gstreamer/gst/playback/gstplaybin2.c

/* GStreamer
 * Copyright (C) <2007> Wim Taymans <wim.taymans@gmail.com>
 * Copyright (C) <2011> Sebastian Dröge <sebastian.droege@collabora.co.uk>
 *
 * 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-playbin
 *
 * Playbin provides a stand-alone everything-in-one abstraction for an
 * audio and/or video player.
 *
 * Playbin can handle both audio and video files and features
 * <itemizedlist>
 * <listitem>
 * automatic file type recognition and based on that automatic
 * selection and usage of the right audio/video/subtitle demuxers/decoders
 * </listitem>
 * <listitem>
 * visualisations for audio files
 * </listitem>
 * <listitem>
 * subtitle support for video files. Subtitles can be store in external
 * files.
 * </listitem>
 * <listitem>
 * stream selection between different video/audio/subtitles streams
 * </listitem>
 * <listitem>
 * meta info (tag) extraction
 * </listitem>
 * <listitem>
 * easy access to the last video frame
 * </listitem>
 * <listitem>
 * buffering when playing streams over a network
 * </listitem>
 * <listitem>
 * volume control with mute option
 * </listitem>
 * </itemizedlist>
 *
 * <refsect2>
 * <title>Usage</title>
 * <para>
 * A playbin element can be created just like any other element using
 * gst_element_factory_make(). The file/URI to play should be set via the #GstPlayBin:uri
 * property. This must be an absolute URI, relative file paths are not allowed.
 * Example URIs are file:///home/joe/movie.avi or http://www.joedoe.com/foo.ogg
 *
 * Playbin is a #GstPipeline. It will notify the application of everything
 * that's happening (errors, end of stream, tags found, state changes, etc.)
 * by posting messages on its #GstBus. The application needs to watch the
 * bus.
 *
 * Playback can be initiated by setting the element to PLAYING state using
 * gst_element_set_state(). Note that the state change will take place in
 * the background in a separate thread, when the function returns playback
 * is probably not happening yet and any errors might not have occured yet.
 * Applications using playbin should ideally be written to deal with things
 * completely asynchroneous.
 *
 * When playback has finished (an EOS message has been received on the bus)
 * or an error has occured (an ERROR message has been received on the bus) or
 * the user wants to play a different track, playbin should be set back to
 * READY or NULL state, then the #GstPlayBin:uri property should be set to the
 * new location and then playbin be set to PLAYING state again.
 *
 * Seeking can be done using gst_element_seek_simple() or gst_element_seek()
 * on the playbin element. Again, the seek will not be executed
 * instantaneously, but will be done in a background thread. When the seek
 * call returns the seek will most likely still be in process. An application
 * may wait for the seek to finish (or fail) using gst_element_get_state() with
 * -1 as the timeout, but this will block the user interface and is not
 * recommended at all.
 *
 * Applications may query the current position and duration of the stream
 * via gst_element_query_position() and gst_element_query_duration() and
 * setting the format passed to GST_FORMAT_TIME. If the query was successful,
 * the duration or position will have been returned in units of nanoseconds.
 * </para>
 * </refsect2>
 * <refsect2>
 * <title>Advanced Usage: specifying the audio and video sink</title>
 * <para>
 * By default, if no audio sink or video sink has been specified via the
 * #GstPlayBin:audio-sink or #GstPlayBin:video-sink property, playbin will use the autoaudiosink
 * and autovideosink elements to find the first-best available output method.
 * This should work in most cases, but is not always desirable. Often either
 * the user or application might want to specify more explicitly what to use
 * for audio and video output.
 *
 * If the application wants more control over how audio or video should be
 * output, it may create the audio/video sink elements itself (for example
 * using gst_element_factory_make()) and provide them to playbin using the
 * #GstPlayBin:audio-sink or #GstPlayBin:video-sink property.
 *
 * GNOME-based applications, for example, will usually want to create
 * gconfaudiosink and gconfvideosink elements and make playbin use those,
 * so that output happens to whatever the user has configured in the GNOME
 * Multimedia System Selector configuration dialog.
 *
 * The sink elements do not necessarily need to be ready-made sinks. It is
 * possible to create container elements that look like a sink to playbin,
 * but in reality contain a number of custom elements linked together. This
 * can be achieved by creating a #GstBin and putting elements in there and
 * linking them, and then creating a sink #GstGhostPad for the bin and pointing
 * it to the sink pad of the first element within the bin. This can be used
 * for a number of purposes, for example to force output to a particular
 * format or to modify or observe the data before it is output.
 *
 * It is also possible to 'suppress' audio and/or video output by using
 * 'fakesink' elements (or capture it from there using the fakesink element's
 * "handoff" signal, which, nota bene, is fired from the streaming thread!).
 * </para>
 * </refsect2>
 * <refsect2>
 * <title>Retrieving Tags and Other Meta Data</title>
 * <para>
 * Most of the common meta data (artist, title, etc.) can be retrieved by
 * watching for TAG messages on the pipeline's bus (see above).
 *
 * Other more specific meta information like width/height/framerate of video
 * streams or samplerate/number of channels of audio streams can be obtained
 * from the negotiated caps on the sink pads of the sinks.
 * </para>
 * </refsect2>
 * <refsect2>
 * <title>Buffering</title>
 * Playbin handles buffering automatically for the most part, but applications
 * need to handle parts of the buffering process as well. Whenever playbin is
 * buffering, it will post BUFFERING messages on the bus with a percentage
 * value that shows the progress of the buffering process. Applications need
 * to set playbin to PLAYING or PAUSED state in response to these messages.
 * They may also want to convey the buffering progress to the user in some
 * way. Here is how to extract the percentage information from the message
 * (requires GStreamer >= 0.10.11):
 * |[
 * switch (GST_MESSAGE_TYPE (msg)) {
 *   case GST_MESSAGE_BUFFERING: {
 *     gint percent = 0;
 *     gst_message_parse_buffering (msg, &amp;percent);
 *     g_print ("Buffering (%%u percent done)", percent);
 *     break;
 *   }
 *   ...
 * }
 * ]|
 * Note that applications should keep/set the pipeline in the PAUSED state when
 * a BUFFERING message is received with a buffer percent value < 100 and set
 * the pipeline back to PLAYING state when a BUFFERING message with a value
 * of 100 percent is received (if PLAYING is the desired state, that is).
 * </refsect2>
 * <refsect2>
 * <title>Embedding the video window in your application</title>
 * By default, playbin (or rather the video sinks used) will create their own
 * window. Applications will usually want to force output to a window of their
 * own, however. This can be done using the #GstXOverlay interface, which most
 * video sinks implement. See the documentation there for more details.
 * </refsect2>
 * <refsect2>
 * <title>Specifying which CD/DVD device to use</title>
 * The device to use for CDs/DVDs needs to be set on the source element
 * playbin creates before it is opened. The only way to do this at the moment
 * is to connect to playbin's "notify::source" signal, which will be emitted
 * by playbin when it has created the source element for a particular URI.
 * In the signal callback you can check if the source element has a "device"
 * property and set it appropriately. In future ways might be added to specify
 * the device as part of the URI, but at the time of writing this is not
 * possible yet.
 * </refsect2>
 * <refsect2>
 * <title>Handling redirects</title>
 * <para>
 * Some elements may post 'redirect' messages on the bus to tell the
 * application to open another location. These are element messages containing
 * a structure named 'redirect' along with a 'new-location' field of string
 * type. The new location may be a relative or an absolute URI. Examples
 * for such redirects can be found in many quicktime movie trailers.
 * </para>
 * </refsect2>
 * <refsect2>
 * <title>Examples</title>
 * |[
 * gst-launch -v playbin uri=file:///path/to/somefile.avi
 * ]| This will play back the given AVI video file, given that the video and
 * audio decoders required to decode the content are installed. Since no
 * special audio sink or video sink is supplied (not possible via gst-launch),
 * playbin will try to find a suitable audio and video sink automatically
 * using the autoaudiosink and autovideosink elements.
 * |[
 * gst-launch -v playbin uri=cdda://4
 * ]| This will play back track 4 on an audio CD in your disc drive (assuming
 * the drive is detected automatically by the plugin).
 * |[
 * gst-launch -v playbin uri=dvd://1
 * ]| This will play back title 1 of a DVD in your disc drive (assuming
 * the drive is detected automatically by the plugin).
 * </refsect2>
 */

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

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

#include <gst/gst-i18n-plugin.h>
#include <gst/pbutils/pbutils.h>
#include <gst/interfaces/streamvolume.h>

#include "gstplay-enum.h"
#include "gstplay-marshal.h"
#include "gstplayback.h"
#include "gstplaysink.h"
#include "gstsubtitleoverlay.h"

GST_DEBUG_CATEGORY_STATIC (gst_play_bin_debug);
#define GST_CAT_DEFAULT gst_play_bin_debug

#define GST_TYPE_PLAY_BIN               (gst_play_bin_get_type())
#define GST_PLAY_BIN(obj)               (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_PLAY_BIN,GstPlayBin))
#define GST_PLAY_BIN_CLASS(klass)       (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_PLAY_BIN,GstPlayBinClass))
#define GST_IS_PLAY_BIN(obj)            (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_PLAY_BIN))
#define GST_IS_PLAY_BIN_CLASS(klass)    (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_PLAY_BIN))

#define VOLUME_MAX_DOUBLE 10.0

typedef struct _GstPlayBin GstPlayBin;
typedef struct _GstPlayBinClass GstPlayBinClass;
typedef struct _GstSourceGroup GstSourceGroup;
typedef struct _GstSourceSelect GstSourceSelect;

typedef GstCaps *(*SourceSelectGetMediaCapsFunc) (void);

/* has the info for a selector and provides the link to the sink */
struct _GstSourceSelect
{
  const gchar *media_list[8];   /* the media types for the selector */
  SourceSelectGetMediaCapsFunc get_media_caps;  /* more complex caps for the selector */
  GstPlaySinkType type;         /* the sink pad type of the selector */

  GstElement *selector;         /* the selector */
  GPtrArray *channels;
  GstPad *srcpad;               /* the source pad of the selector */
  GstPad *sinkpad;              /* the sinkpad of the sink when the selector
                                 * is linked
                                 */
  GstEvent *sinkpad_delayed_event;
  gulong sinkpad_data_probe;
  gulong block_id;
};

#define GST_SOURCE_GROUP_GET_LOCK(group) (((GstSourceGroup*)(group))->lock)
#define GST_SOURCE_GROUP_LOCK(group) (g_mutex_lock (GST_SOURCE_GROUP_GET_LOCK(group)))
#define GST_SOURCE_GROUP_UNLOCK(group) (g_mutex_unlock (GST_SOURCE_GROUP_GET_LOCK(group)))

enum
{
  PLAYBIN_STREAM_AUDIO = 0,
  PLAYBIN_STREAM_VIDEO,
  PLAYBIN_STREAM_TEXT,
  PLAYBIN_STREAM_LAST
};

/* a structure to hold the objects for decoding a uri and the subtitle uri
 */
struct _GstSourceGroup
{
  GstPlayBin *playbin;

  GMutex *lock;

  gboolean valid;               /* the group has valid info to start playback */
  gboolean active;              /* the group is active */

  /* properties */
  gchar *uri;
  gchar *suburi;
  GValueArray *streaminfo;
  GstElement *source;

  GPtrArray *video_channels;    /* links to selector pads */
  GPtrArray *audio_channels;    /* links to selector pads */
  GPtrArray *text_channels;     /* links to selector pads */

  GstElement *audio_sink;       /* autoplugged audio and video sinks */
  GstElement *video_sink;

  /* uridecodebins for uri and subtitle uri */
  GstElement *uridecodebin;
  GstElement *suburidecodebin;
  gint pending;
  gboolean sub_pending;

  gulong pad_added_id;
  gulong pad_removed_id;
  gulong no_more_pads_id;
  gulong notify_source_id;
  gulong drained_id;
  gulong autoplug_factories_id;
  gulong autoplug_select_id;
  gulong autoplug_continue_id;

  gulong sub_pad_added_id;
  gulong sub_pad_removed_id;
  gulong sub_no_more_pads_id;
  gulong sub_autoplug_continue_id;

  gulong block_id;

  GMutex *stream_changed_pending_lock;
  GList *stream_changed_pending;

  /* selectors for different streams */
  GstSourceSelect selector[PLAYBIN_STREAM_LAST];
};

#define GST_PLAY_BIN_GET_LOCK(bin) (&((GstPlayBin*)(bin))->lock)
#define GST_PLAY_BIN_LOCK(bin) (g_static_rec_mutex_lock (GST_PLAY_BIN_GET_LOCK(bin)))
#define GST_PLAY_BIN_UNLOCK(bin) (g_static_rec_mutex_unlock (GST_PLAY_BIN_GET_LOCK(bin)))

/* lock to protect dynamic callbacks, like no-more-pads */
#define GST_PLAY_BIN_DYN_LOCK(bin)    g_mutex_lock ((bin)->dyn_lock)
#define GST_PLAY_BIN_DYN_UNLOCK(bin)  g_mutex_unlock ((bin)->dyn_lock)

/* lock for shutdown */
#define GST_PLAY_BIN_SHUTDOWN_LOCK(bin,label)           \
G_STMT_START {                                          \
  if (G_UNLIKELY (g_atomic_int_get (&bin->shutdown)))   \
    goto label;                                         \
  GST_PLAY_BIN_DYN_LOCK (bin);                          \
  if (G_UNLIKELY (g_atomic_int_get (&bin->shutdown))) { \
    GST_PLAY_BIN_DYN_UNLOCK (bin);                      \
    goto label;                                         \
  }                                                     \
} G_STMT_END

/* unlock for shutdown */
#define GST_PLAY_BIN_SHUTDOWN_UNLOCK(bin)         \
  GST_PLAY_BIN_DYN_UNLOCK (bin);                  \

/**
 * GstPlayBin:
 *
 * playbin element structure
 */
struct _GstPlayBin
{
  GstPipeline parent;

  GStaticRecMutex lock;         /* to protect group switching */

  /* the groups, we use a double buffer to switch between current and next */
  GstSourceGroup groups[2];     /* array with group info */
  GstSourceGroup *curr_group;   /* pointer to the currently playing group */
  GstSourceGroup *next_group;   /* pointer to the next group */

  /* properties */
  guint connection_speed;       /* connection speed in bits/sec (0 = unknown) */
  gint current_video;           /* the currently selected stream */
  gint current_audio;           /* the currently selected stream */
  gint current_text;            /* the currently selected stream */

  guint64 buffer_duration;      /* When buffering, the max buffer duration (ns) */
  guint buffer_size;            /* When buffering, the max buffer size (bytes) */

  /* our play sink */
  GstPlaySink *playsink;

  /* the last activated source */
  GstElement *source;

  /* lock protecting dynamic adding/removing */
  GMutex *dyn_lock;
  /* if we are shutting down or not */
  gint shutdown;

  GMutex *elements_lock;
  guint32 elements_cookie;
  GList *elements;              /* factories we can use for selecting elements */

  gboolean have_selector;       /* set to FALSE when we fail to create an
                                 * input-selector, so that we only post a
                                 * warning once */

  GstElement *audio_sink;       /* configured audio sink, or NULL      */
  GstElement *video_sink;       /* configured video sink, or NULL      */
  GstElement *text_sink;        /* configured text sink, or NULL       */

  struct
  {
    gboolean valid;
    GstFormat format;
    gint64 duration;
  } duration[5];                /* cached durations */

  guint64 ring_buffer_max_size; /* 0 means disabled */
};

struct _GstPlayBinClass
{
  GstPipelineClass parent_class;

  /* notify app that the current uri finished decoding and it is possible to
   * queue a new one for gapless playback */
  void (*about_to_finish) (GstPlayBin * playbin);

  /* notify app that number of audio/video/text streams changed */
  void (*video_changed) (GstPlayBin * playbin);
  void (*audio_changed) (GstPlayBin * playbin);
  void (*text_changed) (GstPlayBin * playbin);

  /* notify app that the tags of audio/video/text streams changed */
  void (*video_tags_changed) (GstPlayBin * playbin, gint stream);
  void (*audio_tags_changed) (GstPlayBin * playbin, gint stream);
  void (*text_tags_changed) (GstPlayBin * playbin, gint stream);

  /* get audio/video/text tags for a stream */
  GstTagList *(*get_video_tags) (GstPlayBin * playbin, gint stream);
  GstTagList *(*get_audio_tags) (GstPlayBin * playbin, gint stream);
  GstTagList *(*get_text_tags) (GstPlayBin * playbin, gint stream);

  /* get the last video frame and convert it to the given caps */
  GstBuffer *(*convert_frame) (GstPlayBin * playbin, GstCaps * caps);

  /* get audio/video/text pad for a stream */
  GstPad *(*get_video_pad) (GstPlayBin * playbin, gint stream);
  GstPad *(*get_audio_pad) (GstPlayBin * playbin, gint stream);
  GstPad *(*get_text_pad) (GstPlayBin * playbin, gint stream);
};

