scenario: add a track switch command, and an audio track switch test

The "switch-track" command can be used to switch tracks. The "type"
argument selects which track type to change (can be "audio", "video",
or "text"). The "index" argument selects which track of this type
to use: it can be either a number, which will be the Nth track of
the given type, or a number with a "+" or "-" prefix, which means
a relative change (eg, "+1" means "next track", "-1" means "previous
track").

Conflicts:
	validate/gst/validate/gst-validate-scenario.c

validate/data/Makefile.am

@@ -7,7 +7,8 @@ scenarios_DATA = simple_seeks.scenario \
                  fast_forward.scenario \
                  fast_backward.scenario \
                  alternate_fast_backward_forward.scenario \
-                 pause_resume.scenario
+                 pause_resume.scenario \
+                 switch_audio_track.scenario
 
 EXTRA_DIST = simple_seeks.scenario \
              seek_forward.scenario \
@@ -17,4 +18,5 @@ EXTRA_DIST = simple_seeks.scenario \
              fast_forward.scenario \
              fast_backward.scenario \
              alternate_fast_backward_forward.scenario \
-             pause_resume.scenario
+             pause_resume.scenario \
+             switch_audio_track.scenario

validate/data/switch_audio_track.scenario

@@ -0,0 +1 @@
+switch-track, name=Next-audio-track, playback_time=5.0, type=audio, index=(string)+1

validate/gst/validate/gst-validate-scenario.c

@@ -252,6 +252,179 @@ _execute_eos (GstValidateScenario * scenario, GstValidateAction * action)
       gst_event_new_eos ());
 }
 
