I was told to use a Gtk.Overlay widget to overlay objects over a GStreamer video (playing in a Gtk.DrawingArea). However, when I do so, I can hear, but not see, the video. When I have no objects overlaying, I can see the video in the Gtk.Overlay just fine. But, again, once I have any objects added via overlay.add_overlay(widget), the video disappears.

How do I fix this? I really need a Gtk.Fixed container to overlay my video. Code below.

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from gi.repository import Gtk, Gdk, GdkPixbuf, GdkX11
import pango
import pygst
pygst.require('0.10')
import gst
import Trailcrest
import os, sys
import cairo
from math import pi

class Video:
    
    def __init__(self):
        
        def on_message(bus, message): 
            if message.type == gst.MESSAGE_EOS: 
                # End of Stream 
                player.seek(1.0, gst.FORMAT_TIME, gst.SEEK_FLAG_FLUSH, gst.SEEK_TYPE_SET, 5000000000, gst.SEEK_TYPE_NONE, 6000000000)
            elif message.type == gst.MESSAGE_ERROR: 
                player.set_state(gst.STATE_NULL) 
                (err, debug) = message.parse_error() 
                print "Error: %s" % err, debug
        
        def on_sync_message(bus, message):
            if message.structure is None:
                return False
            if message.structure.get_name() == "prepare-xwindow-id":
                Gdk.threads_enter()
                Gdk.Display.get_default().sync()
                win_id = videowidget.get_property('window').get_xid()
                imagesink = message.src
                imagesink.set_property("force-aspect-ratio", True)
                imagesink.set_xwindow_id(win_id)
                Gdk.threads_leave()
                        
        def click_me(event, data=None):
            player.seek(1.0, gst.FORMAT_TIME, gst.SEEK_FLAG_FLUSH, gst.SEEK_TYPE_SET, 5000000000, gst.SEEK_TYPE_NONE, 6000000000)

        win = Gtk.Window()
        win.set_resizable(False)
        win.set_decorated(False)
        win.set_position(Gtk.WindowPosition.CENTER)
        
        overlay = Gtk.Overlay()
        win.add(overlay)
        overlay.show()
        
        videowidget = Gtk.DrawingArea()
        overlay.add(videowidget)
        videowidget.set_halign (Gtk.Align.START)
        videowidget.set_valign (Gtk.Align.START)
        videowidget.set_size_request(640, 480)
        videowidget.show()
        
        fixed = Gtk.Fixed()
        overlay.add_overlay(fixed)
        fixed.show()
        
        pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_size("IMG/IMG-MPG-LOGO.png", 250, 50)
        imgMPL = Gtk.Image()
        imgMPL.set_from_pixbuf(pixbuf)
        eb_imgMPL = Gtk.EventBox()
        eb_imgMPL.set_visible_window(False)
        eb_imgMPL.add(imgMPL)
        fixed.put(eb_imgMPL, 10, 10)
        imgMPL.show()
        eb_imgMPL.show()
        
        win.show_all()
        
        # Setup GStreamer 
        player = gst.element_factory_make("playbin", "MultimediaPlayer")
        bus = player.get_bus() 
        bus.add_signal_watch() 
        bus.enable_sync_message_emission() 
        #used to get messages that GStreamer emits 
        bus.connect("message", on_message) 
        #used for connecting video to your application 
        bus.connect("sync-message::element", on_sync_message)
        player.set_property("uri", "file://" + os.getcwd() + "/VID/BGA-HABT-001.ogv")
        player.set_state(gst.STATE_PLAYING)

                
if __name__ == "__main__":
    Gdk.threads_enter()
    Video()
    Gtk.main()