自学教程：C++ GST_PAD_CAST函数代码示例

static voidgst_ghost_pad_init (GstGhostPad * pad){  GST_GHOST_PAD_PRIVATE (pad) = G_TYPE_INSTANCE_GET_PRIVATE (pad,      GST_TYPE_GHOST_PAD, GstGhostPadPrivate);  gst_pad_set_setcaps_function (GST_PAD_CAST (pad),      GST_DEBUG_FUNCPTR (gst_ghost_pad_do_setcaps));  gst_pad_set_activatepull_function (GST_PAD_CAST (pad),      GST_DEBUG_FUNCPTR (gst_ghost_pad_do_activate_pull));  gst_pad_set_activatepush_function (GST_PAD_CAST (pad),      GST_DEBUG_FUNCPTR (gst_ghost_pad_do_activate_push));}

static voidsplitmux_part_reader_reset (GstSplitMuxPartReader * reader){  GList *cur;  SPLITMUX_PART_LOCK (reader);  for (cur = g_list_first (reader->pads); cur != NULL; cur = g_list_next (cur)) {    GstPad *pad = GST_PAD_CAST (cur->data);    gst_pad_set_active (GST_PAD_CAST (pad), FALSE);    gst_object_unref (GST_OBJECT_CAST (pad));  }  g_list_free (reader->pads);  reader->pads = NULL;  SPLITMUX_PART_UNLOCK (reader);}

/** * gst_ghost_pad_set_target: * @gpad: the #GstGhostPad * @newtarget: (transfer none) (allow-none): the new pad target * * Set the new target of the ghostpad @gpad. Any existing target * is unlinked and links to the new target are established. if @newtarget is * %NULL the target will be cleared. * * Returns: (transfer full): %TRUE if the new target could be set. This function *     can return %FALSE when the internal pads could not be linked. */gbooleangst_ghost_pad_set_target (GstGhostPad * gpad, GstPad * newtarget){    GstPad *internal;    GstPad *oldtarget;    GstPadLinkReturn lret;    g_return_val_if_fail (GST_IS_GHOST_PAD (gpad), FALSE);    g_return_val_if_fail (GST_PAD_CAST (gpad) != newtarget, FALSE);    g_return_val_if_fail (newtarget != GST_PROXY_PAD_INTERNAL (gpad), FALSE);    GST_OBJECT_LOCK (gpad);    internal = GST_PROXY_PAD_INTERNAL (gpad);    if (newtarget)        GST_DEBUG_OBJECT (gpad, "set target %s:%s", GST_DEBUG_PAD_NAME (newtarget));    else        GST_DEBUG_OBJECT (gpad, "clearing target");    /* clear old target */    if ((oldtarget = gst_pad_get_peer (internal))) {        GST_OBJECT_UNLOCK (gpad);        /* unlink internal pad */        if (GST_PAD_IS_SRC (internal))            gst_pad_unlink (internal, oldtarget);        else            gst_pad_unlink (oldtarget, internal);        gst_object_unref (oldtarget);    } else {        GST_OBJECT_UNLOCK (gpad);    }    if (newtarget) {        /* and link to internal pad without any checks */        GST_DEBUG_OBJECT (gpad, "connecting internal pad to target %"                          GST_PTR_FORMAT, newtarget);        if (GST_PAD_IS_SRC (internal))            lret =                gst_pad_link_full (internal, newtarget, GST_PAD_LINK_CHECK_NOTHING);        else            lret =                gst_pad_link_full (newtarget, internal, GST_PAD_LINK_CHECK_NOTHING);        if (lret != GST_PAD_LINK_OK)            goto link_failed;    }    return TRUE;    /* ERRORS */link_failed:    {        GST_WARNING_OBJECT (gpad, "could not link internal and target, reason:%s",                            gst_pad_link_get_name (lret));        return FALSE;    }}

