2 * Copyright (C) <2007> Wim Taymans <wim.taymans@gmail.com>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
23 * SECTION:element-gstrtpssrcdemux
25 * gstrtpssrcdemux acts as a demuxer for RTP packets based on the SSRC of the
26 * packets. Its main purpose is to allow an application to easily receive and
27 * decode an RTP stream with multiple SSRCs.
29 * For each SSRC that is detected, a new pad will be created and the
30 * #GstRtpSsrcDemux::new-ssrc-pad signal will be emitted.
33 * <title>Example pipelines</title>
35 * gst-launch udpsrc caps="application/x-rtp" ! gstrtpssrcdemux ! fakesink
36 * ]| Takes an RTP stream and send the RTP packets with the first detected SSRC
37 * to fakesink, discarding the other SSRCs.
40 * Last reviewed on 2007-05-28 (0.10.5)
48 #include <gst/rtp/gstrtpbuffer.h>
49 #include <gst/rtp/gstrtcpbuffer.h>
51 #include "gstrtpbin-marshal.h"
52 #include "gstrtpssrcdemux.h"
54 GST_DEBUG_CATEGORY_STATIC (gst_rtp_ssrc_demux_debug);
55 #define GST_CAT_DEFAULT gst_rtp_ssrc_demux_debug
57 /* generic templates */
58 static GstStaticPadTemplate rtp_ssrc_demux_sink_template =
59 GST_STATIC_PAD_TEMPLATE ("sink",
62 GST_STATIC_CAPS ("application/x-rtp")
65 static GstStaticPadTemplate rtp_ssrc_demux_rtcp_sink_template =
66 GST_STATIC_PAD_TEMPLATE ("rtcp_sink",
69 GST_STATIC_CAPS ("application/x-rtcp")
72 static GstStaticPadTemplate rtp_ssrc_demux_src_template =
73 GST_STATIC_PAD_TEMPLATE ("src_%d",
76 GST_STATIC_CAPS ("application/x-rtp")
79 static GstStaticPadTemplate rtp_ssrc_demux_rtcp_src_template =
80 GST_STATIC_PAD_TEMPLATE ("rtcp_src_%d",
83 GST_STATIC_CAPS ("application/x-rtcp")
86 #define GST_PAD_LOCK(obj) (g_mutex_lock ((obj)->padlock))
87 #define GST_PAD_UNLOCK(obj) (g_mutex_unlock ((obj)->padlock))
93 SIGNAL_REMOVED_SSRC_PAD,
98 GST_BOILERPLATE (GstRtpSsrcDemux, gst_rtp_ssrc_demux, GstElement,
102 /* GObject vmethods */
103 static void gst_rtp_ssrc_demux_dispose (GObject * object);
104 static void gst_rtp_ssrc_demux_finalize (GObject * object);
106 /* GstElement vmethods */
107 static GstStateChangeReturn gst_rtp_ssrc_demux_change_state (GstElement *
108 element, GstStateChange transition);
110 static void gst_rtp_ssrc_demux_clear_ssrc (GstRtpSsrcDemux * demux,
114 static GstFlowReturn gst_rtp_ssrc_demux_chain (GstPad * pad, GstBuffer * buf);
115 static gboolean gst_rtp_ssrc_demux_sink_event (GstPad * pad, GstEvent * event);
117 static GstFlowReturn gst_rtp_ssrc_demux_rtcp_chain (GstPad * pad,
119 static gboolean gst_rtp_ssrc_demux_rtcp_sink_event (GstPad * pad,
123 static gboolean gst_rtp_ssrc_demux_src_event (GstPad * pad, GstEvent * event);
124 static GstIterator *gst_rtp_ssrc_demux_iterate_internal_links (GstPad * pad);
125 static gboolean gst_rtp_ssrc_demux_src_query (GstPad * pad, GstQuery * query);
127 static guint gst_rtp_ssrc_demux_signals[LAST_SIGNAL] = { 0 };
130 * Item for storing GstPad <-> SSRC pairs.
