gstdecodebin2.c

/* GStreamer
 * Copyright (C) <2006> Edward Hervey <edward@fluendo.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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:element-decodebin2
 * @short_description: Next-generation automatic decoding bin
 *
 * #GstBin that auto-magically constructs a decoding pipeline using available
 * decoders and demuxers via auto-plugging.
 *
 * At this stage, decodebin2 is considered UNSTABLE. The API provided in the
 * signals is expected to change in the near future. 
 *
 * To try out decodebin2, you can set the USE_DECODEBIN2 environment 
 * variable (USE_DECODEBIN2=1 for example). This will cause playbin to use
 * decodebin2 instead of the older decodebin for its internal auto-plugging.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gst/gst-i18n-plugin.h>

#include <string.h>
#include <gst/gst.h>
#include <gst/pbutils/pbutils.h>

#include "gstplay-marshal.h"

/* generic templates */
static GstStaticPadTemplate decoder_bin_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS_ANY);

static GstStaticPadTemplate decoder_bin_src_template =
GST_STATIC_PAD_TEMPLATE ("src%d",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS_ANY);

GST_DEBUG_CATEGORY_STATIC (gst_decode_bin_debug);
#define GST_CAT_DEFAULT gst_decode_bin_debug

typedef struct _GstDecodeGroup GstDecodeGroup;
typedef struct _GstDecodePad GstDecodePad;
typedef struct _GstDecodeBin GstDecodeBin;
typedef struct _GstDecodeBin GstDecodeBin2;
typedef struct _GstDecodeBinClass GstDecodeBinClass;

#define GST_TYPE_DECODE_BIN             (gst_decode_bin_get_type())
#define GST_DECODE_BIN_CAST(obj)        ((GstDecodeBin*)(obj))
#define GST_DECODE_BIN(obj)             (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_DECODE_BIN,GstDecodeBin))
#define GST_DECODE_BIN_CLASS(klass)     (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_DECODE_BIN,GstDecodeBinClass))
#define GST_IS_DECODE_BIN(obj)          (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_DECODE_BIN))
#define GST_IS_DECODE_BIN_CLASS(klass)  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_DECODE_BIN))

/**
 *  GstDecodeBin2:
 *
 *  The opaque #DecodeBin2 data structure
 */
struct _GstDecodeBin
{
  GstBin bin;                   /* we extend GstBin */

  /* properties */
  GstCaps *caps;                /* caps on which to stop decoding */
  gchar *encoding;              /* encoding of subtitles */

  GstElement *typefind;         /* this holds the typefind object */
  GstElement *fakesink;

  GMutex *lock;                 /* Protects activegroup and groups */
  GstDecodeGroup *activegroup;  /* group currently active */
  GList *groups;                /* List of non-active GstDecodeGroups, sorted in
                                 * order of creation. */
  GList *oldgroups;             /* List of no-longer-used GstDecodeGroups. 
                                 * Should be freed in dispose */
  gint nbpads;                  /* unique identifier for source pads */

  GList *factories;             /* factories we can use for selecting elements */

  gboolean have_type;           /* if we received the have_type signal */
  guint have_type_id;           /* signal id for have-type from typefind */
};

struct _GstDecodeBinClass
{
  GstBinClass parent_class;

  /* signal we fire when a new pad has been decoded into raw audio/video */
  void (*new_decoded_pad) (GstElement * element, GstPad * pad, gboolean last);
  /* signal we fire when a pad has been removed */
  void (*removed_decoded_pad) (GstElement * element, GstPad * pad);
  /* signal fired when we found a pad that we cannot decode */
  void (*unknown_type) (GstElement * element, GstPad * pad, GstCaps * caps);

  /* signal fired to know if we continue trying to decode the given caps */
    gboolean (*autoplug_continue) (GstElement * element, GstPad * pad,
      GstCaps * caps);
  /* signal fired to get a list of factories to try to autoplug */
  GValueArray *(*autoplug_factories) (GstElement * element, GstPad * pad,
      GstCaps * caps);
  /* signal fired to select from the proposed list of factories */
    gint (*autoplug_select) (GstElement * element, GstPad * pad, GstCaps * caps,
      GValueArray * factories);
};

