examples/switch.py: New file, a basic demo for a single-stream switcher. Could be expanded later -- look at flumotion...

Original commit message from CVS:
2007-12-18  Andy Wingo  <wingo@pobox.com>

* examples/switch.py: New file, a basic demo for a single-stream
switcher. Could be expanded later -- look at
flumotion.component.combiners.switch.switch for some inspiration.

ChangeLog

@@ -1,3 +1,9 @@
+2007-12-18  Andy Wingo  <wingo@pobox.com>
+
+	* examples/switch.py: New file, a basic demo for a single-stream
+	switcher. Could be expanded later -- look at
+	flumotion.component.combiners.switch.switch for some inspiration.
+
 2007-12-18  Tim-Philipp Müller  <tim at centricular dot net>
 
 	* Makefile.am:

common

@@ -1 +1 @@
-Subproject commit 67b8f4e3c576945f4d778c9040876af3a5a0756e
+Subproject commit 970759077c95ee4e85650db023ac6f974e2aa5e1

examples/switch.py

@@ -0,0 +1,187 @@
+#!/usr/bin/env python
+# -*- Mode: Python -*-
+# vi:si:et:sw=4:sts=4:ts=4
+
+import pygtk
+pygtk.require('2.0')
+
+import sys
+
+import gobject
+gobject.threads_init()
+
+import pygst
+pygst.require('0.10')
+import gst
+import gst.interfaces
+import gtk
+
+class SwitchTest:
+    def __init__(self, videowidget):
+        self.playing = False
+        pipestr = ('videotestsrc pattern=0 ! queue ! s.sink0'
+                   ' videotestsrc pattern=1 ! queue ! s.sink1'
+                   ' switch name=s ! autovideosink')
+        self.pipeline = gst.parse_launch(pipestr)
+        self.videowidget = videowidget
+
+        bus = self.pipeline.get_bus()
+        bus.enable_sync_message_emission()
+        bus.add_signal_watch()
+        bus.connect('sync-message::element', self.on_sync_message)
+        bus.connect('message', self.on_message)
+
+    def on_sync_message(self, bus, message):
+        if message.structure is None:
+            return
+        if message.structure.get_name() == 'prepare-xwindow-id':
+            self.videowidget.set_sink(message.src)
+            message.src.set_property('force-aspect-ratio', True)
+            
+    def on_message(self, bus, message):
+        t = message.type
+        if t == gst.MESSAGE_ERROR:
+            err, debug = message.parse_error()
+            print "Error: %s" % err, debug
+            if self.on_eos:
+                self.on_eos()
+            self.playing = False
+        elif t == gst.MESSAGE_EOS:
+            if self.on_eos:
+                self.on_eos()
+            self.playing = False
+
+    def play(self):
+        self.playing = True
+        gst.info("playing player")
+        self.pipeline.set_state(gst.STATE_PLAYING)
+        
+    def stop(self):
+        self.pipeline.set_state(gst.STATE_NULL)
+        gst.info("stopped player")
+        self.playing = False
+
+    def get_state(self, timeout=1):
+        return self.pipeline.get_state(timeout=timeout)
+
+    def is_playing(self):
+        return self.playing
+    
+    def switch(self, padname):
+        switch = self.pipeline.get_by_name('s')
+        stop_time = switch.emit('block')
+        newpad = switch.get_static_pad(padname)
+        start_time = newpad.get_property('running-time')
+        
+        gst.warning('stop time = %d' % (stop_time,))
+        gst.warning('stop time = %s' % (gst.TIME_ARGS(stop_time),))
+
+        gst.warning('start time = %d' % (start_time,))
+        gst.warning('start time = %s' % (gst.TIME_ARGS(start_time),))
+
+        gst.warning('switching from %r to %r'
+                    % (switch.get_property('active-pad'), padname))
+        switch.emit('switch', padname, stop_time, start_time)
+
+class VideoWidget(gtk.DrawingArea):
+    def __init__(self):
+        gtk.DrawingArea.__init__(self)
+        self.imagesink = None
+        self.unset_flags(gtk.DOUBLE_BUFFERED)
+
+    def do_expose_event(self, event):
+        if self.imagesink:
+            self.imagesink.expose()
+            return False
+        else:
+            return True
+
+    def set_sink(self, sink):
+        assert self.window.xid
+        self.imagesink = sink
+        self.imagesink.set_xwindow_id(self.window.xid)
+
+class SwitchWindow(gtk.Window):
+    UPDATE_INTERVAL = 500
+    def __init__(self):
+        gtk.Window.__init__(self)
+        self.set_default_size(410, 325)
+
+        self.create_ui()
+        self.player = SwitchTest(self.videowidget)
+        self.populate_combobox()
+
+        self.update_id = -1
+        self.changed_id = -1
+        self.seek_timeout_id = -1
+
+        self.p_position = gst.CLOCK_TIME_NONE
+        self.p_duration = gst.CLOCK_TIME_NONE
+
+        def on_delete_event():
+            self.player.stop()
+            gtk.main_quit()
+        self.connect('delete-event', lambda *x: on_delete_event())
+
+    def load_file(self, location):
+        self.player.set_location(location)
+                                  
+    def play(self):
+        self.player.play()
+        
+    def populate_combobox(self):
+        switch = self.player.pipeline.get_by_name('s')
+        for i, pad in enumerate([p for p in switch.pads()
+                                 if p.get_direction() == gst.PAD_SINK]):
+            self.combobox.append_text(pad.get_name())
+            if switch.get_property('active-pad') == pad.get_name():
+                self.combobox.set_active(i)
+        if self.combobox.get_active() == -1:
+            self.combobox.set_active(0)
+
+    def combobox_changed(self):
+        model = self.combobox.get_model()
+        row = model[self.combobox.get_active()]
+        padname, = row
+        self.player.switch(padname)
+
+    def create_ui(self):
+        vbox = gtk.VBox()
+        self.add(vbox)
+
+        self.videowidget = VideoWidget()
+        vbox.pack_start(self.videowidget)
+        
+        hbox = gtk.HBox()
+        vbox.pack_start(hbox, fill=False, expand=False)
+        
+        self.combobox = combobox = gtk.combo_box_new_text()
+        combobox.show()
+        hbox.pack_start(combobox)
+
+        self.combobox.connect('changed',
+                              lambda *x: self.combobox_changed())
+
+        self.videowidget.connect_after('realize',
+                                       lambda *x: self.play())
+
+def main(args):
+    def usage():
+        sys.stderr.write("usage: %s\n" % args[0])
+        return 1
+
+    # Need to register our derived widget types for implicit event
+    # handlers to get called.
+    gobject.type_register(SwitchWindow)
+    gobject.type_register(VideoWidget)
+
+    if len(args) != 1:
+        return usage()
+
+    w = SwitchWindow()
+    w.show_all()
+    gtk.main()
+    return 0
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))