find_if_not(s.begin(), s.end(),
+            [](int c){ return std::isspace(c);} );
+    return std::string(wsfront,
+            std::find_if_not(s.rbegin(),
+                std::string::const_reverse_iterator(wsfront),
+                [](int c){ return std::isspace(c);} ).base());
+}
+
+void uhd_msg_handler(uhd::msg::type_t type, const std::string &msg)
+{
+    if (type == uhd::msg::warning) {
+        etiLog.level(warn) << "UHD Warning: " << msg;
+    }
+    else if (type == uhd::msg::error) {
+        etiLog.level(error) << "UHD Error: " << msg;
+    }
+    else {
+        // do not print very short U messages and such
+        if (stringtrim(msg).size() != 1) {
+            etiLog.level(debug) << "UHD Message: " << msg;
+        }
+    }
+}
+
+static void tune_usrp_to(
+        uhd::usrp::multi_usrp::sptr usrp,
+        double lo_offset,
+        double frequency)
+{
+    if (lo_offset != 0.0) {
+        etiLog.level(info) << std::fixed << std::setprecision(3) <<
+            "OutputUHD:Setting freq to " << frequency <<
+            "  with LO offset " << lo_offset << "...";
+
+        const auto tr = uhd::tune_request_t(frequency, lo_offset);
+        uhd::tune_result_t result = usrp->set_tx_freq(tr);
+
+        etiLog.level(debug) << "OutputUHD:" <<
+            std::fixed << std::setprecision(0) <<
+            " Target RF: " << result.target_rf_freq <<
+            " Actual RF: " << result.actual_rf_freq <<
+            " Target DSP: " << result.target_dsp_freq <<
+            " Actual DSP: " << result.actual_dsp_freq;
+    }
+    else {
+        //set the centre frequency
+        etiLog.level(info) << std::fixed << std::setprecision(3) <<
+            "OutputUHD:Setting freq to " << frequency << "...";
+        usrp->set_tx_freq(frequency);
+    }
+
+    usrp->set_rx_freq(frequency);
+}
+
+// Check function for GPS TIMELOCK sensor from the ODR LEA-M8F board GPSDO
+bool check_gps_timelock(uhd::usrp::multi_usrp::sptr usrp)
+{
+    try {
+        std::string sensor_value(
+                usrp->get_mboard_sensor("gps_timelock", 0).to_pp_string());
+
+        if (sensor_value.find("TIME LOCKED") == std::string::npos) {
+            etiLog.level(warn) << "OutputUHD: gps_timelock " << sensor_value;
+            return false;
+        }
+
+        return true;
+    }
+    catch (uhd::lookup_error &e) {
+        etiLog.level(warn) << "OutputUHD: no gps_timelock sensor";
+        return false;
+    }
+}
+
+// Check function for GPS LOCKED sensor from the Ettus GPSDO
+bool check_gps_locked(uhd::usrp::multi_usrp::sptr usrp)
+{
+    try {
+        uhd::sensor_value_t sensor_value(
+                usrp->get_mboard_sensor("gps_locked", 0));
+        if (not sensor_value.to_bool()) {
+            etiLog.level(warn) << "OutputUHD: gps_locked " <<
+                sensor_value.to_pp_string();
+            return false;
+        }
+
+        return true;
+    }
+    catch (uhd::lookup_error &e) {
+        etiLog.level(warn) << "OutputUHD: no gps_locked sensor";
+        return false;
+    }
+}
+
+
+OutputUHD::OutputUHD(
+        OutputUHDConfig& config) :
+    ModOutput(),
+    RemoteControllable("uhd"),
+    myConf(config),
+    // Since we don't know the buffer size, we cannot initialise
+    // the buffers at object initialisation.