/* props */
#define DEFAULT_URI               NULL
#define DEFAULT_SUBURI            NULL
#define DEFAULT_SOURCE            NULL
#define DEFAULT_FLAGS             GST_PLAY_FLAG_AUDIO | GST_PLAY_FLAG_VIDEO | GST_PLAY_FLAG_TEXT | \
                                  GST_PLAY_FLAG_SOFT_VOLUME
#define DEFAULT_N_VIDEO           0
#define DEFAULT_CURRENT_VIDEO     -1
#define DEFAULT_N_AUDIO           0
#define DEFAULT_CURRENT_AUDIO     -1
#define DEFAULT_N_TEXT            0
#define DEFAULT_CURRENT_TEXT      -1
#define DEFAULT_SUBTITLE_ENCODING NULL
#define DEFAULT_AUDIO_SINK        NULL
#define DEFAULT_VIDEO_SINK        NULL
#define DEFAULT_VIS_PLUGIN        NULL
#define DEFAULT_TEXT_SINK         NULL
#define DEFAULT_VOLUME            1.0
#define DEFAULT_MUTE              FALSE
#define DEFAULT_FRAME             NULL
#define DEFAULT_FONT_DESC         NULL
#define DEFAULT_CONNECTION_SPEED  0
#define DEFAULT_BUFFER_DURATION   -1
#define DEFAULT_BUFFER_SIZE       -1
#define DEFAULT_RING_BUFFER_MAX_SIZE 0

enum
{
  PROP_0,
  PROP_URI,
  PROP_SUBURI,
  PROP_SOURCE,
  PROP_FLAGS,
  PROP_N_VIDEO,
  PROP_CURRENT_VIDEO,
  PROP_N_AUDIO,
  PROP_CURRENT_AUDIO,
  PROP_N_TEXT,
  PROP_CURRENT_TEXT,
  PROP_SUBTITLE_ENCODING,
  PROP_AUDIO_SINK,
  PROP_VIDEO_SINK,
  PROP_VIS_PLUGIN,
  PROP_TEXT_SINK,
  PROP_VOLUME,
  PROP_MUTE,
  PROP_FRAME,
  PROP_FONT_DESC,
  PROP_CONNECTION_SPEED,
  PROP_BUFFER_SIZE,
  PROP_BUFFER_DURATION,
  PROP_AV_OFFSET,
  PROP_RING_BUFFER_MAX_SIZE,
  PROP_LAST
};

/* signals */
enum
{
  SIGNAL_ABOUT_TO_FINISH,
  SIGNAL_CONVERT_FRAME,
  SIGNAL_VIDEO_CHANGED,
  SIGNAL_AUDIO_CHANGED,
  SIGNAL_TEXT_CHANGED,
  SIGNAL_VIDEO_TAGS_CHANGED,
  SIGNAL_AUDIO_TAGS_CHANGED,
  SIGNAL_TEXT_TAGS_CHANGED,
  SIGNAL_GET_VIDEO_TAGS,
  SIGNAL_GET_AUDIO_TAGS,
  SIGNAL_GET_TEXT_TAGS,
  SIGNAL_GET_VIDEO_PAD,
  SIGNAL_GET_AUDIO_PAD,
  SIGNAL_GET_TEXT_PAD,
  SIGNAL_SOURCE_SETUP,
  LAST_SIGNAL
};

static void gst_play_bin_class_init (GstPlayBinClass * klass);
static void gst_play_bin_init (GstPlayBin * playbin);
static void gst_play_bin_finalize (GObject * object);

static void gst_play_bin_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * spec);
static void gst_play_bin_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * spec);

static GstStateChangeReturn gst_play_bin_change_state (GstElement * element,
    GstStateChange transition);

static void gst_play_bin_handle_message (GstBin * bin, GstMessage * message);
static gboolean gst_play_bin_query (GstElement * element, GstQuery * query);

static GstTagList *gst_play_bin_get_video_tags (GstPlayBin * playbin,
    gint stream);
static GstTagList *gst_play_bin_get_audio_tags (GstPlayBin * playbin,
    gint stream);
static GstTagList *gst_play_bin_get_text_tags (GstPlayBin * playbin,
    gint stream);

static GstBuffer *gst_play_bin_convert_frame (GstPlayBin * playbin,
    GstCaps * caps);

static GstPad *gst_play_bin_get_video_pad (GstPlayBin * playbin, gint stream);
static GstPad *gst_play_bin_get_audio_pad (GstPlayBin * playbin, gint stream);
static GstPad *gst_play_bin_get_text_pad (GstPlayBin * playbin, gint stream);

static gboolean setup_next_source (GstPlayBin * playbin, GstState target);

static void no_more_pads_cb (GstElement * decodebin, GstSourceGroup * group);
static void pad_removed_cb (GstElement * decodebin, GstPad * pad,
    GstSourceGroup * group);

static void gst_play_bin_suburidecodebin_block (GstSourceGroup * group,
    GstElement * suburidecodebin, gboolean block);
static void gst_play_bin_suburidecodebin_seek_to_start (GstElement *
    suburidecodebin);

static GstElementClass *parent_class;

static guint gst_play_bin_signals[LAST_SIGNAL] = { 0 };

#define REMOVE_SIGNAL(obj,id)            \
if (id) {                                \
  g_signal_handler_disconnect (obj, id); \
  id = 0;                                \
}

static GType
gst_play_bin_get_type (void)
{
  static GType gst_play_bin_type = 0;

  if (!gst_play_bin_type) {
    static const GTypeInfo gst_play_bin_info = {
      sizeof (GstPlayBinClass),
      NULL,
      NULL,
      (GClassInitFunc) gst_play_bin_class_init,
      NULL,
      NULL,
      sizeof (GstPlayBin),
      0,
      (GInstanceInitFunc) gst_play_bin_init,
      NULL
    };
    static const GInterfaceInfo svol_info = {
      NULL, NULL, NULL
    };

    gst_play_bin_type = g_type_register_static (GST_TYPE_PIPELINE,
        "GstPlayBin", &gst_play_bin_info, 0);

    g_type_add_interface_static (gst_play_bin_type, GST_TYPE_STREAM_VOLUME,
        &svol_info);
  }

  return gst_play_bin_type;
}

static void
gst_play_bin_class_init (GstPlayBinClass * 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->set_property = gst_play_bin_set_property;
  gobject_klass->get_property = gst_play_bin_get_property;

  gobject_klass->finalize = gst_play_bin_finalize;

  /**
   * GstPlayBin:uri
   *
   * Set the next URI that playbin will play. This property can be set from the
   * about-to-finish signal to queue the next media file.
   */
  g_object_class_install_property (gobject_klass, PROP_URI,
      g_param_spec_string ("uri", "URI", "URI of the media to play",
          NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstPlayBin:suburi
   *
   * Set the next subtitle URI that playbin will play. This property can be
   * set from the about-to-finish signal to queue the next subtitle media file.
   */
  g_object_class_install_property (gobject_klass, PROP_SUBURI,
      g_param_spec_string ("suburi", ".sub-URI", "Optional URI of a subtitle",
          NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_klass, PROP_SOURCE,
      g_param_spec_object ("source", "Source", "Source element",
          GST_TYPE_ELEMENT, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));

  /**
   * GstPlayBin:flags
   *
   * Control the behaviour of playbin.
   */
  g_object_class_install_property (gobject_klass, PROP_FLAGS,
      g_param_spec_flags ("flags", "Flags", "Flags to control behaviour",
          GST_TYPE_PLAY_FLAGS, DEFAULT_FLAGS,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstPlayBin:n-video
   *
   * Get the total number of available video streams.
   */
  g_object_class_install_property (gobject_klass, PROP_N_VIDEO,
      g_param_spec_int ("n-video", "Number Video",
          "Total number of video streams", 0, G_MAXINT, 0,
          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
  /**
   * GstPlayBin:current-video
   *
   * Get or set the currently playing video stream. By default the first video
   * stream with data is played.
   */
  g_object_class_install_property (gobject_klass, PROP_CURRENT_VIDEO,
      g_param_spec_int ("current-video", "Current Video",
          "Currently playing video stream (-1 = auto)",
          -1, G_MAXINT, -1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  /**
   * GstPlayBin:n-audio
   *
   * Get the total number of available audio streams.
   */
  g_object_class_install_property (gobject_klass, PROP_N_AUDIO,
      g_param_spec_int ("n-audio", "Number Audio",
          "Total number of audio streams", 0, G_MAXINT, 0,
          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
  /**
   * GstPlayBin:current-audio
   *
   * Get or set the currently playing audio stream. By default the first audio
   * stream with data is played.
   */
  g_object_class_install_property (gobject_klass, PROP_CURRENT_AUDIO,
      g_param_spec_int ("current-audio", "Current audio",
          "Currently playing audio stream (-1 = auto)",
          -1, G_MAXINT, -1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  /**
   * GstPlayBin:n-text
   *
   * Get the total number of available subtitle streams.
   */
  g_object_class_install_property (gobject_klass, PROP_N_TEXT,
      g_param_spec_int ("n-text", "Number Text",
          "Total number of text streams", 0, G_MAXINT, 0,
          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
  /**
   * GstPlayBin:current-text:
   *
   * Get or set the currently playing subtitle stream. By default the first
   * subtitle stream with data is played.
   */
  g_object_class_install_property (gobject_klass, PROP_CURRENT_TEXT,
      g_param_spec_int ("current-text", "Current Text",
          "Currently playing text stream (-1 = auto)",
          -1, G_MAXINT, -1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  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 | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_klass, PROP_VIDEO_SINK,
      g_param_spec_object ("video-sink", "Video Sink",
          "the video output element to use (NULL = default sink)",
          GST_TYPE_ELEMENT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_klass, PROP_AUDIO_SINK,
      g_param_spec_object ("audio-sink", "Audio Sink",
          "the audio output element to use (NULL = default sink)",
          GST_TYPE_ELEMENT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_klass, PROP_VIS_PLUGIN,
      g_param_spec_object ("vis-plugin", "Vis plugin",
          "the visualization element to use (NULL = default)",
          GST_TYPE_ELEMENT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_klass, PROP_TEXT_SINK,
      g_param_spec_object ("text-sink", "Text plugin",
          "the text output element to use (NULL = default textoverlay)",
          GST_TYPE_ELEMENT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstPlayBin:volume:
   *
   * Get or set the current audio stream volume. 1.0 means 100%,
   * 0.0 means mute. This uses a linear volume scale.
   *
   */
  g_object_class_install_property (gobject_klass, PROP_VOLUME,
      g_param_spec_double ("volume", "Volume", "The audio volume, 1.0=100%",
          0.0, VOLUME_MAX_DOUBLE, 1.0,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_klass, PROP_MUTE,
      g_param_spec_boolean ("mute", "Mute",
          "Mute the audio channel without changing the volume", FALSE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstPlayBin:frame:
   * @playbin: a #GstPlayBin
   *
   * Get the currently rendered or prerolled frame in the video sink.
   * The #GstCaps on the buffer will describe the format of the buffer.
   */
  g_object_class_install_property (gobject_klass, PROP_FRAME,
      g_param_spec_boxed ("frame", "Frame",
          "The last frame (NULL = no video available)",
          GST_TYPE_BUFFER, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_klass, PROP_FONT_DESC,
      g_param_spec_string ("subtitle-font-desc",
          "Subtitle font description",
          "Pango font description of font "
          "to be used for subtitle rendering", NULL,
          G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_klass, PROP_CONNECTION_SPEED,
      g_param_spec_uint ("connection-speed", "Connection Speed",
          "Network connection speed in kbps (0 = unknown)",
          0, G_MAXUINT / 1000, DEFAULT_CONNECTION_SPEED,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_klass, PROP_BUFFER_SIZE,
      g_param_spec_int ("buffer-size", "Buffer size (bytes)",
          "Buffer size when buffering network streams",
          -1, G_MAXINT, DEFAULT_BUFFER_SIZE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_klass, PROP_BUFFER_DURATION,
      g_param_spec_int64 ("buffer-duration", "Buffer duration (ns)",
          "Buffer duration when buffering network streams",
          -1, G_MAXINT64, DEFAULT_BUFFER_DURATION,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  /**
   * GstPlayBin:av-offset:
   *
   * Control the synchronisation offset between the audio and video streams.
   * Positive values make the audio ahead of the video and negative values make
   * the audio go behind the video.
   *
   * Since: 0.10.30
   */
  g_object_class_install_property (gobject_klass, PROP_AV_OFFSET,
      g_param_spec_int64 ("av-offset", "AV Offset",
          "The synchronisation offset between audio and video in nanoseconds",
          G_MININT64, G_MAXINT64, 0,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstQueue2:ring-buffer-max-size
   *
   * The maximum size of the ring buffer in bytes. If set to 0, the ring
   * buffer is disabled. Default 0.
   *
   * Since: 0.10.31
   */
  g_object_class_install_property (gobject_klass, PROP_RING_BUFFER_MAX_SIZE,
      g_param_spec_uint64 ("ring-buffer-max-size",
          "Max. ring buffer size (bytes)",
          "Max. amount of data in the ring buffer (bytes, 0 = ring buffer disabled)",
          0, G_MAXUINT, DEFAULT_RING_BUFFER_MAX_SIZE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstPlayBin::about-to-finish
   * @playbin: a #GstPlayBin
   *
   * This signal is emitted when the current uri is about to finish. You can
   * set the uri and suburi to make sure that playback continues.
   */
  gst_play_bin_signals[SIGNAL_ABOUT_TO_FINISH] =
      g_signal_new ("about-to-finish", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayBinClass, about_to_finish), NULL, NULL,
      gst_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);

  /**
   * GstPlayBin::video-changed
   * @playbin: a #GstPlayBin
   *
   * This signal is emitted whenever the number or order of the video
   * streams has changed. The application will most likely want to select
   * a new video stream.
   */
  gst_play_bin_signals[SIGNAL_VIDEO_CHANGED] =
      g_signal_new ("video-changed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayBinClass, video_changed), NULL, NULL,
      gst_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
  /**
   * GstPlayBin::audio-changed
   * @playbin: a #GstPlayBin
   *
   * This signal is emitted whenever the number or order of the audio
   * streams has changed. The application will most likely want to select
   * a new audio stream.
   */
  gst_play_bin_signals[SIGNAL_AUDIO_CHANGED] =
      g_signal_new ("audio-changed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayBinClass, audio_changed), NULL, NULL,
      gst_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
  /**
   * GstPlayBin::text-changed
   * @playbin: a #GstPlayBin
   *
   * This signal is emitted whenever the number or order of the text
   * streams has changed. The application will most likely want to select
   * a new text stream.
   */
  gst_play_bin_signals[SIGNAL_TEXT_CHANGED] =
      g_signal_new ("text-changed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayBinClass, text_changed), NULL, NULL,
      gst_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);

  /**
   * GstPlayBin::video-tags-changed
   * @playbin: a #GstPlayBin
   * @stream: stream index with changed tags
   *
   * This signal is emitted whenever the tags of a video stream have changed.
   * The application will most likely want to get the new tags.
   *
   * Since: 0.10.24
   */
  gst_play_bin_signals[SIGNAL_VIDEO_TAGS_CHANGED] =
      g_signal_new ("video-tags-changed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayBinClass, video_tags_changed), NULL, NULL,
      gst_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);

  /**
   * GstPlayBin::audio-tags-changed
   * @playbin: a #GstPlayBin
   * @stream: stream index with changed tags
   *
   * This signal is emitted whenever the tags of an audio stream have changed.
   * The application will most likely want to get the new tags.
   *
   * Since: 0.10.24
   */
  gst_play_bin_signals[SIGNAL_AUDIO_TAGS_CHANGED] =
      g_signal_new ("audio-tags-changed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayBinClass, audio_tags_changed), NULL, NULL,
      gst_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);

  /**
   * GstPlayBin::text-tags-changed
   * @playbin: a #GstPlayBin
   * @stream: stream index with changed tags
   *
   * This signal is emitted whenever the tags of a text stream have changed.
   * The application will most likely want to get the new tags.
   *
   * Since: 0.10.24
   */
  gst_play_bin_signals[SIGNAL_TEXT_TAGS_CHANGED] =
      g_signal_new ("text-tags-changed", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST,
      G_STRUCT_OFFSET (GstPlayBinClass, text_tags_changed), NULL, NULL,
      gst_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);

  /**
   * GstPlayBin::source-setup:
   * @playbin: a #GstPlayBin
   * @source: source element
   *
   * This signal is emitted after the source element has been created, so
   * it can be configured by setting additional properties (e.g. set a
   * proxy server for an http source, or set the device and read speed for
   * an audio cd source). This is functionally equivalent to connecting to
   * the notify::source signal, but more convenient.
   *
   * Since: 0.10.33
   */
  gst_play_bin_signals[SIGNAL_SOURCE_SETUP] =
      g_signal_new ("source-setup", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, 0, NULL, NULL,
      gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);