132 struct _GstRtpSsrcDemuxPad
140 /* find a src pad for a given SSRC, returns NULL if the SSRC was not found
142 static GstRtpSsrcDemuxPad *
143 find_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc)
147 for (walk = demux->srcpads; walk; walk = g_slist_next (walk)) {
148 GstRtpSsrcDemuxPad *pad = (GstRtpSsrcDemuxPad *) walk->data;
150 if (pad->ssrc == ssrc)
157 static GstRtpSsrcDemuxPad *
158 create_demux_pad_for_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc,
159 GstClockTime timestamp)
161 GstPad *rtp_pad, *rtcp_pad;
162 GstElementClass *klass;
163 GstPadTemplate *templ;
165 GstRtpSsrcDemuxPad *demuxpad;
167 GST_DEBUG_OBJECT (demux, "creating pad for SSRC %08x", ssrc);
169 klass = GST_ELEMENT_GET_CLASS (demux);
170 templ = gst_element_class_get_pad_template (klass, "src_%d");
171 padname = g_strdup_printf ("src_%d", ssrc);
172 rtp_pad = gst_pad_new_from_template (templ, padname);
175 templ = gst_element_class_get_pad_template (klass, "rtcp_src_%d");
176 padname = g_strdup_printf ("rtcp_src_%d", ssrc);
177 rtcp_pad = gst_pad_new_from_template (templ, padname);
180 /* we use the first timestamp received to calculate the difference between
181 * timestamps on all streams */
182 GST_DEBUG_OBJECT (demux, "SSRC %08x, first timestamp %" GST_TIME_FORMAT,
183 ssrc, GST_TIME_ARGS (timestamp));
185 /* wrap in structure and add to list */
186 demuxpad = g_new0 (GstRtpSsrcDemuxPad, 1);
187 demuxpad->ssrc = ssrc;
188 demuxpad->rtp_pad = rtp_pad;
189 demuxpad->rtcp_pad = rtcp_pad;
191 GST_DEBUG_OBJECT (demux, "first timestamp %" GST_TIME_FORMAT,
192 GST_TIME_ARGS (timestamp));
194 gst_pad_set_element_private (rtp_pad, demuxpad);
195 gst_pad_set_element_private (rtcp_pad, demuxpad);
197 demux->srcpads = g_slist_prepend (demux->srcpads, demuxpad);
199 /* copy caps from input */
200 gst_pad_set_caps (rtp_pad, GST_PAD_CAPS (demux->rtp_sink));
201 gst_pad_use_fixed_caps (rtp_pad);
202 gst_pad_set_caps (rtcp_pad, GST_PAD_CAPS (demux->rtcp_sink));
203 gst_pad_use_fixed_caps (rtcp_pad);
205 gst_pad_set_event_function (rtp_pad, gst_rtp_ssrc_demux_src_event);
206 gst_pad_set_query_function (rtp_pad, gst_rtp_ssrc_demux_src_query);
207 gst_pad_set_iterate_internal_links_function (rtp_pad,
208 gst_rtp_ssrc_demux_iterate_internal_links);
209 gst_pad_set_active (rtp_pad, TRUE);
211 gst_pad_set_iterate_internal_links_function (rtcp_pad,
212 gst_rtp_ssrc_demux_iterate_internal_links);
213 gst_pad_set_active (rtcp_pad, TRUE);
215 gst_element_add_pad (GST_ELEMENT_CAST (demux), rtp_pad);
216 gst_element_add_pad (GST_ELEMENT_CAST (demux), rtcp_pad);
218 g_signal_emit (G_OBJECT (demux),
219 gst_rtp_ssrc_demux_signals[SIGNAL_NEW_SSRC_PAD], 0, ssrc, rtp_pad);
225 gst_rtp_ssrc_demux_base_init (gpointer g_class)
227 GstElementClass *gstelement_klass = GST_ELEMENT_CLASS (g_class);
229 gst_element_class_add_pad_template (gstelement_klass,
230 gst_static_pad_template_get (&rtp_ssrc_demux_sink_template));
231 gst_element_class_add_pad_template (gstelement_klass,
232 gst_static_pad_template_get (&rtp_ssrc_demux_rtcp_sink_template));
233 gst_element_class_add_pad_template (gstelement_klass,
234 gst_static_pad_template_get (&rtp_ssrc_demux_src_template));
235 gst_element_class_add_pad_template (gstelement_klass,
236 gst_static_pad_template_get (&rtp_ssrc_demux_rtcp_src_template));
238 gst_element_class_set_details_simple (gstelement_klass, "RTP SSRC Demux",
240 "Splits RTP streams based on the SSRC",
241 "Wim Taymans <wim.taymans@gmail.com>");
245 gst_rtp_ssrc_demux_class_init (GstRtpSsrcDemuxClass * klass)
247 GObjectClass *gobject_klass;
248 GstElementClass *gstelement_klass;
249 GstRtpSsrcDemuxClass *gstrtpssrcdemux_klass;
251 gobject_klass = (GObjectClass *) klass;
252 gstelement_klass = (GstElementClass *) klass;
253 gstrtpssrcdemux_klass = (GstRtpSsrcDemuxClass *) klass;
255 gobject_klass->dispose = gst_rtp_ssrc_demux_dispose;
256 gobject_klass->finalize = gst_rtp_ssrc_demux_finalize;
259 * GstRtpSsrcDemux::new-ssrc-pad:
260 * @demux: the object which received the signal
261 * @ssrc: the SSRC of the pad
264 * Emited when a new SSRC pad has been created.