/* signals */
enum
{
  SIGNAL_NEW_DECODED_PAD,
  SIGNAL_REMOVED_DECODED_PAD,
  SIGNAL_UNKNOWN_TYPE,
  SIGNAL_AUTOPLUG_CONTINUE,
  SIGNAL_AUTOPLUG_FACTORIES,
  SIGNAL_AUTOPLUG_SELECT,
  LAST_SIGNAL
};

/* Properties */
enum
{
  PROP_0,
  PROP_CAPS,
  PROP_SUBTITLE_ENCODING
};

static GstBinClass *parent_class;
static guint gst_decode_bin_signals[LAST_SIGNAL] = { 0 };

static const GstElementDetails gst_decode_bin_details =
GST_ELEMENT_DETAILS ("Decoder Bin",
    "Generic/Bin/Decoder",
    "Autoplug and decode to raw media",
    "Edward Hervey <edward@fluendo.com>");


static gboolean add_fakesink (GstDecodeBin * decode_bin);
static void remove_fakesink (GstDecodeBin * decode_bin);

static void type_found (GstElement * typefind, guint probability,
    GstCaps * caps, GstDecodeBin * decode_bin);

static gboolean gst_decode_bin_autoplug_continue (GstElement * element,
    GstPad * pad, GstCaps * caps);
static GValueArray *gst_decode_bin_autoplug_factories (GstElement *
    element, GstPad * pad, GstCaps * caps);
static gint gst_decode_bin_autoplug_select (GstElement * element,
    GstPad * pad, GstCaps * caps, GValueArray * list);

static void gst_decode_bin_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_decode_bin_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static void gst_decode_bin_set_caps (GstDecodeBin * dbin, GstCaps * caps);
static GstCaps *gst_decode_bin_get_caps (GstDecodeBin * dbin);
static void caps_notify_group_cb (GstPad * pad, GParamSpec * unused,
    GstDecodeGroup * group);
static void caps_notify_cb (GstPad * pad, GParamSpec * unused,
    GstDecodeBin * dbin);

static GstPad *find_sink_pad (GstElement * element);
static GstStateChangeReturn gst_decode_bin_change_state (GstElement * element,
    GstStateChange transition);

#define DECODE_BIN_LOCK(dbin) G_STMT_START {				\
    GST_LOG_OBJECT (dbin,						\
		    "locking from thread %p",				\
		    g_thread_self ());					\
    g_mutex_lock (GST_DECODE_BIN_CAST(dbin)->lock);			\
    GST_LOG_OBJECT (dbin,						\
		    "locked from thread %p",				\
		    g_thread_self ());					\
} G_STMT_END

#define DECODE_BIN_UNLOCK(dbin) G_STMT_START {				\
    GST_LOG_OBJECT (dbin,						\
		    "unlocking from thread %p",				\
		    g_thread_self ());					\
    g_mutex_unlock (GST_DECODE_BIN_CAST(dbin)->lock);			\
} G_STMT_END

/* GstDecodeGroup
 *
 * Streams belonging to the same group/chain of a media file
 *
 */

struct _GstDecodeGroup
{
  GstDecodeBin *dbin;
  GMutex *lock;
  GstElement *multiqueue;
  gboolean exposed;             /* TRUE if this group is exposed */
  gboolean drained;             /* TRUE if EOS went throug all endpads */
  gboolean blocked;             /* TRUE if all endpads are blocked */
  gboolean complete;            /* TRUE if we are not expecting anymore streams 
                                 * on this group */
  gulong overrunsig;
  gulong underrunsig;
  guint nbdynamic;              /* number of dynamic pads in the group. */

  GList *endpads;               /* List of GstDecodePad of source pads to be exposed */
  GList *ghosts;                /* List of GstGhostPad for the endpads */

  GList *reqpads;               /* List of RequestPads */
};

#define GROUP_MUTEX_LOCK(group) G_STMT_START {				\
    GST_LOG_OBJECT (group->dbin,					\
		    "locking group %p from thread %p",			\
		    group, g_thread_self ());				\
    g_mutex_lock (group->lock);						\
    GST_LOG_OBJECT (group->dbin,					\
		    "locked group %p from thread %p",			\
		    group, g_thread_self ());				\
} G_STMT_END

