C++ GST_PAD_CAST函數代碼示例

static void
gst_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 void
splitmux_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.
 */
gboolean
gst_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 void
no_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 void
gst_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 void
gst_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 void
gst_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 void
gst_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 gboolean
gst_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 void
gst_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 gboolean
forward_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;
}