ges-video-transition: add a new "fade-in" transition type

This transition is meant to be very similar to crossfade, but
instead of fading out the background video at the same time as the
foreground fades in, the background video stays at 100% opacity
during the whole transition.

This essentially "restores" the old crossfade behaviour that was changed in:
https://gitlab.freedesktop.org/gstreamer/gst-editing-services/-/commit/eb48faf34234811faec1699692a2c096daaceefd
but using a new type enum, so that both behaviours are available,
letting applications choose.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2385>

diff --git a/subprojects/gst-editing-services/ges/ges-enums.c b/subprojects/gst-editing-services/ges/ges-enums.c
index 83b5cd7..b16e6e1 100644 (file)
--- a/subprojects/gst-editing-services/ges/ges-enums.c
+++ b/subprojects/gst-editing-services/ges/ges-enums.c
@@ -437,6 +437,9 @@ static GEnumValue transition_types[] = {
   {GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE,
         "GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE",
       "crossfade"},
+  {GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN,
+        "GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN",
+      "fade-in"},
   {0, NULL, NULL}
 };
 

diff --git a/subprojects/gst-editing-services/ges/ges-enums.h b/subprojects/gst-editing-services/ges/ges-enums.h
index ff7a013..e7ee4ce 100644 (file)
--- a/subprojects/gst-editing-services/ges/ges-enums.h
+++ b/subprojects/gst-editing-services/ges/ges-enums.h
@@ -143,6 +143,7 @@ typedef enum {
  * @GES_VIDEO_STANDARD_TRANSITION_TYPE_WINDSHIELD_V: Two sets of radial hands attached at the midpoints of the top and bottom halves sweep from top to bottom and bottom to top,
  * @GES_VIDEO_STANDARD_TRANSITION_TYPE_WINDSHIELD_H: Two sets of radial hands attached at the midpoints of the left and right halves sweep from left to right and right to left,
  * @GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE: Crossfade
+ * @GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN: Similar to crossfade, but fade in the front video without fading out the background one (Since: 1.22)
  *
  */
 
@@ -218,7 +219,16 @@ typedef enum {
   GES_VIDEO_STANDARD_TRANSITION_TYPE_WINDSHIELD_U = 262,
   GES_VIDEO_STANDARD_TRANSITION_TYPE_WINDSHIELD_V = 263,
   GES_VIDEO_STANDARD_TRANSITION_TYPE_WINDSHIELD_H = 264,
-  GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE = 512
+  GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE = 512,
+  /**
+   * GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN:
+   *
+   * Similar to crossfade, but fade in the front video without fading out
+   * the background one
+   *
+   * Since: 1.22
+   */
+  GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN = 513
 } GESVideoStandardTransitionType;
 
 #define GES_VIDEO_STANDARD_TRANSITION_TYPE_TYPE \

diff --git a/subprojects/gst-editing-services/ges/ges-video-transition.c b/subprojects/gst-editing-services/ges/ges-video-transition.c
index e84af25..a917a9a 100644 (file)
--- a/subprojects/gst-editing-services/ges/ges-video-transition.c
+++ b/subprojects/gst-editing-services/ges/ges-video-transition.c
@@ -337,10 +337,14 @@ ges_video_transition_create_element (GESTrackElement * object)
   GESVideoTransition *self;
   GESVideoTransitionPrivate *priv;
   const gchar *smpte_properties[] = { "invert", "border", NULL };
+  gboolean is_fade;
 
   self = GES_VIDEO_TRANSITION (object);
   priv = self->priv;
 
+  is_fade = (priv->type == GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE ||
+      priv->type == GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN);
+
   GST_LOG ("creating a video bin");
 
   topbin = gst_bin_new ("transition-bin");
@@ -373,11 +377,9 @@ ges_video_transition_create_element (GESTrackElement * object)
   g_object_set (priv->mixer_sinka, "zorder", 0, NULL);
   g_object_set (priv->mixer_sinkb, "zorder", 1, NULL);
   gst_util_set_object_arg (G_OBJECT (priv->mixer_sinka), "operator",
-      priv->type ==
-      GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE ? "source" : "over");
+      is_fade ? "source" : "over");
   gst_util_set_object_arg (G_OBJECT (priv->mixer_sinkb), "operator",
-      priv->type ==
-      GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE ? "add" : "over");
+      is_fade ? "add" : "over");
 
   fast_element_link (mixer, priv->positioner);
 
@@ -480,6 +482,13 @@ ges_video_transition_update_control_sources (GESVideoTransition * self,
         (priv->fade_out_control_source, duration, 1.0, 0.0);
     ges_video_transition_update_control_source (priv->smpte_control_source,
         duration, 0.0, 0.0);
+  } else if (type == GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN) {
+    ges_video_transition_update_control_source
+        (priv->fade_in_control_source, duration, 0.0, 1.0);
+    ges_video_transition_update_control_source
+        (priv->fade_out_control_source, duration, 1.0, 1.0);
+    ges_video_transition_update_control_source (priv->smpte_control_source,
+        duration, 0.0, 0.0);
   } else {
     ges_video_transition_update_control_source
         (priv->fade_in_control_source, duration, 1.0, 1.0);
@@ -531,6 +540,7 @@ ges_video_transition_set_transition_type_internal (GESVideoTransition
     * self, GESVideoStandardTransitionType type)
 {
   GESVideoTransitionPrivate *priv = self->priv;
+  gboolean is_fade;
 
   GST_DEBUG ("%p %d => %d", self, priv->type, type);
 
@@ -547,17 +557,17 @@ ges_video_transition_set_transition_type_internal (GESVideoTransition
   ges_video_transition_update_control_sources (self, type);
 
   priv->type = type;
+  is_fade = (type == GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE ||
+      type == GES_VIDEO_STANDARD_TRANSITION_TYPE_FADE_IN);
 
-  if (type != GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE) {
+  if (!is_fade) {
     g_object_set (priv->smpte, "type", (gint) type, NULL);
   }
 
   gst_util_set_object_arg (G_OBJECT (priv->mixer_sinka), "operator",
-      priv->type ==
-      GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE ? "source" : "over");
+      is_fade ? "source" : "over");
   gst_util_set_object_arg (G_OBJECT (priv->mixer_sinkb), "operator",
-      priv->type ==
-      GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE ? "add" : "over");
+      is_fade ? "add" : "over");
 
   return TRUE;
 }