#define GROUP_MUTEX_UNLOCK(group) G_STMT_START {                        \
    GST_LOG_OBJECT (group->dbin,					\
		    "unlocking group %p from thread %p",		\
		    group, g_thread_self ());				\
    g_mutex_unlock (group->lock);					\
} G_STMT_END


static GstDecodeGroup *gst_decode_group_new (GstDecodeBin * decode_bin,
    gboolean use_queue);
static GstPad *gst_decode_group_control_demuxer_pad (GstDecodeGroup * group,
    GstPad * pad);
static gboolean gst_decode_group_control_source_pad (GstDecodeGroup * group,
    GstPad * pad);
static gboolean gst_decode_group_expose (GstDecodeGroup * group);
static void gst_decode_group_check_if_blocked (GstDecodeGroup * group);
static void gst_decode_group_set_complete (GstDecodeGroup * group);
static void gst_decode_group_hide (GstDecodeGroup * group);
static void gst_decode_group_free (GstDecodeGroup * group);

/* GstDecodePad
 *
 * GstPad private used for source pads of groups
 */

struct _GstDecodePad
{
  GstPad *pad;
  GstDecodeGroup *group;
  gboolean blocked;
  gboolean drained;
};

static GstDecodePad *gst_decode_pad_new (GstDecodeGroup * group, GstPad * pad,
    gboolean block);
static void source_pad_blocked_cb (GstPad * pad, gboolean blocked,
    GstDecodePad * dpad);

/* TempPadStruct
 * Internal structure used for pads which have more than one structure.
 */
typedef struct _TempPadStruct
{
  GstDecodeBin *dbin;
  GstDecodeGroup *group;
} TempPadStruct;

/********************************
 * Standard GObject boilerplate *
 ********************************/

static void gst_decode_bin_class_init (GstDecodeBinClass * klass);
static void gst_decode_bin_init (GstDecodeBin * decode_bin);
static void gst_decode_bin_dispose (GObject * object);
static void gst_decode_bin_finalize (GObject * object);

static GType
gst_decode_bin_get_type (void)
{
  static GType gst_decode_bin_type = 0;

  if (!gst_decode_bin_type) {
    static const GTypeInfo gst_decode_bin_info = {
      sizeof (GstDecodeBinClass),
      NULL,
      NULL,
      (GClassInitFunc) gst_decode_bin_class_init,
      NULL,
      NULL,
      sizeof (GstDecodeBin),
      0,
      (GInstanceInitFunc) gst_decode_bin_init,
      NULL
    };

    gst_decode_bin_type =
        g_type_register_static (GST_TYPE_BIN, "GstDecodeBin2",
        &gst_decode_bin_info, 0);
  }

  return gst_decode_bin_type;
}

static gboolean
_gst_boolean_accumulator (GSignalInvocationHint * ihint,
    GValue * return_accu, const GValue * handler_return, gpointer dummy)
{
  gboolean myboolean;

  myboolean = g_value_get_boolean (handler_return);
  if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
    g_value_set_boolean (return_accu, myboolean);

  /* stop emission if FALSE */
  return myboolean;
}

static void
gst_decode_bin_class_init (GstDecodeBinClass * klass)
{
  GObjectClass *gobject_klass;
  GstElementClass *gstelement_klass;
  GstBinClass *gstbin_klass;

  gobject_klass = (GObjectClass *) klass;
  gstelement_klass = (GstElementClass *) klass;
  gstbin_klass = (GstBinClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gobject_klass->dispose = GST_DEBUG_FUNCPTR (gst_decode_bin_dispose);
  gobject_klass->finalize = GST_DEBUG_FUNCPTR (gst_decode_bin_finalize);
  gobject_klass->set_property = GST_DEBUG_FUNCPTR (gst_decode_bin_set_property);
  gobject_klass->get_property = GST_DEBUG_FUNCPTR (gst_decode_bin_get_property);

  /**
   * GstDecodeBin2::new-decoded-pad:
   * @pad: the newly created pad
   * @islast: #TRUE if this is the last pad to be added. Deprecated.
   *
   * This signal gets emitted as soon as a new pad of the same type as one of
   * the valid 'raw' types is added.
   */
  gst_decode_bin_signals[SIGNAL_NEW_DECODED_PAD] =
      g_signal_new ("new-decoded-pad", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstDecodeBinClass, new_decoded_pad), NULL, NULL,
      gst_play_marshal_VOID__OBJECT_BOOLEAN, G_TYPE_NONE, 2, GST_TYPE_PAD,
      G_TYPE_BOOLEAN);