static voidno_more_pads (GstElement * element, GstSplitMuxPartReader * reader){  GstClockTime duration = GST_CLOCK_TIME_NONE;  GList *cur;  /* Query the minimum duration of any pad in this piece and store it.   * FIXME: Only consider audio and video */  SPLITMUX_PART_LOCK (reader);  for (cur = g_list_first (reader->pads); cur != NULL; cur = g_list_next (cur)) {    GstPad *target = GST_PAD_CAST (cur->data);    if (target) {      gint64 cur_duration;      if (gst_pad_peer_query_duration (target, GST_FORMAT_TIME, &cur_duration)) {        GST_INFO_OBJECT (reader,            "file %s pad %" GST_PTR_FORMAT " duration %" GST_TIME_FORMAT,            reader->path, target, GST_TIME_ARGS (cur_duration));        if (cur_duration < duration)          duration = cur_duration;      }    }  }  GST_INFO_OBJECT (reader, "file %s duration %" GST_TIME_FORMAT,      reader->path, GST_TIME_ARGS (duration));  reader->duration = (GstClockTime) duration;  reader->no_more_pads = TRUE;  check_if_pads_collected (reader);  SPLITMUX_PART_UNLOCK (reader);}

static voidgst_play_sink_video_convert_init (GstPlaySinkVideoConvert * self){    GstPadTemplate *templ;    self->lock = g_mutex_new ();    gst_segment_init (&self->segment, GST_FORMAT_UNDEFINED);    templ = gst_static_pad_template_get (&sinktemplate);    self->sinkpad = gst_ghost_pad_new_no_target_from_template ("sink", templ);    gst_pad_set_event_function (self->sinkpad,                                GST_DEBUG_FUNCPTR (gst_play_sink_video_convert_sink_event));    gst_pad_set_setcaps_function (self->sinkpad,                                  GST_DEBUG_FUNCPTR (gst_play_sink_video_convert_sink_setcaps));    gst_pad_set_getcaps_function (self->sinkpad,                                  GST_DEBUG_FUNCPTR (gst_play_sink_video_convert_getcaps));    self->sink_proxypad =        GST_PAD_CAST (gst_proxy_pad_get_internal (GST_PROXY_PAD (self->sinkpad)));    gst_element_add_pad (GST_ELEMENT_CAST (self), self->sinkpad);    gst_object_unref (templ);    templ = gst_static_pad_template_get (&srctemplate);    self->srcpad = gst_ghost_pad_new_no_target_from_template ("src", templ);    gst_pad_set_getcaps_function (self->srcpad,                                  GST_DEBUG_FUNCPTR (gst_play_sink_video_convert_getcaps));    gst_element_add_pad (GST_ELEMENT_CAST (self), self->srcpad);    gst_object_unref (templ);    gst_ghost_pad_set_target (GST_GHOST_PAD_CAST (self->srcpad),                              self->sink_proxypad);}

static voidgst_selector_pad_get_property (GObject * object, guint prop_id,    GValue * value, GParamSpec * pspec){  GstSelectorPad *spad = GST_SELECTOR_PAD_CAST (object);  switch (prop_id) {    case PROP_PAD_RUNNING_TIME:      g_value_set_int64 (value, gst_selector_pad_get_running_time (spad));      break;    case PROP_PAD_TAGS:      GST_OBJECT_LOCK (object);      g_value_set_boxed (value, spad->tags);      GST_OBJECT_UNLOCK (object);      break;    case PROP_PAD_ACTIVE:    {      GstInputSelector *sel;      sel = GST_INPUT_SELECTOR (gst_pad_get_parent (spad));      g_value_set_boolean (value, gst_input_selector_is_active_sinkpad (sel,              GST_PAD_CAST (spad)));      gst_object_unref (sel);      break;    }    case PROP_PAD_ALWAYS_OK:      GST_OBJECT_LOCK (object);      g_value_set_boolean (value, spad->always_ok);      GST_OBJECT_UNLOCK (object);      break;    default:      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);      break;  }}

static voidgst_play_sink_convert_bin_init (GstPlaySinkConvertBin * self){  GstPadTemplate *templ;  g_mutex_init (&self->lock);  templ = gst_static_pad_template_get (&sinktemplate);  self->sinkpad = gst_ghost_pad_new_no_target_from_template ("sink", templ);  gst_pad_set_event_function (self->sinkpad,      GST_DEBUG_FUNCPTR (gst_play_sink_convert_bin_sink_event));  gst_pad_set_query_function (self->sinkpad,      GST_DEBUG_FUNCPTR (gst_play_sink_convert_bin_query));  self->sink_proxypad =      GST_PAD_CAST (gst_proxy_pad_get_internal (GST_PROXY_PAD (self->sinkpad)));  gst_element_add_pad (GST_ELEMENT_CAST (self), self->sinkpad);  gst_object_unref (templ);  templ = gst_static_pad_template_get (&srctemplate);  self->srcpad = gst_ghost_pad_new_no_target_from_template ("src", templ);  gst_pad_set_query_function (self->srcpad,      GST_DEBUG_FUNCPTR (gst_play_sink_convert_bin_query));  gst_element_add_pad (GST_ELEMENT_CAST (self), self->srcpad);  gst_object_unref (templ);  gst_play_sink_convert_bin_add_identity (self);}

