/* GStreamer

 * (c) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>

 * (c) 2006 Jan Schmidt <thaytan@noraisin.net>

 * (c) 2008 Stefan Kost <ensonic@users.sf.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-autovideosrc

 * @see_also: autoaudiosrc, v4l2src, v4lsrc

 *

 * autovideosrc is a video src that automatically detects an appropriate

 * video source to use.  It does so by scanning the registry for all elements

 * that have <quote>Source</quote> and <quote>Video</quote> in the class field

 * of their element information, and also have a non-zero autoplugging rank.

 *

 * <refsect2>

 * <title>Example launch line</title>

 * |[

 * gst-launch -v -m autovideosrc ! xvimagesink

 * ]|

 * </refsect2>

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <string.h>

#include "gstautovideosrc.h"

#include "gstautodetect.h"

/* Properties */

enum

{

  PROP_0,

  PROP_CAPS,

};

static GstStateChangeReturn

gst_auto_video_src_change_state (GstElement * element,

    GstStateChange transition);

static void gst_auto_video_src_dispose (GstAutoVideoSrc * src);

static void gst_auto_video_src_clear_kid (GstAutoVideoSrc * src);

static void gst_auto_video_src_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec);

static void gst_auto_video_src_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec);

GST_BOILERPLATE (GstAutoVideoSrc, gst_auto_video_src, GstBin, GST_TYPE_BIN);

static const GstElementDetails gst_auto_video_src_details =

GST_ELEMENT_DETAILS ("Auto video source",

    "Source/Video",

    "Wrapper video source for automatically detected video source",

    "Ronald Bultje <rbultje@ronald.bitfreak.net>\n"

    "Jan Schmidt <thaytan@noraisin.net>\n"

    "Stefan Kost <ensonic@users.sf.net>");

static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",

    GST_PAD_SRC,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS_ANY);

static void

gst_auto_video_src_base_init (gpointer klass)

{

  GstElementClass *eklass = GST_ELEMENT_CLASS (klass);

  gst_element_class_add_pad_template (eklass,

      gst_static_pad_template_get (&src_template));

  gst_element_class_set_details (eklass, &gst_auto_video_src_details);

}

static void

gst_auto_video_src_class_init (GstAutoVideoSrcClass * 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_src_dispose);

  eklass->change_state = GST_DEBUG_FUNCPTR (gst_auto_video_src_change_state);

  gobject_class->set_property =

      GST_DEBUG_FUNCPTR (gst_auto_video_src_set_property);

  gobject_class->get_property =

      GST_DEBUG_FUNCPTR (gst_auto_video_src_get_property);

  /**

   * GstAutoVideoSrc:filter-caps

   *

   * This property will filter out candidate sources that can handle the specified

   * caps. By default only video sources that support raw rgb and yuv video

   * are selected.

   *

   * This property can only be set before the element goes to the READY state.

   *

   * Since: 0.10.14

   **/

  g_object_class_install_property (gobject_class, PROP_CAPS,

      g_param_spec_boxed ("filter-caps", "Filter caps",

          "Filter src candidates using these caps.", GST_TYPE_CAPS,

          G_PARAM_READWRITE));

}

static void

gst_auto_video_src_dispose (GstAutoVideoSrc * src)

{

  gst_auto_video_src_clear_kid (src);

  if (src->filter_caps)

    gst_caps_unref (src->filter_caps);

  src->filter_caps = NULL;

  G_OBJECT_CLASS (parent_class)->dispose ((GObject *) src);

}

static void

gst_auto_video_src_clear_kid (GstAutoVideoSrc * src)

{

  if (src->kid) {

    gst_element_set_state (src->kid, GST_STATE_NULL);

    gst_bin_remove (GST_BIN (src), src->kid);

    src->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_src_reset (GstAutoVideoSrc * src)

{

  GstPad *targetpad;

  /* Remove any existing element */

  gst_auto_video_src_clear_kid (src);

  /* fakesrc placeholder */

  src->kid = gst_element_factory_make ("fakesrc", "tempsrc");

  gst_bin_add (GST_BIN (src), src->kid);

  /* pad */

  targetpad = gst_element_get_static_pad (src->kid, "src");

  gst_ghost_pad_set_target (GST_GHOST_PAD (src->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_src_init (GstAutoVideoSrc * src, GstAutoVideoSrcClass * g_class)

{

  src->pad = gst_ghost_pad_new_no_target ("src", GST_PAD_SRC);

  gst_element_add_pad (GST_ELEMENT (src), src->pad);

  gst_auto_video_src_reset (src);

  /* set the default raw video caps */

  src->filter_caps = gst_static_caps_get (&raw_caps);

  /* mark as source */

  GST_OBJECT_FLAG_UNSET (src, GST_ELEMENT_IS_SINK);