  /**
   * GstDecodeBin2::removed-decoded-pad:
   * @pad: the pad that was removed
   *
   * This signal is emitted when a 'final' caps pad has been removed.
   */
  gst_decode_bin_signals[SIGNAL_REMOVED_DECODED_PAD] =
      g_signal_new ("removed-decoded-pad", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstDecodeBinClass, removed_decoded_pad), NULL, NULL,
      gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_PAD);

  /**
   * GstDecodeBin2::unknown-type:
   * @pad: the new pad containing caps that cannot be resolved to a 'final' stream type.
   * @caps: the #GstCaps of the pad that cannot be resolved.
   *
   * This signal is emitted when a pad for which there is no further possible
   * decoding is added to the decodebin.
   */
  gst_decode_bin_signals[SIGNAL_UNKNOWN_TYPE] =
      g_signal_new ("unknown-type", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstDecodeBinClass, unknown_type),
      NULL, NULL, gst_marshal_VOID__OBJECT_OBJECT, G_TYPE_NONE, 2,
      GST_TYPE_PAD, GST_TYPE_CAPS);

  /**
   * GstDecodeBin2::autoplug-continue:
   * @pad: The #GstPad.
   * @caps: The #GstCaps found.
   *
   * This signal is emitted whenever decodebin2 finds a new stream. It is
   * emitted before looking for any elements that can handle that stream.
   *
   * Returns: #TRUE if you wish decodebin2 to look for elements that can
   * handle the given @caps. If #FALSE, those caps will be considered as
   * final and the pad will be exposed as such (see 'new-decoded-pad'
   * signal).
   */
  gst_decode_bin_signals[SIGNAL_AUTOPLUG_CONTINUE] =
      g_signal_new ("autoplug-continue", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstDecodeBinClass, autoplug_continue),
      _gst_boolean_accumulator, NULL, gst_play_marshal_BOOLEAN__OBJECT_OBJECT,
      G_TYPE_BOOLEAN, 2, GST_TYPE_PAD, GST_TYPE_CAPS);

  /**
   * GstDecodeBin2::autoplug-factories:
   * @pad: The #GstPad.
   * @caps: The #GstCaps found.
   *
   * This function is emited when an array of possible factories for @caps on
   * @pad is needed. Decodebin2 will by default return 
   *
   * Returns: a #GValueArray* with a list of factories to try. The factories are
   * by default tried in the returned order or based on the index returned by
   * "autoplug-select".
   */
  gst_decode_bin_signals[SIGNAL_AUTOPLUG_FACTORIES] =
      g_signal_new ("autoplug-factories", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstDecodeBinClass,
          autoplug_factories), NULL, NULL,
      gst_play_marshal_BOXED__OBJECT_OBJECT, G_TYPE_VALUE_ARRAY, 2,
      GST_TYPE_PAD, GST_TYPE_CAPS);

  /**
   * GstDecodeBin2::autoplug-select:
   * @pad: The #GstPad.
   * @caps: The #GstCaps.
   * @factories: A #GValueArray of possible #GstElementFactory to use, sorted by
   * rank (higher ranks come first).
   *
   * This signal is emitted once decodebin2 has found all the possible
   * #GstElementFactory that can be used to handle the given @caps.
   *
   * Returns: A #gint indicating what factory index from the @factories array
   * that you wish decodebin2 to use for trying to decode the given @caps.
   * -1 to stop selection of a factory. The default handler always
   * returns the first possible factory.
   */
  gst_decode_bin_signals[SIGNAL_AUTOPLUG_SELECT] =
      g_signal_new ("autoplug-select", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstDecodeBinClass, autoplug_select),
      NULL, NULL, gst_play_marshal_INT__OBJECT_OBJECT_BOXED,
      G_TYPE_INT, 3, GST_TYPE_PAD, GST_TYPE_CAPS, G_TYPE_VALUE_ARRAY);

  g_object_class_install_property (gobject_klass, PROP_CAPS,
      g_param_spec_boxed ("caps", "Caps", "The caps on which to stop decoding.",
          GST_TYPE_CAPS, G_PARAM_READWRITE));

  g_object_class_install_property (gobject_klass, PROP_SUBTITLE_ENCODING,
      g_param_spec_string ("subtitle-encoding", "subtitle encoding",
          "Encoding to assume if input subtitles are not in UTF-8 encoding. "
          "If not set, the GST_SUBTITLE_ENCODING environment variable will "
          "be checked for an encoding to use. If that is not set either, "
          "ISO-8859-15 will be assumed.", NULL, G_PARAM_READWRITE));