static voidgst_selector_pad_get_property (GObject * object,    guint prop_id, GValue * value, GParamSpec * pspec){  RsnSelectorPad *pad;  pad = GST_SELECTOR_PAD (object);  switch (prop_id) {    case PROP_PAD_TAGS:      GST_OBJECT_LOCK (object);      g_value_set_boxed (value, pad->tags);      GST_OBJECT_UNLOCK (object);      break;    case PROP_PAD_ACTIVE:    {      RsnStreamSelector *sel;      sel = RSN_STREAM_SELECTOR (gst_pad_get_parent (pad));      g_value_set_boolean (value, rsn_stream_selector_is_active_sinkpad (sel,              GST_PAD_CAST (pad)));      gst_object_unref (sel);      break;    }    default:      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);      break;  }}

static GstPad *gst_ghost_pad_new_full (const gchar * name, GstPadDirection dir,    GstPadTemplate * templ){  GstGhostPad *ret;  g_return_val_if_fail (dir != GST_PAD_UNKNOWN, NULL);  /* OBJECT CREATION */  if (templ) {    ret = g_object_new (GST_TYPE_GHOST_PAD, "name", name,        "direction", dir, "template", templ, NULL);  } else {    ret = g_object_new (GST_TYPE_GHOST_PAD, "name", name,        "direction", dir, NULL);  }  if (!gst_ghost_pad_construct (ret))    goto construct_failed;  return GST_PAD_CAST (ret);construct_failed:  /* already logged */  gst_object_unref (ret);  return NULL;}

static gbooleangst_audiomixer_sink_event (GstAggregator * agg, GstAggregatorPad * aggpad,    GstEvent * event){  GstAudioMixer *audiomixer = GST_AUDIO_MIXER (agg);  gboolean res = TRUE;  GST_DEBUG_OBJECT (aggpad, "Got %s event on sink pad",      GST_EVENT_TYPE_NAME (event));  switch (GST_EVENT_TYPE (event)) {    case GST_EVENT_CAPS:    {      GstCaps *caps;      gst_event_parse_caps (event, &caps);      res = gst_audiomixer_setcaps (audiomixer, GST_PAD_CAST (aggpad), caps);      gst_event_unref (event);      event = NULL;      break;    }    default:      break;  }  if (event != NULL)    return GST_AGGREGATOR_CLASS (parent_class)->sink_event (agg, aggpad, event);  return res;}

static GstPad *gst_funnel_request_new_pad (GstElement * element, GstPadTemplate * templ,    const gchar * name, const GstCaps * caps){  GstPad *sinkpad;  GST_DEBUG_OBJECT (element, "requesting pad");  sinkpad = GST_PAD_CAST (g_object_new (GST_TYPE_FUNNEL_PAD,          "name", name, "direction", templ->direction, "template", templ,          NULL));  gst_pad_set_chain_function (sinkpad,      GST_DEBUG_FUNCPTR (gst_funnel_sink_chain));  gst_pad_set_chain_list_function (sinkpad,      GST_DEBUG_FUNCPTR (gst_funnel_sink_chain_list));  gst_pad_set_event_function (sinkpad,      GST_DEBUG_FUNCPTR (gst_funnel_sink_event));  GST_OBJECT_FLAG_SET (sinkpad, GST_PAD_FLAG_PROXY_CAPS);  GST_OBJECT_FLAG_SET (sinkpad, GST_PAD_FLAG_PROXY_ALLOCATION);  gst_pad_set_active (sinkpad, TRUE);  gst_element_add_pad (element, sinkpad);  GST_DEBUG_OBJECT (element, "requested pad %s:%s",      GST_DEBUG_PAD_NAME (sinkpad));  return sinkpad;}