+static int
+find_input_selector (GValue * velement, const gchar *type)
+{
+  GstElement *element = g_value_get_object (velement);
+
+  if (G_OBJECT_TYPE (element) == g_type_from_name ("GstInputSelector")) {
+    GstPad *srcpad = gst_element_get_static_pad (element, "src");
+
+    if (srcpad) {
+      GstCaps *caps = gst_pad_query_caps (srcpad, NULL);
+
+      if (caps) {
+        const char *mime =
+            gst_structure_get_name (gst_caps_get_structure (caps, 0));
+        gboolean found = FALSE;
+
+        if (g_strcmp0 (type, "audio") == 0)
+            found = g_str_has_prefix (mime, "audio/");
+        else if (g_strcmp0 (type, "video") == 0)
+            found = g_str_has_prefix (mime, "video/")
+                && !g_str_has_prefix (mime, "video/x-dvd-subpicture");
+        else if (g_strcmp0 (type, "text") == 0)
+            found = g_str_has_prefix (mime, "text/")
+                || g_str_has_prefix (mime, "subtitle/")
+                || g_str_has_prefix (mime, "video/x-dvd-subpicture");
+
+        gst_object_unref (srcpad);
+        if (found)
+          return 0;
+      }
+    }
+  }
+  return !0;
+}
+
+static GstElement *
+find_input_selector_with_type (GstBin * bin, const gchar *type)
+{
+  GValue result = {0, };
+  GstElement *input_selector = NULL;
+  GstIterator *iterator = gst_bin_iterate_recurse (bin);
+
+  if (gst_iterator_find_custom (iterator,
+      (GCompareFunc) find_input_selector, &result, (gpointer) type)) {
+    input_selector = g_value_get_object (&result);
+  }
+  gst_iterator_free (iterator);
+
+  return input_selector;
+}
+
+static GstPad *
+find_nth_sink_pad (GstElement * element, int index)
+{
+  GstIterator *iterator;
+  gboolean done = FALSE;
+  GstPad *pad = NULL;
+  int dec_index = index;
+  GValue data = { 0, };
+
+  iterator = gst_element_iterate_sink_pads (element);
+  while (!done) {
+    switch (gst_iterator_next (iterator, &data)) {
+      case GST_ITERATOR_OK:
+        if (!dec_index--) {
+          done = TRUE;
+          pad = g_value_get_object (&data);
+          break;
+        }
+        g_value_reset (&data);
+        break;
+      case GST_ITERATOR_RESYNC:
+        gst_iterator_resync (iterator);
+        dec_index = index;
+        break;
+      case GST_ITERATOR_ERROR:
+        done = TRUE;
+        break;
+      case GST_ITERATOR_DONE:
+        done = TRUE;
+        break;
+    }
+  }
+  gst_iterator_free (iterator);
+  return pad;
+}
+
+static int
+find_sink_pad_index (GstElement * element, GstPad * pad)
+{
+  GstIterator *iterator;
+  gboolean done = FALSE;
+  int index = 0;
+  GValue data = { 0, };
+
+  iterator = gst_element_iterate_sink_pads (element);
+  while (!done) {
+    switch (gst_iterator_next (iterator, &data)) {
+      case GST_ITERATOR_OK:
+        if (pad == g_value_get_object (&data)) {
+          done = TRUE;
+        } else {
+          index++;
+        }
+        g_value_reset (&data);
+        break;
+      case GST_ITERATOR_RESYNC:
+        gst_iterator_resync (iterator);
+        index = 0;
+        break;
+      case GST_ITERATOR_ERROR:
+        done = TRUE;
+        break;
+      case GST_ITERATOR_DONE:
+        done = TRUE;
+        break;
+    }
+  }
+  gst_iterator_free (iterator);
+  return index;
+}
+
+static gboolean
+_execute_switch_track (GstValidateScenario * scenario, GstValidateAction * action)
+{
+  guint index;
+  gboolean relative = FALSE;
+  const gchar *type, *str_index;
+  GstElement *input_selector;
+
+  if (!(type = gst_structure_get_string (action->structure, "type")))
+    type = "audio";
+
+  /* First find an input selector that has the right type */
+  input_selector = find_input_selector_with_type (GST_BIN (scenario->priv->pipeline), type);
+  if (input_selector) {
+    GstPad *pad;
+
+    if ((str_index = gst_structure_get_string (action->structure, "index"))) {
+      if (!gst_structure_get_uint (action->structure, "index", &index)) {
+        GST_WARNING ("No index given, defaulting to +1");
+        index = 1;
+        relative = TRUE;
+      }
+    } else {
+      relative = strchr ("+-", str_index[0]) != NULL;
+      index = g_ascii_strtoll (str_index, NULL, 10);
+    }
+
+    if (relative) { /* We are changing track relatively to current track */
+      int npads;
+
+      g_object_get (input_selector, "active-pad", &pad, "n-pads", &npads, NULL);
+      if (pad) {
+        int current_index = find_sink_pad_index (input_selector, pad);
+
+        index = (current_index + index) % npads;
+        gst_object_unref (pad);
+      }
+    }
+
+    g_print ("Switching to track number: %i\n", index);
+    pad = find_nth_sink_pad (input_selector, index);
+    g_object_set (input_selector, "active-pad", pad, NULL);
+    gst_object_unref (pad);
+    gst_object_unref (input_selector);
+
+    return TRUE;
+  }
+
+  /* No selector found -> Failed */
+  return FALSE;
+}
 
 static gboolean
 get_position (GstValidateScenario * scenario)
@@ -303,7 +476,9 @@ get_position (GstValidateScenario * scenario)
       return TRUE;
 
     func = g_hash_table_lookup (action_types_table, act->type);
-    func (scenario, act);
+    if (!func (scenario, act))
+      GST_WARNING_OBJECT (scenario, "Could not execute %" GST_PTR_FORMAT,
+          act->structure);
 
     tmp = priv->actions;
     priv->actions = g_list_remove_link (priv->actions, tmp);
@@ -671,4 +846,5 @@ init_scenarios (void)
   gst_validate_add_action_type ("pause",_execute_pause);
   gst_validate_add_action_type ("play",_execute_play);
   gst_validate_add_action_type ("eos",_execute_eos);
+  gst_validate_add_action_type ("switch-track", _execute_switch_track);
 }