  klass->autoplug_continue =
      GST_DEBUG_FUNCPTR (gst_decode_bin_autoplug_continue);
  klass->autoplug_factories =
      GST_DEBUG_FUNCPTR (gst_decode_bin_autoplug_factories);
  klass->autoplug_select = GST_DEBUG_FUNCPTR (gst_decode_bin_autoplug_select);

  gst_element_class_add_pad_template (gstelement_klass,
      gst_static_pad_template_get (&decoder_bin_sink_template));
  gst_element_class_add_pad_template (gstelement_klass,
      gst_static_pad_template_get (&decoder_bin_src_template));

  gst_element_class_set_details (gstelement_klass, &gst_decode_bin_details);

  gstelement_klass->change_state =
      GST_DEBUG_FUNCPTR (gst_decode_bin_change_state);
}

/* the filter function for selecting the elements we can use in
 * autoplugging */
static gboolean
gst_decode_bin_factory_filter (GstPluginFeature * feature,
    GstDecodeBin * decode_bin)
{
  guint rank;
  const gchar *klass;

  /* we only care about element factories */
  if (!GST_IS_ELEMENT_FACTORY (feature))
    return FALSE;

  klass = gst_element_factory_get_klass (GST_ELEMENT_FACTORY (feature));
  /* only demuxers, decoders, depayloaders and parsers can play */
  if (strstr (klass, "Demux") == NULL &&
      strstr (klass, "Decoder") == NULL &&
      strstr (klass, "Depayloader") == NULL &&
      strstr (klass, "Parse") == NULL) {
    return FALSE;
  }

  /* only select elements with autoplugging rank */
  rank = gst_plugin_feature_get_rank (feature);
  if (rank < GST_RANK_MARGINAL)
    return FALSE;

  return TRUE;
}

/* function used to sort element features */
static gint
compare_ranks (GstPluginFeature * f1, GstPluginFeature * f2)
{
  gint diff;
  const gchar *rname1, *rname2;

  diff = gst_plugin_feature_get_rank (f2) - gst_plugin_feature_get_rank (f1);
  if (diff != 0)
    return diff;

  rname1 = gst_plugin_feature_get_name (f1);
  rname2 = gst_plugin_feature_get_name (f2);

  diff = strcmp (rname2, rname1);

  return diff;
}

static void
print_feature (GstPluginFeature * feature)
{
  const gchar *rname;

  rname = gst_plugin_feature_get_name (feature);

  GST_DEBUG ("%s", rname);
}

static void
gst_decode_bin_init (GstDecodeBin * decode_bin)
{
  GList *factories;

  /* first filter out the interesting element factories */
  factories = gst_default_registry_feature_filter (
      (GstPluginFeatureFilter) gst_decode_bin_factory_filter,
      FALSE, decode_bin);

  /* sort them according to their ranks */
  decode_bin->factories = g_list_sort (factories, (GCompareFunc) compare_ranks);
  /* do some debugging */
  g_list_foreach (decode_bin->factories, (GFunc) print_feature, NULL);


  /* we create the typefind element only once */
  decode_bin->typefind = gst_element_factory_make ("typefind", "typefind");
  if (!decode_bin->typefind) {
    g_warning ("can't find typefind element, decodebin will not work");
  } else {
    GstPad *pad;
    GstPad *gpad;

    /* add the typefind element */
    if (!gst_bin_add (GST_BIN (decode_bin), decode_bin->typefind)) {
      g_warning ("Could not add typefind element, decodebin will not work");
      gst_object_unref (decode_bin->typefind);
      decode_bin->typefind = NULL;
    }

    /* get the sinkpad */
    pad = gst_element_get_pad (decode_bin->typefind, "sink");

    /* ghost the sink pad to ourself */
    gpad = gst_ghost_pad_new ("sink", pad);
    gst_pad_set_active (gpad, TRUE);
    gst_element_add_pad (GST_ELEMENT (decode_bin), gpad);

    gst_object_unref (pad);

    /* connect a signal to find out when the typefind element found
     * a type */
    decode_bin->have_type_id =
        g_signal_connect (G_OBJECT (decode_bin->typefind), "have-type",
        G_CALLBACK (type_found), decode_bin);
  }

  decode_bin->lock = g_mutex_new ();
  decode_bin->activegroup = NULL;
  decode_bin->groups = NULL;

  decode_bin->caps =
      gst_caps_from_string ("video/x-raw-yuv;video/x-raw-rgb;video/x-raw-gray;"
      "audio/x-raw-int;audio/x-raw-float;" "text/plain;text/x-pango-markup");

  add_fakesink (decode_bin);

