[totem] backend: Fix calculating the display aspect ratio

[Bastien Nocera <hadess src gnome org>]

commit 08e9a2fda308e4e3ec5f94604539b37ba5776e6a
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Mar 18 19:15:14 2013 +0100

    backend: Fix calculating the display aspect ratio
    
    Based on the size of the monitor where the video is being displayed,
    as opposed to the full "GdkScreen" (which might include multiple
    monitors).
    
    This doesn't handle moving the video between 2 displays with different
    display aspect ratio, but should fix the worst case scenarios in dual
    head setups.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=658292

 src/backend/bacon-video-widget.c |   25 +++++++++++++++++++------
 1 files changed, 19 insertions(+), 6 deletions(-)
---
diff --git a/src/backend/bacon-video-widget.c b/src/backend/bacon-video-widget.c
index 7944b80..be3e298 100644
--- a/src/backend/bacon-video-widget.c
+++ b/src/backend/bacon-video-widget.c
@@ -417,6 +417,7 @@ bvw_check_if_video_decoder_is_missing (BaconVideoWidget * bvw)
 
 static void
 set_display_pixel_aspect_ratio (GdkScreen *screen,
+                               int        monitor,
                                GValue    *value)
 {
   static const gint par[][2] = {
@@ -426,19 +427,22 @@ set_display_pixel_aspect_ratio (GdkScreen *screen,
     {54, 59},                   /* 625 line Rec.601 video */
     {64, 45},                   /* 1280x1024 on 16:9 display */
     {5, 3},                     /* 1280x1024 on 4:3 display */
-    {4, 3}                      /*  800x600 on 16:9 display */
+    {4, 3}                      /* 800x600 on 16:9 display */
   };
   guint i;
   gint par_index;
   gdouble ratio;
   gdouble delta;
+  GdkRectangle rect;
 
 #define DELTA(idx) (ABS (ratio - ((gdouble) par[idx][0] / par[idx][1])))
 
   /* first calculate the "real" ratio based on the X values;
-   *    * which is the "physical" w/h divided by the w/h in pixels of the display */
-  ratio = (gdouble) (gdk_screen_get_width_mm (screen) * gdk_screen_get_height (screen))
-    / (gdk_screen_get_height_mm (screen) * gdk_screen_get_width (screen));
+   * which is the "physical" w/h divided by the w/h in pixels of the display */
+  gdk_screen_get_monitor_geometry (screen, monitor, &rect);
+
+  ratio = (gdouble) (gdk_screen_get_monitor_width_mm (screen, monitor) * rect.height) /
+    (gdk_screen_get_monitor_height_mm (screen, monitor) * rect.width);
 
   GST_DEBUG ("calculated pixel aspect ratio: %f", ratio);
   /* now find the one from par[][2] with the lowest delta to the real one */
@@ -490,8 +494,17 @@ get_media_size (BaconVideoWidget *bvw, gint *width, gint *height)
       gst_value_set_fraction (&disp_par, 1, 1);
 
       /* Now try getting display's pixel aspect ratio */
-      if (gtk_widget_get_realized (GTK_WIDGET (bvw)))
-       set_display_pixel_aspect_ratio (gtk_widget_get_screen (GTK_WIDGET (bvw)), &disp_par);
+      if (gtk_widget_get_realized (GTK_WIDGET (bvw))) {
+       GdkScreen *screen;
+       GdkWindow *window;
+       int monitor;
+
+       screen = gtk_widget_get_screen (GTK_WIDGET (bvw));
+       window = gtk_widget_get_window (GTK_WIDGET (bvw));
+       if (window)
+         monitor = gdk_screen_get_monitor_at_window (screen, window);
+       set_display_pixel_aspect_ratio (screen, monitor, &disp_par);
+      }
 
       disp_par_n = gst_value_get_fraction_numerator (&disp_par);
       disp_par_d = gst_value_get_fraction_denominator (&disp_par);