static GstPad *_create_pad (GstMssDemux * mssdemux, GstMssStream * manifeststream){  gchar *name = NULL;  GstPad *srcpad = NULL;  GstMssStreamType streamtype;  GstPadTemplate *tmpl = NULL;  streamtype = gst_mss_stream_get_type (manifeststream);  GST_DEBUG_OBJECT (mssdemux, "Found stream of type: %s",      gst_mss_stream_type_name (streamtype));  /* TODO use stream's name/bitrate/index as the pad name? */  if (streamtype == MSS_STREAM_TYPE_VIDEO) {    name = g_strdup_printf ("video_%02u", mssdemux->n_videos++);    tmpl = gst_static_pad_template_get (&gst_mss_demux_videosrc_template);  } else if (streamtype == MSS_STREAM_TYPE_AUDIO) {    name = g_strdup_printf ("audio_%02u", mssdemux->n_audios++);    tmpl = gst_static_pad_template_get (&gst_mss_demux_audiosrc_template);  }  if (tmpl != NULL) {    srcpad =        GST_PAD_CAST (gst_ghost_pad_new_no_target_from_template (name, tmpl));    g_free (name);    gst_object_unref (tmpl);  }  if (!srcpad) {    GST_WARNING_OBJECT (mssdemux, "Ignoring unknown type stream");    return NULL;  }  return srcpad;}

static voidgst_ghost_pad_init (GstGhostPad * pad){  GST_GHOST_PAD_PRIVATE (pad) = gst_ghost_pad_get_instance_private (pad);  gst_pad_set_activatemode_function (GST_PAD_CAST (pad),      gst_ghost_pad_activate_mode_default);}

void notifyGstTagsOnPad(GstElement* element, GstPad* pad, GstTagList* tags){#ifdef GST_API_VERSION_1    UNUSED_PARAM(element);    gst_pad_push_event(GST_PAD_CAST(pad), gst_event_new_tag(tags));#else    gst_element_found_tags_for_pad(element, pad, tags);#endif}

static gbooleanforward_sticky_events (GstPad * pad, GstEvent ** event, gpointer user_data){  GstPad *srcpad = GST_PAD_CAST (user_data);  gst_pad_push_event (srcpad, gst_event_ref (*event));  return TRUE;}

static voidgst_ghost_pad_init (GstGhostPad * pad){  GST_GHOST_PAD_PRIVATE (pad) = G_TYPE_INSTANCE_GET_PRIVATE (pad,      GST_TYPE_GHOST_PAD, GstGhostPadPrivate);  gst_pad_set_activatemode_function (GST_PAD_CAST (pad),      gst_ghost_pad_activate_mode_default);}

static voidkms_agnostic_bin2_link_to_tee (KmsAgnosticBin2 * self, GstPad * pad,    GstElement * tee, GstCaps * caps){  GstElement *queue = gst_element_factory_make ("queue", NULL);  GstPad *target;  GstProxyPad *proxy;  gst_bin_add (GST_BIN (self), queue);  gst_element_sync_state_with_parent (queue);  if (!(gst_caps_is_any (caps) || gst_caps_is_empty (caps))      && kms_utils_caps_are_raw (caps)) {    GstElement *convert = kms_utils_create_convert_for_caps (caps);    GstElement *rate = kms_utils_create_rate_for_caps (caps);    GstElement *mediator = kms_utils_create_mediator_element (caps);    remove_element_on_unlinked (convert, "src", "sink");    if (rate) {      remove_element_on_unlinked (rate, "src", "sink");    }    remove_element_on_unlinked (mediator, "src", "sink");    if (rate) {      gst_bin_add (GST_BIN (self), rate);    }    gst_bin_add_many (GST_BIN (self), convert, mediator, NULL);    gst_element_sync_state_with_parent (mediator);    gst_element_sync_state_with_parent (convert);    if (rate) {      gst_element_sync_state_with_parent (rate);    }    if (rate) {      gst_element_link_many (queue, rate, mediator, NULL);    } else {      gst_element_link (queue, mediator);    }    gst_element_link_many (mediator, convert, NULL);    target = gst_element_get_static_pad (convert, "src");  } else {    target = gst_element_get_static_pad (queue, "src");  }  gst_ghost_pad_set_target (GST_GHOST_PAD (pad), target);  proxy = gst_proxy_pad_get_internal (GST_PROXY_PAD (pad));  gst_pad_set_query_function (GST_PAD_CAST (proxy),      proxy_src_pad_query_function);  g_object_unref (proxy);  g_object_unref (target);  link_element_to_tee (tee, queue);}