  /* FILLME */
}

static void
gst_decode_bin_dispose (GObject * object)
{
  GstDecodeBin *decode_bin;
  GList *tmp;

  decode_bin = GST_DECODE_BIN (object);

  if (decode_bin->factories)
    gst_plugin_feature_list_free (decode_bin->factories);
  decode_bin->factories = NULL;

  if (decode_bin->activegroup) {
    gst_decode_group_free (decode_bin->activegroup);
    decode_bin->activegroup = NULL;
  }

  /* remove groups */
  for (tmp = decode_bin->groups; tmp; tmp = g_list_next (tmp)) {
    GstDecodeGroup *group = (GstDecodeGroup *) tmp->data;

    gst_decode_group_free (group);
  }
  g_list_free (decode_bin->groups);
  decode_bin->groups = NULL;

  for (tmp = decode_bin->oldgroups; tmp; tmp = g_list_next (tmp)) {
    GstDecodeGroup *group = (GstDecodeGroup *) tmp->data;

    gst_decode_group_free (group);
  }
  g_list_free (decode_bin->oldgroups);
  decode_bin->oldgroups = NULL;

  if (decode_bin->caps)
    gst_caps_unref (decode_bin->caps);
  decode_bin->caps = NULL;

  g_free (decode_bin->encoding);
  decode_bin->encoding = NULL;

  remove_fakesink (decode_bin);

  G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
gst_decode_bin_finalize (GObject * object)
{
  GstDecodeBin *decode_bin;

  decode_bin = GST_DECODE_BIN (object);

  if (decode_bin->lock) {
    g_mutex_free (decode_bin->lock);
    decode_bin->lock = NULL;
  }

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

/* _set_caps
 * Changes the caps on which decodebin will stop decoding.
 * Will unref the previously set one. The refcount of the given caps will be
 * increased.
 * @caps can be NULL.
 *
 * MT-safe
 */
static void
gst_decode_bin_set_caps (GstDecodeBin * dbin, GstCaps * caps)
{
  GST_DEBUG_OBJECT (dbin, "Setting new caps: %" GST_PTR_FORMAT, caps);

  DECODE_BIN_LOCK (dbin);
  if (dbin->caps)
    gst_caps_unref (dbin->caps);
  if (caps)
    gst_caps_ref (caps);
  dbin->caps = caps;
  DECODE_BIN_UNLOCK (dbin);
}

/* _get_caps
 * Returns the currently configured caps on which decodebin will stop decoding.
 * The returned caps (if not NULL), will have its refcount incremented.
 *
 * MT-safe
 */

static GstCaps *
gst_decode_bin_get_caps (GstDecodeBin * dbin)
{
  GstCaps *caps;

  GST_DEBUG_OBJECT (dbin, "Getting currently set caps");

  DECODE_BIN_LOCK (dbin);
  caps = dbin->caps;
  if (caps)
    gst_caps_ref (caps);
  DECODE_BIN_UNLOCK (dbin);

  return caps;
}

static void
gst_decode_bin_set_subs_encoding (GstDecodeBin * dbin, const gchar * encoding)
{
  GST_DEBUG_OBJECT (dbin, "Setting new encoding: %s", GST_STR_NULL (encoding));

  DECODE_BIN_LOCK (dbin);
  g_free (dbin->encoding);
  dbin->encoding = g_strdup (encoding);
  DECODE_BIN_UNLOCK (dbin);
}

static gchar *
gst_decode_bin_get_subs_encoding (GstDecodeBin * dbin)
{
  gchar *encoding;

  GST_DEBUG_OBJECT (dbin, "Getting currently set encoding");

