--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_good/gst/autodetect/gstautovideosink.c	Wed Sep 01 12:16:41 2010 +0100
@@ -0,0 +1,435 @@
+/* GStreamer
+ * (c) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
+ * (c) 2006 Jan Schmidt <thaytan@noraisin.net>
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:element-autovideosink
+ * @see_also: autoaudiosink, ximagesink, xvimagesink, sdlvideosink
+ *
+ * <refsect2>
+ * <para>
+ * autovideosink is a video sink that automatically detects an appropriate
+ * video sink to use.  It does so by scanning the registry for all elements
+ * that have <quote>Sink</quote> and <quote>Video</quote> in the class field
+ * of their element information, and also have a non-zero autoplugging rank.
+ * </para>
+ * <title>Example launch line</title>
+ * <para>
+ * <programlisting>
+ * gst-launch -v -m videotestsrc ! autovideosink
+ * </programlisting>
+ * </para>
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+
+#include "gstautovideosink.h"
+#include "gstautodetect.h"
+
+/* Properties */
+enum
+{
+  PROP_0,
+  PROP_CAPS,
+};
+
+static GstStateChangeReturn
+gst_auto_video_sink_change_state (GstElement * element,
+    GstStateChange transition);
+static void gst_auto_video_sink_dispose (GstAutoVideoSink * sink);
+static void gst_auto_video_sink_clear_kid (GstAutoVideoSink * sink);
+
+static void gst_auto_video_sink_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_auto_video_sink_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+
+GST_BOILERPLATE (GstAutoVideoSink, gst_auto_video_sink, GstBin, GST_TYPE_BIN);
+
+static const GstElementDetails gst_auto_video_sink_details =
+GST_ELEMENT_DETAILS ("Auto video sink",
+    "Sink/Video",
+    "Wrapper video sink for automatically detected video sink",
+    "Ronald Bultje <rbultje@ronald.bitfreak.net>\n"
+    "Jan Schmidt <thaytan@noraisin.net");
+
+static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS_ANY);
+
+static void
+gst_auto_video_sink_base_init (gpointer klass)
+{
+  GstElementClass *eklass = GST_ELEMENT_CLASS (klass);
+
+  gst_element_class_add_pad_template (eklass,
+      gst_static_pad_template_get (&sink_template));
+  gst_element_class_set_details (eklass, &gst_auto_video_sink_details);
+}
+
+static void
+gst_auto_video_sink_class_init (GstAutoVideoSinkClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *eklass = GST_ELEMENT_CLASS (klass);
+
+  gobject_class = G_OBJECT_CLASS (klass);
+  gobject_class->dispose =
+      (GObjectFinalizeFunc) GST_DEBUG_FUNCPTR (gst_auto_video_sink_dispose);
+  eklass->change_state = GST_DEBUG_FUNCPTR (gst_auto_video_sink_change_state);
+  gobject_class->set_property =
+      GST_DEBUG_FUNCPTR (gst_auto_video_sink_set_property);
+  gobject_class->get_property =
+      GST_DEBUG_FUNCPTR (gst_auto_video_sink_get_property);
+
+  /**
+   * GstAutoVideoSink:filter-caps
+   *
+   * This property will filter out candidate sinks that can handle the specified
+   * caps. By default only video sinks that support raw rgb and yuv video
+   * are selected.
+   *
+   * This property can only be set before the element goes to the READY state.
+   *
+   * Since: 0.10.7
+   **/
+  g_object_class_install_property (gobject_class, PROP_CAPS,
+      g_param_spec_boxed ("filter-caps", "Filter caps",
+          "Filter sink candidates using these caps.", GST_TYPE_CAPS,
+          G_PARAM_READWRITE));
+}
+
+static void
+gst_auto_video_sink_dispose (GstAutoVideoSink * sink)
+{
+  gst_auto_video_sink_clear_kid (sink);
+
+  if (sink->filter_caps)
+    gst_caps_unref (sink->filter_caps);
+  sink->filter_caps = NULL;
+
+  G_OBJECT_CLASS (parent_class)->dispose ((GObject *) sink);
+}
+
+static void
+gst_auto_video_sink_clear_kid (GstAutoVideoSink * sink)
+{
+  if (sink->kid) {
+    gst_element_set_state (sink->kid, GST_STATE_NULL);
+    gst_bin_remove (GST_BIN (sink), sink->kid);
+    sink->kid = NULL;
+  }
+}
+
+/*
+ * Hack to make initial linking work; ideally, this'd work even when
+ * no target has been assigned to the ghostpad yet.
