Automatic call of backup pipeline when feed is lost.

Need to improve the transition delay (Elphel --> Webcam)
Second audio vu-meter added ('level' Gst element has to
be modified to have a truly stereo vu-meter).

diff --git a/stream_2016/libre-streamer.py b/stream_2016/libre-streamer.py
index 027ea54da65672ab873f28812e26a48420a803f4..a9951abf68fed2dcc968225fcd117bdb43d86b32 100755 (executable)
--- a/stream_2016/libre-streamer.py
+++ b/stream_2016/libre-streamer.py
@@ -29,7 +29,6 @@
 #      and the pipeline construction went well (or not))
 #    - Add an input source choice for the user (camera on IP or webcam)
 #    - Add a time counter 
-#    - Add a VU-meter to check if audio feed is emitting signal
 #    - Add a 'CPU load' widget 
 #    - Add the FSF logo (need to do some pixel art) as an application icon
 #    - Add the FSF logo inside the streamer use the 'textoverlay' method in ElementFactory.make()
@@ -69,6 +68,7 @@ metadata = {'speaker_name':'NC',
             'organisation':'NC',}
 start_time = 0
 
+
 class Streamgui(object):
 
 
@@ -91,9 +91,13 @@ class Streamgui(object):
         self.videowidget = Gtk.DrawingArea()
         self.videowidget.set_size_request(600, 400)
 
-        self.vumeter = Gtk.ProgressBar()
-        self.vumeter.set_orientation(Gtk.Orientation.VERTICAL)
-        self.vumeter.set_inverted(True)
+        # True stereo feed has to be implemented:
+        self.vumeter_l = Gtk.ProgressBar()
+        self.vumeter_l.set_orientation(Gtk.Orientation.VERTICAL)
+        self.vumeter_l.set_inverted(True)
+        self.vumeter_r = Gtk.ProgressBar()
+        self.vumeter_r.set_orientation(Gtk.Orientation.VERTICAL)
+        self.vumeter_r.set_inverted(True)
 ## Use CSS to modify the color of ProgressBar
 ##        color = Gdk.RGBA()
 ##        Gdk.RGBA.parse(color, 'rgb(240,0,150)')
@@ -115,7 +119,8 @@ class Streamgui(object):
         self.streamtime_value = Gtk.Label('00:00:00')
         
         hbox_videoaudio.pack_start(self.videowidget, True, True, 0)
-        hbox_videoaudio.pack_start(self.vumeter, True, True, 0)
+        hbox_videoaudio.pack_start(self.vumeter_l, False, False, 3)
+        hbox_videoaudio.pack_start(self.vumeter_r, False, False, 3)
         vbox_labels.pack_start(self.baseinfo_label, True, True, 0)
         vbox_labels.pack_start(self.speakerinfo_label, True, True, 0)
         vbox_labels.pack_start(self.sessioninfo_label, True, True, 0)
@@ -142,7 +147,7 @@ class Streamgui(object):
 
         bus = gstconf.get_gstreamer_bus()
         bus.connect('sync-message::element', self.on_sync_message)
-        bus.connect('message', self.on_level_message)
+        bus.connect('message', self.on_message)
         ## Try to use 'sync-message::element' instead of 'message''
         
     def on_sync_message(self, bus, message):
@@ -152,14 +157,30 @@ class Streamgui(object):
             imagesink.set_property('force-aspect-ratio', True)
             imagesink.set_window_handle(self.videowidget.get_property('window').get_xid())
 
-    def on_level_message(self, bus, message):
+    def on_message(self, bus, message):
+        # Getting the RMS audio level value:
         s = Gst.Message.get_structure(message)
         if message.type == Gst.MessageType.ELEMENT:
             if str(Gst.Structure.get_name(s)) == 'level':
                 pct = self.iec_scale(s.get_value('rms')[0])
-                ##print('Level value: ', pct, '%')
-                self.vumeter.set_fraction(pct)
+                ##print('Level value: ', pct, '%') # [DEBUG]
+                self.vumeter_l.set_fraction(pct)
+                self.vumeter_r.set_fraction(pct)
+        # Watching for feed loss during streaming:
+        t = message.type
+        if t == Gst.MessageType.ERROR:
+            self.create_backup_pipeline()
+            #pass
 
+    def create_backup_pipeline(self):
+        labelname = self.stream_button.get_label()
+        if labelname == 'ON AIR':
+            self.pipel = gstconf.New_user_pipeline(feed='backup',)
+            bus = gstconf.get_gstreamer_bus()
+            bus.connect('sync-message::element', self.on_sync_message)
+            self.pipel.stream_play()
+            print('[WARNING] Backup pipeline started.')
+            
     def on_stream_clicked(self, widget):
 
         labelname = self.stream_button.get_label()