  DECODE_BIN_LOCK (dbin);
  encoding = g_strdup (dbin->encoding);
  DECODE_BIN_UNLOCK (dbin);

  return encoding;
}

static void
gst_decode_bin_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstDecodeBin *dbin;

  dbin = GST_DECODE_BIN (object);

  switch (prop_id) {
    case PROP_CAPS:
      gst_decode_bin_set_caps (dbin, g_value_get_boxed (value));
      break;
    case PROP_SUBTITLE_ENCODING:
      gst_decode_bin_set_subs_encoding (dbin, g_value_get_string (value));
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_decode_bin_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstDecodeBin *dbin;

  dbin = GST_DECODE_BIN (object);
  switch (prop_id) {
    case PROP_CAPS:
      g_value_take_boxed (value, gst_decode_bin_get_caps (dbin));
      break;
    case PROP_SUBTITLE_ENCODING:
      g_value_take_string (value, gst_decode_bin_get_subs_encoding (dbin));
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}


static GValueArray *find_compatibles (GstDecodeBin * decode_bin,
    GstPad * pad, const GstCaps * caps);

/*****
 * Default autoplug signal handlers
 *****/
static gboolean
gst_decode_bin_autoplug_continue (GstElement * element, GstPad * pad,
    GstCaps * caps)
{
  /* by default we always continue */
  return TRUE;
}

static GValueArray *
gst_decode_bin_autoplug_factories (GstElement * element, GstPad * pad,
    GstCaps * caps)
{
  GValueArray *result;

  /* return all compatible factories for caps */
  result = find_compatibles (GST_DECODE_BIN (element), pad, caps);

  return result;
}

static gint
gst_decode_bin_autoplug_select (GstElement * element, GstPad * pad,
    GstCaps * caps, GValueArray * factories)
{
  g_return_val_if_fail (factories != NULL, -1);
  g_return_val_if_fail (factories->n_values > 0, -1);

  /* Return first factory. */
  return 0;
}

/********
 * Discovery methods
 *****/

static gboolean are_raw_caps (GstDecodeBin * dbin, GstCaps * caps);
static gboolean is_demuxer_element (GstElement * srcelement);

static gboolean connect_pad (GstDecodeBin * dbin, GstElement * src,
    GstPad * pad, GstCaps * caps, GValueArray * factories,
    GstDecodeGroup * group);
static gboolean connect_element (GstDecodeBin * dbin, GstElement * element,
    GstDecodeGroup * group);
static void expose_pad (GstDecodeBin * dbin, GstElement * src, GstPad * pad,
    GstDecodeGroup * group);

static void pad_added_group_cb (GstElement * element, GstPad * pad,
    GstDecodeGroup * group);
static void pad_removed_group_cb (GstElement * element, GstPad * pad,
    GstDecodeGroup * group);
static void no_more_pads_group_cb (GstElement * element,
    GstDecodeGroup * group);
static void pad_added_cb (GstElement * element, GstPad * pad,
    GstDecodeBin * dbin);
static void pad_removed_cb (GstElement * element, GstPad * pad,
    GstDecodeBin * dbin);
static void no_more_pads_cb (GstElement * element, GstDecodeBin * dbin);

static GstDecodeGroup *get_current_group (GstDecodeBin * dbin);

/* called when a new pad is discovered. It will perform some basic actions
 * before trying to link something to it.
 *
 *  - Check the caps, don't do anything when there are no caps or when they have
 *    no good type.
 *  - signal AUTOPLUG_CONTINUE to check if we need to continue autoplugging this
 *    pad.
 *  - if the caps are non-fixed, setup a handler to continue autoplugging when
 *    the caps become fixed (connect to notify::caps).
 *  - get list of factories to autoplug.
 *  - continue autoplugging to one of the factories.
 */
static void
analyze_new_pad (GstDecodeBin * dbin, GstElement * src, GstPad * pad,
    GstCaps * caps, GstDecodeGroup * group)
{
  gboolean apcontinue = TRUE;
  GValueArray *factories = NULL;

  GST_DEBUG_OBJECT (dbin, "Pad %s:%s caps:%" GST_PTR_FORMAT,
      GST_DEBUG_PAD_NAME (pad), caps);

  if ((caps == NULL) || gst_caps_is_empty (caps))
    goto unknown_type;

  if (gst_caps_is_any (caps))
    goto any_caps;

  /* 1. Emit 'autoplug-continue' the result will tell us if this pads needs
   * further autoplugging. */
  g_signal_emit (G_OBJECT (dbin),
      gst_decode_bin_signals[SIGNAL_AUTOPLUG_CONTINUE], 0, pad, caps,
      &apcontinue);

  /* 1.a if autoplug-continue is FALSE or caps is a raw format, goto pad_is_final */
  if ((!apcontinue) || are_raw_caps (dbin, caps))
    goto expose_pad;