  /**
   * GstPlayBin::get-video-tags
   * @playbin: a #GstPlayBin
   * @stream: a video stream number
   *
   * Action signal to retrieve the tags of a specific video stream number.
   * This information can be used to select a stream.
   *
   * Returns: a GstTagList with tags or NULL when the stream number does not
   * exist.
   */
  gst_play_bin_signals[SIGNAL_GET_VIDEO_TAGS] =
      g_signal_new ("get-video-tags", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
      G_STRUCT_OFFSET (GstPlayBinClass, get_video_tags), NULL, NULL,
      gst_play_marshal_BOXED__INT, GST_TYPE_TAG_LIST, 1, G_TYPE_INT);
  /**
   * GstPlayBin::get-audio-tags
   * @playbin: a #GstPlayBin
   * @stream: an audio stream number
   *
   * Action signal to retrieve the tags of a specific audio stream number.
   * This information can be used to select a stream.
   *
   * Returns: a GstTagList with tags or NULL when the stream number does not
   * exist.
   */
  gst_play_bin_signals[SIGNAL_GET_AUDIO_TAGS] =
      g_signal_new ("get-audio-tags", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
      G_STRUCT_OFFSET (GstPlayBinClass, get_audio_tags), NULL, NULL,
      gst_play_marshal_BOXED__INT, GST_TYPE_TAG_LIST, 1, G_TYPE_INT);
  /**
   * GstPlayBin::get-text-tags
   * @playbin: a #GstPlayBin
   * @stream: a text stream number
   *
   * Action signal to retrieve the tags of a specific text stream number.
   * This information can be used to select a stream.
   *
   * Returns: a GstTagList with tags or NULL when the stream number does not
   * exist.
   */
  gst_play_bin_signals[SIGNAL_GET_TEXT_TAGS] =
      g_signal_new ("get-text-tags", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
      G_STRUCT_OFFSET (GstPlayBinClass, get_text_tags), NULL, NULL,
      gst_play_marshal_BOXED__INT, GST_TYPE_TAG_LIST, 1, G_TYPE_INT);
  /**
   * GstPlayBin::convert-frame
   * @playbin: a #GstPlayBin
   * @caps: the target format of the frame
   *
   * Action signal to retrieve the currently playing video frame in the format
   * specified by @caps.
   * If @caps is %NULL, no conversion will be performed and this function is
   * equivalent to the #GstPlayBin::frame property.
   *
   * Returns: a #GstBuffer of the current video frame converted to #caps.
   * The caps on the buffer will describe the final layout of the buffer data.
   * %NULL is returned when no current buffer can be retrieved or when the
   * conversion failed.
   */
  gst_play_bin_signals[SIGNAL_CONVERT_FRAME] =
      g_signal_new ("convert-frame", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
      G_STRUCT_OFFSET (GstPlayBinClass, convert_frame), NULL, NULL,
      gst_play_marshal_BUFFER__BOXED, GST_TYPE_BUFFER, 1, GST_TYPE_CAPS);

  /**
   * GstPlayBin::get-video-pad
   * @playbin: a #GstPlayBin
   * @stream: a video stream number
   *
   * Action signal to retrieve the stream-selector sinkpad for a specific
   * video stream.
   * This pad can be used for notifications of caps changes, stream-specific
   * queries, etc.
   *
   * Returns: a #GstPad, or NULL when the stream number does not exist.
   */
  gst_play_bin_signals[SIGNAL_GET_VIDEO_PAD] =
      g_signal_new ("get-video-pad", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
      G_STRUCT_OFFSET (GstPlayBinClass, get_video_pad), NULL, NULL,
      gst_play_marshal_OBJECT__INT, GST_TYPE_PAD, 1, G_TYPE_INT);
  /**
   * GstPlayBin::get-audio-pad
   * @playbin: a #GstPlayBin
   * @stream: an audio stream number
   *
   * Action signal to retrieve the stream-selector sinkpad for a specific
   * audio stream.
   * This pad can be used for notifications of caps changes, stream-specific
   * queries, etc.
   *
   * Returns: a #GstPad, or NULL when the stream number does not exist.
   */
  gst_play_bin_signals[SIGNAL_GET_AUDIO_PAD] =
      g_signal_new ("get-audio-pad", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
      G_STRUCT_OFFSET (GstPlayBinClass, get_audio_pad), NULL, NULL,
      gst_play_marshal_OBJECT__INT, GST_TYPE_PAD, 1, G_TYPE_INT);
  /**
   * GstPlayBin::get-text-pad
   * @playbin: a #GstPlayBin
   * @stream: a text stream number
   *
   * Action signal to retrieve the stream-selector sinkpad for a specific
   * text stream.
   * This pad can be used for notifications of caps changes, stream-specific
   * queries, etc.
   *
   * Returns: a #GstPad, or NULL when the stream number does not exist.
   */
  gst_play_bin_signals[SIGNAL_GET_TEXT_PAD] =
      g_signal_new ("get-text-pad", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
      G_STRUCT_OFFSET (GstPlayBinClass, get_text_pad), NULL, NULL,
      gst_play_marshal_OBJECT__INT, GST_TYPE_PAD, 1, G_TYPE_INT);

  klass->get_video_tags = gst_play_bin_get_video_tags;
  klass->get_audio_tags = gst_play_bin_get_audio_tags;
  klass->get_text_tags = gst_play_bin_get_text_tags;

  klass->convert_frame = gst_play_bin_convert_frame;

  klass->get_video_pad = gst_play_bin_get_video_pad;
  klass->get_audio_pad = gst_play_bin_get_audio_pad;
  klass->get_text_pad = gst_play_bin_get_text_pad;

  gst_element_class_set_details_simple (gstelement_klass,
      "Player Bin 2", "Generic/Bin/Player",
      "Autoplug and play media from an uri",
      "Wim Taymans <wim.taymans@gmail.com>");

  gstelement_klass->change_state =
      GST_DEBUG_FUNCPTR (gst_play_bin_change_state);
  gstelement_klass->query = GST_DEBUG_FUNCPTR (gst_play_bin_query);

  gstbin_klass->handle_message =
      GST_DEBUG_FUNCPTR (gst_play_bin_handle_message);
}

static void
init_group (GstPlayBin * playbin, GstSourceGroup * group)
{
  int n;

  /* store the array for the different channels */
  group->video_channels = g_ptr_array_new ();
  group->audio_channels = g_ptr_array_new ();
  group->text_channels = g_ptr_array_new ();
  group->lock = g_mutex_new ();
  /* init selectors. The selector is found by finding the first prefix that
   * matches the media. */
  group->playbin = playbin;
  /* If you add any items to these lists, check that media_list[] is defined
   * above to be large enough to hold MAX(items)+1, so as to accomodate a
   * NULL terminator (set when the memory is zeroed on allocation) */
  group->selector[PLAYBIN_STREAM_AUDIO].media_list[0] = "audio/";
  group->selector[PLAYBIN_STREAM_AUDIO].type = GST_PLAY_SINK_TYPE_AUDIO;
  group->selector[PLAYBIN_STREAM_AUDIO].channels = group->audio_channels;
  group->selector[PLAYBIN_STREAM_VIDEO].media_list[0] = "video/";
  group->selector[PLAYBIN_STREAM_VIDEO].type = GST_PLAY_SINK_TYPE_VIDEO;
  group->selector[PLAYBIN_STREAM_VIDEO].channels = group->video_channels;
  group->selector[PLAYBIN_STREAM_TEXT].media_list[0] = "text/";
  group->selector[PLAYBIN_STREAM_TEXT].media_list[1] = "application/x-subtitle";
  group->selector[PLAYBIN_STREAM_TEXT].media_list[2] = "application/x-ssa";
  group->selector[PLAYBIN_STREAM_TEXT].media_list[3] = "application/x-ass";
  group->selector[PLAYBIN_STREAM_TEXT].media_list[4] = "video/x-dvd-subpicture";
  group->selector[PLAYBIN_STREAM_TEXT].media_list[5] = "subpicture/";
  group->selector[PLAYBIN_STREAM_TEXT].media_list[6] = "subtitle/";
  group->selector[PLAYBIN_STREAM_TEXT].get_media_caps =
      gst_subtitle_overlay_create_factory_caps;
  group->selector[PLAYBIN_STREAM_TEXT].type = GST_PLAY_SINK_TYPE_TEXT;
  group->selector[PLAYBIN_STREAM_TEXT].channels = group->text_channels;

  for (n = 0; n < PLAYBIN_STREAM_LAST; n++) {
    GstSourceSelect *select = &group->selector[n];
    select->sinkpad_delayed_event = NULL;
    select->sinkpad_data_probe = 0;
  }
}

static void
free_group (GstPlayBin * playbin, GstSourceGroup * group)
{
  int n;

  for (n = 0; n < PLAYBIN_STREAM_LAST; n++) {
    GstSourceSelect *select = &group->selector[n];
    if (select->sinkpad && select->sinkpad_data_probe)
      gst_pad_remove_probe (select->sinkpad, select->sinkpad_data_probe);
    if (select->sinkpad_delayed_event)
      gst_event_unref (select->sinkpad_delayed_event);
  }

  g_free (group->uri);
  g_free (group->suburi);
  g_ptr_array_free (group->video_channels, TRUE);
  g_ptr_array_free (group->audio_channels, TRUE);
  g_ptr_array_free (group->text_channels, TRUE);

  g_mutex_free (group->lock);
  if (group->audio_sink) {
    if (group->audio_sink != playbin->audio_sink)
      gst_element_set_state (group->audio_sink, GST_STATE_NULL);
    gst_object_unref (group->audio_sink);
  }
  group->audio_sink = NULL;
  if (group->video_sink) {
    if (group->video_sink != playbin->video_sink)
      gst_element_set_state (group->video_sink, GST_STATE_NULL);
    gst_object_unref (group->video_sink);
  }
  group->video_sink = NULL;

  g_list_free (group->stream_changed_pending);
  group->stream_changed_pending = NULL;

  if (group->stream_changed_pending_lock)
    g_mutex_free (group->stream_changed_pending_lock);
  group->stream_changed_pending_lock = NULL;
}

static void
notify_volume_cb (GObject * selector, GParamSpec * pspec, GstPlayBin * playbin)
{
  g_object_notify (G_OBJECT (playbin), "volume");
}

static void
notify_mute_cb (GObject * selector, GParamSpec * pspec, GstPlayBin * playbin)
{
  g_object_notify (G_OBJECT (playbin), "mute");
}

/* Must be called with elements lock! */
static void
gst_play_bin_update_elements_list (GstPlayBin * playbin)
{
  GList *res, *tmp;

  if (!playbin->elements ||
      playbin->elements_cookie !=
      gst_default_registry_get_feature_list_cookie ()) {
    if (playbin->elements)
      gst_plugin_feature_list_free (playbin->elements);
    res =
        gst_element_factory_list_get_elements
        (GST_ELEMENT_FACTORY_TYPE_DECODABLE, GST_RANK_MARGINAL);
    tmp =
        gst_element_factory_list_get_elements
        (GST_ELEMENT_FACTORY_TYPE_AUDIOVIDEO_SINKS, GST_RANK_MARGINAL);
    playbin->elements = g_list_concat (res, tmp);
    playbin->elements =
        g_list_sort (playbin->elements, gst_plugin_feature_rank_compare_func);
    playbin->elements_cookie = gst_default_registry_get_feature_list_cookie ();
  }
}

static void
gst_play_bin_init (GstPlayBin * playbin)
{
  g_static_rec_mutex_init (&playbin->lock);
  playbin->dyn_lock = g_mutex_new ();

  /* assume we can create a selector */
  playbin->have_selector = TRUE;

  /* init groups */
  playbin->curr_group = &playbin->groups[0];
  playbin->next_group = &playbin->groups[1];
  init_group (playbin, &playbin->groups[0]);
  init_group (playbin, &playbin->groups[1]);

  /* first filter out the interesting element factories */
  playbin->elements_lock = g_mutex_new ();

  /* add sink */
  playbin->playsink = g_object_new (GST_TYPE_PLAY_SINK, NULL);
  gst_bin_add (GST_BIN_CAST (playbin), GST_ELEMENT_CAST (playbin->playsink));
  gst_play_sink_set_flags (playbin->playsink, DEFAULT_FLAGS);
  /* Connect to notify::volume and notify::mute signals for proxying */
  g_signal_connect (playbin->playsink, "notify::volume",
      G_CALLBACK (notify_volume_cb), playbin);
  g_signal_connect (playbin->playsink, "notify::mute",
      G_CALLBACK (notify_mute_cb), playbin);

  playbin->current_video = DEFAULT_CURRENT_VIDEO;
  playbin->current_audio = DEFAULT_CURRENT_AUDIO;
  playbin->current_text = DEFAULT_CURRENT_TEXT;

  playbin->buffer_duration = DEFAULT_BUFFER_DURATION;
  playbin->buffer_size = DEFAULT_BUFFER_SIZE;
  playbin->ring_buffer_max_size = DEFAULT_RING_BUFFER_MAX_SIZE;
}

static void
gst_play_bin_finalize (GObject * object)
{
  GstPlayBin *playbin;

  playbin = GST_PLAY_BIN (object);

  free_group (playbin, &playbin->groups[0]);
  free_group (playbin, &playbin->groups[1]);

  if (playbin->source)
    gst_object_unref (playbin->source);
  if (playbin->video_sink) {
    gst_element_set_state (playbin->video_sink, GST_STATE_NULL);
    gst_object_unref (playbin->video_sink);
  }
  if (playbin->audio_sink) {
    gst_element_set_state (playbin->audio_sink, GST_STATE_NULL);
    gst_object_unref (playbin->audio_sink);
  }
  if (playbin->text_sink) {
    gst_element_set_state (playbin->text_sink, GST_STATE_NULL);
    gst_object_unref (playbin->text_sink);
  }

  if (playbin->elements)
    gst_plugin_feature_list_free (playbin->elements);

  g_static_rec_mutex_free (&playbin->lock);
  g_mutex_free (playbin->dyn_lock);
  g_mutex_free (playbin->elements_lock);

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

static gboolean
gst_playbin_uri_is_valid (GstPlayBin * playbin, const gchar * uri)
{
  const gchar *c;

  GST_LOG_OBJECT (playbin, "checking uri '%s'", uri);

  /* this just checks the protocol */
  if (!gst_uri_is_valid (uri))
    return FALSE;

  for (c = uri; *c != '\0'; ++c) {
    if (!g_ascii_isprint (*c))
      goto invalid;
    if (*c == ' ')
      goto invalid;
  }

  return TRUE;

invalid:
  {
    GST_WARNING_OBJECT (playbin, "uri '%s' not valid, character #%u",
        uri, (guint) ((guintptr) c - (guintptr) uri));
    return FALSE;
  }
}

static void
gst_play_bin_set_uri (GstPlayBin * playbin, const gchar * uri)
{
  GstSourceGroup *group;

  if (uri == NULL) {
    g_warning ("cannot set NULL uri");
    return;
  }

  if (!gst_playbin_uri_is_valid (playbin, uri)) {
    if (g_str_has_prefix (uri, "file:")) {
      GST_ERROR_OBJECT (playbin, "malformed file URI '%s' - make sure to "
          "escape spaces and non-ASCII characters properly and specify an "
          "absolute path. Use gst_filename_to_uri() to convert filenames "
          "to URIs", uri);
    } else {
      GST_ERROR_OBJECT (playbin, "malformed URI '%s'", uri);
    }
  }

  GST_PLAY_BIN_LOCK (playbin);
  group = playbin->next_group;

  GST_SOURCE_GROUP_LOCK (group);
  /* store the uri in the next group we will play */
  g_free (group->uri);
  group->uri = g_strdup (uri);
  group->valid = TRUE;
  GST_SOURCE_GROUP_UNLOCK (group);

  GST_DEBUG ("set new uri to %s", uri);
  GST_PLAY_BIN_UNLOCK (playbin);
}

static void
gst_play_bin_set_suburi (GstPlayBin * playbin, const gchar * suburi)
{
  GstSourceGroup *group;

  GST_PLAY_BIN_LOCK (playbin);
  group = playbin->next_group;

  GST_SOURCE_GROUP_LOCK (group);
  g_free (group->suburi);
  group->suburi = g_strdup (suburi);
  GST_SOURCE_GROUP_UNLOCK (group);

  GST_DEBUG ("setting new .sub uri to %s", suburi);

  GST_PLAY_BIN_UNLOCK (playbin);
}

static void
gst_play_bin_set_flags (GstPlayBin * playbin, GstPlayFlags flags)
{
  gst_play_sink_set_flags (playbin->playsink, flags);
  gst_play_sink_reconfigure (playbin->playsink);
}

static GstPlayFlags
gst_play_bin_get_flags (GstPlayBin * playbin)
{
  GstPlayFlags flags;

  flags = gst_play_sink_get_flags (playbin->playsink);

  return flags;
}

/* get the currently playing group or if nothing is playing, the next
 * group. Must be called with the PLAY_BIN_LOCK. */
static GstSourceGroup *
get_group (GstPlayBin * playbin)
{
  GstSourceGroup *result;

  if (!(result = playbin->curr_group))
    result = playbin->next_group;

  return result;
}

static GstPad *
gst_play_bin_get_video_pad (GstPlayBin * playbin, gint stream)
{
  GstPad *sinkpad = NULL;
  GstSourceGroup *group;

  GST_PLAY_BIN_LOCK (playbin);
  group = get_group (playbin);
  if (stream < group->video_channels->len) {
    sinkpad = g_ptr_array_index (group->video_channels, stream);
    gst_object_ref (sinkpad);
  }
  GST_PLAY_BIN_UNLOCK (playbin);

  return sinkpad;
}

static GstPad *
gst_play_bin_get_audio_pad (GstPlayBin * playbin, gint stream)
{
  GstPad *sinkpad = NULL;
  GstSourceGroup *group;

  GST_PLAY_BIN_LOCK (playbin);
  group = get_group (playbin);
  if (stream < group->audio_channels->len) {
    sinkpad = g_ptr_array_index (group->audio_channels, stream);
    gst_object_ref (sinkpad);
  }
  GST_PLAY_BIN_UNLOCK (playbin);

  return sinkpad;
}

static GstPad *
gst_play_bin_get_text_pad (GstPlayBin * playbin, gint stream)
{
  GstPad *sinkpad = NULL;
  GstSourceGroup *group;