+    myDelayBuf(0),
+    running(false)
+{
+    myConf.muting = true;     // is remote-controllable, and reset by the GPS fix check
+
+    // Variables needed for GPS fix check
+    first_gps_fix_check.tv_sec = 0;
+    last_gps_fix_check.tv_sec = 0;
+    time_last_frame.tv_sec = 0;
+
+
+    std::stringstream device;
+    device << myConf.device;
+
+    if (myConf.masterClockRate != 0) {
+        if (device.str() != "") {
+            device << ",";
+        }
+        device << "master_clock_rate=" << myConf.masterClockRate;
+    }
+
+    if (myConf.usrpType != "") {
+        if (device.str() != "") {
+            device << ",";
+        }
+        device << "type=" << myConf.usrpType;
+    }
+
+    MDEBUG("OutputUHD::OutputUHD(device: %s) @ %p\n",
+            device.str().c_str(), this);
+
+    /* register the parameters that can be remote controlled */
+    RC_ADD_PARAMETER(txgain, "UHD analog daughterboard TX gain");
+    RC_ADD_PARAMETER(rxgain, "UHD analog daughterboard RX gain for DPD feedback");
+    RC_ADD_PARAMETER(freq, "UHD transmission frequency");
+    RC_ADD_PARAMETER(muting, "Mute the output by stopping the transmitter");
+    RC_ADD_PARAMETER(underruns, "Read-only counter of number of underruns");
+    RC_ADD_PARAMETER(latepackets, "Read-only counter of number of late packets");
+    RC_ADD_PARAMETER(frames, "Read-only counter of number of frames modulated");
+
+    uhd::msg::register_handler(uhd_msg_handler);
+
+    uhd::set_thread_priority_safe();
+
+    etiLog.log(info, "OutputUHD:Creating the usrp device with: %s...",
+            device.str().c_str());
+
+    myUsrp = uhd::usrp::multi_usrp::make(device.str());
+
+    etiLog.log(info, "OutputUHD:Using device: %s...",
+            myUsrp->get_pp_string().c_str());
+
+    if (myConf.masterClockRate != 0.0) {
+        double master_clk_rate = myUsrp->get_master_clock_rate();
+        etiLog.log(debug, "OutputUHD:Checking master clock rate: %f...",
+                master_clk_rate);
+
+        if (fabs(master_clk_rate - myConf.masterClockRate) >
+                (myConf.masterClockRate * 1e-6)) {
+            throw std::runtime_error("Cannot set USRP master_clock_rate. Aborted.");
+        }
+    }
+
+    MDEBUG("OutputUHD:Setting REFCLK and PPS input...\n");
+
+    if (myConf.refclk_src == "gpsdo-ettus") {
+        myUsrp->set_clock_source("gpsdo");
+    }
+    else {
+        myUsrp->set_clock_source(myConf.refclk_src);
+    }
+    myUsrp->set_time_source(myConf.pps_src);
+
+    if (myConf.subDevice != "") {
+        myUsrp->set_tx_subdev_spec(uhd::usrp::subdev_spec_t(myConf.subDevice),
+                uhd::usrp::multi_usrp::ALL_MBOARDS);
+    }
+
+    etiLog.level(debug) << "UHD clock source is " << myUsrp->get_clock_source(0);
+
+    etiLog.level(debug) << "UHD time source is " << myUsrp->get_time_source(0);
+
+    myUsrp->set_tx_rate(myConf.sampleRate);
+    etiLog.log(debug, "OutputUHD:Set rate to %d. Actual TX Rate: %f sps...",
+            myConf.sampleRate, myUsrp->get_tx_rate());
+
+    if (fabs(myUsrp->get_tx_rate() / myConf.sampleRate) >
+             myConf.sampleRate * 1e-6) {
+        throw std::runtime_error("Cannot set USRP sample rate. Aborted.");
+    }
+
+    tune_usrp_to(myUsrp, myConf.lo_offset, myConf.frequency);
+
+    myConf.frequency = myUsrp->get_tx_freq();
+    etiLog.level(info) << std::fixed << std::setprecision(3) <<
+        "OutputUHD:Actual TX frequency: " << myConf.frequency;
+
+    etiLog.level(info) << std::fixed << std::setprecision(3) <<
+        "OutputUHD:Actual RX frequency: " << myUsrp->get_tx_freq();
+
+    myUsrp->set_tx_gain(myConf.txgain);
+    etiLog.log(debug, "OutputUHD:Actual TX Gain: %f", myUsrp->get_tx_gain());
+
+    etiLog.log(debug, "OutputUHD:Mute on missing timestamps: %s",
+            myConf.muteNoTimestamps ? "enabled" : "disabled");