  /* 1.b when the caps are not fixed yet, we can't be sure what element to
   * connect. We delay autoplugging until the caps are fixed */
  if (!gst_caps_is_fixed (caps))
    goto non_fixed;

  /* 1.c else get the factories and if there's no compatible factory goto
   * unknown_type */
  g_signal_emit (G_OBJECT (dbin),
      gst_decode_bin_signals[SIGNAL_AUTOPLUG_FACTORIES], 0, pad, caps,
      &factories);
  if (factories == NULL) {
    /* no compatible factories */
    goto unknown_type;
  }

  /* 1.d else continue autoplugging something from the list. */
  GST_LOG_OBJECT (pad, "Let's continue discovery on this pad");
  connect_pad (dbin, src, pad, caps, factories, group);

  g_value_array_free (factories);

  return;

expose_pad:
  {
    GST_LOG_OBJECT (dbin, "Pad is final. autoplug-continue:%d", apcontinue);
    expose_pad (dbin, src, pad, group);
    return;
  }
unknown_type:
  {
    GST_LOG_OBJECT (pad, "Unknown type, firing signal");
    g_signal_emit (G_OBJECT (dbin),
        gst_decode_bin_signals[SIGNAL_UNKNOWN_TYPE], 0, pad, caps);

    /* Check if there are no pending groups, if so, remove fakesink */
    if (dbin->groups == NULL)
      remove_fakesink (dbin);

    if (src == dbin->typefind) {
      gchar *desc;

      desc = gst_pb_utils_get_decoder_description (caps);
      GST_ELEMENT_ERROR (dbin, STREAM, CODEC_NOT_FOUND,
          (_("A %s plugin is required to play this stream, but not installed."),
              desc),
          ("No decoder to handle media type '%s'",
              gst_structure_get_name (gst_caps_get_structure (caps, 0))));
      g_free (desc);
    }

    gst_element_post_message (GST_ELEMENT_CAST (dbin),
        gst_missing_decoder_message_new (GST_ELEMENT_CAST (dbin), caps));
    return;
  }
non_fixed:
  {
    GST_DEBUG_OBJECT (pad, "pad has non-fixed caps delay autoplugging");
    goto setup_caps_delay;
  }
any_caps:
  {
    GST_WARNING_OBJECT (pad,
        "pad has ANY caps, not able to autoplug to anything");
    goto setup_caps_delay;
  }
setup_caps_delay:
  {
    /* connect to caps notification */
    if (group) {
      GROUP_MUTEX_LOCK (group);
      group->nbdynamic++;
      GST_LOG ("Group %p has now %d dynamic elements", group, group->nbdynamic);
      GROUP_MUTEX_UNLOCK (group);
      g_signal_connect (G_OBJECT (pad), "notify::caps",
          G_CALLBACK (caps_notify_group_cb), group);
    } else
      g_signal_connect (G_OBJECT (pad), "notify::caps",
          G_CALLBACK (caps_notify_cb), dbin);
    return;
  }
}


/* connect_pad:
 *
 * Try to connect the given pad to an element created from one of the factories,
 * and recursively.
 *
 * Returns TRUE if an element was properly created and linked
 */
static gboolean
connect_pad (GstDecodeBin * dbin, GstElement * src, GstPad * pad,
    GstCaps * caps, GValueArray * factories, GstDecodeGroup * group)
{
  gboolean res = FALSE;
  GstPad *mqpad = NULL;

  g_return_val_if_fail (factories != NULL, FALSE);
  g_return_val_if_fail (factories->n_values > 0, FALSE);

  GST_DEBUG_OBJECT (dbin, "pad %s:%s , group:%p",
      GST_DEBUG_PAD_NAME (pad), group);

  /* 1. is element demuxer or parser */
  if (is_demuxer_element (src)) {
    GST_LOG_OBJECT (src, "is a demuxer, connecting the pad through multiqueue");

    if (!group)
      if (!(group = get_current_group (dbin))) {
        group = gst_decode_group_new (dbin, TRUE);
        DECODE_BIN_LOCK (dbin);
        dbin->groups = g_list_append (dbin->groups, group);
        DECODE_BIN_UNLOCK (dbin);
      }

    if (!(mqpad = gst_decode_group_control_demuxer_pad (group, pad)))
      goto beach;
    pad = mqpad;
  }

  /* 2. Try to create an element and link to it */