  GST_PLAY_BIN_LOCK (playbin);
  group = get_group (playbin);
  if (stream < group->text_channels->len) {
    sinkpad = g_ptr_array_index (group->text_channels, stream);
    gst_object_ref (sinkpad);
  }
  GST_PLAY_BIN_UNLOCK (playbin);

  return sinkpad;
}


static GstTagList *
get_tags (GstPlayBin * playbin, GPtrArray * channels, gint stream)
{
  GstTagList *result;
  GstPad *sinkpad;

  if (!channels || stream >= channels->len)
    return NULL;

  sinkpad = g_ptr_array_index (channels, stream);
  g_object_get (sinkpad, "tags", &result, NULL);

  return result;
}

static GstTagList *
gst_play_bin_get_video_tags (GstPlayBin * playbin, gint stream)
{
  GstTagList *result;
  GstSourceGroup *group;

  GST_PLAY_BIN_LOCK (playbin);
  group = get_group (playbin);
  result = get_tags (playbin, group->video_channels, stream);
  GST_PLAY_BIN_UNLOCK (playbin);

  return result;
}

static GstTagList *
gst_play_bin_get_audio_tags (GstPlayBin * playbin, gint stream)
{
  GstTagList *result;
  GstSourceGroup *group;

  GST_PLAY_BIN_LOCK (playbin);
  group = get_group (playbin);
  result = get_tags (playbin, group->audio_channels, stream);
  GST_PLAY_BIN_UNLOCK (playbin);

  return result;
}

static GstTagList *
gst_play_bin_get_text_tags (GstPlayBin * playbin, gint stream)
{
  GstTagList *result;
  GstSourceGroup *group;

  GST_PLAY_BIN_LOCK (playbin);
  group = get_group (playbin);
  result = get_tags (playbin, group->text_channels, stream);
  GST_PLAY_BIN_UNLOCK (playbin);

  return result;
}

static GstBuffer *
gst_play_bin_convert_frame (GstPlayBin * playbin, GstCaps * caps)
{
  return gst_play_sink_convert_frame (playbin->playsink, caps);
}

/* Returns current stream number, or -1 if none has been selected yet */
static int
get_current_stream_number (GstPlayBin * playbin, GPtrArray * channels)
{
  /* Internal API cleanup would make this easier... */
  int i;
  GstPad *pad, *current;
  GstObject *selector = NULL;
  int ret = -1;

  for (i = 0; i < channels->len; i++) {
    pad = g_ptr_array_index (channels, i);
    if ((selector = gst_pad_get_parent (pad))) {
      g_object_get (selector, "active-pad", &current, NULL);
      gst_object_unref (selector);

      if (pad == current) {
        gst_object_unref (current);
        ret = i;
        break;
      }

      if (current)
        gst_object_unref (current);
    }
  }

  return ret;
}

static gboolean
gst_play_bin_set_current_video_stream (GstPlayBin * playbin, gint stream)
{
  GstSourceGroup *group;
  GPtrArray *channels;
  GstPad *sinkpad;

  GST_PLAY_BIN_LOCK (playbin);

  GST_DEBUG_OBJECT (playbin, "Changing current video stream %d -> %d",
      playbin->current_video, stream);

  group = get_group (playbin);
  if (!(channels = group->video_channels))
    goto no_channels;

  if (stream == -1 || channels->len <= stream) {
    sinkpad = NULL;
  } else {
    /* take channel from selected stream */
    sinkpad = g_ptr_array_index (channels, stream);
  }

  if (sinkpad)
    gst_object_ref (sinkpad);
  GST_PLAY_BIN_UNLOCK (playbin);

  if (sinkpad) {
    GstObject *selector;

    if ((selector = gst_pad_get_parent (sinkpad))) {
      /* activate the selected pad */
      g_object_set (selector, "active-pad", sinkpad, NULL);
      gst_object_unref (selector);
    }
    gst_object_unref (sinkpad);
  }
  return TRUE;

no_channels:
  {
    GST_PLAY_BIN_UNLOCK (playbin);
    GST_DEBUG_OBJECT (playbin, "can't switch video, we have no channels");
    return FALSE;
  }
}

static gboolean
gst_play_bin_set_current_audio_stream (GstPlayBin * playbin, gint stream)
{
  GstSourceGroup *group;
  GPtrArray *channels;
  GstPad *sinkpad;

  GST_PLAY_BIN_LOCK (playbin);

  GST_DEBUG_OBJECT (playbin, "Changing current audio stream %d -> %d",
      playbin->current_audio, stream);

  group = get_group (playbin);
  if (!(channels = group->audio_channels))
    goto no_channels;

  if (stream == -1 || channels->len <= stream) {
    sinkpad = NULL;
  } else {
    /* take channel from selected stream */
    sinkpad = g_ptr_array_index (channels, stream);
  }

  if (sinkpad)
    gst_object_ref (sinkpad);
  GST_PLAY_BIN_UNLOCK (playbin);

  if (sinkpad) {
    GstObject *selector;

    if ((selector = gst_pad_get_parent (sinkpad))) {
      /* activate the selected pad */
      g_object_set (selector, "active-pad", sinkpad, NULL);
      gst_object_unref (selector);
    }
    gst_object_unref (sinkpad);
  }
  return TRUE;

no_channels:
  {
    GST_PLAY_BIN_UNLOCK (playbin);
    GST_DEBUG_OBJECT (playbin, "can't switch audio, we have no channels");
    return FALSE;
  }
}

static void
gst_play_bin_suburidecodebin_seek_to_start (GstElement * suburidecodebin)
{
  GstIterator *it = gst_element_iterate_src_pads (suburidecodebin);
  GstPad *sinkpad;
  GValue item = { 0, };

  if (it && gst_iterator_next (it, &item) == GST_ITERATOR_OK
      && ((sinkpad = g_value_get_object (&item)) != NULL)) {
    GstEvent *event;

    event =
        gst_event_new_seek (1.0, GST_FORMAT_BYTES, GST_SEEK_FLAG_NONE,
        GST_SEEK_TYPE_SET, 0, GST_SEEK_TYPE_NONE, -1);
    if (!gst_pad_send_event (sinkpad, event)) {
      event =
          gst_event_new_seek (1.0, GST_FORMAT_TIME, GST_SEEK_FLAG_NONE,
          GST_SEEK_TYPE_SET, 0, GST_SEEK_TYPE_NONE, -1);
      if (!gst_pad_send_event (sinkpad, event))
        GST_DEBUG_OBJECT (suburidecodebin, "Seeking to the beginning failed!");
    }

    g_value_unset (&item);
  }

  if (it)
    gst_iterator_free (it);
}

static void
gst_play_bin_suburidecodebin_block (GstSourceGroup * group,
    GstElement * suburidecodebin, gboolean block)
{
  GstIterator *it = gst_element_iterate_src_pads (suburidecodebin);
  gboolean done = FALSE;
  GValue item = { 0, };

  GST_DEBUG_OBJECT (suburidecodebin, "Blocking suburidecodebin: %d", block);

  if (!it)
    return;
  while (!done) {
    GstPad *sinkpad;

    switch (gst_iterator_next (it, &item)) {
      case GST_ITERATOR_OK:
        sinkpad = g_value_get_object (&item);
        if (block) {
          group->block_id =
              gst_pad_add_probe (sinkpad, GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM,
              NULL, NULL, NULL);
        } else if (group->block_id) {
          gst_pad_remove_probe (sinkpad, group->block_id);
          group->block_id = 0;
        }
        g_value_reset (&item);
        break;
      case GST_ITERATOR_DONE:
        done = TRUE;
        break;
      case GST_ITERATOR_RESYNC:
        gst_iterator_resync (it);
        break;
      case GST_ITERATOR_ERROR:
        done = TRUE;
        break;
    }
  }
  g_value_unset (&item);
  gst_iterator_free (it);
}

static gboolean
gst_play_bin_set_current_text_stream (GstPlayBin * playbin, gint stream)
{
  GstSourceGroup *group;
  GPtrArray *channels;
  GstPad *sinkpad;

  GST_PLAY_BIN_LOCK (playbin);

  GST_DEBUG_OBJECT (playbin, "Changing current text stream %d -> %d",
      playbin->current_text, stream);

  group = get_group (playbin);
  if (!(channels = group->text_channels))
    goto no_channels;

  if (stream == -1 || channels->len <= stream) {
    sinkpad = NULL;
  } else {
    /* take channel from selected stream */
    sinkpad = g_ptr_array_index (channels, stream);
  }

  if (sinkpad)
    gst_object_ref (sinkpad);
  GST_PLAY_BIN_UNLOCK (playbin);

  if (sinkpad) {
    GstObject *selector;

    if ((selector = gst_pad_get_parent (sinkpad))) {
      GstPad *old_sinkpad;

      g_object_get (selector, "active-pad", &old_sinkpad, NULL);

      if (old_sinkpad != sinkpad) {
        gboolean need_unblock, need_block, need_seek;
        GstPad *src, *peer = NULL, *oldpeer = NULL;
        GstElement *parent_element = NULL, *old_parent_element = NULL;

        /* Now check if we need to seek the suburidecodebin to the beginning
         * or if we need to block all suburidecodebin sinkpads or if we need
         * to unblock all suburidecodebin sinkpads
         */
        if (sinkpad)
          peer = gst_pad_get_peer (sinkpad);
        if (old_sinkpad)
          oldpeer = gst_pad_get_peer (old_sinkpad);

        if (peer)
          parent_element = gst_pad_get_parent_element (peer);
        if (oldpeer)
          old_parent_element = gst_pad_get_parent_element (oldpeer);

        need_block = (old_parent_element == group->suburidecodebin
            && parent_element != old_parent_element);
        need_unblock = (parent_element == group->suburidecodebin
            && parent_element != old_parent_element);
        need_seek = (parent_element == group->suburidecodebin);

        if (peer)
          gst_object_unref (peer);
        if (oldpeer)
          gst_object_unref (oldpeer);
        if (parent_element)
          gst_object_unref (parent_element);
        if (old_parent_element)
          gst_object_unref (old_parent_element);

        /* Block all suburidecodebin sinkpads */
        if (need_block)
          gst_play_bin_suburidecodebin_block (group, group->suburidecodebin,
              TRUE);

        /* activate the selected pad */
        g_object_set (selector, "active-pad", sinkpad, NULL);

        src = gst_element_get_static_pad (GST_ELEMENT_CAST (selector), "src");
        peer = gst_pad_get_peer (src);
        if (peer) {
          GstStructure *s;
          GstEvent *event;
          /* Flush the subtitle renderer to remove any
           * currently displayed subtitles. This event will
           * never travel outside subtitleoverlay!
           */
          s = gst_structure_new_empty ("subtitleoverlay-flush-subtitle");
          event = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM_OOB, s);
          gst_pad_send_event (peer, event);
          gst_object_unref (peer);
        }
        gst_object_unref (src);

        /* Unblock pads if necessary */
        if (need_unblock)
          gst_play_bin_suburidecodebin_block (group, group->suburidecodebin,
              FALSE);

        /* seek to the beginning */
        if (need_seek)
          gst_play_bin_suburidecodebin_seek_to_start (group->suburidecodebin);
      }
      gst_object_unref (selector);

      if (old_sinkpad)
        gst_object_unref (old_sinkpad);
    }
    gst_object_unref (sinkpad);
  }
  return TRUE;

no_channels:
  {
    GST_PLAY_BIN_UNLOCK (playbin);
    return FALSE;
  }
}

static void
gst_play_bin_set_sink (GstPlayBin * playbin, GstElement ** elem,
    const gchar * dbg, GstElement * sink)
{
  GST_INFO_OBJECT (playbin, "Setting %s sink to %" GST_PTR_FORMAT, dbg, sink);

  GST_PLAY_BIN_LOCK (playbin);
  if (*elem != sink) {
    GstElement *old;

    old = *elem;
    if (sink)
      gst_object_ref_sink (sink);

    *elem = sink;
    if (old)
      gst_object_unref (old);
  }
  GST_LOG_OBJECT (playbin, "%s sink now %" GST_PTR_FORMAT, dbg, *elem);
  GST_PLAY_BIN_UNLOCK (playbin);
}

static void
gst_play_bin_set_encoding (GstPlayBin * playbin, const gchar * encoding)
{
  GstElement *elem;

  GST_PLAY_BIN_LOCK (playbin);

  /* set subtitles on all current and next decodebins. */
  if ((elem = playbin->groups[0].uridecodebin))
    g_object_set (G_OBJECT (elem), "subtitle-encoding", encoding, NULL);
  if ((elem = playbin->groups[0].suburidecodebin))
    g_object_set (G_OBJECT (elem), "subtitle-encoding", encoding, NULL);
  if ((elem = playbin->groups[1].uridecodebin))
    g_object_set (G_OBJECT (elem), "subtitle-encoding", encoding, NULL);
  if ((elem = playbin->groups[1].suburidecodebin))
    g_object_set (G_OBJECT (elem), "subtitle-encoding", encoding, NULL);

  gst_play_sink_set_subtitle_encoding (playbin->playsink, encoding);
  GST_PLAY_BIN_UNLOCK (playbin);
}

static void
gst_play_bin_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstPlayBin *playbin = GST_PLAY_BIN (object);

  switch (prop_id) {
    case PROP_URI:
      gst_play_bin_set_uri (playbin, g_value_get_string (value));
      break;
    case PROP_SUBURI:
      gst_play_bin_set_suburi (playbin, g_value_get_string (value));
      break;
    case PROP_FLAGS:
      gst_play_bin_set_flags (playbin, g_value_get_flags (value));
      break;
    case PROP_CURRENT_VIDEO:
      gst_play_bin_set_current_video_stream (playbin, g_value_get_int (value));
      break;
    case PROP_CURRENT_AUDIO:
      gst_play_bin_set_current_audio_stream (playbin, g_value_get_int (value));
      break;
    case PROP_CURRENT_TEXT:
      gst_play_bin_set_current_text_stream (playbin, g_value_get_int (value));
      break;
    case PROP_SUBTITLE_ENCODING:
      gst_play_bin_set_encoding (playbin, g_value_get_string (value));
      break;
    case PROP_VIDEO_SINK:
      gst_play_bin_set_sink (playbin, &playbin->video_sink, "video",
          g_value_get_object (value));
      break;
    case PROP_AUDIO_SINK:
      gst_play_bin_set_sink (playbin, &playbin->audio_sink, "audio",
          g_value_get_object (value));
      break;
    case PROP_VIS_PLUGIN:
      gst_play_sink_set_vis_plugin (playbin->playsink,
          g_value_get_object (value));
      break;
    case PROP_TEXT_SINK:
      gst_play_bin_set_sink (playbin, &playbin->text_sink, "text",
          g_value_get_object (value));
      break;
    case PROP_VOLUME:
      gst_play_sink_set_volume (playbin->playsink, g_value_get_double (value));
      break;
    case PROP_MUTE:
      gst_play_sink_set_mute (playbin->playsink, g_value_get_boolean (value));
      break;
    case PROP_FONT_DESC:
      gst_play_sink_set_font_desc (playbin->playsink,
          g_value_get_string (value));
      break;
    case PROP_CONNECTION_SPEED:
      GST_PLAY_BIN_LOCK (playbin);
      playbin->connection_speed = g_value_get_uint (value) * 1000;
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    case PROP_BUFFER_SIZE:
      playbin->buffer_size = g_value_get_int (value);
      break;
    case PROP_BUFFER_DURATION:
      playbin->buffer_duration = g_value_get_int64 (value);
      break;
    case PROP_AV_OFFSET:
      gst_play_sink_set_av_offset (playbin->playsink,
          g_value_get_int64 (value));
      break;
    case PROP_RING_BUFFER_MAX_SIZE:
      playbin->ring_buffer_max_size = g_value_get_uint64 (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static GstElement *
gst_play_bin_get_current_sink (GstPlayBin * playbin, GstElement ** elem,
    const gchar * dbg, GstPlaySinkType type)
{
  GstElement *sink = gst_play_sink_get_sink (playbin->playsink, type);

  GST_LOG_OBJECT (playbin, "play_sink_get_sink() returned %s sink %"
      GST_PTR_FORMAT ", the originally set %s sink is %" GST_PTR_FORMAT,
      dbg, sink, dbg, *elem);

  if (sink == NULL) {
    GST_PLAY_BIN_LOCK (playbin);
    if ((sink = *elem))
      gst_object_ref (sink);
    GST_PLAY_BIN_UNLOCK (playbin);
  }

  return sink;
}

static void
gst_play_bin_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstPlayBin *playbin = GST_PLAY_BIN (object);

  switch (prop_id) {
    case PROP_URI:
    {
      GstSourceGroup *group;

      GST_PLAY_BIN_LOCK (playbin);
      group = get_group (playbin);
      g_value_set_string (value, group->uri);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    }
    case PROP_SUBURI:
    {
      GstSourceGroup *group;

      GST_PLAY_BIN_LOCK (playbin);
      group = get_group (playbin);
      g_value_set_string (value, group->suburi);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    }
    case PROP_SOURCE:
    {
      GST_OBJECT_LOCK (playbin);
      g_value_set_object (value, playbin->source);
      GST_OBJECT_UNLOCK (playbin);
      break;
    }
    case PROP_FLAGS:
      g_value_set_flags (value, gst_play_bin_get_flags (playbin));
      break;
    case PROP_N_VIDEO:
    {
      GstSourceGroup *group;
      gint n_video;

      GST_PLAY_BIN_LOCK (playbin);
      group = get_group (playbin);
      n_video = (group->video_channels ? group->video_channels->len : 0);
      g_value_set_int (value, n_video);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    }
    case PROP_CURRENT_VIDEO:
      GST_PLAY_BIN_LOCK (playbin);
      g_value_set_int (value, playbin->current_video);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    case PROP_N_AUDIO:
    {
      GstSourceGroup *group;
      gint n_audio;

