From e7807712231f0674a3a0d31534e3d5699272e48d Mon Sep 17 00:00:00 2001
From: =?utf8?q?Tim-Philipp=20M=C3=BCller?= <tim.muller@collabora.co.uk>
Date: Sun, 25 Mar 2012 00:00:59 +0000
Subject: [PATCH] gdkpixbufoverlay: add "alpha" property to set alpha of
 overlay image

.. or turn the overlay off by setting alpha to 0.0
---
 configure.ac                         |  2 +-
 ext/gdk_pixbuf/gstgdkpixbufoverlay.c | 36 ++++++++++++++++++++++++++++++------
 ext/gdk_pixbuf/gstgdkpixbufoverlay.h |  2 ++
 3 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index 50b7794..fddc97d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -55,7 +55,7 @@ AM_PROG_LIBTOOL
 
 dnl *** required versions of GStreamer stuff ***
 GST_REQ=0.10.36
-GSTPB_REQ=0.10.36
+GSTPB_REQ=0.10.36.1
 
 dnl *** autotools stuff ****
 
diff --git a/ext/gdk_pixbuf/gstgdkpixbufoverlay.c b/ext/gdk_pixbuf/gstgdkpixbufoverlay.c
index 0e844f4..59ef712 100644
--- a/ext/gdk_pixbuf/gstgdkpixbufoverlay.c
+++ b/ext/gdk_pixbuf/gstgdkpixbufoverlay.c
@@ -82,7 +82,8 @@ enum
   PROP_RELATIVE_X,
   PROP_RELATIVE_Y,
   PROP_OVERLAY_WIDTH,
-  PROP_OVERLAY_HEIGHT
+  PROP_OVERLAY_HEIGHT,
+  PROP_ALPHA
 };
 
 #define VIDEO_CAPS \
@@ -188,6 +189,10 @@ gst_gdk_pixbuf_overlay_class_init (GstGdkPixbufOverlayClass * klass)
           G_MAXINT, 0,
           GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE
           | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (gobject_class, PROP_ALPHA,
+      g_param_spec_double ("alpha", "Alpha", "Global alpha of overlay image",
+          0.0, 1.0, 1.0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING
+          | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   GST_DEBUG_CATEGORY_INIT (gdkpixbufoverlay_debug, "gdkpixbufoverlay", 0,
       "debug category for gdkpixbufoverlay element");
@@ -205,6 +210,8 @@ gst_gdk_pixbuf_overlay_init (GstGdkPixbufOverlay * overlay,
 
   overlay->overlay_width = 0;
   overlay->overlay_height = 0;
+
+  overlay->alpha = 1.0;
 }
 
 void
@@ -244,6 +251,10 @@ gst_gdk_pixbuf_overlay_set_property (GObject * object, guint property_id,
       overlay->overlay_height = g_value_get_int (value);
       overlay->update_composition = TRUE;
       break;
+    case PROP_ALPHA:
+      overlay->alpha = g_value_get_double (value);
+      overlay->update_composition = TRUE;
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
       break;
@@ -282,6 +293,9 @@ gst_gdk_pixbuf_overlay_get_property (GObject * object, guint property_id,
     case PROP_OVERLAY_HEIGHT:
       g_value_set_int (value, overlay->overlay_height);
       break;
+    case PROP_ALPHA:
+      g_value_set_double (value, overlay->alpha);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
       break;
@@ -438,6 +452,14 @@ gst_gdk_pixbuf_overlay_update_composition (GstGdkPixbufOverlay * overlay)
   GstVideoOverlayRectangle *rect;
   gint x, y, width, height;
 
+  if (overlay->comp) {
+    gst_video_overlay_composition_unref (overlay->comp);
+    overlay->comp = NULL;
+  }
+
+  if (overlay->alpha == 0.0)
+    return;
+
   x = overlay->offset_x + (overlay->relative_x * overlay->pixels_width);
   y = overlay->offset_y + (overlay->relative_y * overlay->pixels_height);
 
@@ -455,8 +477,8 @@ gst_gdk_pixbuf_overlay_update_composition (GstGdkPixbufOverlay * overlay)
   if (height == 0)
     height = overlay->pixels_height;
 
-  GST_DEBUG_OBJECT (overlay, "overlay image dimensions: %d x %d",
-      overlay->pixels_width, overlay->pixels_height);
+  GST_DEBUG_OBJECT (overlay, "overlay image dimensions: %d x %d, alpha=%.2f",
+      overlay->pixels_width, overlay->pixels_height, overlay->alpha);
   GST_DEBUG_OBJECT (overlay, "properties: x,y: %d,%d (%g%%,%g%%) - WxH: %dx%d",
       overlay->offset_x, overlay->offset_y,
       overlay->relative_x * 100.0, overlay->relative_y * 100.0,
@@ -468,11 +490,12 @@ gst_gdk_pixbuf_overlay_update_composition (GstGdkPixbufOverlay * overlay)
       overlay->pixels_width, overlay->pixels_height, overlay->pixels_stride,
       x, y, width, height, GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE);
 
+  if (overlay->alpha != 1.0)
+    gst_video_overlay_rectangle_set_global_alpha (rect, overlay->alpha);
+
   comp = gst_video_overlay_composition_new (rect);
   gst_video_overlay_rectangle_unref (rect);
 
-  if (overlay->comp)
-    gst_video_overlay_composition_unref (overlay->comp);
   overlay->comp = comp;
 }
 
@@ -503,7 +526,8 @@ gst_gdk_pixbuf_overlay_transform_ip (GstBaseTransform * trans, GstBuffer * buf)
 
   GST_OBJECT_UNLOCK (overlay);
 
-  gst_video_overlay_composition_blend (overlay->comp, buf);
+  if (overlay->comp != NULL)
+    gst_video_overlay_composition_blend (overlay->comp, buf);
 
   return GST_FLOW_OK;
 }
diff --git a/ext/gdk_pixbuf/gstgdkpixbufoverlay.h b/ext/gdk_pixbuf/gstgdkpixbufoverlay.h
index 9c94090..f815e31 100644
--- a/ext/gdk_pixbuf/gstgdkpixbufoverlay.h
+++ b/ext/gdk_pixbuf/gstgdkpixbufoverlay.h
@@ -63,6 +63,8 @@ struct _GstGdkPixbufOverlay
   gint                         overlay_width;
   gint                         overlay_height;
 
+  gdouble                      alpha;
+
   /* the loaded image */
   GstBuffer                  * pixels;
   guint                        pixels_width;
-- 
2.7.4