Development Team/Almanac/GStreamer: Difference between revisions

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 === How can I play back video files in my activity? ===
 Sugar, by default, can play back audio (encoded in Vorbis) and video (encoded in Theora) files in ogg containers.
+The following file will be helpful for embedding video or audio files into your activity.  After the code posting is a code snippet showing how to use this.
+<pre>
+import gtk
+import pygtk
+pygtk.require('2.0')
+import sys
+import pygst
+pygst.require('0.10')
+import gst
+import gst.interfaces
+import gobject
+import time
+gobject.threads_init()
+class Gplay:
+	def __init__(self):
+		self.window = None
+		self.playing = False
+		self.player = gst.element_factory_make("playbin", "playbin")
+		xis = gst.element_factory_make("xvimagesink", "xvimagesink")
+		self.player.set_property("video-sink", xis)
+		bus = self.player.get_bus()
+		bus.enable_sync_message_emission()
+		bus.add_signal_watch()
+		self.SYNC_ID = bus.connect('sync-message::element', self._onSyncMessageCb)
+	def _onSyncMessageCb(self, bus, message):
+		if message.structure is None:
+			return True
+		if message.structure.get_name() == 'prepare-xwindow-id':
+			self.window.set_sink(message.src)
+			message.src.set_property('force-aspect-ratio', True)
+			return True
+	def setFile(self, path):
+		uri = "file://" + str( path )
+		if (self.player.get_property('uri') == uri):
+			self.seek(gst.SECOND*0)
+			return
+		self.player.set_state(gst.STATE_READY)
+		self.player.set_property('uri', uri)
+		ext = uri[len(uri)-3:]
+		if (ext == "jpg"):
+			self.pause()
+		else:
+			self.play()
+	def queryPosition(self):
+		#"Returns a (position, duration) tuple"
+		try:
+			position, format = self.player.query_position(gst.FORMAT_TIME)
+		except:
+			position = gst.CLOCK_TIME_NONE
+		try:
+			duration, format = self.player.query_duration(gst.FORMAT_TIME)
+		except:
+			duration = gst.CLOCK_TIME_NONE
+		return (position, duration)
+	def seek(self, time):
+		event = gst.event_new_seek(1.0, gst.FORMAT_TIME, gst.SEEK_FLAG_FLUSH | gst.SEEK_FLAG_ACCURATE, gst.SEEK_TYPE_SET, time, gst.SEEK_TYPE_NONE, 0)
+		res = self.player.send_event(event)
+		if res:
+			self.player.set_new_stream_time(0L)
+	def pause(self):
+		self.playing = False
+		self.player.set_state(gst.STATE_PAUSED)
+	def play(self):
+		self.playing = True
+		self.player.set_state(gst.STATE_PLAYING)
+	def stop(self):
+		self.playing = False
+		self.player.set_state(gst.STATE_NULL)
+		self.nextMovie()
+	def get_state(self, timeout=1):
+		return self.player.get_state(timeout=timeout)
+	def is_playing(self):
+		return self.playing
+class PlayVideoWindow(gtk.Window):
+	def __init__(self):
+		gtk.Window.__init__(self)
+		self.imagesink = None
+		self.unset_flags(gtk.DOUBLE_BUFFERED)
+		self.set_flags(gtk.APP_PAINTABLE)
+	def set_sink(self, sink):
+		if (self.imagesink != None):
+			assert self.window.xid
+			self.imagesink = None
+			del self.imagesink
+		self.imagesink = sink
+		self.imagesink.set_xwindow_id(self.window.xid)
+</pre>
+And here is a code snippet showing how you would use this file to embed media playback in your activity:
+<pre>
+		#this is our video playback window
+		self.gplay = Gplay( )
+		self.gplayWin = PlayVideoWindow( )
+		self.gplay.window = self.gplayWin
+		self.gplayWin.set_type_hint( gtk.gdk.WINDOW_TYPE_HINT_DIALOG )
+		self.gplayWin.set_decorated( False )
+		self.gplayWin.set_transient_for( self ) #activity subclass
+		self.gplayWin.move( 100, 100 )
+		self.gplayWin.resize( 300, 400 )
+		self.gplayWin.show_all( )
+</pre>