+
+    // preparing output thread worker data
+    sourceContainsTimestamp = false;
+
+    SetDelayBuffer(myConf.dabMode);
+
+    myUsrp->set_rx_rate(myConf.sampleRate);
+    etiLog.log(debug, "OutputUHD:Actual RX Rate: %f sps.", myUsrp->get_rx_rate());
+
+    myUsrp->set_rx_antenna("RX2");
+    etiLog.log(debug, "OutputUHD:Set RX Antenna: %s",
+            myUsrp->get_rx_antenna().c_str());
+
+    myUsrp->set_rx_gain(myConf.rxgain);
+    etiLog.log(debug, "OutputUHD:Actual RX Gain: %f", myUsrp->get_rx_gain());
+
+    uhdFeedback = std::make_shared<OutputUHDFeedback>(
+            myUsrp, myConf.dpdFeedbackServerPort, myConf.sampleRate);
+
+    MDEBUG("OutputUHD:UHD ready.\n");
+}
+
+bool OutputUHD::refclk_loss_needs_check() const
+{
+    if (suppress_refclk_loss_check) {
+        return false;
+    }
+    return myConf.refclk_src != "internal";
+}
+
+bool OutputUHD::gpsfix_needs_check() const
+{
+    if (myConf.refclk_src == "internal") {
+        return false;
+    }
+    else if (myConf.refclk_src == "gpsdo") {
+        return (myConf.maxGPSHoldoverTime != 0);
+    }
+    else if (myConf.refclk_src == "gpsdo-ettus") {
+        return (myConf.maxGPSHoldoverTime != 0);
+    }
+    else {
+        return false;
+    }
+}
+
+bool OutputUHD::gpsdo_is_ettus() const
+{
+    return (myConf.refclk_src == "gpsdo-ettus");
+}
+
+OutputUHD::~OutputUHD()
+{
+    stop_threads();
+}
+
+void OutputUHD::stop_threads()
+{
+    running.store(false);
+    uhd_thread.interrupt();
+    uhd_thread.join();
+    async_rx_thread.join();
+}
+
+
+void OutputUHD::setETISource(EtiSource *etiSource)
+{
+    myEtiSource = etiSource;
+}
+
+int transmission_frame_duration_ms(unsigned int dabMode)
+{
+    switch (dabMode) {
+        // could happen when called from constructor and we take the mode from ETI
+        case 0: return 0;
+
+        case 1: return 96;
+        case 2: return 24;
+        case 3: return 24;
+        case 4: return 48;
+        default:
+            throw std::runtime_error("OutputUHD: invalid DAB mode");
+    }
+}
+
+void OutputUHD::SetDelayBuffer(unsigned int dabMode)
+{
+    // find out the duration of the transmission frame (Table 2 in ETSI 300 401)
+    myTFDurationMs = transmission_frame_duration_ms(dabMode);
+
+    // The buffer size equals the number of samples per transmission frame so
+    // we calculate it by multiplying the duration of the transmission frame
+    // with the samplerate.
+    myDelayBuf.resize(myTFDurationMs * myConf.sampleRate / 1000);
+}
+
+int OutputUHD::process(Buffer* dataIn)
+{
+    if (not gps_fix_verified) {
+        if (gpsfix_needs_check()) {
+            initial_gps_check();
+
+            if (num_checks_without_gps_fix == 0) {
+                set_usrp_time();
+                gps_fix_verified = true;
+                myConf.muting = false;
+            }
+        }
+        else {
+            set_usrp_time();
+            gps_fix_verified = true;
+            myConf.muting = false;
+        }
+    }
+    else {
+        if (first_run) {
+            etiLog.level(debug) << "OutputUHD: UHD initialising...";
+
+            // we only set the delay buffer from the dab mode signaled in ETI if the
+            // dab mode was not set in contructor
+            if (myTFDurationMs == 0) {
+                SetDelayBuffer(myEtiSource->getMode());
+            }
+
+            running.store(true);
+            uhd_thread = boost::thread(&OutputUHD::workerthread, this);
+            async_rx_thread = boost::thread(
+                    &OutputUHD::print_async_thread, this);
+
+            lastLen = dataIn->getLength();
+            first_run = false;
+            etiLog.level(debug) << "OutputUHD: UHD initialising complete";
+        }
+
+        if (lastLen != dataIn->getLength()) {
+            // I expect that this never happens.
