ground/gcs/src/libs/gstreamer/devicemonitor.cpp

   1 /**
   2  ******************************************************************************
   3  *
   4  * @file       devicemonitor.cpp
   5  * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
   6  * @brief
   7  * @see        The GNU Public License (GPL) Version 3
   8  * @defgroup
   9  * @{
  10  *
  11  *****************************************************************************/
  12 /*
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 3 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful, but
  19  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  20  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  21  * for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with this program; if not, write to the Free Software Foundation, Inc.,
  25  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  26  */
  27 #include "devicemonitor.h"
  28
  29 #include "gst_util.h"
  30
  31 #include <gst/gst.h>
  32
  33 #include <QDebug>
  34
  35 static GstBusSyncReply my_bus_sync_func(GstBus *bus, GstMessage *message, gpointer user_data)
  36 {
  37     Q_UNUSED(bus)
  38
  39     DeviceMonitor * dm;
  40     GstDevice *device;
  41     gchar *name;
  42
  43     switch (GST_MESSAGE_TYPE(message)) {
  44     case GST_MESSAGE_DEVICE_ADDED:
  45         gst_message_parse_device_added(message, &device);
  46         name = gst_device_get_display_name(device);
  47
  48         dm   = (DeviceMonitor *)user_data;
  49         QMetaObject::invokeMethod(dm, "device_added", Qt::QueuedConnection,
  50                                   Q_ARG(QString, QString(name)));
  51
  52         g_free(name);
  53         break;
  54     case GST_MESSAGE_DEVICE_REMOVED:
  55         gst_message_parse_device_removed(message, &device);
  56         name = gst_device_get_display_name(device);
  57
  58         dm   = (DeviceMonitor *)user_data;
  59         QMetaObject::invokeMethod(dm, "device_removed", Qt::QueuedConnection,
  60                                   Q_ARG(QString, QString(name)));
  61
  62         g_free(name);
  63         break;
  64     default:
  65         break;
  66     }
  67
  68     // no need to pass it to the async queue, there is none...
  69     return GST_BUS_DROP;
  70 }
  71
  72 DeviceMonitor::DeviceMonitor(QObject *parent) : QObject(parent)
  73 {
  74     // initialize gstreamer
  75     gst::init(NULL, NULL);
  76
  77     monitor = gst_device_monitor_new();
  78
  79     GstBus *bus = gst_device_monitor_get_bus(monitor);
  80     gst_bus_set_sync_handler(bus, (GstBusSyncHandler)my_bus_sync_func, this, NULL);
  81     gst_object_unref(bus);
  82
  83     GstCaps *caps = NULL; // gst_caps_new_empty_simple("video/x-raw");
  84     const gchar *classes = "Video/Source";
  85     gst_device_monitor_add_filter(monitor, classes, caps);
  86     if (caps) {
  87         gst_caps_unref(caps);
  88     }
  89
  90     if (!gst_device_monitor_start(monitor)) {
  91         qWarning() << "Failed to start device monitor";
  92     }
  93 }
  94
  95 DeviceMonitor::~DeviceMonitor()
  96 {
  97     gst_device_monitor_stop(monitor);
  98     gst_object_unref(monitor);
  99 }
 100
 101 QList<Device> DeviceMonitor::devices() const
 102 {
 103     QList<Device> devices;
 104
 105     GList *list = gst_device_monitor_get_devices(monitor);
 106     while (list != NULL) {
 107         gchar *name;
 108         gchar *device_class;
 109
 110         GstDevice *device = (GstDevice *)list->data;
 111         name = gst_device_get_display_name(device);
 112         device_class = gst_device_get_device_class(device);
 113
 114         devices << Device(name, device_class);
 115
 116         g_free(name);
 117         g_free(device_class);
 118
 119         gst_object_unref(device);
 120         list = g_list_remove_link(list, list);
 121     }
 122
 123     return devices;
 124 }
 125
 126 void DeviceMonitor::device_added(QString name)
 127 {
 128     // qDebug() << "**** ADDED:" << name;
 129     emit deviceAdded(name);
 130 }
 131
 132 void DeviceMonitor::device_removed(QString name)
 133 {
 134     // qDebug() << "**** REMOVED:" << name;
 135     emit deviceRemoved(name);
 136 }