      GST_PLAY_BIN_LOCK (playbin);
      group = get_group (playbin);
      n_audio = (group->audio_channels ? group->audio_channels->len : 0);
      g_value_set_int (value, n_audio);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    }
    case PROP_CURRENT_AUDIO:
      GST_PLAY_BIN_LOCK (playbin);
      g_value_set_int (value, playbin->current_audio);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    case PROP_N_TEXT:
    {
      GstSourceGroup *group;
      gint n_text;

      GST_PLAY_BIN_LOCK (playbin);
      group = get_group (playbin);
      n_text = (group->text_channels ? group->text_channels->len : 0);
      g_value_set_int (value, n_text);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    }
    case PROP_CURRENT_TEXT:
      GST_PLAY_BIN_LOCK (playbin);
      g_value_set_int (value, playbin->current_text);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    case PROP_SUBTITLE_ENCODING:
      GST_PLAY_BIN_LOCK (playbin);
      g_value_take_string (value,
          gst_play_sink_get_subtitle_encoding (playbin->playsink));
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    case PROP_VIDEO_SINK:
      g_value_take_object (value,
          gst_play_bin_get_current_sink (playbin, &playbin->video_sink,
              "video", GST_PLAY_SINK_TYPE_VIDEO));
      break;
    case PROP_AUDIO_SINK:
      g_value_take_object (value,
          gst_play_bin_get_current_sink (playbin, &playbin->audio_sink,
              "audio", GST_PLAY_SINK_TYPE_AUDIO));
      break;
    case PROP_VIS_PLUGIN:
      g_value_take_object (value,
          gst_play_sink_get_vis_plugin (playbin->playsink));
      break;
    case PROP_TEXT_SINK:
      g_value_take_object (value,
          gst_play_bin_get_current_sink (playbin, &playbin->text_sink,
              "text", GST_PLAY_SINK_TYPE_TEXT));
      break;
    case PROP_VOLUME:
      g_value_set_double (value, gst_play_sink_get_volume (playbin->playsink));
      break;
    case PROP_MUTE:
      g_value_set_boolean (value, gst_play_sink_get_mute (playbin->playsink));
      break;
    case PROP_FRAME:
      gst_value_take_buffer (value,
          gst_play_sink_get_last_frame (playbin->playsink));
      break;
    case PROP_FONT_DESC:
      g_value_take_string (value,
          gst_play_sink_get_font_desc (playbin->playsink));
      break;
    case PROP_CONNECTION_SPEED:
      GST_PLAY_BIN_LOCK (playbin);
      g_value_set_uint (value, playbin->connection_speed / 1000);
      GST_PLAY_BIN_UNLOCK (playbin);
      break;
    case PROP_BUFFER_SIZE:
      GST_OBJECT_LOCK (playbin);
      g_value_set_int (value, playbin->buffer_size);
      GST_OBJECT_UNLOCK (playbin);
      break;
    case PROP_BUFFER_DURATION:
      GST_OBJECT_LOCK (playbin);
      g_value_set_int64 (value, playbin->buffer_duration);
      GST_OBJECT_UNLOCK (playbin);
      break;
    case PROP_AV_OFFSET:
      g_value_set_int64 (value,
          gst_play_sink_get_av_offset (playbin->playsink));
      break;
    case PROP_RING_BUFFER_MAX_SIZE:
      g_value_set_uint64 (value, playbin->ring_buffer_max_size);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_play_bin_update_cached_duration_from_query (GstPlayBin * playbin,
    gboolean valid, GstQuery * query)
{
  GstFormat fmt;
  gint64 duration;
  gint i;

  GST_DEBUG_OBJECT (playbin, "Updating cached duration from query");
  gst_query_parse_duration (query, &fmt, &duration);

  for (i = 0; i < G_N_ELEMENTS (playbin->duration); i++) {
    if (playbin->duration[i].format == 0 || fmt == playbin->duration[i].format) {
      playbin->duration[i].valid = valid;
      playbin->duration[i].format = fmt;
      playbin->duration[i].duration = valid ? duration : -1;
      break;
    }
  }
}

static void
gst_play_bin_update_cached_duration (GstPlayBin * playbin)
{
  const GstFormat formats[] =
      { GST_FORMAT_TIME, GST_FORMAT_BYTES, GST_FORMAT_DEFAULT };
  gboolean ret;
  GstQuery *query;
  gint i;

  GST_DEBUG_OBJECT (playbin, "Updating cached durations before group switch");
  for (i = 0; i < G_N_ELEMENTS (formats); i++) {
    query = gst_query_new_duration (formats[i]);
    ret =
        GST_ELEMENT_CLASS (parent_class)->query (GST_ELEMENT_CAST (playbin),
        query);
    gst_play_bin_update_cached_duration_from_query (playbin, ret, query);
    gst_query_unref (query);
  }
}

static gboolean
gst_play_bin_query (GstElement * element, GstQuery * query)
{
  GstPlayBin *playbin = GST_PLAY_BIN (element);
  gboolean ret;

  /* During a group switch we shouldn't allow duration queries
   * because it's not clear if the old or new group's duration
   * is returned and if the sinks are already playing new data
   * or old data. See bug #585969
   *
   * While we're at it, also don't do any other queries during
   * a group switch or any other event that causes topology changes
   * by taking the playbin lock in any case.
   */
  GST_PLAY_BIN_LOCK (playbin);

  if (GST_QUERY_TYPE (query) == GST_QUERY_DURATION) {
    GstSourceGroup *group = playbin->curr_group;
    gboolean pending;

    GST_SOURCE_GROUP_LOCK (group);
    if (group->stream_changed_pending_lock) {
      g_mutex_lock (group->stream_changed_pending_lock);
      pending = group->pending || group->stream_changed_pending;
      g_mutex_unlock (group->stream_changed_pending_lock);
    } else {
      pending = group->pending;
    }
    if (pending) {
      GstFormat fmt;
      gint i;

      ret = FALSE;
      gst_query_parse_duration (query, &fmt, NULL);
      for (i = 0; i < G_N_ELEMENTS (playbin->duration); i++) {
        if (fmt == playbin->duration[i].format) {
          ret = playbin->duration[i].valid;
          gst_query_set_duration (query, fmt,
              (ret ? playbin->duration[i].duration : -1));
          break;
        }
      }
      /* if nothing cached yet, we might as well request duration,
       * such as during initial startup */
      if (ret) {
        GST_DEBUG_OBJECT (playbin,
            "Taking cached duration because of pending group switch: %d", ret);
        GST_SOURCE_GROUP_UNLOCK (group);
        GST_PLAY_BIN_UNLOCK (playbin);
        return ret;
      }
    }
    GST_SOURCE_GROUP_UNLOCK (group);
  }

  ret = GST_ELEMENT_CLASS (parent_class)->query (element, query);

  if (GST_QUERY_TYPE (query) == GST_QUERY_DURATION)
    gst_play_bin_update_cached_duration_from_query (playbin, ret, query);
  GST_PLAY_BIN_UNLOCK (playbin);

  return ret;
}

/* mime types we are not handling on purpose right now, don't post a
 * missing-plugin message for these */
static const gchar *blacklisted_mimes[] = {
  NULL
};

static void
gst_play_bin_handle_message (GstBin * bin, GstMessage * msg)
{
  GstPlayBin *playbin = GST_PLAY_BIN (bin);
  GstSourceGroup *group;

  if (gst_is_missing_plugin_message (msg)) {
    gchar *detail;
    guint i;

    detail = gst_missing_plugin_message_get_installer_detail (msg);
    for (i = 0; detail != NULL && blacklisted_mimes[i] != NULL; ++i) {
      if (strstr (detail, "|decoder-") && strstr (detail, blacklisted_mimes[i])) {
        GST_LOG_OBJECT (bin, "suppressing message %" GST_PTR_FORMAT, msg);
        gst_message_unref (msg);
        g_free (detail);
        return;
      }
    }
    g_free (detail);
  } else if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_ELEMENT) {
    const GstStructure *s = gst_message_get_structure (msg);

    /* Drop all stream-changed messages except the last one */
    if (strcmp ("playbin-stream-changed", gst_structure_get_name (s)) == 0) {
      guint32 seqnum = gst_message_get_seqnum (msg);
      GList *l, *l_prev;

      group = playbin->curr_group;
      g_mutex_lock (group->stream_changed_pending_lock);
      for (l = group->stream_changed_pending; l;) {
        guint32 l_seqnum = GPOINTER_TO_UINT (l->data);

        if (l_seqnum == seqnum) {
          l_prev = l;
          l = l->next;
          group->stream_changed_pending =
              g_list_delete_link (group->stream_changed_pending, l_prev);
          if (group->stream_changed_pending) {
            gst_message_unref (msg);
            msg = NULL;
            break;
          }
        } else {
          l = l->next;
        }
      }
      g_mutex_unlock (group->stream_changed_pending_lock);
    }
  } else if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_ASYNC_START ||
      GST_MESSAGE_TYPE (msg) == GST_MESSAGE_ASYNC_DONE) {
    GstObject *src = GST_OBJECT_CAST (msg->src);

    /* Ignore async state changes from the uridecodebin children,
     * see bug #602000. */
    group = playbin->curr_group;
    if (src && (group = playbin->curr_group) &&
        ((group->uridecodebin && src == GST_OBJECT_CAST (group->uridecodebin))
            || (group->suburidecodebin
                && src == GST_OBJECT_CAST (group->suburidecodebin)))) {
      GST_DEBUG_OBJECT (playbin,
          "Ignoring async state change of uridecodebin: %s",
          GST_OBJECT_NAME (src));
      gst_message_unref (msg);
      msg = NULL;
    }
  } else if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_ERROR) {
    /* If we get an error of the subtitle uridecodebin transform
     * them into warnings and disable the subtitles */
    group = playbin->curr_group;
    if (group && group->suburidecodebin) {
      if (G_UNLIKELY (gst_object_has_ancestor (msg->src, GST_OBJECT_CAST
                  (group->suburidecodebin)))) {
        GError *err;
        gchar *debug = NULL;
        GstMessage *new_msg;
        GstIterator *it;
        gboolean done = FALSE;
        GValue item = { 0, };

        gst_message_parse_error (msg, &err, &debug);
        new_msg = gst_message_new_warning (msg->src, err, debug);

        gst_message_unref (msg);
        g_error_free (err);
        g_free (debug);
        msg = new_msg;

        REMOVE_SIGNAL (group->suburidecodebin, group->sub_pad_added_id);
        REMOVE_SIGNAL (group->suburidecodebin, group->sub_pad_removed_id);
        REMOVE_SIGNAL (group->suburidecodebin, group->sub_no_more_pads_id);
        REMOVE_SIGNAL (group->suburidecodebin, group->sub_autoplug_continue_id);

        it = gst_element_iterate_src_pads (group->suburidecodebin);
        while (it && !done) {
          GstPad *p = NULL;
          GstIteratorResult res;

          res = gst_iterator_next (it, &item);

          switch (res) {
            case GST_ITERATOR_DONE:
              done = TRUE;
              break;
            case GST_ITERATOR_OK:
              p = g_value_get_object (&item);
              pad_removed_cb (NULL, p, group);
              g_value_reset (&item);
              break;

            case GST_ITERATOR_RESYNC:
              gst_iterator_resync (it);
              break;
            case GST_ITERATOR_ERROR:
              done = TRUE;
              break;
          }
        }
        g_value_unset (&item);
        if (it)
          gst_iterator_free (it);

        gst_object_ref (group->suburidecodebin);
        gst_bin_remove (bin, group->suburidecodebin);
        gst_element_set_locked_state (group->suburidecodebin, FALSE);

        if (group->sub_pending) {
          group->sub_pending = FALSE;
          no_more_pads_cb (NULL, group);
        }
      }
    }
  }

  if (msg)
    GST_BIN_CLASS (parent_class)->handle_message (bin, msg);
}

static void
selector_active_pad_changed (GObject * selector, GParamSpec * pspec,
    GstPlayBin * playbin)
{
  const gchar *property;
  GstSourceGroup *group;
  GstSourceSelect *select = NULL;
  int i;

  GST_PLAY_BIN_LOCK (playbin);
  group = get_group (playbin);

  for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
    if (selector == G_OBJECT (group->selector[i].selector)) {
      select = &group->selector[i];
    }
  }

  /* We got a pad-change after our group got switched out; no need to notify */
  if (!select) {
    GST_PLAY_BIN_UNLOCK (playbin);
    return;
  }

  switch (select->type) {
    case GST_PLAY_SINK_TYPE_VIDEO:
    case GST_PLAY_SINK_TYPE_VIDEO_RAW:
      property = "current-video";
      playbin->current_video = get_current_stream_number (playbin,
          group->video_channels);
      break;
    case GST_PLAY_SINK_TYPE_AUDIO:
    case GST_PLAY_SINK_TYPE_AUDIO_RAW:
      property = "current-audio";
      playbin->current_audio = get_current_stream_number (playbin,
          group->audio_channels);
      break;
    case GST_PLAY_SINK_TYPE_TEXT:
      property = "current-text";
      playbin->current_text = get_current_stream_number (playbin,
          group->text_channels);
      break;
    default:
      property = NULL;
  }
  GST_PLAY_BIN_UNLOCK (playbin);

  if (property)
    g_object_notify (G_OBJECT (playbin), property);
}

/* this callback sends a delayed event once the pad becomes unblocked */
static GstPadProbeReturn
stream_changed_data_probe (GstPad * pad, GstPadProbeInfo * info, gpointer data)
{
  GstMiniObject *object = GST_PAD_PROBE_INFO_DATA (info);
  GstSourceSelect *select = (GstSourceSelect *) data;
  GstEvent *e;

  /* we need do this just once, so cleanup first */
  gst_pad_remove_probe (pad, select->sinkpad_data_probe);
  select->sinkpad_data_probe = 0;
  e = select->sinkpad_delayed_event;
  select->sinkpad_delayed_event = NULL;

  /* really, this should not happen */
  if (!e) {
    GST_WARNING ("Data probed called, but no delayed event");
    return GST_PAD_PROBE_OK;
  }

  if (GST_IS_EVENT (object)
      && GST_EVENT_TYPE (GST_EVENT_CAST (object)) == GST_EVENT_SEGMENT) {
    /* push the event first, then send the delayed one */
    gst_event_ref (GST_EVENT_CAST (object));
    gst_pad_send_event (pad, GST_EVENT_CAST (object));
    gst_pad_send_event (pad, e);
    return GST_PAD_PROBE_DROP;
  } else {
    /* send delayed event, then allow the caller to go on */
    gst_pad_send_event (pad, e);
    return GST_PAD_PROBE_OK;
  }
}

/* helper function to lookup stuff in lists */
static gboolean
array_has_value (const gchar * values[], const gchar * value, gboolean exact)
{
  gint i;

  for (i = 0; values[i]; i++) {
    if (exact && !strcmp (value, values[i]))
      return TRUE;
    if (!exact && g_str_has_prefix (value, values[i]))
      return TRUE;
  }
  return FALSE;
}

typedef struct
{
  GstPlayBin *playbin;
  gint stream_id;
  GstPlaySinkType type;
} NotifyTagsData;

static void
notify_tags_cb (GObject * object, GParamSpec * pspec, gpointer user_data)
{
  NotifyTagsData *ntdata = (NotifyTagsData *) user_data;
  gint signal;

  GST_DEBUG_OBJECT (ntdata->playbin, "Tags on pad %" GST_PTR_FORMAT
      " with stream id %d and type %d have changed",
      object, ntdata->stream_id, ntdata->type);

  switch (ntdata->type) {
    case GST_PLAY_SINK_TYPE_VIDEO:
    case GST_PLAY_SINK_TYPE_VIDEO_RAW:
      signal = SIGNAL_VIDEO_TAGS_CHANGED;
      break;
    case GST_PLAY_SINK_TYPE_AUDIO:
    case GST_PLAY_SINK_TYPE_AUDIO_RAW:
      signal = SIGNAL_AUDIO_TAGS_CHANGED;
      break;
    case GST_PLAY_SINK_TYPE_TEXT:
      signal = SIGNAL_TEXT_TAGS_CHANGED;
      break;
    default:
      signal = -1;
      break;
  }

  if (signal >= 0)
    g_signal_emit (G_OBJECT (ntdata->playbin), gst_play_bin_signals[signal], 0,
        ntdata->stream_id);
}

/* this function is called when a new pad is added to decodebin. We check the
 * type of the pad and add it to the selector element of the group.
 */
static void
pad_added_cb (GstElement * decodebin, GstPad * pad, GstSourceGroup * group)
{
  GstPlayBin *playbin;
  GstCaps *caps;
  const GstStructure *s;
  const gchar *name;
  GstPad *sinkpad;
  GstPadLinkReturn res;
  GstSourceSelect *select = NULL;
  gint i, pass;
  gboolean changed = FALSE;

  playbin = group->playbin;

  caps = gst_pad_get_caps (pad, NULL);
  s = gst_caps_get_structure (caps, 0);
  name = gst_structure_get_name (s);

  GST_DEBUG_OBJECT (playbin,
      "pad %s:%s with caps %" GST_PTR_FORMAT " added in group %p",
      GST_DEBUG_PAD_NAME (pad), caps, group);

  /* major type of the pad, this determines the selector to use,
     try exact match first so we don't prematurely match video/
     for video/x-dvd-subpicture */
  for (pass = 0; !select && pass < 2; pass++) {
    for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
      if (array_has_value (group->selector[i].media_list, name, pass == 0)) {
        select = &group->selector[i];
        break;
      } else if (group->selector[i].get_media_caps) {
        GstCaps *media_caps = group->selector[i].get_media_caps ();

        if (media_caps && gst_caps_can_intersect (media_caps, caps)) {
          select = &group->selector[i];
          gst_caps_unref (media_caps);
          break;
        }
        gst_caps_unref (media_caps);
      }
    }
  }
  /* no selector found for the media type, don't bother linking it to a
   * selector. This will leave the pad unlinked and thus ignored. */
  if (select == NULL)
    goto unknown_type;