static gbooleanforward_sticky_events (GstPad * pad, GstEvent ** event, gpointer user_data){  GstPad *srcpad = GST_PAD_CAST (user_data);  /* Stream start and caps have already been pushed */  if (GST_EVENT_TYPE (*event) >= GST_EVENT_SEGMENT)    gst_pad_push_event (srcpad, gst_event_ref (*event));  return TRUE;}

gbooleangst_stream_info_set_mute (GstStreamInfo * stream_info, gboolean mute){  g_return_val_if_fail (GST_IS_STREAM_INFO (stream_info), FALSE);  if (stream_info->type == GST_STREAM_TYPE_ELEMENT) {    g_warning ("cannot mute element stream");    return FALSE;  }  if (mute != stream_info->mute) {    /* nothing really happens here. it looks like gstplaybasebin installs a     * buffer probe hat drops buffers when muting. but the this removes it self     * after first call.     */    stream_info->mute = mute;#if 0    gst_pad_set_active ((GstPad *) GST_PAD_CAST (stream_info->object), !mute);#endif#if 0    {      GstElement *element;      element = gst_pad_get_parent_element ((GstPad *)          GST_PAD_CAST (stream_info->object));      if (element) {        if (mute) {          g_signal_connect (element, "state-changed",              G_CALLBACK (stream_info_change_state), stream_info);        } else {          g_signal_handlers_disconnect_by_func (element,              G_CALLBACK (stream_info_change_state), stream_info);        }        gst_object_unref (element);      }    }#endif  }  return TRUE;}

/** * gst_ghost_pad_get_target: * @gpad: the #GstGhostPad * * Get the target pad of @gpad. Unref target pad after usage. * * Returns: (transfer full): the target #GstPad, can be NULL if the ghostpad * has no target set. Unref target pad after usage. */GstPad *gst_ghost_pad_get_target (GstGhostPad * gpad){  GstPad *ret;  g_return_val_if_fail (GST_IS_GHOST_PAD (gpad), NULL);  ret = gst_proxy_pad_get_target (GST_PAD_CAST (gpad));  GST_DEBUG_OBJECT (gpad, "get target %s:%s", GST_DEBUG_PAD_NAME (ret));  return ret;}

static gbooleanproxy_src_pad_query_function (GstPad * pad, GstObject * parent,    GstQuery * query){  gboolean ret = gst_pad_query_default (pad, parent, query);  if (!ret) {    return ret;  }  if (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS) {    gboolean accepted;    gst_query_parse_accept_caps_result (query, &accepted);    if (!accepted) {      GstProxyPad *gp = gst_proxy_pad_get_internal (GST_PROXY_PAD (pad));      KmsAgnosticBin2 *self = NULL;      GST_ERROR_OBJECT (pad, "Caps not accepted: %" GST_PTR_FORMAT, query);      if (gp) {        self = KMS_AGNOSTIC_BIN2 (GST_OBJECT_PARENT (gp));      }      if (self) {        KMS_AGNOSTIC_BIN2_LOCK (self);        remove_target_pad (GST_PAD_CAST (gp));        kms_agnostic_bin2_process_pad (self, GST_PAD_CAST (gp));        KMS_AGNOSTIC_BIN2_UNLOCK (self);      }      g_object_unref (gp);    }  }  return ret;}

static gbooleanforward_sticky_events (GstPad * pad, GstEvent ** event, gpointer user_data){  GstPad *srcpad = GST_PAD_CAST (user_data);  GstFlowReturn ret;  ret = gst_pad_store_sticky_event (srcpad, *event);  if (ret != GST_FLOW_OK) {    GST_DEBUG_OBJECT (srcpad, "storing sticky event %p (%s) failed: %s", *event,        GST_EVENT_TYPE_NAME (*event), gst_flow_get_name (ret));  }  return TRUE;}

static voidrsn_dec_init (RsnDec * self, RsnDecClass * klass){  GstPadTemplate *templ;  templ =      gst_element_class_get_pad_template (GST_ELEMENT_CLASS (klass), "sink");  g_assert (templ != NULL);  self->sinkpad =      GST_GHOST_PAD_CAST (gst_ghost_pad_new_no_target_from_template ("sink",          templ));  self->sink_event_func = GST_PAD_EVENTFUNC (self->sinkpad);  gst_pad_set_event_function (GST_PAD_CAST (self->sinkpad),      GST_DEBUG_FUNCPTR (rsn_dec_sink_event));  templ = gst_element_class_get_pad_template (GST_ELEMENT_CLASS (klass), "src");  g_assert (templ != NULL);  self->srcpad =      GST_GHOST_PAD_CAST (gst_ghost_pad_new_no_target_from_template ("src",          templ));  gst_element_add_pad (GST_ELEMENT (self), GST_PAD_CAST (self->sinkpad));  gst_element_add_pad (GST_ELEMENT (self), GST_PAD_CAST (self->srcpad));}

