tests: examples: Add a simple crossfade example

https://bugzilla.gnome.org/show_bug.cgi?id=784827

tests/examples/compositor/crossfade.c

@@ -0,0 +1,135 @@
+/*
+ * GStreamer
+ * Copyright (C) 2017 Thibault Saunier <thibault.saunier@osg-samsung.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+/**
+ * Simple crossfade example using the compositor element.
+ *
+ * Takes a list of uri/path to video files and crossfade them
+ * for 10 seconds and returns.
+ */
+
+#include <stdlib.h>
+#include <gst/gst.h>
+#include <gst/controller/gstdirectcontrolbinding.h>
+#include <gst/controller/gstinterpolationcontrolsource.h>
+
+typedef struct
+{
+  GstElement *compositor;
+  guint z_order;
+  gboolean is_last;
+} VideoInfo;
+
+gchar *
+ensure_uri (const gchar * location)
+{
+  if (gst_uri_is_valid (location))
+    return g_strdup (location);
+  else
+    return gst_filename_to_uri (location, NULL);
+}
+
+static void
+_pad_added_cb (GstElement * decodebin, GstPad * pad, VideoInfo * info)
+{
+  GstPad *sinkpad =
+      gst_element_get_request_pad (GST_ELEMENT (info->compositor), "sink_%u");
+
+  if (!info->is_last) {
+    GstControlSource *control_source;
+
+    control_source = gst_interpolation_control_source_new ();
+
+    g_object_set (sinkpad, "crossfade-ratio", 1.0, NULL);
+    gst_object_add_control_binding (GST_OBJECT (sinkpad),
+        gst_direct_control_binding_new_absolute (GST_OBJECT (sinkpad),
+            "crossfade-ratio", control_source));
+
+    g_object_set (control_source, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
+
+    gst_timed_value_control_source_set (GST_TIMED_VALUE_CONTROL_SOURCE
+        (control_source), 0, 1.0);
+    gst_timed_value_control_source_set (GST_TIMED_VALUE_CONTROL_SOURCE
+        (control_source), 10 * GST_SECOND, 0.0);
+  }
+  g_object_set (sinkpad, "zorder", info->z_order, NULL);
+
+  gst_pad_link (pad, sinkpad);
+
+  g_free (info);
+}
+
+int
+main (int argc, char *argv[])
+{
+  gint i;
+  GstMessage *message;
+  GstElement *compositor, *sink, *pipeline;
+  GstBus *bus;
+
+  if (argc < 2) {
+    g_error ("At least 1 valid video file paths/urls need to " "be provided");
+    return -1;
+  }
+
+  gst_init (&argc, &argv);
+  pipeline = gst_element_factory_make ("pipeline", NULL);
+  compositor = gst_element_factory_make ("compositor", NULL);
+  sink =
+      gst_parse_bin_from_description ("videoconvert ! autovideosink", TRUE,
+      NULL);
+
+  gst_util_set_object_arg (G_OBJECT (compositor), "background", "black");
+
+  gst_bin_add_many (GST_BIN (pipeline), compositor, sink, NULL);
+  g_assert (gst_element_link (compositor, sink));
+
+  for (i = 1; i < argc; i++) {
+    gchar *uri = ensure_uri (argv[i]);
+    VideoInfo *info = g_malloc0 (sizeof (VideoInfo));
+    GstElement *uridecodebin = gst_element_factory_make ("uridecodebin", NULL);
+
+    g_object_set (uridecodebin, "uri", uri, "expose-all-streams", FALSE,
+        "caps", gst_caps_from_string ("video/x-raw(ANY)"), NULL);
+
+    info->compositor = compositor;
+    info->z_order = i - 1;
+    info->is_last = (i == (argc - 1)) && (argc > 2);
+    g_signal_connect (uridecodebin, "pad-added", (GCallback) _pad_added_cb,
+        info);
+
+    gst_bin_add (GST_BIN (pipeline), uridecodebin);
+  }
+
+  bus = gst_element_get_bus (pipeline);
+  gst_element_set_state (pipeline, GST_STATE_PLAYING);
+
+  message =
+      gst_bus_timed_pop_filtered (bus, 11 * GST_SECOND,
+      GST_MESSAGE_EOS | GST_MESSAGE_ERROR);
+  GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipeline),
+      GST_DEBUG_GRAPH_SHOW_ALL, "go");
+  if (message)
+    gst_print ("%" GST_PTR_FORMAT "\n", message);
+  else
+    gst_print ("Timeout\n");
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_object_unref (pipeline);
+}

tests/examples/compositor/meson.build

@@ -0,0 +1,15 @@
+examples = [ 'crossfade' ]
+
+foreach example : examples
+  exe_name = example
+  src_file = '@0@.c'.format(example)
+
+  executable(exe_name,
+    src_file,
+    install: true,
+    include_directories : [configinc],
+    dependencies : [glib_dep, gst_dep, gstcontroller_dep],
+    c_args : ['-DHAVE_CONFIG_H=1' ],
+  )
+endforeach
+

tests/examples/meson.build

@@ -0,0 +1,2 @@
+# FIXME - Add other missing examples!
+subdir('compositor')

tests/meson.build

@@ -2,3 +2,5 @@
 if host_machine.system() != 'windows'
   subdir('check')
 endif
+
+subdir('examples')