266 gst_rtp_ssrc_demux_signals[SIGNAL_NEW_SSRC_PAD] =
267 g_signal_new ("new-ssrc-pad",
268 G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
269 G_STRUCT_OFFSET (GstRtpSsrcDemuxClass, new_ssrc_pad),
270 NULL, NULL, gst_rtp_bin_marshal_VOID__UINT_OBJECT,
271 G_TYPE_NONE, 2, G_TYPE_UINT, GST_TYPE_PAD);
274 * GstRtpSsrcDemux::removed-ssrc-pad:
275 * @demux: the object which received the signal
276 * @ssrc: the SSRC of the pad
277 * @pad: the removed pad.
279 * Emited when a SSRC pad has been removed.
281 gst_rtp_ssrc_demux_signals[SIGNAL_REMOVED_SSRC_PAD] =
282 g_signal_new ("removed-ssrc-pad",
283 G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
284 G_STRUCT_OFFSET (GstRtpSsrcDemuxClass, removed_ssrc_pad),
285 NULL, NULL, gst_rtp_bin_marshal_VOID__UINT_OBJECT,
286 G_TYPE_NONE, 2, G_TYPE_UINT, GST_TYPE_PAD);
289 * GstRtpSsrcDemux::clear-ssrc:
290 * @demux: the object which received the signal
291 * @ssrc: the SSRC of the pad
293 * Action signal to remove the pad for SSRC.
295 gst_rtp_ssrc_demux_signals[SIGNAL_CLEAR_SSRC] =
296 g_signal_new ("clear-ssrc",
297 G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
298 G_STRUCT_OFFSET (GstRtpSsrcDemuxClass, clear_ssrc),
299 NULL, NULL, gst_rtp_bin_marshal_VOID__UINT, G_TYPE_NONE, 1, G_TYPE_UINT);
301 gstelement_klass->change_state =
302 GST_DEBUG_FUNCPTR (gst_rtp_ssrc_demux_change_state);
303 gstrtpssrcdemux_klass->clear_ssrc =
304 GST_DEBUG_FUNCPTR (gst_rtp_ssrc_demux_clear_ssrc);
306 GST_DEBUG_CATEGORY_INIT (gst_rtp_ssrc_demux_debug,
307 "rtpssrcdemux", 0, "RTP SSRC demuxer");
311 gst_rtp_ssrc_demux_init (GstRtpSsrcDemux * demux,
312 GstRtpSsrcDemuxClass * g_class)
314 GstElementClass *klass = GST_ELEMENT_GET_CLASS (demux);
317 gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
319 gst_pad_set_chain_function (demux->rtp_sink, gst_rtp_ssrc_demux_chain);
320 gst_pad_set_event_function (demux->rtp_sink, gst_rtp_ssrc_demux_sink_event);
321 gst_element_add_pad (GST_ELEMENT_CAST (demux), demux->rtp_sink);
324 gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
325 "rtcp_sink"), "rtcp_sink");
326 gst_pad_set_chain_function (demux->rtcp_sink, gst_rtp_ssrc_demux_rtcp_chain);
327 gst_pad_set_event_function (demux->rtcp_sink,
328 gst_rtp_ssrc_demux_rtcp_sink_event);
329 gst_element_add_pad (GST_ELEMENT_CAST (demux), demux->rtcp_sink);
331 demux->padlock = g_mutex_new ();
333 gst_segment_init (&demux->segment, GST_FORMAT_UNDEFINED);
337 gst_rtp_ssrc_demux_reset (GstRtpSsrcDemux * demux)
341 for (walk = demux->srcpads; walk; walk = g_slist_next (walk)) {
342 GstRtpSsrcDemuxPad *dpad = (GstRtpSsrcDemuxPad *) walk->data;
344 gst_pad_set_active (dpad->rtp_pad, FALSE);
345 gst_pad_set_active (dpad->rtcp_pad, FALSE);