  GST_SOURCE_GROUP_LOCK (group);
  if (select->selector == NULL && playbin->have_selector) {
    /* no selector, create one */
    GST_DEBUG_OBJECT (playbin, "creating new input selector");
    select->selector = gst_element_factory_make ("input-selector", NULL);
    if (select->selector == NULL) {
      /* post the missing selector message only once */
      playbin->have_selector = FALSE;
      gst_element_post_message (GST_ELEMENT_CAST (playbin),
          gst_missing_element_message_new (GST_ELEMENT_CAST (playbin),
              "input-selector"));
      GST_ELEMENT_WARNING (playbin, CORE, MISSING_PLUGIN,
          (_("Missing element '%s' - check your GStreamer installation."),
              "input-selector"), (NULL));
    } else {
      g_object_set (select->selector, "sync-streams", TRUE, NULL);

      g_signal_connect (select->selector, "notify::active-pad",
          G_CALLBACK (selector_active_pad_changed), playbin);

      GST_DEBUG_OBJECT (playbin, "adding new selector %p", select->selector);
      gst_bin_add (GST_BIN_CAST (playbin), select->selector);
      gst_element_set_state (select->selector, GST_STATE_PAUSED);
    }
  }

  if (select->srcpad == NULL) {
    if (select->selector) {
      /* save source pad of the selector */
      select->srcpad = gst_element_get_static_pad (select->selector, "src");
    } else {
      /* no selector, use the pad as the source pad then */
      select->srcpad = gst_object_ref (pad);
    }

    /* block the selector srcpad. It's possible that multiple decodebins start
     * pushing data into the selectors before we have a chance to collect all
     * streams and connect the sinks, resulting in not-linked errors. After we
     * configured the sinks we will unblock them all. */
    GST_DEBUG_OBJECT (playbin, "blocking %" GST_PTR_FORMAT, select->srcpad);
    select->block_id =
        gst_pad_add_probe (select->srcpad, GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM,
        NULL, NULL, NULL);
  }

  /* get sinkpad for the new stream */
  if (select->selector) {
    if ((sinkpad = gst_element_get_request_pad (select->selector, "sink_%u"))) {
      gulong notify_tags_handler = 0;
      NotifyTagsData *ntdata;

      GST_DEBUG_OBJECT (playbin, "got pad %s:%s from selector",
          GST_DEBUG_PAD_NAME (sinkpad));

      /* store the selector for the pad */
      g_object_set_data (G_OBJECT (sinkpad), "playbin.select", select);

      /* connect to the notify::tags signal for our
       * own *-tags-changed signals
       */
      ntdata = g_new0 (NotifyTagsData, 1);
      ntdata->playbin = playbin;
      ntdata->stream_id = select->channels->len;
      ntdata->type = select->type;

      notify_tags_handler =
          g_signal_connect_data (G_OBJECT (sinkpad), "notify::tags",
          G_CALLBACK (notify_tags_cb), ntdata, (GClosureNotify) g_free,
          (GConnectFlags) 0);
      g_object_set_data (G_OBJECT (sinkpad), "playbin.notify_tags_handler",
          (gpointer) (guintptr) notify_tags_handler);

      /* store the pad in the array */
      GST_DEBUG_OBJECT (playbin, "pad %p added to array", sinkpad);
      g_ptr_array_add (select->channels, sinkpad);

      res = gst_pad_link (pad, sinkpad);
      if (GST_PAD_LINK_FAILED (res))
        goto link_failed;

      /* store selector pad so we can release it */
      g_object_set_data (G_OBJECT (pad), "playbin.sinkpad", sinkpad);

      changed = TRUE;
      GST_DEBUG_OBJECT (playbin, "linked pad %s:%s to selector %p",
          GST_DEBUG_PAD_NAME (pad), select->selector);
    }
  } else {
    /* no selector, don't configure anything, we'll link the new pad directly to
     * the sink. */
    changed = FALSE;
    sinkpad = NULL;
  }
  GST_SOURCE_GROUP_UNLOCK (group);

  if (changed) {
    int signal;
    gboolean always_ok = (decodebin == group->suburidecodebin);

    switch (select->type) {
      case GST_PLAY_SINK_TYPE_VIDEO:
      case GST_PLAY_SINK_TYPE_VIDEO_RAW:
        /* we want to return NOT_LINKED for unselected pads but only for pads
         * from the normal uridecodebin. This makes sure that subtitle streams
         * are not raced past audio/video from decodebin's multiqueue.
         * For pads from suburidecodebin OK should always be returned, otherwise
         * it will most likely stop. */
        g_object_set (sinkpad, "always-ok", always_ok, NULL);
        signal = SIGNAL_VIDEO_CHANGED;
        break;
      case GST_PLAY_SINK_TYPE_AUDIO:
      case GST_PLAY_SINK_TYPE_AUDIO_RAW:
        g_object_set (sinkpad, "always-ok", always_ok, NULL);
        signal = SIGNAL_AUDIO_CHANGED;
        break;
      case GST_PLAY_SINK_TYPE_TEXT:
        g_object_set (sinkpad, "always-ok", always_ok, NULL);
        signal = SIGNAL_TEXT_CHANGED;
        break;
      default:
        signal = -1;
    }

    if (signal >= 0)
      g_signal_emit (G_OBJECT (playbin), gst_play_bin_signals[signal], 0, NULL);
  }

done:
  gst_caps_unref (caps);
  return;

  /* ERRORS */
unknown_type:
  {
    GST_ERROR_OBJECT (playbin, "unknown type %s for pad %s:%s",
        name, GST_DEBUG_PAD_NAME (pad));
    goto done;
  }
link_failed:
  {
    GST_ERROR_OBJECT (playbin,
        "failed to link pad %s:%s to selector, reason %d",
        GST_DEBUG_PAD_NAME (pad), res);
    GST_SOURCE_GROUP_UNLOCK (group);
    goto done;
  }
}

/* called when a pad is removed from the uridecodebin. We unlink the pad from
 * the selector. This will make the selector select a new pad. */
static void
pad_removed_cb (GstElement * decodebin, GstPad * pad, GstSourceGroup * group)
{
  GstPlayBin *playbin;
  GstPad *peer;
  GstElement *selector;
  GstSourceSelect *select;

  playbin = group->playbin;

  GST_DEBUG_OBJECT (playbin,
      "pad %s:%s removed from group %p", GST_DEBUG_PAD_NAME (pad), group);

  GST_SOURCE_GROUP_LOCK (group);
  /* get the selector sinkpad */
  if (!(peer = g_object_get_data (G_OBJECT (pad), "playbin.sinkpad")))
    goto not_linked;

  if ((select = g_object_get_data (G_OBJECT (peer), "playbin.select"))) {
    gulong notify_tags_handler;

    notify_tags_handler =
        (guintptr) g_object_get_data (G_OBJECT (peer),
        "playbin.notify_tags_handler");
    if (notify_tags_handler != 0)
      g_signal_handler_disconnect (G_OBJECT (peer), notify_tags_handler);
    g_object_set_data (G_OBJECT (peer), "playbin.notify_tags_handler", NULL);

    /* remove the pad from the array */
    g_ptr_array_remove (select->channels, peer);
    GST_DEBUG_OBJECT (playbin, "pad %p removed from array", peer);
  }

  /* unlink the pad now (can fail, the pad is unlinked before it's removed) */
  gst_pad_unlink (pad, peer);

  /* get selector, this can be NULL when the element is removing the pads
   * because it's being disposed. */
  selector = GST_ELEMENT_CAST (gst_pad_get_parent (peer));
  if (!selector) {
    gst_object_unref (peer);
    goto no_selector;
  }

  /* release the pad to the selector, this will make the selector choose a new
   * pad. */
  gst_element_release_request_pad (selector, peer);
  gst_object_unref (peer);

  gst_object_unref (selector);
  GST_SOURCE_GROUP_UNLOCK (group);

  return;

  /* ERRORS */
not_linked:
  {
    GST_DEBUG_OBJECT (playbin, "pad not linked");
    GST_SOURCE_GROUP_UNLOCK (group);
    return;
  }
no_selector:
  {
    GST_DEBUG_OBJECT (playbin, "selector not found");
    GST_SOURCE_GROUP_UNLOCK (group);
    return;
  }
}

/* we get called when all pads are available and we must connect the sinks to
 * them.
 * The main purpose of the code is to see if we have video/audio and subtitles
 * and pick the right pipelines to display them.
 *
 * The selectors installed on the group tell us about the presence of
 * audio/video and subtitle streams. This allows us to see if we need
 * visualisation, video or/and audio.
 */
static void
no_more_pads_cb (GstElement * decodebin, GstSourceGroup * group)
{
  GstPlayBin *playbin;
  GstPadLinkReturn res;
  gint i;
  gboolean configure;

  playbin = group->playbin;

  GST_DEBUG_OBJECT (playbin, "no more pads in group %p", group);

  GST_PLAY_BIN_SHUTDOWN_LOCK (playbin, shutdown);

  GST_SOURCE_GROUP_LOCK (group);
  for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
    GstSourceSelect *select = &group->selector[i];

    /* check if the specific media type was detected and thus has a selector
     * created for it. If there is the media type, get a sinkpad from the sink
     * and link it. We only do this if we have not yet requested the sinkpad
     * before. */
    if (select->srcpad && select->sinkpad == NULL) {
      GST_DEBUG_OBJECT (playbin, "requesting new sink pad %d", select->type);
      select->sinkpad =
          gst_play_sink_request_pad (playbin->playsink, select->type);

      res = gst_pad_link (select->srcpad, select->sinkpad);
      GST_DEBUG_OBJECT (playbin, "linked type %s, result: %d",
          select->media_list[0], res);
      if (res != GST_PAD_LINK_OK) {
        GST_ELEMENT_ERROR (playbin, CORE, PAD,
            ("Internal playbin error."),
            ("Failed to link selector to sink. Error %d", res));
      }
    }
  }
  GST_DEBUG_OBJECT (playbin, "pending %d > %d", group->pending,
      group->pending - 1);

  if (group->pending > 0)
    group->pending--;

  if (group->suburidecodebin == decodebin)
    group->sub_pending = FALSE;

  if (group->pending == 0) {
    /* we are the last group to complete, we will configure the output and then
     * signal the other waiters. */
    GST_LOG_OBJECT (playbin, "last group complete");
    configure = TRUE;
  } else {
    GST_LOG_OBJECT (playbin, "have more pending groups");
    configure = FALSE;
  }
  GST_SOURCE_GROUP_UNLOCK (group);

  if (configure) {
    /* if we have custom sinks, configure them now */
    GST_SOURCE_GROUP_LOCK (group);

    if (group->audio_sink) {
      GST_INFO_OBJECT (playbin, "setting custom audio sink %" GST_PTR_FORMAT,
          group->audio_sink);
      gst_play_sink_set_sink (playbin->playsink, GST_PLAY_SINK_TYPE_AUDIO,
          group->audio_sink);
    }

    if (group->video_sink) {
      GST_INFO_OBJECT (playbin, "setting custom video sink %" GST_PTR_FORMAT,
          group->video_sink);
      gst_play_sink_set_sink (playbin->playsink, GST_PLAY_SINK_TYPE_VIDEO,
          group->video_sink);
    }

    if (playbin->text_sink) {
      GST_INFO_OBJECT (playbin, "setting custom text sink %" GST_PTR_FORMAT,
          playbin->text_sink);
      gst_play_sink_set_sink (playbin->playsink, GST_PLAY_SINK_TYPE_TEXT,
          playbin->text_sink);
    }

    GST_SOURCE_GROUP_UNLOCK (group);

    /* signal the other decodebins that they can continue now. */
    GST_SOURCE_GROUP_LOCK (group);
    /* unblock all selectors */
    for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
      GstSourceSelect *select = &group->selector[i];

      /* All streamsynchronizer streams should see stream-changed message,
       * to arrange for blocking unblocking. */
      if (select->sinkpad) {
        GstStructure *s;
        GstMessage *msg;
        GstEvent *event;
        guint32 seqnum;

        s = gst_structure_new ("playbin-stream-changed", "uri", G_TYPE_STRING,
            group->uri, NULL);
        if (group->suburi)
          gst_structure_set (s, "suburi", G_TYPE_STRING, group->suburi, NULL);
        msg = gst_message_new_element (GST_OBJECT_CAST (playbin), s);
        seqnum = gst_message_get_seqnum (msg);
        event = gst_event_new_sink_message (msg);
        g_mutex_lock (group->stream_changed_pending_lock);
        group->stream_changed_pending =
            g_list_prepend (group->stream_changed_pending,
            GUINT_TO_POINTER (seqnum));

        /* remove any data probe we might have, and replace */
        if (select->sinkpad_delayed_event)
          gst_event_unref (select->sinkpad_delayed_event);
        select->sinkpad_delayed_event = event;
        if (select->sinkpad_data_probe)
          gst_pad_remove_probe (select->sinkpad, select->sinkpad_data_probe);

        /* we go to the trouble of setting a probe on the pad to send
           the playbin-stream-changed event as sending it here might
           find that the pad is blocked, so we'd block here, and the
           pad might not be linked yet. Additionally, sending it here
           apparently would be on the wrong thread */
        select->sinkpad_data_probe =
            gst_pad_add_probe (select->sinkpad,
            GST_PAD_PROBE_TYPE_DATA_DOWNSTREAM,
            stream_changed_data_probe, (gpointer) select, NULL);

        g_mutex_unlock (group->stream_changed_pending_lock);
        gst_message_unref (msg);
      }

      if (select->srcpad) {
        GST_DEBUG_OBJECT (playbin, "unblocking %" GST_PTR_FORMAT,
            select->srcpad);
        if (select->block_id) {
          gst_pad_remove_probe (select->srcpad, select->block_id);
          select->block_id = 0;
        }
      }
    }
    GST_SOURCE_GROUP_UNLOCK (group);
  }

  GST_PLAY_BIN_SHUTDOWN_UNLOCK (playbin);

  return;

shutdown:
  {
    GST_DEBUG ("ignoring, we are shutting down");
    /* Request a flushing pad from playsink that we then link to the selector.
     * Then we unblock the selectors so that they stop with a WRONG_STATE
     * instead of a NOT_LINKED error.
     */
    GST_SOURCE_GROUP_LOCK (group);
    for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
      GstSourceSelect *select = &group->selector[i];

      if (select->srcpad) {
        if (select->sinkpad == NULL) {
          GST_DEBUG_OBJECT (playbin, "requesting new flushing sink pad");
          select->sinkpad =
              gst_play_sink_request_pad (playbin->playsink,
              GST_PLAY_SINK_TYPE_FLUSHING);
          res = gst_pad_link (select->srcpad, select->sinkpad);
          GST_DEBUG_OBJECT (playbin, "linked flushing, result: %d", res);
        }
        GST_DEBUG_OBJECT (playbin, "unblocking %" GST_PTR_FORMAT,
            select->srcpad);
        if (select->block_id) {
          gst_pad_remove_probe (select->srcpad, select->block_id);
          select->block_id = 0;
        }
      }
    }
    GST_SOURCE_GROUP_UNLOCK (group);
    return;
  }
}

static void
drained_cb (GstElement * decodebin, GstSourceGroup * group)
{
  GstPlayBin *playbin;

  playbin = group->playbin;

  GST_DEBUG_OBJECT (playbin, "about to finish in group %p", group);

  /* after this call, we should have a next group to activate or we EOS */
  g_signal_emit (G_OBJECT (playbin),
      gst_play_bin_signals[SIGNAL_ABOUT_TO_FINISH], 0, NULL);

  /* now activate the next group. If the app did not set a uri, this will
   * fail and we can do EOS */
  setup_next_source (playbin, GST_STATE_PAUSED);
}

/* Like gst_element_factory_can_sink_any_caps() but doesn't
 * allow ANY caps on the sinkpad template */
static gboolean
_factory_can_sink_caps (GstElementFactory * factory, GstCaps * caps)
{
  const GList *templs;

  templs = gst_element_factory_get_static_pad_templates (factory);

  while (templs) {
    GstStaticPadTemplate *templ = (GstStaticPadTemplate *) templs->data;

    if (templ->direction == GST_PAD_SINK) {
      GstCaps *templcaps = gst_static_caps_get (&templ->static_caps);

      if (!gst_caps_is_any (templcaps)
          && gst_caps_can_intersect (templcaps, caps)) {
        gst_caps_unref (templcaps);
        return TRUE;
      }
      gst_caps_unref (templcaps);
    }
    templs = g_list_next (templs);
  }

  return FALSE;
}

/* Called when we must provide a list of factories to plug to @pad with @caps.
 * We first check if we have a sink that can handle the format and if we do, we
 * return NULL, to expose the pad. If we have no sink (or the sink does not
 * work), we return the list of elements that can connect. */
static GValueArray *
autoplug_factories_cb (GstElement * decodebin, GstPad * pad,
    GstCaps * caps, GstSourceGroup * group)
{
  GstPlayBin *playbin;
  GList *mylist, *tmp;
  GValueArray *result;

  playbin = group->playbin;

  GST_DEBUG_OBJECT (playbin, "factories group %p for %s:%s, %" GST_PTR_FORMAT,
      group, GST_DEBUG_PAD_NAME (pad), caps);