+            etiLog.level(emerg) <<
+                "OutputUHD: Fatal error, input length changed from " << lastLen <<
+                " to " << dataIn->getLength();
+            throw std::runtime_error("Non-constant input length!");
+        }
+
+        sourceContainsTimestamp = myConf.enableSync and
+            myEtiSource->sourceContainsTimestamp();
+
+        if (gpsfix_needs_check()) {
+            try {
+                check_gps();
+            }
+            catch (std::runtime_error& e) {
+                running.store(false);
+                etiLog.level(error) << e.what();
+            }
+        }
+
+        // Prepare the frame for the worker
+        UHDWorkerFrameData frame;
+        frame.buf.resize(dataIn->getLength());
+
+        std::copy(pInData, pInData + dataIn->getLength(),
+                frame.buf.begin());
+
+        myEtiSource->calculateTimestamp(frame.ts);
+
+        if (not running.load()) {
+            uhd_thread.interrupt();
+            uhd_thread.join();
+            async_rx_thread.join();
+            first_run = true;
+
+            etiLog.level(error) << "OutputUHD UHD worker failed";
+            throw std::runtime_error("UHD worker failed");
+        }
+
+        if (frame.ts.fct == -1) {
+            etiLog.level(info) <<
+                "OutputUHD: dropping one frame with invalid FCT";
+        }
+        else {
+            try {
+                uhdFeedback->set_tx_frame(frame.buf, frame.ts);
+            }
+            catch (const runtime_error& e) {
+                etiLog.level(warn) <<
+                    "OutputUHD: Feedback server failed, restarting...";
+
+                uhdFeedback = std::make_shared<OutputUHDFeedback>(
+                        myUsrp, myConf.dpdFeedbackServerPort, myConf.sampleRate);
+            }
+
+            size_t num_frames = frames.push_wait_if_full(frame,
+                    FRAMES_MAX_SIZE);
+            etiLog.log(trace, "UHD,push %zu", num_frames);
+        }
+    }
+
+    return dataIn->getLength();
+}
+
+
+void OutputUHD::set_usrp_time()
+{
+    if (myConf.enableSync and (myConf.pps_src == "none")) {
+        etiLog.level(warn) <<
+            "OutputUHD: WARNING:"
+            " you are using synchronous transmission without PPS input!";
+
+        struct timespec now;
+        if (clock_gettime(CLOCK_REALTIME, &now)) {
+            perror("OutputUHD:Error: could not get time: ");
+            etiLog.level(error) << "OutputUHD: could not get time";
+        }
+        else {
+            myUsrp->set_time_now(uhd::time_spec_t(now.tv_sec));
+            etiLog.level(info) << "OutputUHD: Setting USRP time to " <<
+                std::fixed <<
+                uhd::time_spec_t(now.tv_sec).get_real_secs();
+        }
+    }
+
+    if (myConf.pps_src != "none") {
+        /* handling time for synchronisation: wait until the next full
+         * second, and set the USRP time at next PPS */
+        struct timespec now;
+        time_t seconds;
+        if (clock_gettime(CLOCK_REALTIME, &now)) {
+            etiLog.level(error) << "OutputUHD: could not get time :" <<
+                strerror(errno);
+            throw std::runtime_error("OutputUHD: could not get time.");
+        }
+        else {
+            seconds = now.tv_sec;
+
+            MDEBUG("OutputUHD:sec+1: %ld ; now: %ld ...\n", seconds+1, now.tv_sec);
+            while (seconds + 1 > now.tv_sec) {
+                usleep(1);
+                if (clock_gettime(CLOCK_REALTIME, &now)) {
+                    etiLog.level(error) << "OutputUHD: could not get time :" <<
+                        strerror(errno);
+                    throw std::runtime_error("OutputUHD: could not get time.");
+                }
+            }
+            MDEBUG("OutputUHD:sec+1: %ld ; now: %ld ...\n", seconds+1, now.tv_sec);
+            /* We are now shortly after the second change. */
+
+            usleep(200000); // 200ms, we want the PPS to be later
