facedetect: Add unit test

I created four utilities of the detected features:
1- If you hide your mouth, the volume of video is low.
2- If you hide the nose, the volume of the video is up.
3- If you hide the full face, the video stops.

You can see proof of this here:
https://www.youtube.com/watch?v=pxzejNKV_WQ

https://bugzilla.gnome.org/show_bug.cgi?id=748377

tests/examples/opencv/Makefile.am

@@ -1,8 +1,10 @@
 noinst_PROGRAMS = gstmotioncells_dynamic_test \
-		  gsthanddetect_test
+		  gsthanddetect_test \
+		  gstfacedetect_test
 
 gstmotioncells_dynamic_test_SOURCES = gstmotioncells_dynamic_test.c
 gsthanddetect_test_SOURCES = gsthanddetect_test.c
+gstfacedetect_test_SOURCES = gstfacedetect_test.c
 
 gstmotioncells_dynamic_test_CFLAGS = $(GST_CFLAGS) $(GST_BASE_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS)
 gstmotioncells_dynamic_test_LDFLAGS = $(GST_LIBS) $(GST_BASE_LIBS) $(GST_PLUGINS_BASE_LIBS) $(GSTPB_BASE_LIBS)
@@ -10,3 +12,5 @@ gstmotioncells_dynamic_test_LDFLAGS = $(GST_LIBS) $(GST_BASE_LIBS) $(GST_PLUGINS
 gsthanddetect_test_CFLAGS = $(GST_CFLAGS) $(GST_BASE_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS)
 gsthanddetect_test_LDFLAGS = $(GST_LIBS) $(GST_BASE_LIBS) $(GST_PLUGINS_BASE_LIBS) $(GSTPB_BASE_LIBS)
 
+gstfacedetect_test_CFLAGS = $(GST_CFLAGS) $(GST_BASE_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS)
+gstfacedetect_test_LDFLAGS = $(GST_LIBS) $(GST_BASE_LIBS) $(GST_PLUGINS_BASE_LIBS) $(GSTPB_BASE_LIBS)