  /* filter out the elements based on the caps. */
  g_mutex_lock (playbin->elements_lock);
  gst_play_bin_update_elements_list (playbin);
  mylist =
      gst_element_factory_list_filter (playbin->elements, caps, GST_PAD_SINK,
      FALSE);
  g_mutex_unlock (playbin->elements_lock);

  GST_DEBUG_OBJECT (playbin, "found factories %p", mylist);
  GST_PLUGIN_FEATURE_LIST_DEBUG (mylist);

  /* 2 additional elements for the already set audio/video sinks */
  result = g_value_array_new (g_list_length (mylist) + 2);

  /* Check if we already have an audio/video sink and if this is the case
   * put it as the first element of the array */
  if (group->audio_sink) {
    GstElementFactory *factory = gst_element_get_factory (group->audio_sink);

    if (factory && _factory_can_sink_caps (factory, caps)) {
      GValue val = { 0, };

      g_value_init (&val, G_TYPE_OBJECT);
      g_value_set_object (&val, factory);
      result = g_value_array_append (result, &val);
      g_value_unset (&val);
    }
  }

  if (group->video_sink) {
    GstElementFactory *factory = gst_element_get_factory (group->video_sink);

    if (factory && _factory_can_sink_caps (factory, caps)) {
      GValue val = { 0, };

      g_value_init (&val, G_TYPE_OBJECT);
      g_value_set_object (&val, factory);
      result = g_value_array_append (result, &val);
      g_value_unset (&val);
    }
  }

  for (tmp = mylist; tmp; tmp = tmp->next) {
    GstElementFactory *factory = GST_ELEMENT_FACTORY_CAST (tmp->data);
    GValue val = { 0, };

    if (group->audio_sink && gst_element_factory_list_is_type (factory,
            GST_ELEMENT_FACTORY_TYPE_SINK |
            GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO)) {
      continue;
    }
    if (group->video_sink && gst_element_factory_list_is_type (factory,
            GST_ELEMENT_FACTORY_TYPE_SINK | GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO
            | GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE)) {
      continue;
    }

    g_value_init (&val, G_TYPE_OBJECT);
    g_value_set_object (&val, factory);
    g_value_array_append (result, &val);
    g_value_unset (&val);
  }
  gst_plugin_feature_list_free (mylist);

  return result;
}

/* autoplug-continue decides, if a pad has raw caps that can be exposed
 * directly or if further decoding is necessary. We use this to expose
 * supported subtitles directly */

/* FIXME 0.11: Remove the checks for ANY caps, a sink should specify
 * explicitely the caps it supports and if it claims to support ANY
 * caps it really should support everything */
static gboolean
autoplug_continue_cb (GstElement * element, GstPad * pad, GstCaps * caps,
    GstSourceGroup * group)
{
  gboolean ret = TRUE;
  GstElement *sink;
  GstPad *sinkpad = NULL;

  GST_PLAY_BIN_LOCK (group->playbin);
  GST_SOURCE_GROUP_LOCK (group);

  if ((sink = group->playbin->text_sink))
    sinkpad = gst_element_get_static_pad (sink, "sink");
  if (sinkpad) {
    GstCaps *sinkcaps;

    /* Ignore errors here, if a custom sink fails to go
     * to READY things are wrong and will error out later
     */
    if (GST_STATE (sink) < GST_STATE_READY)
      gst_element_set_state (sink, GST_STATE_READY);

    sinkcaps = gst_pad_get_caps (sinkpad, NULL);
    if (!gst_caps_is_any (sinkcaps))
      ret = !gst_pad_accept_caps (sinkpad, caps);
    gst_caps_unref (sinkcaps);
    gst_object_unref (sinkpad);
  } else {
    GstCaps *subcaps = gst_subtitle_overlay_create_factory_caps ();
    ret = !gst_caps_is_subset (caps, subcaps);
    gst_caps_unref (subcaps);
  }
  /* If autoplugging can stop don't do additional checks */
  if (!ret)
    goto done;

  /* If this is from the subtitle uridecodebin we don't need to
   * check the audio and video sink */
  if (group->suburidecodebin
      && gst_object_has_ancestor (GST_OBJECT_CAST (element),
          GST_OBJECT_CAST (group->suburidecodebin)))
    goto done;

  if ((sink = group->audio_sink)) {
    sinkpad = gst_element_get_static_pad (sink, "sink");
    if (sinkpad) {
      GstCaps *sinkcaps;

      /* Ignore errors here, if a custom sink fails to go
       * to READY things are wrong and will error out later
       */
      if (GST_STATE (sink) < GST_STATE_READY)
        gst_element_set_state (sink, GST_STATE_READY);

      sinkcaps = gst_pad_get_caps (sinkpad, NULL);
      if (!gst_caps_is_any (sinkcaps))
        ret = !gst_pad_accept_caps (sinkpad, caps);
      gst_caps_unref (sinkcaps);
      gst_object_unref (sinkpad);
    }
  }
  if (!ret)
    goto done;

  if ((sink = group->video_sink)) {
    sinkpad = gst_element_get_static_pad (sink, "sink");
    if (sinkpad) {
      GstCaps *sinkcaps;

      /* Ignore errors here, if a custom sink fails to go
       * to READY things are wrong and will error out later
       */
      if (GST_STATE (sink) < GST_STATE_READY)
        gst_element_set_state (sink, GST_STATE_READY);

      sinkcaps = gst_pad_get_caps (sinkpad, NULL);
      if (!gst_caps_is_any (sinkcaps))
        ret = !gst_pad_accept_caps (sinkpad, caps);
      gst_caps_unref (sinkcaps);
      gst_object_unref (sinkpad);
    }
  }

done:
  GST_SOURCE_GROUP_UNLOCK (group);
  GST_PLAY_BIN_UNLOCK (group->playbin);

  GST_DEBUG_OBJECT (group->playbin,
      "continue autoplugging group %p for %s:%s, %" GST_PTR_FORMAT ": %d",
      group, GST_DEBUG_PAD_NAME (pad), caps, ret);

  return ret;
}

static gboolean
sink_accepts_caps (GstElement * sink, GstCaps * caps)
{
  GstPad *sinkpad;

  /* ... activate it ... We do this before adding it to the bin so that we
   * don't accidentally make it post error messages that will stop
   * everything. */
  if (GST_STATE (sink) < GST_STATE_READY &&
      gst_element_set_state (sink,
          GST_STATE_READY) == GST_STATE_CHANGE_FAILURE) {
    return FALSE;
  }

  if ((sinkpad = gst_element_get_static_pad (sink, "sink"))) {
    /* Got the sink pad, now let's see if the element actually does accept the
     * caps that we have */
    if (!gst_pad_accept_caps (sinkpad, caps)) {
      gst_object_unref (sinkpad);
      return FALSE;
    }
    gst_object_unref (sinkpad);
  }

  return TRUE;
}

/* We are asked to select an element. See if the next element to check
 * is a sink. If this is the case, we see if the sink works by setting it to
 * READY. If the sink works, we return SELECT_EXPOSE to make decodebin
 * expose the raw pad so that we can setup the mixers. */
static GstAutoplugSelectResult
autoplug_select_cb (GstElement * decodebin, GstPad * pad,
    GstCaps * caps, GstElementFactory * factory, GstSourceGroup * group)
{
  GstPlayBin *playbin;
  GstElement *element;
  const gchar *klass;
  GstPlaySinkType type;
  GstElement **sinkp;

  playbin = group->playbin;

  GST_DEBUG_OBJECT (playbin, "select group %p for %s:%s, %" GST_PTR_FORMAT,
      group, GST_DEBUG_PAD_NAME (pad), caps);

  GST_DEBUG_OBJECT (playbin, "checking factory %s", GST_OBJECT_NAME (factory));

  /* if it's not a sink, we make sure the element is compatible with
   * the fixed sink */
  if (!gst_element_factory_list_is_type (factory,
          GST_ELEMENT_FACTORY_TYPE_SINK)) {
    gboolean isvideodec = gst_element_factory_list_is_type (factory,
        GST_ELEMENT_FACTORY_TYPE_DECODER |
        GST_ELEMENT_FACTORY_TYPE_MEDIA_VIDEO |
        GST_ELEMENT_FACTORY_TYPE_MEDIA_IMAGE);
    gboolean isaudiodec = gst_element_factory_list_is_type (factory,
        GST_ELEMENT_FACTORY_TYPE_DECODER |
        GST_ELEMENT_FACTORY_TYPE_MEDIA_AUDIO);

    /* If it is a decoder and we have a fixed sink for the media
     * type it outputs, check that the decoder is compatible with this sink */
    if ((isvideodec && group->video_sink) || (isaudiodec && group->audio_sink)) {
      gboolean compatible = TRUE;
      GstPad *sinkpad;
      GstCaps *caps;
      GstElement *sink;

      if (isaudiodec)
        sink = group->audio_sink;
      else
        sink = group->video_sink;

      if ((sinkpad = gst_element_get_static_pad (sink, "sink"))) {
        caps = gst_pad_get_caps (sinkpad, NULL);

        compatible = gst_element_factory_can_src_any_caps (factory, caps);

        gst_object_unref (sinkpad);
        gst_caps_unref (caps);
      }

      if (compatible)
        return GST_AUTOPLUG_SELECT_TRY;

      GST_DEBUG_OBJECT (playbin, "%s not compatible with the fixed sink",
          GST_OBJECT_NAME (factory));

      return GST_AUTOPLUG_SELECT_SKIP;
    } else
      return GST_AUTOPLUG_SELECT_TRY;
  }

  /* it's a sink, see if an instance of it actually works */
  GST_DEBUG_OBJECT (playbin, "we found a sink");

  klass = gst_element_factory_get_klass (factory);

  /* figure out the klass */
  if (strstr (klass, "Audio")) {
    GST_DEBUG_OBJECT (playbin, "we found an audio sink");
    type = GST_PLAY_SINK_TYPE_AUDIO;
    sinkp = &group->audio_sink;
  } else if (strstr (klass, "Video")) {
    GST_DEBUG_OBJECT (playbin, "we found a video sink");
    type = GST_PLAY_SINK_TYPE_VIDEO;
    sinkp = &group->video_sink;
  } else {
    /* unknown klass, skip this element */
    GST_WARNING_OBJECT (playbin, "unknown sink klass %s found", klass);
    return GST_AUTOPLUG_SELECT_SKIP;
  }

  /* if we are asked to do visualisations and it's an audio sink, skip the
   * element. We can only do visualisations with raw sinks */
  if (gst_play_sink_get_flags (playbin->playsink) & GST_PLAY_FLAG_VIS) {
    if (type == GST_PLAY_SINK_TYPE_AUDIO) {
      GST_DEBUG_OBJECT (playbin, "skip audio sink because of vis");
      return GST_AUTOPLUG_SELECT_SKIP;
    }
  }

  /* now see if we already have a sink element */
  GST_SOURCE_GROUP_LOCK (group);
  if (*sinkp) {
    GstElement *sink = gst_object_ref (*sinkp);

    if (sink_accepts_caps (sink, caps)) {
      GST_DEBUG_OBJECT (playbin,
          "Existing sink '%s' accepts caps: %" GST_PTR_FORMAT,
          GST_ELEMENT_NAME (sink), caps);
      gst_object_unref (sink);
      GST_SOURCE_GROUP_UNLOCK (group);
      return GST_AUTOPLUG_SELECT_EXPOSE;
    } else {
      GST_DEBUG_OBJECT (playbin,
          "Existing sink '%s' does not accept caps: %" GST_PTR_FORMAT,
          GST_ELEMENT_NAME (sink), caps);
      gst_object_unref (sink);
      GST_SOURCE_GROUP_UNLOCK (group);
      return GST_AUTOPLUG_SELECT_SKIP;
    }
  }
  GST_DEBUG_OBJECT (playbin, "we have no pending sink, try to create one");

  if ((element = gst_element_factory_create (factory, NULL)) == NULL) {
    GST_WARNING_OBJECT (playbin, "Could not create an element from %s",
        gst_plugin_feature_get_name (GST_PLUGIN_FEATURE (factory)));
    GST_SOURCE_GROUP_UNLOCK (group);
    return GST_AUTOPLUG_SELECT_SKIP;
  }

  /* Check if the selected sink actually supports the
   * caps and can be set to READY*/
  if (!sink_accepts_caps (element, caps)) {
    gst_element_set_state (element, GST_STATE_NULL);
    gst_object_unref (element);
    GST_SOURCE_GROUP_UNLOCK (group);
    return GST_AUTOPLUG_SELECT_SKIP;
  }

  /* remember the sink in the group now, the element is floating, we take
   * ownership now 
   *
   * store the sink in the group, we will configure it later when we
   * reconfigure the sink */
  GST_DEBUG_OBJECT (playbin, "remember sink");
  gst_object_ref_sink (element);
  *sinkp = element;
  GST_SOURCE_GROUP_UNLOCK (group);

  /* tell decodebin to expose the pad because we are going to use this
   * sink */
  GST_DEBUG_OBJECT (playbin, "we found a working sink, expose pad");

  return GST_AUTOPLUG_SELECT_EXPOSE;
}

static void
notify_source_cb (GstElement * uridecodebin, GParamSpec * pspec,
    GstSourceGroup * group)
{
  GstPlayBin *playbin;
  GstElement *source;

  playbin = group->playbin;

  g_object_get (group->uridecodebin, "source", &source, NULL);

  GST_OBJECT_LOCK (playbin);
  if (playbin->source)
    gst_object_unref (playbin->source);
  playbin->source = source;
  GST_OBJECT_UNLOCK (playbin);

  g_object_notify (G_OBJECT (playbin), "source");

  g_signal_emit (playbin, gst_play_bin_signals[SIGNAL_SOURCE_SETUP],
      0, playbin->source);
}

/* must be called with the group lock */
static gboolean
group_set_locked_state_unlocked (GstPlayBin * playbin, GstSourceGroup * group,
    gboolean locked)
{
  GST_DEBUG_OBJECT (playbin, "locked_state %d on group %p", locked, group);

  if (group->uridecodebin)
    gst_element_set_locked_state (group->uridecodebin, locked);
  if (group->suburidecodebin)
    gst_element_set_locked_state (group->suburidecodebin, locked);

  return TRUE;
}

/* must be called with PLAY_BIN_LOCK */
static gboolean
activate_group (GstPlayBin * playbin, GstSourceGroup * group, GstState target)
{
  GstElement *uridecodebin;
  GstElement *suburidecodebin = NULL;
  GstPlayFlags flags;

  g_return_val_if_fail (group->valid, FALSE);
  g_return_val_if_fail (!group->active, FALSE);

  GST_DEBUG_OBJECT (playbin, "activating group %p", group);

  GST_SOURCE_GROUP_LOCK (group);

  /* First set up the custom sources */
  if (playbin->audio_sink)
    group->audio_sink = gst_object_ref (playbin->audio_sink);
  if (playbin->video_sink)
    group->video_sink = gst_object_ref (playbin->video_sink);

  g_list_free (group->stream_changed_pending);
  group->stream_changed_pending = NULL;
  if (!group->stream_changed_pending_lock)
    group->stream_changed_pending_lock = g_mutex_new ();

  if (group->uridecodebin) {
    GST_DEBUG_OBJECT (playbin, "reusing existing uridecodebin");
    uridecodebin = group->uridecodebin;
    gst_element_set_state (uridecodebin, GST_STATE_READY);
    gst_bin_add (GST_BIN_CAST (playbin), gst_object_ref (uridecodebin));
  } else {
    GST_DEBUG_OBJECT (playbin, "making new uridecodebin");
    uridecodebin = gst_element_factory_make ("uridecodebin", NULL);
    if (!uridecodebin)
      goto no_decodebin;
    gst_bin_add (GST_BIN_CAST (playbin), uridecodebin);
    group->uridecodebin = gst_object_ref (uridecodebin);
  }

  flags = gst_play_sink_get_flags (playbin->playsink);

  g_object_set (uridecodebin,
      /* configure connection speed */
      "connection-speed", playbin->connection_speed / 1000,
      /* configure uri */
      "uri", group->uri,
      /* configure download buffering */
      "download", ((flags & GST_PLAY_FLAG_DOWNLOAD) != 0),
      /* configure buffering of demuxed/parsed data */
      "use-buffering", ((flags & GST_PLAY_FLAG_BUFFERING) != 0),
      /* configure buffering parameters */
      "buffer-duration", playbin->buffer_duration,
      "buffer-size", playbin->buffer_size,
      "ring-buffer-max-size", playbin->ring_buffer_max_size, NULL);

  /* connect pads and other things */
  group->pad_added_id = g_signal_connect (uridecodebin, "pad-added",
      G_CALLBACK (pad_added_cb), group);
  group->pad_removed_id = g_signal_connect (uridecodebin, "pad-removed",
      G_CALLBACK (pad_removed_cb), group);
  group->no_more_pads_id = g_signal_connect (uridecodebin, "no-more-pads",
      G_CALLBACK (no_more_pads_cb), group);
  group->notify_source_id = g_signal_connect (uridecodebin, "notify::source",
      G_CALLBACK (notify_source_cb), group);

  /* we have 1 pending no-more-pads */
  group->pending = 1;

  /* is called when the uridecodebin is out of data and we can switch to the
   * next uri */
  group->drained_id =
      g_signal_connect (uridecodebin, "drained", G_CALLBACK (drained_cb),
      group);