+            myUsrp->set_time_unknown_pps(uhd::time_spec_t(seconds + 2));
+            etiLog.level(info) << "OutputUHD: Setting USRP time next pps to " <<
+                std::fixed <<
+                uhd::time_spec_t(seconds + 2).get_real_secs();
+        }
+
+        usleep(1e6);
+        etiLog.log(info,  "OutputUHD: USRP time %f\n",
+                myUsrp->get_time_now().get_real_secs());
+    }
+}
+
+void OutputUHD::initial_gps_check()
+{
+    if (first_gps_fix_check.tv_sec == 0) {
+        etiLog.level(info) << "Waiting for GPS fix";
+
+        if (clock_gettime(CLOCK_MONOTONIC, &first_gps_fix_check) != 0) {
+            stringstream ss;
+            ss << "clock_gettime failure: " << strerror(errno);
+            throw std::runtime_error(ss.str());
+        }
+    }
+
+    check_gps();
+
+    if (last_gps_fix_check.tv_sec >
+            first_gps_fix_check.tv_sec + initial_gps_fix_wait) {
+        stringstream ss;
+        ss << "GPS did not show time lock in " << initial_gps_fix_wait << " seconds";
+        throw std::runtime_error(ss.str());
+    }
+
+    if (time_last_frame.tv_sec == 0) {
+        if (clock_gettime(CLOCK_MONOTONIC, &time_last_frame) != 0) {
+            stringstream ss;
+            ss << "clock_gettime failure: " << strerror(errno);
+            throw std::runtime_error(ss.str());
+        }
+    }
+
+    struct timespec now;
+    if (clock_gettime(CLOCK_MONOTONIC, &now) != 0) {
+        stringstream ss;
+        ss << "clock_gettime failure: " << strerror(errno);
+        throw std::runtime_error(ss.str());
+    }
+
+    long delta_us = timespecdiff_us(time_last_frame, now);
+    long wait_time_us = transmission_frame_duration_ms(myConf.dabMode);
+
+    if (wait_time_us - delta_us > 0) {
+        usleep(wait_time_us - delta_us);
+    }
+
+    time_last_frame.tv_nsec += wait_time_us * 1000;
+    if (time_last_frame.tv_nsec >= 1000000000L) {
+        time_last_frame.tv_nsec -= 1000000000L;
+        time_last_frame.tv_sec++;
+    }
+}
+
+void OutputUHD::check_gps()
+{
+    struct timespec time_now;
+    if (clock_gettime(CLOCK_MONOTONIC, &time_now) != 0) {
+        stringstream ss;
+        ss << "clock_gettime failure: " << strerror(errno);
+        throw std::runtime_error(ss.str());
+    }
+
+    // Divide interval by two because we alternate between
+    // launch and check
+    if (gpsfix_needs_check() and
+            last_gps_fix_check.tv_sec + gps_fix_check_interval/2.0 <
+            time_now.tv_sec) {
+        last_gps_fix_check = time_now;
+
+        // Alternate between launching thread and checking the
+        // result.
+        if (gps_fix_task.joinable()) {
+            if (gps_fix_future.has_value()) {
+
+                gps_fix_future.wait();
+
+                gps_fix_task.join();
+
+                if (not gps_fix_future.get()) {
+                    if (num_checks_without_gps_fix == 0) {
+                        etiLog.level(alert) <<
+                            "OutputUHD: GPS Time Lock lost";
+                    }
+                    num_checks_without_gps_fix++;
+                }
+                else {
+                    if (num_checks_without_gps_fix) {
+                        etiLog.level(info) <<
+                            "OutputUHD: GPS Time Lock recovered";
+                    }
+                    num_checks_without_gps_fix = 0;
+                }
+
+                if (gps_fix_check_interval * num_checks_without_gps_fix >
+                        myConf.maxGPSHoldoverTime) {
+                    std::stringstream ss;
+                    ss << "Lost GPS Time Lock for " << gps_fix_check_interval *
+                        num_checks_without_gps_fix << " seconds";
+                    throw std::runtime_error(ss.str());
+                }
+            }
+        }
+        else {
+            // Checking the sensor here takes too much
+            // time, it has to be done in a separate thread.