tests/examples/opencv/gstfacedetect_test.c

@@ -0,0 +1,205 @@
+/* GStreamer
+ * Copyright (C) 2015 Vanessa Chipirrás <vchipirras6@gmail.com>
+ *
+ *  gstfacedetect_test: gsteramer facedetect plugin demo application,
+ *  part work of Outreachy 2015 project
+ *
+ * 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.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <gst/gst.h>
+
+GstElement *playbin, *pipeline;
+GstElement *v4l2src, *videoscale, *videoconvert_in, *facedetect,
+    *videoconvert_out, *autovideosink;
+
+static GstBusSyncReply
+bus_sync_handler (GstBus * bus, GstMessage * message, GstPipeline * pipeline)
+{
+  const GstStructure *structure;
+  const GValue *value;
+  const GstStructure *faces_structure;
+  const GValue *faces_value;
+  gboolean have_mouth_x, have_mouth_y;
+  gboolean have_nose_x, have_nose_y;
+  gchar *contents;
+  gint i;
+  guint size = 0;
+  gdouble volume = 0.0;
+
+  /* select msg */
+  if (GST_MESSAGE_TYPE (message) != GST_MESSAGE_ELEMENT ||
+      !gst_structure_has_name (gst_message_get_structure (message),
+          "facedetect"))
+    return GST_BUS_PASS;
+
+  /* parse msg structure */
+  structure = gst_message_get_structure (message);
+
+  /* if facedetect is into buffer */
+  if (structure &&
+      strcmp (gst_structure_get_name (structure), "facedetect") == 0) {
+    /* print message type and structure name */
+    g_print ("Type message, name message: %s{{%s}}\n",
+        gst_message_type_get_name (message->type),
+        gst_structure_get_name (structure));
+    /* print msg structure names&type */
+    for (i = 0; i < gst_structure_n_fields (structure); i++) {
+      const gchar *name = gst_structure_nth_field_name (structure, i);
+      GType type = gst_structure_get_field_type (structure, name);
+      g_print ("-Name field, type: %s[%s]\n", name, g_type_name (type));
+    }
+    g_print ("\n");
+
+    /* get structure of faces */
+    value = gst_structure_get_value (structure, "faces");
+    /* obtain the contents into the structure */
+    contents = g_strdup_value_contents (value);
+    g_print ("Detected objects: %s\n", *(&contents));
+
+    /* list size */
+    size = gst_value_list_get_size (value);
+
+    /* if face is detected, obtain the values X and Y of mouth and of nose. */
+    if (size != 0) {
+      faces_value = gst_value_list_get_value (value, 0);
+      faces_structure = gst_value_get_structure (faces_value);
+      have_mouth_y = gst_structure_has_field (faces_structure, "mouth->y");
+      have_mouth_x = gst_structure_has_field (faces_structure, "mouth->x");
+      have_nose_y = gst_structure_has_field (faces_structure, "nose->y");
+      have_nose_x = gst_structure_has_field (faces_structure, "nose->x");
+
+      /* get the volume value and playbin changed the state to play */
+      g_object_get (G_OBJECT (playbin), "volume", &volume, NULL);
+      gst_element_set_state (GST_ELEMENT (playbin), GST_STATE_PLAYING);
+
+      /* media operation - hide your mouth for down the volume of the video */
+      if (have_mouth_y == 0 && have_mouth_x == 0) {
+        volume = volume - 0.5;
+        if (volume <= 0.5)
+          volume = 0.0;
+        g_object_set (G_OBJECT (playbin), "volume", volume, NULL);
+      }
+      /* media operation - hide your nose for up the volume of the video */
+      if (have_nose_y == 0 && have_nose_x == 0) {
+        volume = volume + 0.5;
+        if (volume >= 9.5)
+          volume = 10.0;
+        g_object_set (G_OBJECT (playbin), "volume", volume, NULL);
+      }
+      /* if face is not detected */
+    } else {
+      /* media operation - hide your face to stop media play */
+      gst_element_set_state (playbin, GST_STATE_PAUSED);
+    }
+  }
+  gst_message_unref (message);
+  return GST_BUS_DROP;
+}
+
+int
+main (gint argc, gchar ** argv)
+{
+  static GMainLoop *loop;
+  GstCaps *caps;
+  GstBus *bus;
+  gchar *uri;
+
+  const gchar *video_device = "/dev/video0";
+
+  if (argc < 2) {
+    fprintf (stderr, "oops, please give a file to play\n");
+    return -1;
+  }
+
+  uri = g_filename_to_uri (argv[1], NULL, NULL);
+  if (!uri) {
+    fprintf (stderr, "failed to create the uri\n");
+    return -1;
+  }
+
+  /* init gst */
+  gst_init (&argc, &argv);
+
+  loop = g_main_loop_new (NULL, FALSE);
+  /* init elements */
+  playbin = gst_element_factory_make ("playbin", "app_playbin");
+  pipeline = gst_pipeline_new ("app_pipeline");
+  v4l2src = gst_element_factory_make ("v4l2src", "app_v4l2src");
+  videoscale = gst_element_factory_make ("videoscale", "app_videoscale");
+  videoconvert_in =
+      gst_element_factory_make ("videoconvert", "app_videoconvert_in");
+  facedetect = gst_element_factory_make ("facedetect", "app_facedetect");
+  videoconvert_out =
+      gst_element_factory_make ("videoconvert", "app_videoconvert_out");
+  autovideosink =
+      gst_element_factory_make ("autovideosink", "app_autovideosink");
+
+  /* check init results */
+  if (!playbin || !pipeline || !v4l2src || !videoscale || !videoconvert_in
+      || !facedetect || !videoconvert_out || !autovideosink)
+    g_error ("ERROR: element init failed.\n");
+
+  /* set values */
+  g_object_set (G_OBJECT (playbin), "uri", uri, NULL);
+  g_object_set (G_OBJECT (v4l2src), "device", video_device, NULL);
+
+  /* set caps */
+  caps =
+      gst_caps_from_string
+      ("video/x-raw, format=(string)RGB, width=320, height=240, framerate=(fraction)30/1");
+
+  /* set bus */
+  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
+  gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bus_sync_handler, pipeline,
+      NULL);
+  gst_object_unref (bus);
+
+  /* add elements to pipeline */
+  gst_bin_add_many (GST_BIN (pipeline),
+      v4l2src,
+      videoscale,
+      videoconvert_in, facedetect, videoconvert_out, autovideosink, NULL);
+
+  /* negotiate caps */
+  if (!gst_element_link_filtered (v4l2src, videoscale, caps)) {
+    g_printerr ("ERROR:v4l2src -> videoscale caps\n");
+    return 0;
+  }
+  gst_caps_unref (caps);
+
+  /* link elements */
+  gst_element_link_many (videoscale,
+      videoconvert_in, facedetect, videoconvert_out, autovideosink, NULL);
+
+  /* change states */
+  gst_element_set_state (pipeline, GST_STATE_PLAYING);
+
+  /* start main loop */
+  g_main_loop_run (loop);
+
+  /* clean all */
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_object_unref (GST_OBJECT (pipeline));
+  gst_element_set_state (playbin, GST_STATE_NULL);
+  gst_object_unref (GST_OBJECT (playbin));
+
+  return 0;
+}