+ */
+
+static void
+gst_auto_video_sink_reset (GstAutoVideoSink * sink)
+{
+  GstPad *targetpad;
+
+  /* Remove any existing element */
+  gst_auto_video_sink_clear_kid (sink);
+
+  /* fakesink placeholder */
+  sink->kid = gst_element_factory_make ("fakesink", "tempsink");
+  gst_bin_add (GST_BIN (sink), sink->kid);
+
+  /* pad */
+  targetpad = gst_element_get_pad (sink->kid, "sink");
+  gst_ghost_pad_set_target (GST_GHOST_PAD (sink->pad), targetpad);
+  gst_object_unref (targetpad);
+}
+
+static GstStaticCaps raw_caps =
+    GST_STATIC_CAPS ("video/x-raw-yuv; video/x-raw-rgb");
+
+static void
+gst_auto_video_sink_init (GstAutoVideoSink * sink,
+    GstAutoVideoSinkClass * g_class)
+{
+  sink->pad = gst_ghost_pad_new_no_target ("sink", GST_PAD_SINK);
+  gst_element_add_pad (GST_ELEMENT (sink), sink->pad);
+
+  gst_auto_video_sink_reset (sink);
+
+  /* set the default raw video caps */
+  sink->filter_caps = gst_static_caps_get (&raw_caps);
+
+  /* mark as sink */
+  GST_OBJECT_FLAG_SET (sink, GST_ELEMENT_IS_SINK);
+}
+
+static gboolean
+gst_auto_video_sink_factory_filter (GstPluginFeature * feature, gpointer data)
+{
+  guint rank;
+  const gchar *klass;
+
+  /* we only care about element factories */
+  if (!GST_IS_ELEMENT_FACTORY (feature))
+    return FALSE;
+
+  /* video sinks */
+  klass = gst_element_factory_get_klass (GST_ELEMENT_FACTORY (feature));
+  if (!(strstr (klass, "Sink") && strstr (klass, "Video")))
+    return FALSE;
+
+  /* only select elements with autoplugging rank */
+  rank = gst_plugin_feature_get_rank (feature);
+  if (rank < GST_RANK_MARGINAL)
+    return FALSE;
+
+  return TRUE;
+}
+
+static gint
+gst_auto_video_sink_compare_ranks (GstPluginFeature * f1, GstPluginFeature * f2)
+{
+  gint diff;
+
+  diff = gst_plugin_feature_get_rank (f2) - gst_plugin_feature_get_rank (f1);
+  if (diff != 0)
+    return diff;
+  return strcmp (gst_plugin_feature_get_name (f2),
+      gst_plugin_feature_get_name (f1));
+}
+
+static GstElement *
+gst_auto_video_sink_create_element_with_pretty_name (GstAutoVideoSink * sink,
+    GstElementFactory * factory)
+{
+  GstElement *element;
+  gchar *name, *marker;
+
+  marker = g_strdup (GST_PLUGIN_FEATURE (factory)->name);
+  if (g_str_has_suffix (marker, "sink"))
+    marker[strlen (marker) - 4] = '\0';
+  if (g_str_has_prefix (marker, "gst"))
+    g_memmove (marker, marker + 3, strlen (marker + 3) + 1);
+  name = g_strdup_printf ("%s-actual-sink-%s", GST_OBJECT_NAME (sink), marker);
+  g_free (marker);
+
+  element = gst_element_factory_create (factory, name);
+  g_free (name);
+
+  return element;
+}
+
+static GstElement *
+gst_auto_video_sink_find_best (GstAutoVideoSink * sink)
+{
+  GList *list, *item;
+  GstElement *choice = NULL;
+  GstMessage *message = NULL;
+  GSList *errors = NULL;
+  GstBus *bus = gst_bus_new ();
+  GstPad *el_pad = NULL;
+  GstCaps *el_caps = NULL, *intersect = NULL;
+  gboolean no_match = TRUE;
+
+  list = gst_registry_feature_filter (gst_registry_get_default (),
+      (GstPluginFeatureFilter) gst_auto_video_sink_factory_filter, FALSE, sink);
+  list = g_list_sort (list, (GCompareFunc) gst_auto_video_sink_compare_ranks);
+
+  GST_LOG_OBJECT (sink, "Trying to find usable video devices ...");
+
+  for (item = list; item != NULL; item = item->next) {
+    GstElementFactory *f = GST_ELEMENT_FACTORY (item->data);
+    GstElement *el;
+
+    if ((el = gst_auto_video_sink_create_element_with_pretty_name (sink, f))) {
+      GstStateChangeReturn ret;
+
+      GST_DEBUG_OBJECT (sink, "Testing %s", GST_PLUGIN_FEATURE (f)->name);
+
+      /* If autovideosink has been provided with filter caps,
+       * accept only sinks that match with the filter caps */
+      if (sink->filter_caps) {
+        el_pad = gst_element_get_static_pad (GST_ELEMENT (el), "sink");
+        el_caps = gst_pad_get_caps (el_pad);
+        gst_object_unref (el_pad);
+        GST_DEBUG_OBJECT (sink,
+            "Checking caps: %" GST_PTR_FORMAT " vs. %" GST_PTR_FORMAT,
+            sink->filter_caps, el_caps);
+        intersect = gst_caps_intersect (sink->filter_caps, el_caps);