  /* will be called when a new media type is found. We return a list of decoders
   * including sinks for decodebin to try */
  group->autoplug_factories_id =
      g_signal_connect (uridecodebin, "autoplug-factories",
      G_CALLBACK (autoplug_factories_cb), group);
  group->autoplug_select_id =
      g_signal_connect (uridecodebin, "autoplug-select",
      G_CALLBACK (autoplug_select_cb), group);
  group->autoplug_continue_id =
      g_signal_connect (uridecodebin, "autoplug-continue",
      G_CALLBACK (autoplug_continue_cb), group);

  if (group->suburi) {
    /* subtitles */
    if (group->suburidecodebin) {
      GST_DEBUG_OBJECT (playbin, "reusing existing suburidecodebin");
      suburidecodebin = group->suburidecodebin;
      gst_element_set_state (suburidecodebin, GST_STATE_READY);
      gst_bin_add (GST_BIN_CAST (playbin), gst_object_ref (suburidecodebin));
    } else {
      GST_DEBUG_OBJECT (playbin, "making new suburidecodebin");
      suburidecodebin = gst_element_factory_make ("uridecodebin", NULL);
      if (!suburidecodebin)
        goto no_decodebin;

      gst_bin_add (GST_BIN_CAST (playbin), suburidecodebin);
      group->suburidecodebin = gst_object_ref (suburidecodebin);
    }

    g_object_set (suburidecodebin,
        /* configure connection speed */
        "connection-speed", playbin->connection_speed,
        /* configure uri */
        "uri", group->suburi, NULL);

    /* connect pads and other things */
    group->sub_pad_added_id = g_signal_connect (suburidecodebin, "pad-added",
        G_CALLBACK (pad_added_cb), group);
    group->sub_pad_removed_id = g_signal_connect (suburidecodebin,
        "pad-removed", G_CALLBACK (pad_removed_cb), group);
    group->sub_no_more_pads_id = g_signal_connect (suburidecodebin,
        "no-more-pads", G_CALLBACK (no_more_pads_cb), group);

    group->sub_autoplug_continue_id =
        g_signal_connect (suburidecodebin, "autoplug-continue",
        G_CALLBACK (autoplug_continue_cb), group);

    /* we have 2 pending no-more-pads */
    group->pending = 2;
    group->sub_pending = TRUE;
  } else {
    group->sub_pending = FALSE;
  }

  /* release the group lock before setting the state of the decodebins, they
   * might fire signals in this thread that we need to handle with the
   * group_lock taken. */
  GST_SOURCE_GROUP_UNLOCK (group);

  if (suburidecodebin) {
    if (gst_element_set_state (suburidecodebin,
            target) == GST_STATE_CHANGE_FAILURE) {
      GST_DEBUG_OBJECT (playbin,
          "failed state change of subtitle uridecodebin");
      GST_SOURCE_GROUP_LOCK (group);

      REMOVE_SIGNAL (group->suburidecodebin, group->sub_pad_added_id);
      REMOVE_SIGNAL (group->suburidecodebin, group->sub_pad_removed_id);
      REMOVE_SIGNAL (group->suburidecodebin, group->sub_no_more_pads_id);
      REMOVE_SIGNAL (group->suburidecodebin, group->sub_autoplug_continue_id);
      /* Might already be removed because of an error message */
      if (GST_OBJECT_PARENT (suburidecodebin) == GST_OBJECT_CAST (playbin))
        gst_bin_remove (GST_BIN_CAST (playbin), suburidecodebin);
      if (group->sub_pending) {
        group->pending--;
        group->sub_pending = FALSE;
      }
      gst_element_set_state (suburidecodebin, GST_STATE_READY);
      GST_SOURCE_GROUP_UNLOCK (group);
    }
  }
  if (gst_element_set_state (uridecodebin, target) == GST_STATE_CHANGE_FAILURE)
    goto uridecodebin_failure;

  GST_SOURCE_GROUP_LOCK (group);
  /* alow state changes of the playbin affect the group elements now */
  group_set_locked_state_unlocked (playbin, group, FALSE);
  group->active = TRUE;
  GST_SOURCE_GROUP_UNLOCK (group);

  return TRUE;

  /* ERRORS */
no_decodebin:
  {
    GstMessage *msg;

    /* delete any custom sinks we might have */
    if (group->audio_sink) {
      /* If this is a automatically created sink set it to NULL */
      if (group->audio_sink != playbin->audio_sink)
        gst_element_set_state (group->audio_sink, GST_STATE_NULL);
      gst_object_unref (group->audio_sink);
    }
    group->audio_sink = NULL;
    if (group->video_sink) {
      /* If this is a automatically created sink set it to NULL */
      if (group->video_sink != playbin->video_sink)
        gst_element_set_state (group->video_sink, GST_STATE_NULL);
      gst_object_unref (group->video_sink);
    }
    group->video_sink = NULL;

    GST_SOURCE_GROUP_UNLOCK (group);
    msg =
        gst_missing_element_message_new (GST_ELEMENT_CAST (playbin),
        "uridecodebin");
    gst_element_post_message (GST_ELEMENT_CAST (playbin), msg);

    GST_ELEMENT_ERROR (playbin, CORE, MISSING_PLUGIN,
        (_("Could not create \"uridecodebin\" element.")), (NULL));
    return FALSE;
  }
uridecodebin_failure:
  {
    /* delete any custom sinks we might have */
    if (group->audio_sink) {
      /* If this is a automatically created sink set it to NULL */
      if (group->audio_sink != playbin->audio_sink)
        gst_element_set_state (group->audio_sink, GST_STATE_NULL);
      gst_object_unref (group->audio_sink);
    }
    group->audio_sink = NULL;
    if (group->video_sink) {
      /* If this is a automatically created sink set it to NULL */
      if (group->video_sink != playbin->video_sink)
        gst_element_set_state (group->video_sink, GST_STATE_NULL);
      gst_object_unref (group->video_sink);
    }
    group->video_sink = NULL;

    GST_DEBUG_OBJECT (playbin, "failed state change of uridecodebin");
    return FALSE;
  }
}

/* unlink a group of uridecodebins from the sink.
 * must be called with PLAY_BIN_LOCK */
static gboolean
deactivate_group (GstPlayBin * playbin, GstSourceGroup * group)
{
  gint i;

  g_return_val_if_fail (group->valid, FALSE);
  g_return_val_if_fail (group->active, FALSE);

  GST_DEBUG_OBJECT (playbin, "unlinking group %p", group);

  GST_SOURCE_GROUP_LOCK (group);
  group->active = FALSE;
  for (i = 0; i < PLAYBIN_STREAM_LAST; i++) {
    GstSourceSelect *select = &group->selector[i];

    GST_DEBUG_OBJECT (playbin, "unlinking selector %s", select->media_list[0]);

    if (select->srcpad) {
      if (select->sinkpad) {
        GST_LOG_OBJECT (playbin, "unlinking from sink");
        gst_pad_unlink (select->srcpad, select->sinkpad);

        /* release back */
        GST_LOG_OBJECT (playbin, "release sink pad");
        gst_play_sink_release_pad (playbin->playsink, select->sinkpad);
        select->sinkpad = NULL;
      }

      gst_object_unref (select->srcpad);
      select->srcpad = NULL;
    }

    if (select->selector) {
      gint n;

      /* release and unref requests pad from the selector */
      for (n = 0; n < select->channels->len; n++) {
        GstPad *sinkpad = g_ptr_array_index (select->channels, n);

        gst_element_release_request_pad (select->selector, sinkpad);
        gst_object_unref (sinkpad);
      }
      g_ptr_array_set_size (select->channels, 0);

      gst_element_set_state (select->selector, GST_STATE_NULL);
      gst_bin_remove (GST_BIN_CAST (playbin), select->selector);
      select->selector = NULL;
    }
  }
  /* delete any custom sinks we might have */
  if (group->audio_sink) {
    /* If this is a automatically created sink set it to NULL */
    if (group->audio_sink != playbin->audio_sink)
      gst_element_set_state (group->audio_sink, GST_STATE_NULL);
    gst_object_unref (group->audio_sink);
  }
  group->audio_sink = NULL;
  if (group->video_sink) {
    /* If this is a automatically created sink set it to NULL */
    if (group->video_sink != playbin->video_sink)
      gst_element_set_state (group->video_sink, GST_STATE_NULL);
    gst_object_unref (group->video_sink);
  }
  group->video_sink = NULL;

  if (group->uridecodebin) {
    REMOVE_SIGNAL (group->uridecodebin, group->pad_added_id);
    REMOVE_SIGNAL (group->uridecodebin, group->pad_removed_id);
    REMOVE_SIGNAL (group->uridecodebin, group->no_more_pads_id);
    REMOVE_SIGNAL (group->uridecodebin, group->notify_source_id);
    REMOVE_SIGNAL (group->uridecodebin, group->drained_id);
    REMOVE_SIGNAL (group->uridecodebin, group->autoplug_factories_id);
    REMOVE_SIGNAL (group->uridecodebin, group->autoplug_select_id);
    REMOVE_SIGNAL (group->uridecodebin, group->autoplug_continue_id);
    gst_bin_remove (GST_BIN_CAST (playbin), group->uridecodebin);
  }

  if (group->suburidecodebin) {
    REMOVE_SIGNAL (group->suburidecodebin, group->sub_pad_added_id);
    REMOVE_SIGNAL (group->suburidecodebin, group->sub_pad_removed_id);
    REMOVE_SIGNAL (group->suburidecodebin, group->sub_no_more_pads_id);
    REMOVE_SIGNAL (group->suburidecodebin, group->sub_autoplug_continue_id);

    /* Might already be removed because of errors */
    if (GST_OBJECT_PARENT (group->suburidecodebin) == GST_OBJECT_CAST (playbin))
      gst_bin_remove (GST_BIN_CAST (playbin), group->suburidecodebin);
  }

  GST_SOURCE_GROUP_UNLOCK (group);

  return TRUE;
}

/* setup the next group to play, this assumes the next_group is valid and
 * configured. It swaps out the current_group and activates the valid
 * next_group. */
static gboolean
setup_next_source (GstPlayBin * playbin, GstState target)
{
  GstSourceGroup *new_group, *old_group;

  GST_DEBUG_OBJECT (playbin, "setup sources");

  /* see if there is a next group */
  GST_PLAY_BIN_LOCK (playbin);
  new_group = playbin->next_group;
  if (!new_group || !new_group->valid)
    goto no_next_group;

  /* first unlink the current source, if any */
  old_group = playbin->curr_group;
  if (old_group && old_group->valid && old_group->active) {
    gst_play_bin_update_cached_duration (playbin);
    /* unlink our pads with the sink */
    deactivate_group (playbin, old_group);
    old_group->valid = FALSE;
  }

  /* swap old and new */
  playbin->curr_group = new_group;
  playbin->next_group = old_group;

  /* activate the new group */
  if (!activate_group (playbin, new_group, target))
    goto activate_failed;

  GST_PLAY_BIN_UNLOCK (playbin);

  return TRUE;

  /* ERRORS */
no_next_group:
  {
    GST_DEBUG_OBJECT (playbin, "no next group");
    if (target == GST_STATE_READY && new_group && new_group->uri == NULL)
      GST_ELEMENT_ERROR (playbin, RESOURCE, NOT_FOUND, ("No URI set"), (NULL));
    GST_PLAY_BIN_UNLOCK (playbin);
    return FALSE;
  }
activate_failed:
  {
    GST_DEBUG_OBJECT (playbin, "activate failed");
    GST_PLAY_BIN_UNLOCK (playbin);
    return FALSE;
  }
}

/* The group that is currently playing is copied again to the
 * next_group so that it will start playing the next time.
 */
static gboolean
save_current_group (GstPlayBin * playbin)
{
  GstSourceGroup *curr_group;

  GST_DEBUG_OBJECT (playbin, "save current group");

  /* see if there is a current group */
  GST_PLAY_BIN_LOCK (playbin);
  curr_group = playbin->curr_group;
  if (curr_group && curr_group->valid) {
    /* unlink our pads with the sink */
    deactivate_group (playbin, curr_group);
  }
  /* swap old and new */
  playbin->curr_group = playbin->next_group;
  playbin->next_group = curr_group;
  GST_PLAY_BIN_UNLOCK (playbin);

  return TRUE;
}

/* clear the locked state from all groups. This function is called before a
 * state change to NULL is performed on them. */
static gboolean
groups_set_locked_state (GstPlayBin * playbin, gboolean locked)
{
  GST_DEBUG_OBJECT (playbin, "setting locked state to %d on all groups",
      locked);

  GST_PLAY_BIN_LOCK (playbin);
  GST_SOURCE_GROUP_LOCK (playbin->curr_group);
  group_set_locked_state_unlocked (playbin, playbin->curr_group, locked);
  GST_SOURCE_GROUP_UNLOCK (playbin->curr_group);
  GST_SOURCE_GROUP_LOCK (playbin->next_group);
  group_set_locked_state_unlocked (playbin, playbin->next_group, locked);
  GST_SOURCE_GROUP_UNLOCK (playbin->next_group);
  GST_PLAY_BIN_UNLOCK (playbin);

  return TRUE;
}

static GstStateChangeReturn
gst_play_bin_change_state (GstElement * element, GstStateChange transition)
{
  GstStateChangeReturn ret;
  GstPlayBin *playbin;
  gboolean do_save = FALSE;

  playbin = GST_PLAY_BIN (element);

  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
      memset (&playbin->duration, 0, sizeof (playbin->duration));
      break;
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      GST_LOG_OBJECT (playbin, "clearing shutdown flag");
      memset (&playbin->duration, 0, sizeof (playbin->duration));
      g_atomic_int_set (&playbin->shutdown, 0);

      if (!setup_next_source (playbin, GST_STATE_READY)) {
        ret = GST_STATE_CHANGE_FAILURE;
        goto failure;
      }
      break;
    case GST_STATE_CHANGE_PAUSED_TO_READY:
    async_down:
      /* FIXME unlock our waiting groups */
      GST_LOG_OBJECT (playbin, "setting shutdown flag");
      g_atomic_int_set (&playbin->shutdown, 1);
      memset (&playbin->duration, 0, sizeof (playbin->duration));

      /* wait for all callbacks to end by taking the lock.
       * No dynamic (critical) new callbacks will
       * be able to happen as we set the shutdown flag. */
      GST_PLAY_BIN_DYN_LOCK (playbin);
      GST_LOG_OBJECT (playbin, "dynamic lock taken, we can continue shutdown");
      GST_PLAY_BIN_DYN_UNLOCK (playbin);
      if (!do_save)
        break;
    case GST_STATE_CHANGE_READY_TO_NULL:
      /* we go async to PAUSED, so if that fails, we never make it to PAUSED
       * an no state change PAUSED to READY passes here,
       * though it is a nice-to-have ... */
      if (!g_atomic_int_get (&playbin->shutdown)) {
        do_save = TRUE;
        goto async_down;
      }
      memset (&playbin->duration, 0, sizeof (playbin->duration));

      /* unlock so that all groups go to NULL */
      groups_set_locked_state (playbin, FALSE);
      break;
    default:
      break;
  }

  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
  if (ret == GST_STATE_CHANGE_FAILURE)
    goto failure;

  switch (transition) {
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      break;
    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
      /* FIXME Release audio device when we implement that */
      break;
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      save_current_group (playbin);
      break;
    case GST_STATE_CHANGE_READY_TO_NULL:
    {
      guint i;

      /* also do missed state change down to READY */
      if (do_save)
        save_current_group (playbin);
      /* Deactive the groups, set the uridecodebins to NULL
       * and unref them.
       */
      for (i = 0; i < 2; i++) {
        if (playbin->groups[i].active && playbin->groups[i].valid) {
          deactivate_group (playbin, &playbin->groups[i]);
          playbin->groups[i].valid = FALSE;
        }

        if (playbin->groups[i].uridecodebin) {
          gst_element_set_state (playbin->groups[i].uridecodebin,
              GST_STATE_NULL);
          gst_object_unref (playbin->groups[i].uridecodebin);
          playbin->groups[i].uridecodebin = NULL;
        }

        if (playbin->groups[i].suburidecodebin) {
          gst_element_set_state (playbin->groups[i].suburidecodebin,
              GST_STATE_NULL);
          gst_object_unref (playbin->groups[i].suburidecodebin);
          playbin->groups[i].suburidecodebin = NULL;
        }
      }

      /* Set our sinks back to NULL, they might not be child of playbin */
      if (playbin->audio_sink)
        gst_element_set_state (playbin->audio_sink, GST_STATE_NULL);
      if (playbin->video_sink)
        gst_element_set_state (playbin->video_sink, GST_STATE_NULL);
      if (playbin->text_sink)
        gst_element_set_state (playbin->text_sink, GST_STATE_NULL);

      /* make sure the groups don't perform a state change anymore until we
       * enable them again */
      groups_set_locked_state (playbin, TRUE);
      break;
    }
    default:
      break;
  }

  return ret;

  /* ERRORS */
failure:
  {
    if (transition == GST_STATE_CHANGE_READY_TO_PAUSED) {
      GstSourceGroup *curr_group;

      curr_group = playbin->curr_group;
      if (curr_group && curr_group->active && curr_group->valid) {
        /* unlink our pads with the sink */
        deactivate_group (playbin, curr_group);
        curr_group->valid = FALSE;
      }

      /* Swap current and next group back */
      playbin->curr_group = playbin->next_group;
      playbin->next_group = curr_group;
    }
    return ret;
  }
}

gboolean
gst_play_bin2_plugin_init (GstPlugin * plugin)
{
  GST_DEBUG_CATEGORY_INIT (gst_play_bin_debug, "playbin", 0, "play bin");

  return gst_element_register (plugin, "playbin", GST_RANK_NONE,
      GST_TYPE_PLAY_BIN);
}