FlightDisplayWidget.cc

/*=====================================================================

QGroundControl Open Source Ground Control Station

(c) 2009, 2015 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>

This file is part of the QGROUNDCONTROL project

    QGROUNDCONTROL 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.

    QGROUNDCONTROL 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 QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.

======================================================================*/

#include <QQmlContext>
#include <QQmlEngine>
#include <QSettings>

#include <VideoItem.h>
#include <VideoSurface.h>
#include "VideoReceiver.h"

#include "ScreenToolsController.h"
#include "FlightDisplayWidget.h"

const char* kMainFlightDisplayWidgetGroup = "FlightDisplayWidget";

FlightDisplayWidget::FlightDisplayWidget(const QString& title, QAction* action, QWidget *parent)
    : QGCQmlWidgetHolder(title, action, parent)
{
    setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::MinimumExpanding);
    setObjectName("FlightDisplayWidget");
    // Get rid of layout default margins
    QLayout* pl = layout();
    if(pl) {
        pl->setContentsMargins(0,0,0,0);
    }
#ifndef __android__
    setMinimumWidth( 31 * ScreenToolsController::defaultFontPixelSize_s());
    setMinimumHeight(33 * ScreenToolsController::defaultFontPixelSize_s());
#endif
    setContextPropertyObject("flightDisplay", this);

    /*
     * This is the receiving end of an UDP RTP stream. The sender can be setup with this command:
     *
     * gst-launch-1.0 uvch264src initial-bitrate=1000000 average-bitrate=1000000 iframe-period=1000 name=src auto-start=true src.vidsrc ! \
     * video/x-h264,width=1280,height=720,framerate=24/1 ! h264parse ! rtph264pay ! udpsink host=192.168.1.9 port=5000
     *
     * Where the main parameters are:
     *
     *  uvch264src:         Your h264 video source (the example above uses a Logitech C920 on an Raspberry PI 2+ or Odroid C1
     *  host=192.168.1.9    This is the IP address of QGC. You can use Avahi/Zeroconf to find QGC using the "_qgroundcontrol._udp" service.
     *
     * Advanced settings (you should probably read the gstreamer documentation before changing these):
     *
     * initial-bitrate=1000000 average-bitrate=1000000
     * The bit rate to use. The greater, the better quality at the cost of higher bandwidth.
     *
     * width=1280,height=720,framerate=24/1
     * The video resolution and frame rate. This depends on the camera used.
     *
     * iframe-period=1000
     * Interval between iFrames. The greater the interval the lesser bandwidth at the cost of a longer time to recover from lost packets.
     *
     * Do not change anything else unless you know what you are doing. Any other change will require a matching change on the receiving end.
     *
     */
    VideoSurface* pSurface = new VideoSurface;
    setContextPropertyObject("videoDisplay", pSurface);
    VideoReceiver* pReceiver = new VideoReceiver(this);
    pReceiver->setUri(QLatin1Literal("udp://0.0.0.0:5000"));
#if defined(QGC_GST_STREAMING)
    pReceiver->setVideoSink(pSurface->videoSink());
#endif
    setContextPropertyObject("videoReceiver", pReceiver);

    setSource(QUrl::fromUserInput("qrc:/qml/FlightDisplayWidget.qml"));
    setVisible(true);
    
    loadSettings();
}

FlightDisplayWidget::~FlightDisplayWidget()
{
}

void FlightDisplayWidget::saveSetting(const QString &name, const QString& value)
{
    QSettings settings;
    QString key(kMainFlightDisplayWidgetGroup);
    key += "/" + name;
    settings.setValue(key, value);
}

QString FlightDisplayWidget::loadSetting(const QString &name, const QString& defaultValue)
{
    QSettings settings;
    QString key(kMainFlightDisplayWidgetGroup);
    key += "/" + name;
    return settings.value(key, defaultValue).toString();
}