+            if (gpsdo_is_ettus()) {
+                gps_fix_pt = boost::packaged_task<bool>(
+                        boost::bind(check_gps_locked, myUsrp) );
+            }
+            else {
+                gps_fix_pt = boost::packaged_task<bool>(
+                        boost::bind(check_gps_timelock, myUsrp) );
+            }
+            gps_fix_future = gps_fix_pt.get_future();
+
+            gps_fix_task = boost::thread(boost::move(gps_fix_pt));
+        }
+    }
+}
+
+void OutputUHD::workerthread()
+{
+    // Set thread priority to realtime
+    if (int ret = set_realtime_prio(1)) {
+        etiLog.level(error) << "Could not set priority for UHD worker:" << ret;
+    }
+
+    set_thread_name("uhdworker");
+
+    last_tx_time_initialised = false;
+
+    uhd::stream_args_t stream_args("fc32"); //complex floats
+    myTxStream = myUsrp->get_tx_stream(stream_args);
+
+    md.start_of_burst = false;
+    md.end_of_burst   = false;
+
+    num_underflows   = 0;
+    num_late_packets = 0;
+
+    size_t last_num_underflows = 0;
+    size_t pop_prebuffering = FRAMES_MAX_SIZE;
+
+    while (running.load()) {
+        md.has_time_spec  = false;
+        md.time_spec      = uhd::time_spec_t(0.0);
+
+        struct UHDWorkerFrameData frame;
+        etiLog.log(trace, "UHD,wait");
+        frames.wait_and_pop(frame, pop_prebuffering);
+        etiLog.log(trace, "UHD,pop");
+
+        handle_frame(&frame);
+        num_frames_modulated++;
+
+        /* Ensure we fill frames after every underrun and
+         * at startup to reduce underrun likelihood. */
+        if (last_num_underflows < num_underflows) {
+            pop_prebuffering = FRAMES_MAX_SIZE;
+        }
+        else {
+            pop_prebuffering = 1;
+        }
+        last_num_underflows = num_underflows;
+    }
+    running.store(false);
+    etiLog.level(warn) << "UHD worker terminated";
+}
+
+void OutputUHD::handle_frame(const struct UHDWorkerFrameData *frame)
+{
+    // Transmit timeout
+    static const double tx_timeout = 20.0;
+
+    // Check for ref_lock
+    if (refclk_loss_needs_check()) {
+        try {
+            if (not myUsrp->get_mboard_sensor("ref_locked", 0).to_bool()) {
+                etiLog.log(alert,
+                        "OutputUHD: External reference clock lock lost !");
+                if (myConf.refclk_lock_loss_behaviour == CRASH) {
+                    throw std::runtime_error(
+                            "OutputUHD: External reference clock lock lost.");
+                }
+            }
+        }
+        catch (uhd::lookup_error &e) {
+            suppress_refclk_loss_check = true;
+            etiLog.log(warn, "OutputUHD: This USRP does not have mboard "
+                    "sensor for ext clock loss. Check disabled.");
+        }
+    }
+
+    double usrp_time = myUsrp->get_time_now().get_real_secs();
+    bool timestamp_discontinuity = false;
+
+    if (sourceContainsTimestamp) {
+        // Tx time from MNSC and TIST
+        uint32_t tx_second = frame->ts.timestamp_sec;
+        uint32_t tx_pps    = frame->ts.timestamp_pps;
+
+        if (!frame->ts.timestamp_valid) {
+            /* We have not received a full timestamp through
+             * MNSC. We sleep through the frame.
+             */
+            etiLog.level(info) <<
+                "OutputUHD: Throwing sample " << frame->ts.fct <<
+                " away: incomplete timestamp " << tx_second <<
+                " / " << tx_pps;
+            usleep(20000); //TODO should this be TM-dependant ?