}

static gboolean

gst_auto_video_src_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 sources */

  klass = gst_element_factory_get_klass (GST_ELEMENT_FACTORY (feature));

  if (!(strstr (klass, "Source") && 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_src_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_src_create_element_with_pretty_name (GstAutoVideoSrc * src,

    GstElementFactory * factory)

{

  GstElement *element;

  gchar *name, *marker;

  marker = g_strdup (GST_PLUGIN_FEATURE (factory)->name);

  if (g_str_has_suffix (marker, "src"))

    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-src-%s", GST_OBJECT_NAME (src), marker);

  g_free (marker);

  element = gst_element_factory_create (factory, name);

  g_free (name);

  return element;

}

static GstElement *

gst_auto_video_src_find_best (GstAutoVideoSrc * src)

{

  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_src_factory_filter, FALSE, src);

  list = g_list_sort (list, (GCompareFunc) gst_auto_video_src_compare_ranks);

  GST_LOG_OBJECT (src, "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_src_create_element_with_pretty_name (src, f))) {

      GstStateChangeReturn ret;

      GST_DEBUG_OBJECT (src, "Testing %s", GST_PLUGIN_FEATURE (f)->name);

      /* If AutoVideoSrc has been provided with filter caps,

       * accept only sources that match with the filter caps */

      if (src->filter_caps) {

        el_pad = gst_element_get_static_pad (GST_ELEMENT (el), "src");

        el_caps = gst_pad_get_caps (el_pad);

        gst_object_unref (el_pad);

        GST_DEBUG_OBJECT (src,

            "Checking caps: %" GST_PTR_FORMAT " vs. %" GST_PTR_FORMAT,

            src->filter_caps, el_caps);

        intersect = gst_caps_intersect (src->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 (src, "Incompatible caps");

          gst_object_unref (el);

          continue;

        } else {

          GST_DEBUG_OBJECT (src, "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 (src, "This worked!");

        choice = el;

        break;

      }

      /* collect all error messages */

      while ((message = gst_bus_pop_filtered (bus, GST_MESSAGE_ERROR))) {

        GST_DEBUG_OBJECT (src, "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 (src, "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 (src, "reposting message %p", errors->data);

      gst_element_post_message (GST_ELEMENT (src), GST_MESSAGE (errors->data));

    } else {

      /* send warning message to application and use a fakesrc */

      GST_ELEMENT_WARNING (src, RESOURCE, NOT_FOUND, (NULL),

          ("Failed to find a usable video source"));

      choice = gst_element_factory_make ("fakesrc", "fake-video-src");

      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_src_detect (GstAutoVideoSrc * src)

{

  GstElement *esrc;

  GstPad *targetpad;

  gst_auto_video_src_clear_kid (src);

  /* find element */

  GST_DEBUG_OBJECT (src, "Creating new kid");

  if (!(esrc = gst_auto_video_src_find_best (src)))

    goto no_src;

  src->kid = esrc;

  gst_bin_add (GST_BIN (src), esrc);

  /* attach ghost pad */

  GST_DEBUG_OBJECT (src, "Re-assigning ghostpad");

  targetpad = gst_element_get_static_pad (src->kid, "src");

  if (!gst_ghost_pad_set_target (GST_GHOST_PAD (src->pad), targetpad))

    goto target_failed;

  gst_object_unref (targetpad);

  GST_DEBUG_OBJECT (src, "done changing auto video source");

  return TRUE;

  /* ERRORS */

no_src:

  {

    GST_ELEMENT_ERROR (src, LIBRARY, INIT, (NULL),

        ("Failed to find a supported video source"));

    return FALSE;

  }

target_failed:

  {

    GST_ELEMENT_ERROR (src, LIBRARY, INIT, (NULL),

        ("Failed to set target pad"));

    gst_object_unref (targetpad);

    return FALSE;

  }

}

static GstStateChangeReturn

gst_auto_video_src_change_state (GstElement * element,

    GstStateChange transition)

{

  GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;

  GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (element);

  switch (transition) {

    case GST_STATE_CHANGE_NULL_TO_READY:

      if (!gst_auto_video_src_detect (src))

        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_src_reset (src);

      break;

    default:

      break;

  }

  return ret;

}

static void

gst_auto_video_src_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec)

{

  GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (object);

  switch (prop_id) {

    case PROP_CAPS:

      if (src->filter_caps)

        gst_caps_unref (src->filter_caps);

      src->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_src_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec)

{

  GstAutoVideoSrc *src = GST_AUTO_VIDEO_SRC (object);

  switch (prop_id) {

    case PROP_CAPS:{

      gst_value_set_caps (value, src->filter_caps);

      break;

    }

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}