347 gst_element_remove_pad (GST_ELEMENT_CAST (demux), dpad->rtp_pad);
348 gst_element_remove_pad (GST_ELEMENT_CAST (demux), dpad->rtcp_pad);
351 g_slist_free (demux->srcpads);
352 demux->srcpads = NULL;
356 gst_rtp_ssrc_demux_dispose (GObject * object)
358 GstRtpSsrcDemux *demux;
360 demux = GST_RTP_SSRC_DEMUX (object);
362 gst_rtp_ssrc_demux_reset (demux);
364 G_OBJECT_CLASS (parent_class)->dispose (object);
368 gst_rtp_ssrc_demux_finalize (GObject * object)
370 GstRtpSsrcDemux *demux;
372 demux = GST_RTP_SSRC_DEMUX (object);
373 g_mutex_free (demux->padlock);
375 G_OBJECT_CLASS (parent_class)->finalize (object);
379 gst_rtp_ssrc_demux_clear_ssrc (GstRtpSsrcDemux * demux, guint32 ssrc)
381 GstRtpSsrcDemuxPad *dpad;
383 GST_PAD_LOCK (demux);
384 dpad = find_demux_pad_for_ssrc (demux, ssrc);
388 GST_DEBUG_OBJECT (demux, "clearing pad for SSRC %08x", ssrc);
390 demux->srcpads = g_slist_remove (demux->srcpads, dpad);
391 GST_PAD_UNLOCK (demux);
393 gst_pad_set_active (dpad->rtp_pad, FALSE);
394 gst_pad_set_active (dpad->rtcp_pad, FALSE);
396 g_signal_emit (G_OBJECT (demux),
397 gst_rtp_ssrc_demux_signals[SIGNAL_REMOVED_SSRC_PAD], 0, ssrc,
400 gst_element_remove_pad (GST_ELEMENT_CAST (demux), dpad->rtp_pad);
401 gst_element_remove_pad (GST_ELEMENT_CAST (demux), dpad->rtcp_pad);
410 g_warning ("unknown SSRC %08x", ssrc);
416 gst_rtp_ssrc_demux_sink_event (GstPad * pad, GstEvent * event)
418 GstRtpSsrcDemux *demux;
419 gboolean res = FALSE;
421 demux = GST_RTP_SSRC_DEMUX (gst_pad_get_parent (pad));
423 switch (GST_EVENT_TYPE (event)) {
424 case GST_EVENT_FLUSH_STOP:
425 gst_segment_init (&demux->segment, GST_FORMAT_UNDEFINED);
426 case GST_EVENT_NEWSEGMENT:
433 /* need local snapshot of pads;
434 * should not push downstream while holding lock as that might deadlock
435 * with stuff traveling upstream tyring to get this lock while holding
436 * other (stream)lock */
437 GST_PAD_LOCK (demux);
438 for (walk = demux->srcpads; walk; walk = g_slist_next (walk)) {
439 GstRtpSsrcDemuxPad *pad = (GstRtpSsrcDemuxPad *) walk->data;
441 pads = g_slist_prepend (pads, gst_object_ref (pad->rtp_pad));
443 GST_PAD_UNLOCK (demux);
444 for (walk = pads; walk; walk = g_slist_next (walk)) {
445 GstPad *pad = (GstPad *) walk->data;
447 gst_event_ref (event);
448 res &= gst_pad_push_event (pad, event);
449 gst_object_unref (pad);
452 gst_event_unref (event);
457 gst_object_unref (demux);
462 gst_rtp_ssrc_demux_rtcp_sink_event (GstPad * pad, GstEvent * event)
464 GstRtpSsrcDemux *demux;
465 gboolean res = FALSE;
467 demux = GST_RTP_SSRC_DEMUX (gst_pad_get_parent (pad));
469 switch (GST_EVENT_TYPE (event)) {
470 case GST_EVENT_NEWSEGMENT:
477 GST_PAD_LOCK (demux);
478 for (walk = demux->srcpads; walk; walk = g_slist_next (walk)) {