+            return;
+        }
+
+        if (last_tx_time_initialised) {
+            const size_t sizeIn = frame->buf.size() / sizeof(complexf);
+            uint64_t increment = (uint64_t)sizeIn * 16384000ul /
+                                 (uint64_t)myConf.sampleRate;
+                                  // samps  * ticks/s  / (samps/s)
+                                  // (samps * ticks * s) / (s * samps)
+                                  // ticks
+
+            uint32_t expected_sec = last_tx_second + increment / 16384000ul;
+            uint32_t expected_pps = last_tx_pps + increment % 16384000ul;
+
+            while (expected_pps >= 16384000) {
+                expected_sec++;
+                expected_pps -= 16384000;
+            }
+
+            if (expected_sec != tx_second or
+                    expected_pps != tx_pps) {
+                etiLog.level(warn) << "OutputUHD: timestamp irregularity!" <<
+                    std::fixed <<
+                    " Expected " <<
+                    expected_sec << "+" << (double)expected_pps/16384000.0 <<
+                    "(" << expected_pps << ")" <<
+                    " Got " <<
+                    tx_second << "+" << (double)tx_pps/16384000.0 <<
+                    "(" << tx_pps << ")";
+
+                timestamp_discontinuity = true;
+            }
+        }
+
+        last_tx_second = tx_second;
+        last_tx_pps    = tx_pps;
+        last_tx_time_initialised = true;
+
+        double pps_offset = tx_pps / 16384000.0;
+
+        md.has_time_spec = true;
+        md.time_spec = uhd::time_spec_t(tx_second, pps_offset);
+        etiLog.log(trace, "UHD,tist %f", md.time_spec.get_real_secs());
+
+        // md is defined, let's do some checks
+        if (md.time_spec.get_real_secs() + tx_timeout < usrp_time) {
+            etiLog.level(warn) <<
+                "OutputUHD: Timestamp in the past! offset: " <<
+                std::fixed <<
+                md.time_spec.get_real_secs() - usrp_time <<
+                "  (" << usrp_time << ")"
+                " frame " << frame->ts.fct <<
+                ", tx_second " << tx_second <<
+                ", pps " << pps_offset;
+            return;
+        }
+
+        if (md.time_spec.get_real_secs() > usrp_time + TIMESTAMP_ABORT_FUTURE) {
+            etiLog.level(error) <<
+                "OutputUHD: Timestamp way too far in the future! offset: " <<
+                std::fixed <<
+                md.time_spec.get_real_secs() - usrp_time;
+            throw std::runtime_error("Timestamp error. Aborted.");
+        }
+    }
+    else { // !sourceContainsTimestamp
+        if (myConf.muting or myConf.muteNoTimestamps) {
+            /* There was some error decoding the timestamp */
+            if (myConf.muting) {
+                etiLog.log(info,
+                        "OutputUHD: Muting sample %d requested\n",
+                        frame->ts.fct);
+            }
+            else {
+                etiLog.log(info,
+                        "OutputUHD: Muting sample %d : no timestamp\n",
+                        frame->ts.fct);
+            }
+            usleep(20000);
+            return;
+        }
+    }
+
+    tx_frame(frame, timestamp_discontinuity);
+}
+
+void OutputUHD::tx_frame(const struct UHDWorkerFrameData *frame, bool ts_update)
+{
+    const double tx_timeout = 20.0;
+    const size_t sizeIn = frame->buf.size() / sizeof(complexf);
+    const complexf* in_data = reinterpret_cast<const complexf*>(&frame->buf[0]);
+
+    size_t usrp_max_num_samps = myTxStream->get_max_num_samps();
+    size_t num_acc_samps = 0; //number of accumulated samples
+    while (running.load() and (not myConf.muting) and (num_acc_samps < sizeIn)) {
+        size_t samps_to_send = std::min(sizeIn - num_acc_samps, usrp_max_num_samps);
+
+        uhd::tx_metadata_t md_tx = md;
+
+        //ensure the the last packet has EOB set if the timestamps has been
+        //refreshed and need to be reconsidered.