static GstPad *gst_tcp_mix_src_request_new_pad (GstElement * element, GstPadTemplate * templ,    const gchar * unused, const GstCaps * caps){  GstTCPMixSrc *src = GST_TCP_MIX_SRC (element);  GstPad *srcpad;  gchar *name;  gboolean res;  int num;  //g_print ("%s:%d: %s/n", __FILE__, __LINE__, __FUNCTION__);  GST_INFO_OBJECT (src, "Requesting new pad %s.%s (caps: %s)",      GST_ELEMENT_NAME (src), GST_PAD_TEMPLATE_NAME_TEMPLATE (templ),      gst_caps_to_string (caps));  GST_OBJECT_LOCK (src);  num = g_list_length (GST_ELEMENT_PADS (src));  name = g_strdup_printf ("src_%u", num);  srcpad = GST_PAD_CAST (g_object_new (GST_TYPE_TCP_MIX_SRC_PAD,          "name", name, "direction", templ->direction, "template", templ,          NULL));  g_free (name);  GST_OBJECT_UNLOCK (src);  // see: gst_tcp_mix_src_activate_push  gst_pad_set_active (srcpad, TRUE);  gst_pad_activate_mode (srcpad, GST_PAD_MODE_PUSH, TRUE);  gst_pad_set_activatemode_function (srcpad,      (GstPadActivateModeFunction) gst_tcp_mix_src_activate_mode);  gst_pad_set_query_function (srcpad, gst_tcp_mix_src_query);  gst_pad_set_event_function (srcpad, gst_tcp_mix_src_event);  gst_pad_set_getrange_function (srcpad, gst_tcp_mix_src_getrange);  //GST_OBJECT_FLAG_SET (srcpad, GST_PAD_FLAG_PROXY_CAPS);  //INFO ("add-pad: %s.%s", GST_ELEMENT_NAME (src), GST_PAD_NAME (srcpad));  res = gst_element_add_pad (GST_ELEMENT_CAST (src), srcpad);  gst_tcp_mix_src_start (src, GST_TCP_MIX_SRC_PAD (srcpad));  if (G_UNLIKELY (!res)) {    GST_ERROR_OBJECT (src, "Failed to add new pad");  }  return srcpad;}

static gbooleanrsn_dec_sink_event (GstPad * pad, GstObject * parent, GstEvent * event){  RsnDec *self = RSN_DEC (parent);  gboolean ret = TRUE;  const GstStructure *s = gst_event_get_structure (event);  const gchar *name = (s ? gst_structure_get_name (s) : NULL);  if (name && g_str_equal (name, "application/x-gst-dvd"))    ret = gst_pad_push_event (GST_PAD_CAST (self->srcpad), event);  else    ret = self->sink_event_func (pad, parent, event);  return ret;}

static GstSplitMuxPartPad *gst_splitmux_part_reader_new_proxy_pad (GstSplitMuxPartReader * reader,    GstPad * target){  GstSplitMuxPartPad *pad = g_object_new (SPLITMUX_TYPE_PART_PAD,      "name", GST_PAD_NAME (target),      "direction", GST_PAD_SINK,      NULL);  pad->target = target;  pad->reader = reader;  gst_pad_set_active (GST_PAD_CAST (pad), TRUE);  return pad;}

/* TODO(ensonic): gst_pad_get_parent_element() would not work here, should we * add this as new api, e.g. gst_pad_find_parent_element(); */static GstElement *get_real_pad_parent (GstPad * pad){  GstObject *parent;  if (!pad)    return NULL;  parent = GST_OBJECT_PARENT (pad);  /* if parent of pad is a ghost-pad, then pad is a proxy_pad */  if (parent && GST_IS_GHOST_PAD (parent)) {    pad = GST_PAD_CAST (parent);    parent = GST_OBJECT_PARENT (pad);  }  return GST_ELEMENT_CAST (parent);}