479 GstRtpSsrcDemuxPad *pad = (GstRtpSsrcDemuxPad *) walk->data;
481 pads = g_slist_prepend (pads, gst_object_ref (pad->rtcp_pad));
483 GST_PAD_UNLOCK (demux);
484 for (walk = pads; walk; walk = g_slist_next (walk)) {
485 GstPad *pad = (GstPad *) walk->data;
487 gst_event_ref (event);
488 res &= gst_pad_push_event (pad, event);
489 gst_object_unref (pad);
492 gst_event_unref (event);
496 gst_object_unref (demux);
501 gst_rtp_ssrc_demux_chain (GstPad * pad, GstBuffer * buf)
504 GstRtpSsrcDemux *demux;
506 GstRtpSsrcDemuxPad *dpad;
508 demux = GST_RTP_SSRC_DEMUX (GST_OBJECT_PARENT (pad));
510 if (!gst_rtp_buffer_validate (buf))
511 goto invalid_payload;
513 ssrc = gst_rtp_buffer_get_ssrc (buf);
515 GST_DEBUG_OBJECT (demux, "received buffer of SSRC %08x", ssrc);
517 GST_PAD_LOCK (demux);
518 dpad = find_demux_pad_for_ssrc (demux, ssrc);
521 create_demux_pad_for_ssrc (demux, ssrc,
522 GST_BUFFER_TIMESTAMP (buf))))
525 GST_PAD_UNLOCK (demux);
528 ret = gst_pad_push (dpad->rtp_pad, buf);
535 /* this is fatal and should be filtered earlier */
536 GST_ELEMENT_ERROR (demux, STREAM, DECODE, (NULL),
537 ("Dropping invalid RTP payload"));
538 gst_buffer_unref (buf);
539 return GST_FLOW_ERROR;
543 GST_ELEMENT_ERROR (demux, STREAM, DECODE, (NULL),
544 ("Could not create new pad"));
545 GST_PAD_UNLOCK (demux);
546 gst_buffer_unref (buf);
547 return GST_FLOW_ERROR;
552 gst_rtp_ssrc_demux_rtcp_chain (GstPad * pad, GstBuffer * buf)
555 GstRtpSsrcDemux *demux;
557 GstRtpSsrcDemuxPad *dpad;
558 GstRTCPPacket packet;
560 demux = GST_RTP_SSRC_DEMUX (GST_OBJECT_PARENT (pad));
562 if (!gst_rtcp_buffer_validate (buf))
565 if (!gst_rtcp_buffer_get_first_packet (buf, &packet))
568 /* first packet must be SR or RR or else the validate would have failed */
569 switch (gst_rtcp_packet_get_type (&packet)) {
570 case GST_RTCP_TYPE_SR:
571 /* get the ssrc so that we can route it to the right source pad */
572 gst_rtcp_packet_sr_get_sender_info (&packet, &ssrc, NULL, NULL, NULL,
576 goto unexpected_rtcp;
579 GST_DEBUG_OBJECT (demux, "received RTCP of SSRC %08x", ssrc);
581 GST_PAD_LOCK (demux);
582 dpad = find_demux_pad_for_ssrc (demux, ssrc);
584 GST_DEBUG_OBJECT (demux, "creating pad for SSRC %08x", ssrc);
585 if (!(dpad = create_demux_pad_for_ssrc (demux, ssrc, -1)))
588 GST_PAD_UNLOCK (demux);
591 ret = gst_pad_push (dpad->rtcp_pad, buf);
598 /* this is fatal and should be filtered earlier */
599 GST_ELEMENT_ERROR (demux, STREAM, DECODE, (NULL),
600 ("Dropping invalid RTCP packet"));
601 gst_buffer_unref (buf);
602 return GST_FLOW_ERROR;
606 GST_DEBUG_OBJECT (demux, "dropping unexpected RTCP packet");
607 gst_buffer_unref (buf);
612 GST_ELEMENT_ERROR (demux, STREAM, DECODE, (NULL),