+        md_tx.end_of_burst = (
+                sourceContainsTimestamp and
+                (frame->ts.timestamp_refresh or ts_update) and
+                samps_to_send <= usrp_max_num_samps );
+
+
+        //send a single packet
+        size_t num_tx_samps = myTxStream->send(
+                &in_data[num_acc_samps],
+                samps_to_send, md_tx, tx_timeout);
+        etiLog.log(trace, "UHD,sent %zu of %zu", num_tx_samps, samps_to_send);
+
+        num_acc_samps += num_tx_samps;
+
+        md_tx.time_spec = md.time_spec +
+            uhd::time_spec_t(0, num_tx_samps/myConf.sampleRate);
+
+        if (num_tx_samps == 0) {
+            etiLog.log(warn,
+                    "OutputUHD::workerthread() unable to write to device, skipping frame!\n");
+            break;
+        }
+    }
+}
+
+void OutputUHD::print_async_thread()
+{
+    while (running.load()) {
+        uhd::async_metadata_t async_md;
+        if (myUsrp->get_device()->recv_async_msg(async_md, 1)) {
+            const char* uhd_async_message = "";
+            bool failure = false;
+            switch (async_md.event_code) {
+                case uhd::async_metadata_t::EVENT_CODE_BURST_ACK:
+                    break;
+                case uhd::async_metadata_t::EVENT_CODE_UNDERFLOW:
+                    uhd_async_message = "Underflow";
+                    num_underflows++;
+                    break;
+                case uhd::async_metadata_t::EVENT_CODE_SEQ_ERROR:
+                    uhd_async_message = "Packet loss between host and device.";
+                    failure = true;
+                    break;
+                case uhd::async_metadata_t::EVENT_CODE_TIME_ERROR:
+                    uhd_async_message = "Packet had time that was late.";
+                    num_late_packets++;
+                    break;
+                case uhd::async_metadata_t::EVENT_CODE_UNDERFLOW_IN_PACKET:
+                    uhd_async_message = "Underflow occurred inside a packet.";
+                    failure = true;
+                    break;
+                case uhd::async_metadata_t::EVENT_CODE_SEQ_ERROR_IN_BURST:
+                    uhd_async_message = "Packet loss within a burst.";
+                    failure = true;
+                    break;
+                default:
+                    uhd_async_message = "unknown event code";
+                    failure = true;
+                    break;
+            }
+
+            if (failure) {
+                etiLog.level(alert) <<
+                    "Received Async UHD Message '" <<
+                    uhd_async_message << "' at time " <<
+                    md.time_spec.get_real_secs();
+
+            }
+        }
+
+        auto time_now = std::chrono::steady_clock::now();
+        if (last_print_time + std::chrono::seconds(1) < time_now) {
+            const double usrp_time =
+                myUsrp->get_time_now().get_real_secs();
+
+            if ( (num_underflows > num_underflows_previous) or
+                 (num_late_packets > num_late_packets_previous)) {
+                etiLog.log(info,
+                        "OutputUHD status (usrp time: %f): "
+                        "%d underruns and %d late packets since last status.\n",
+                        usrp_time,
+                        num_underflows, num_late_packets);
+            }
+
+            num_underflows_previous = num_underflows;
+            num_late_packets_previous = num_late_packets;
+
+            last_print_time = time_now;
+        }
+    }
+}
+
+// =======================================
+// Remote Control for UHD
+// =======================================
+void OutputUHD::set_parameter(const string& parameter, const string& value)
+{
+    stringstream ss(value);
+    ss.exceptions ( stringstream::failbit | stringstream::badbit );
+
+    if (parameter == "txgain") {
+        ss >> myConf.txgain;
+        myUsrp->set_tx_gain(myConf.txgain);
+    }
+    else if (parameter == "rxgain") {
+        ss >> myConf.rxgain;
+        myUsrp->set_rx_gain(myConf.rxgain);
+    }
+    else if (parameter == "freq") {
+        ss >> myConf.frequency;
+        tune_usrp_to(myUsrp, myConf.lo_offset, myConf.frequency);
+        myConf.frequency = myUsrp->get_tx_freq();
+    }
+    else if (parameter == "muting") {
+        ss >> myConf.muting;
+    }
+    else if (parameter == "underruns" or
+            parameter == "latepackets" or
+            parameter == "frames") {
+        throw ParameterError("Parameter " + parameter + " is read-only.");
+    }
+    else {
+        stringstream ss;
+        ss << "Parameter '" << parameter
+            << "' is not exported by controllable " << get_rc_name();
+        throw ParameterError(ss.str());
+    }
+}
+
+const string OutputUHD::get_parameter(const string& parameter) const
+{
+    stringstream ss;
+    if (parameter == "txgain") {
+        ss << myConf.txgain;
+    }
+    else if (parameter == "rxgain") {
+        ss << myConf.rxgain;
+    }
+    else if (parameter == "freq") {
+        ss << myConf.frequency;
+    }
+    else if (parameter == "muting") {
+        ss << myConf.muting;
+    }
+    else if (parameter == "underruns") {
+        ss << num_underflows;
+    }
+    else if (parameter == "latepackets") {
+        ss << num_late_packets;
+    }
+    else if (parameter == "frames") {
+        ss << num_frames_modulated;
+    }
+    else {
+        ss << "Parameter '" << parameter <<
+            "' is not exported by controllable " << get_rc_name();
+        throw ParameterError(ss.str());
+    }
+    return ss.str();
+}
+
+#endif // HAVE_OUTPUT_UHD
+