+        no_match = gst_caps_is_empty (intersect);
+        gst_caps_unref (el_caps);
+        gst_caps_unref (intersect);
+
+        if (no_match) {
+          GST_DEBUG_OBJECT (sink, "Incompatible caps");
+          gst_object_unref (el);
+          continue;
+        } else {
+          GST_DEBUG_OBJECT (sink, "Found compatible caps");
+        }
+      }
+
+      gst_element_set_bus (el, bus);
+      ret = gst_element_set_state (el, GST_STATE_READY);
+      if (ret == GST_STATE_CHANGE_SUCCESS) {
+        GST_DEBUG_OBJECT (sink, "This worked!");
+        choice = el;
+        break;
+      }
+
+      /* collect all error messages */
+      while ((message = gst_bus_pop_filtered (bus, GST_MESSAGE_ERROR))) {
+        GST_DEBUG_OBJECT (sink, "error message %" GST_PTR_FORMAT, message);
+        errors = g_slist_append (errors, message);
+      }
+
+      gst_element_set_state (el, GST_STATE_NULL);
+      gst_object_unref (el);
+    }
+  }
+
+  GST_DEBUG_OBJECT (sink, "done trying");
+  if (!choice) {
+    if (errors) {
+      /* FIXME: we forward the first error for now; but later on it might make
+       * sense to actually analyse them */
+      gst_message_ref (GST_MESSAGE (errors->data));
+      GST_DEBUG_OBJECT (sink, "reposting message %p", errors->data);
+      gst_element_post_message (GST_ELEMENT (sink), GST_MESSAGE (errors->data));
+    } else {
+      /* send warning message to application and use a fakesink */
+      GST_ELEMENT_WARNING (sink, RESOURCE, NOT_FOUND, (NULL),
+          ("Failed to find a usable video sink"));
+      choice = gst_element_factory_make ("fakesink", "fake-video-sink");
+      if (g_object_class_find_property (G_OBJECT_GET_CLASS (choice), "sync"))
+        g_object_set (choice, "sync", TRUE, NULL);
+      gst_element_set_state (choice, GST_STATE_READY);
+    }
+  }
+  gst_object_unref (bus);
+  gst_plugin_feature_list_free (list);
+  g_slist_foreach (errors, (GFunc) gst_mini_object_unref, NULL);
+  g_slist_free (errors);
+
+  return choice;
+}
+
+static gboolean
+gst_auto_video_sink_detect (GstAutoVideoSink * sink)
+{
+  GstElement *esink;
+  GstPad *targetpad;
+
+  gst_auto_video_sink_clear_kid (sink);
+
+  /* find element */
+  GST_DEBUG_OBJECT (sink, "Creating new kid");
+  if (!(esink = gst_auto_video_sink_find_best (sink)))
+    goto no_sink;
+
+  sink->kid = esink;
+  gst_bin_add (GST_BIN (sink), esink);
+
+  /* attach ghost pad */
+  GST_DEBUG_OBJECT (sink, "Re-assigning ghostpad");
+  targetpad = gst_element_get_pad (sink->kid, "sink");
+  gst_ghost_pad_set_target (GST_GHOST_PAD (sink->pad), targetpad);
+  gst_object_unref (targetpad);
+  GST_DEBUG_OBJECT (sink, "done changing auto video sink");
+
+  return TRUE;
+
+  /* ERRORS */
+no_sink:
+  {
+    GST_ELEMENT_ERROR (sink, LIBRARY, INIT, (NULL),
+        ("Failed to find a supported video sink"));
+    return FALSE;
+  }
+}
+
+static GstStateChangeReturn
+gst_auto_video_sink_change_state (GstElement * element,
+    GstStateChange transition)
+{
+  GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
+  GstAutoVideoSink *sink = GST_AUTO_VIDEO_SINK (element);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+      if (!gst_auto_video_sink_detect (sink))
+        return GST_STATE_CHANGE_FAILURE;
+      break;
+    default:
+      break;
+  }
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      gst_auto_video_sink_reset (sink);
+      break;
+    default:
+      break;
+  }
+
+  return ret;
+}
+
+static void
+gst_auto_video_sink_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstAutoVideoSink *sink = GST_AUTO_VIDEO_SINK (object);
+
+  switch (prop_id) {
+    case PROP_CAPS:
+      if (sink->filter_caps)
+        gst_caps_unref (sink->filter_caps);
+      sink->filter_caps = gst_caps_copy (gst_value_get_caps (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_auto_video_sink_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstAutoVideoSink *sink = GST_AUTO_VIDEO_SINK (object);
+
+  switch (prop_id) {
+    case PROP_CAPS:{
+      gst_value_set_caps (value, sink->filter_caps);
+      break;
+    }
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}