613 ("Could not create new pad"));
614 GST_PAD_UNLOCK (demux);
615 gst_buffer_unref (buf);
616 return GST_FLOW_ERROR;
621 gst_rtp_ssrc_demux_src_event (GstPad * pad, GstEvent * event)
623 GstRtpSsrcDemux *demux;
624 gboolean res = FALSE;
626 demux = GST_RTP_SSRC_DEMUX (gst_pad_get_parent (pad));
628 switch (GST_EVENT_TYPE (event)) {
631 res = gst_pad_event_default (pad, event);
634 gst_object_unref (demux);
639 gst_rtp_ssrc_demux_iterate_internal_links (GstPad * pad)
641 GstRtpSsrcDemux *demux;
642 GstPad *otherpad = NULL;
646 demux = GST_RTP_SSRC_DEMUX (gst_pad_get_parent (pad));
648 GST_PAD_LOCK (demux);
649 for (current = demux->srcpads; current; current = g_slist_next (current)) {
650 GstRtpSsrcDemuxPad *dpad = (GstRtpSsrcDemuxPad *) current->data;
652 if (pad == demux->rtp_sink) {
653 otherpad = dpad->rtp_pad;
655 } else if (pad == demux->rtcp_sink) {
656 otherpad = dpad->rtcp_pad;
657 } else if (pad == dpad->rtp_pad) {
658 otherpad = demux->rtp_sink;
660 } else if (pad == dpad->rtcp_pad) {
661 otherpad = demux->rtcp_sink;
665 it = gst_iterator_new_single (GST_TYPE_PAD, otherpad,
666 (GstCopyFunction) gst_object_ref, (GFreeFunc) gst_object_unref);
667 GST_PAD_UNLOCK (demux);
669 gst_object_unref (demux);
674 gst_rtp_ssrc_demux_src_query (GstPad * pad, GstQuery * query)
676 GstRtpSsrcDemux *demux;
677 gboolean res = FALSE;
679 demux = GST_RTP_SSRC_DEMUX (gst_pad_get_parent (pad));
681 switch (GST_QUERY_TYPE (query)) {
682 case GST_QUERY_LATENCY:
685 if ((res = gst_pad_peer_query (demux->rtp_sink, query))) {
687 GstClockTime min_latency, max_latency;
688 GstRtpSsrcDemuxPad *demuxpad;
690 demuxpad = gst_pad_get_element_private (pad);
692 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
694 GST_DEBUG_OBJECT (demux, "peer min latency %" GST_TIME_FORMAT,
695 GST_TIME_ARGS (min_latency));
697 GST_DEBUG_OBJECT (demux, "latency for SSRC %08x", demuxpad->ssrc);
699 gst_query_set_latency (query, live, min_latency, max_latency);
704 res = gst_pad_query_default (pad, query);
707 gst_object_unref (demux);
712 static GstStateChangeReturn
713 gst_rtp_ssrc_demux_change_state (GstElement * element,
714 GstStateChange transition)
716 GstStateChangeReturn ret;
717 GstRtpSsrcDemux *demux;
719 demux = GST_RTP_SSRC_DEMUX (element);
721 switch (transition) {
722 case GST_STATE_CHANGE_NULL_TO_READY:
723 case GST_STATE_CHANGE_READY_TO_PAUSED:
724 case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
729 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
731 switch (transition) {
732 case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
734 case GST_STATE_CHANGE_PAUSED_TO_READY:
735 gst_rtp_ssrc_demux_reset (demux);
737 case GST_STATE_CHANGE_READY_TO_NULL: