1 /* RTP Retransmission sender element for GStreamer
2 *
3 * gstrtprtxsend.c:
4 *
5 * Copyright (C) 2013 Collabora Ltd.
6 * @author Julien Isorce <julien.isorce@collabora.co.uk>
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 */
23
24 /**
25 * SECTION:element-rtprtxsend
26 *
27 * See #GstRtpRtxReceive for examples
28 *
29 * The purpose of the sender RTX object is to keep a history of RTP packets up
30 * to a configurable limit (max-size-time or max-size-packets). It will listen
31 * for upstream custom retransmission events (GstRTPRetransmissionRequest) that
32 * comes from downstream (#GstRtpSession). When receiving a request it will
33 * look up the requested seqnum in its list of stored packets. If the packet
34 * is available, it will create a RTX packet according to RFC 4588 and send
35 * this as an auxiliary stream. RTX is SSRC-multiplexed
36 */
37
38 #ifdef HAVE_CONFIG_H
39 #include "config.h"
40 #endif
41
42 #include <gst/gst.h>
43 #include <gst/rtp/gstrtpbuffer.h>
44 #include <string.h>
45 #include <stdlib.h>
46
47 #include "gstrtprtxsend.h"
48
49 GST_DEBUG_CATEGORY_STATIC (gst_rtp_rtx_send_debug);
50 #define GST_CAT_DEFAULT gst_rtp_rtx_send_debug
51
52 #define DEFAULT_RTX_PAYLOAD_TYPE 0
53 #define DEFAULT_MAX_SIZE_TIME 0
54 #define DEFAULT_MAX_SIZE_PACKETS 100
55
56 enum
57 {
58 PROP_0,
59 PROP_SSRC_MAP,
60 PROP_PAYLOAD_TYPE_MAP,
61 PROP_MAX_SIZE_TIME,
62 PROP_MAX_SIZE_PACKETS,
63 PROP_NUM_RTX_REQUESTS,
64 PROP_NUM_RTX_PACKETS
65 };
66
67 static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
68 GST_PAD_SRC,
69 GST_PAD_ALWAYS,
70 GST_STATIC_CAPS ("application/x-rtp")
71 );
72
73 static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
74 GST_PAD_SINK,
75 GST_PAD_ALWAYS,
76 GST_STATIC_CAPS ("application/x-rtp, " "clock-rate = (int) [1, MAX]")
77 );
78
79 static gboolean gst_rtp_rtx_send_queue_check_full (GstDataQueue * queue,
80 guint visible, guint bytes, guint64 time, gpointer checkdata);
81
82 static gboolean gst_rtp_rtx_send_src_event (GstPad * pad, GstObject * parent,
83 GstEvent * event);
84 static gboolean gst_rtp_rtx_send_sink_event (GstPad * pad, GstObject * parent,
85 GstEvent * event);
86 static GstFlowReturn gst_rtp_rtx_send_chain (GstPad * pad, GstObject * parent,
87 GstBuffer * buffer);
88 static GstFlowReturn gst_rtp_rtx_send_chain_list (GstPad * pad,
89 GstObject * parent, GstBufferList * list);
90
91 static void gst_rtp_rtx_send_src_loop (GstRtpRtxSend * rtx);
92 static gboolean gst_rtp_rtx_send_activate_mode (GstPad * pad,
93 GstObject * parent, GstPadMode mode, gboolean active);
94
95 static GstStateChangeReturn gst_rtp_rtx_send_change_state (GstElement *
96 element, GstStateChange transition);
97
98 static void gst_rtp_rtx_send_set_property (GObject * object, guint prop_id,
99 const GValue * value, GParamSpec * pspec);
100 static void gst_rtp_rtx_send_get_property (GObject * object, guint prop_id,
101 GValue * value, GParamSpec * pspec);
102 static void gst_rtp_rtx_send_finalize (GObject * object);
103
104 G_DEFINE_TYPE (GstRtpRtxSend, gst_rtp_rtx_send, GST_TYPE_ELEMENT);
105
106 typedef struct
107 {
108 guint16 seqnum;
109 guint32 timestamp;
110 GstBuffer *buffer;
111 } BufferQueueItem;
112
113 static void
buffer_queue_item_free(BufferQueueItem * item)114 buffer_queue_item_free (BufferQueueItem * item)
115 {
116 gst_buffer_unref (item->buffer);
117 g_slice_free (BufferQueueItem, item);
118 }
119
120 typedef struct
121 {
122 guint32 rtx_ssrc;
123 guint16 seqnum_base, next_seqnum;
124 gint clock_rate;
125
126 /* history of rtp packets */
127 GSequence *queue;
128 } SSRCRtxData;
129
130 static SSRCRtxData *
ssrc_rtx_data_new(guint32 rtx_ssrc)131 ssrc_rtx_data_new (guint32 rtx_ssrc)
132 {
133 SSRCRtxData *data = g_slice_new0 (SSRCRtxData);
134
135 data->rtx_ssrc = rtx_ssrc;
136 data->next_seqnum = data->seqnum_base = g_random_int_range (0, G_MAXUINT16);
137 data->queue = g_sequence_new ((GDestroyNotify) buffer_queue_item_free);
138
139 return data;
140 }
141
142 static void
ssrc_rtx_data_free(SSRCRtxData * data)143 ssrc_rtx_data_free (SSRCRtxData * data)
144 {
145 g_sequence_free (data->queue);
146 g_slice_free (SSRCRtxData, data);
147 }
148
149 static void
gst_rtp_rtx_send_class_init(GstRtpRtxSendClass * klass)150 gst_rtp_rtx_send_class_init (GstRtpRtxSendClass * klass)
151 {
152 GObjectClass *gobject_class;
153 GstElementClass *gstelement_class;
154
155 gobject_class = (GObjectClass *) klass;
156 gstelement_class = (GstElementClass *) klass;
157
158 gobject_class->get_property = gst_rtp_rtx_send_get_property;
159 gobject_class->set_property = gst_rtp_rtx_send_set_property;
160 gobject_class->finalize = gst_rtp_rtx_send_finalize;
161
162 g_object_class_install_property (gobject_class, PROP_SSRC_MAP,
163 g_param_spec_boxed ("ssrc-map", "SSRC Map",
164 "Map of SSRCs to their retransmission SSRCs for SSRC-multiplexed mode"
165 " (default = random)", GST_TYPE_STRUCTURE,
166 G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS));
167
168 g_object_class_install_property (gobject_class, PROP_PAYLOAD_TYPE_MAP,
169 g_param_spec_boxed ("payload-type-map", "Payload Type Map",
170 "Map of original payload types to their retransmission payload types",
171 GST_TYPE_STRUCTURE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
172
173 g_object_class_install_property (gobject_class, PROP_MAX_SIZE_TIME,
174 g_param_spec_uint ("max-size-time", "Max Size Time",
175 "Amount of ms to queue (0 = unlimited)", 0, G_MAXUINT,
176 DEFAULT_MAX_SIZE_TIME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
177
178 g_object_class_install_property (gobject_class, PROP_MAX_SIZE_PACKETS,
179 g_param_spec_uint ("max-size-packets", "Max Size Packets",
180 "Amount of packets to queue (0 = unlimited)", 0, G_MAXINT16,
181 DEFAULT_MAX_SIZE_PACKETS,
182 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
183
184 g_object_class_install_property (gobject_class, PROP_NUM_RTX_REQUESTS,
185 g_param_spec_uint ("num-rtx-requests", "Num RTX Requests",
186 "Number of retransmission events received", 0, G_MAXUINT,
187 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
188
189 g_object_class_install_property (gobject_class, PROP_NUM_RTX_PACKETS,
190 g_param_spec_uint ("num-rtx-packets", "Num RTX Packets",
191 " Number of retransmission packets sent", 0, G_MAXUINT,
192 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
193
194 gst_element_class_add_static_pad_template (gstelement_class, &src_factory);
195 gst_element_class_add_static_pad_template (gstelement_class, &sink_factory);
196
197 gst_element_class_set_static_metadata (gstelement_class,
198 "RTP Retransmission Sender", "Codec",
199 "Retransmit RTP packets when needed, according to RFC4588",
200 "Julien Isorce <julien.isorce@collabora.co.uk>");
201
202 gstelement_class->change_state =
203 GST_DEBUG_FUNCPTR (gst_rtp_rtx_send_change_state);
204 }
205
206 static void
gst_rtp_rtx_send_reset(GstRtpRtxSend * rtx)207 gst_rtp_rtx_send_reset (GstRtpRtxSend * rtx)
208 {
209 GST_OBJECT_LOCK (rtx);
210 gst_data_queue_flush (rtx->queue);
211 g_hash_table_remove_all (rtx->ssrc_data);
212 g_hash_table_remove_all (rtx->rtx_ssrcs);
213 rtx->num_rtx_requests = 0;
214 rtx->num_rtx_packets = 0;
215 GST_OBJECT_UNLOCK (rtx);
216 }
217
218 static void
gst_rtp_rtx_send_finalize(GObject * object)219 gst_rtp_rtx_send_finalize (GObject * object)
220 {
221 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (object);
222
223 g_hash_table_unref (rtx->ssrc_data);
224 g_hash_table_unref (rtx->rtx_ssrcs);
225 if (rtx->external_ssrc_map)
226 gst_structure_free (rtx->external_ssrc_map);
227 g_hash_table_unref (rtx->rtx_pt_map);
228 if (rtx->rtx_pt_map_structure)
229 gst_structure_free (rtx->rtx_pt_map_structure);
230 g_object_unref (rtx->queue);
231
232 G_OBJECT_CLASS (gst_rtp_rtx_send_parent_class)->finalize (object);
233 }
234
235 static void
gst_rtp_rtx_send_init(GstRtpRtxSend * rtx)236 gst_rtp_rtx_send_init (GstRtpRtxSend * rtx)
237 {
238 GstElementClass *klass = GST_ELEMENT_GET_CLASS (rtx);
239
240 rtx->srcpad =
241 gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
242 "src"), "src");
243 GST_PAD_SET_PROXY_CAPS (rtx->srcpad);
244 GST_PAD_SET_PROXY_ALLOCATION (rtx->srcpad);
245 gst_pad_set_event_function (rtx->srcpad,
246 GST_DEBUG_FUNCPTR (gst_rtp_rtx_send_src_event));
247 gst_pad_set_activatemode_function (rtx->srcpad,
248 GST_DEBUG_FUNCPTR (gst_rtp_rtx_send_activate_mode));
249 gst_element_add_pad (GST_ELEMENT (rtx), rtx->srcpad);
250
251 rtx->sinkpad =
252 gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
253 "sink"), "sink");
254 GST_PAD_SET_PROXY_CAPS (rtx->sinkpad);
255 GST_PAD_SET_PROXY_ALLOCATION (rtx->sinkpad);
256 gst_pad_set_event_function (rtx->sinkpad,
257 GST_DEBUG_FUNCPTR (gst_rtp_rtx_send_sink_event));
258 gst_pad_set_chain_function (rtx->sinkpad,
259 GST_DEBUG_FUNCPTR (gst_rtp_rtx_send_chain));
260 gst_pad_set_chain_list_function (rtx->sinkpad,
261 GST_DEBUG_FUNCPTR (gst_rtp_rtx_send_chain_list));
262 gst_element_add_pad (GST_ELEMENT (rtx), rtx->sinkpad);
263
264 rtx->queue = gst_data_queue_new (gst_rtp_rtx_send_queue_check_full, NULL,
265 NULL, rtx);
266 rtx->ssrc_data = g_hash_table_new_full (g_direct_hash, g_direct_equal,
267 NULL, (GDestroyNotify) ssrc_rtx_data_free);
268 rtx->rtx_ssrcs = g_hash_table_new (g_direct_hash, g_direct_equal);
269 rtx->rtx_pt_map = g_hash_table_new (g_direct_hash, g_direct_equal);
270
271 rtx->max_size_time = DEFAULT_MAX_SIZE_TIME;
272 rtx->max_size_packets = DEFAULT_MAX_SIZE_PACKETS;
273 }
274
275 static void
gst_rtp_rtx_send_set_flushing(GstRtpRtxSend * rtx,gboolean flush)276 gst_rtp_rtx_send_set_flushing (GstRtpRtxSend * rtx, gboolean flush)
277 {
278 GST_OBJECT_LOCK (rtx);
279 gst_data_queue_set_flushing (rtx->queue, flush);
280 gst_data_queue_flush (rtx->queue);
281 GST_OBJECT_UNLOCK (rtx);
282 }
283
284 static gboolean
gst_rtp_rtx_send_queue_check_full(GstDataQueue * queue,guint visible,guint bytes,guint64 time,gpointer checkdata)285 gst_rtp_rtx_send_queue_check_full (GstDataQueue * queue,
286 guint visible, guint bytes, guint64 time, gpointer checkdata)
287 {
288 return FALSE;
289 }
290
291 static void
gst_rtp_rtx_data_queue_item_free(gpointer item)292 gst_rtp_rtx_data_queue_item_free (gpointer item)
293 {
294 GstDataQueueItem *data = item;
295 if (data->object)
296 gst_mini_object_unref (data->object);
297 g_slice_free (GstDataQueueItem, data);
298 }
299
300 static gboolean
gst_rtp_rtx_send_push_out(GstRtpRtxSend * rtx,gpointer object)301 gst_rtp_rtx_send_push_out (GstRtpRtxSend * rtx, gpointer object)
302 {
303 GstDataQueueItem *data;
304 gboolean success;
305
306 data = g_slice_new0 (GstDataQueueItem);
307 data->object = GST_MINI_OBJECT (object);
308 data->size = 1;
309 data->duration = 1;
310 data->visible = TRUE;
311 data->destroy = gst_rtp_rtx_data_queue_item_free;
312
313 success = gst_data_queue_push (rtx->queue, data);
314
315 if (!success)
316 data->destroy (data);
317
318 return success;
319 }
320
321 static guint32
gst_rtp_rtx_send_choose_ssrc(GstRtpRtxSend * rtx,guint32 choice,gboolean consider_choice)322 gst_rtp_rtx_send_choose_ssrc (GstRtpRtxSend * rtx, guint32 choice,
323 gboolean consider_choice)
324 {
325 guint32 ssrc = consider_choice ? choice : g_random_int ();
326
327 /* make sure to be different than any other */
328 while (g_hash_table_contains (rtx->ssrc_data, GUINT_TO_POINTER (ssrc)) ||
329 g_hash_table_contains (rtx->rtx_ssrcs, GUINT_TO_POINTER (ssrc))) {
330 ssrc = g_random_int ();
331 }
332
333 return ssrc;
334 }
335
336 static SSRCRtxData *
gst_rtp_rtx_send_get_ssrc_data(GstRtpRtxSend * rtx,guint32 ssrc)337 gst_rtp_rtx_send_get_ssrc_data (GstRtpRtxSend * rtx, guint32 ssrc)
338 {
339 SSRCRtxData *data;
340 guint32 rtx_ssrc = 0;
341 gboolean consider = FALSE;
342
343 if (G_UNLIKELY (!g_hash_table_contains (rtx->ssrc_data,
344 GUINT_TO_POINTER (ssrc)))) {
345 if (rtx->external_ssrc_map) {
346 gchar *ssrc_str;
347 ssrc_str = g_strdup_printf ("%" G_GUINT32_FORMAT, ssrc);
348 consider = gst_structure_get_uint (rtx->external_ssrc_map, ssrc_str,
349 &rtx_ssrc);
350 g_free (ssrc_str);
351 }
352 rtx_ssrc = gst_rtp_rtx_send_choose_ssrc (rtx, rtx_ssrc, consider);
353 data = ssrc_rtx_data_new (rtx_ssrc);
354 g_hash_table_insert (rtx->ssrc_data, GUINT_TO_POINTER (ssrc), data);
355 g_hash_table_insert (rtx->rtx_ssrcs, GUINT_TO_POINTER (rtx_ssrc),
356 GUINT_TO_POINTER (ssrc));
357 } else {
358 data = g_hash_table_lookup (rtx->ssrc_data, GUINT_TO_POINTER (ssrc));
359 }
360 return data;
361 }
362
363 /* Copy fixed header and extension. Add OSN before to copy payload
364 * Copy memory to avoid to manually copy each rtp buffer field.
365 */
366 static GstBuffer *
gst_rtp_rtx_buffer_new(GstRtpRtxSend * rtx,GstBuffer * buffer)367 gst_rtp_rtx_buffer_new (GstRtpRtxSend * rtx, GstBuffer * buffer)
368 {
369 GstMemory *mem = NULL;
370 GstRTPBuffer rtp = GST_RTP_BUFFER_INIT;
371 GstRTPBuffer new_rtp = GST_RTP_BUFFER_INIT;
372 GstBuffer *new_buffer = gst_buffer_new ();
373 GstMapInfo map;
374 guint payload_len = 0;
375 SSRCRtxData *data;
376 guint32 ssrc;
377 guint16 seqnum;
378 guint8 fmtp;
379
380 gst_rtp_buffer_map (buffer, GST_MAP_READ, &rtp);
381
382 /* get needed data from GstRtpRtxSend */
383 ssrc = gst_rtp_buffer_get_ssrc (&rtp);
384 data = gst_rtp_rtx_send_get_ssrc_data (rtx, ssrc);
385 ssrc = data->rtx_ssrc;
386 seqnum = data->next_seqnum++;
387 fmtp = GPOINTER_TO_UINT (g_hash_table_lookup (rtx->rtx_pt_map,
388 GUINT_TO_POINTER (gst_rtp_buffer_get_payload_type (&rtp))));
389
390 GST_DEBUG_OBJECT (rtx, "creating rtx buffer, orig seqnum: %u, "
391 "rtx seqnum: %u, rtx ssrc: %X", gst_rtp_buffer_get_seq (&rtp),
392 seqnum, ssrc);
393
394 /* gst_rtp_buffer_map does not map the payload so do it now */
395 gst_rtp_buffer_get_payload (&rtp);
396
397 /* copy fixed header */
398 mem = gst_memory_copy (rtp.map[0].memory, 0, rtp.size[0]);
399 gst_buffer_append_memory (new_buffer, mem);
400
401 /* copy extension if any */
402 if (rtp.size[1]) {
403 mem = gst_allocator_alloc (NULL, rtp.size[1], NULL);
404 gst_memory_map (mem, &map, GST_MAP_WRITE);
405 memcpy (map.data, rtp.data[1], rtp.size[1]);
406 gst_memory_unmap (mem, &map);
407 gst_buffer_append_memory (new_buffer, mem);
408 }
409
410 /* copy payload and add OSN just before */
411 payload_len = 2 + rtp.size[2];
412 mem = gst_allocator_alloc (NULL, payload_len, NULL);
413
414 gst_memory_map (mem, &map, GST_MAP_WRITE);
415 GST_WRITE_UINT16_BE (map.data, gst_rtp_buffer_get_seq (&rtp));
416 if (rtp.size[2])
417 memcpy (map.data + 2, rtp.data[2], rtp.size[2]);
418 gst_memory_unmap (mem, &map);
419 gst_buffer_append_memory (new_buffer, mem);
420
421 /* everything needed is copied */
422 gst_rtp_buffer_unmap (&rtp);
423
424 /* set ssrc, seqnum and fmtp */
425 gst_rtp_buffer_map (new_buffer, GST_MAP_WRITE, &new_rtp);
426 gst_rtp_buffer_set_ssrc (&new_rtp, ssrc);
427 gst_rtp_buffer_set_seq (&new_rtp, seqnum);
428 gst_rtp_buffer_set_payload_type (&new_rtp, fmtp);
429 /* RFC 4588: let other elements do the padding, as normal */
430 gst_rtp_buffer_set_padding (&new_rtp, FALSE);
431 gst_rtp_buffer_unmap (&new_rtp);
432
433 /* Copy over timestamps */
434 gst_buffer_copy_into (new_buffer, buffer, GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
435
436 return new_buffer;
437 }
438
439 static gint
buffer_queue_items_cmp(BufferQueueItem * a,BufferQueueItem * b,gpointer user_data)440 buffer_queue_items_cmp (BufferQueueItem * a, BufferQueueItem * b,
441 gpointer user_data)
442 {
443 /* gst_rtp_buffer_compare_seqnum returns the opposite of what we want,
444 * it returns negative when seqnum1 > seqnum2 and we want negative
445 * when b > a, i.e. a is smaller, so it comes first in the sequence */
446 return gst_rtp_buffer_compare_seqnum (b->seqnum, a->seqnum);
447 }
448
449 static gboolean
gst_rtp_rtx_send_src_event(GstPad * pad,GstObject * parent,GstEvent * event)450 gst_rtp_rtx_send_src_event (GstPad * pad, GstObject * parent, GstEvent * event)
451 {
452 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (parent);
453 gboolean res;
454
455 switch (GST_EVENT_TYPE (event)) {
456 case GST_EVENT_CUSTOM_UPSTREAM:
457 {
458 const GstStructure *s = gst_event_get_structure (event);
459
460 /* This event usually comes from the downstream gstrtpsession */
461 if (gst_structure_has_name (s, "GstRTPRetransmissionRequest")) {
462 guint seqnum = 0;
463 guint ssrc = 0;
464 GstBuffer *rtx_buf = NULL;
465
466 /* retrieve seqnum of the packet that need to be retransmitted */
467 if (!gst_structure_get_uint (s, "seqnum", &seqnum))
468 seqnum = -1;
469
470 /* retrieve ssrc of the packet that need to be retransmitted */
471 if (!gst_structure_get_uint (s, "ssrc", &ssrc))
472 ssrc = -1;
473
474 GST_DEBUG_OBJECT (rtx, "got rtx request for seqnum: %u, ssrc: %X",
475 seqnum, ssrc);
476
477 GST_OBJECT_LOCK (rtx);
478 /* check if request is for us */
479 if (g_hash_table_contains (rtx->ssrc_data, GUINT_TO_POINTER (ssrc))) {
480 SSRCRtxData *data;
481 GSequenceIter *iter;
482 BufferQueueItem search_item;
483
484 /* update statistics */
485 ++rtx->num_rtx_requests;
486
487 data = gst_rtp_rtx_send_get_ssrc_data (rtx, ssrc);
488
489 search_item.seqnum = seqnum;
490 iter = g_sequence_lookup (data->queue, &search_item,
491 (GCompareDataFunc) buffer_queue_items_cmp, NULL);
492 if (iter) {
493 BufferQueueItem *item = g_sequence_get (iter);
494 GST_LOG_OBJECT (rtx, "found %u", item->seqnum);
495 rtx_buf = gst_rtp_rtx_buffer_new (rtx, item->buffer);
496 }
497 #ifndef GST_DISABLE_DEBUG
498 else {
499 BufferQueueItem *item = NULL;
500
501 iter = g_sequence_get_begin_iter (data->queue);
502 if (!g_sequence_iter_is_end (iter))
503 item = g_sequence_get (iter);
504
505 if (item && seqnum < item->seqnum) {
506 GST_DEBUG_OBJECT (rtx, "requested seqnum %u has already been "
507 "removed from the rtx queue; the first available is %u",
508 seqnum, item->seqnum);
509 } else {
510 GST_WARNING_OBJECT (rtx, "requested seqnum %u has not been "
511 "transmitted yet in the original stream; either the remote end "
512 "is not configured correctly, or the source is too slow",
513 seqnum);
514 }
515 }
516 #endif
517 }
518 GST_OBJECT_UNLOCK (rtx);
519
520 if (rtx_buf)
521 gst_rtp_rtx_send_push_out (rtx, rtx_buf);
522
523 gst_event_unref (event);
524 res = TRUE;
525
526 /* This event usually comes from the downstream gstrtpsession */
527 } else if (gst_structure_has_name (s, "GstRTPCollision")) {
528 guint ssrc = 0;
529
530 if (!gst_structure_get_uint (s, "ssrc", &ssrc))
531 ssrc = -1;
532
533 GST_DEBUG_OBJECT (rtx, "got ssrc collision, ssrc: %X", ssrc);
534
535 GST_OBJECT_LOCK (rtx);
536
537 /* choose another ssrc for our retransmited stream */
538 if (g_hash_table_contains (rtx->rtx_ssrcs, GUINT_TO_POINTER (ssrc))) {
539 guint master_ssrc;
540 SSRCRtxData *data;
541
542 master_ssrc = GPOINTER_TO_UINT (g_hash_table_lookup (rtx->rtx_ssrcs,
543 GUINT_TO_POINTER (ssrc)));
544 data = gst_rtp_rtx_send_get_ssrc_data (rtx, master_ssrc);
545
546 /* change rtx_ssrc and update the reverse map */
547 data->rtx_ssrc = gst_rtp_rtx_send_choose_ssrc (rtx, 0, FALSE);
548 g_hash_table_remove (rtx->rtx_ssrcs, GUINT_TO_POINTER (ssrc));
549 g_hash_table_insert (rtx->rtx_ssrcs,
550 GUINT_TO_POINTER (data->rtx_ssrc),
551 GUINT_TO_POINTER (master_ssrc));
552
553 GST_OBJECT_UNLOCK (rtx);
554
555 /* no need to forward to payloader because we make sure to have
556 * a different ssrc
557 */
558 gst_event_unref (event);
559 res = TRUE;
560 } else {
561 /* if master ssrc has collided, remove it from our data, as it
562 * is not going to be used any longer */
563 if (g_hash_table_contains (rtx->ssrc_data, GUINT_TO_POINTER (ssrc))) {
564 SSRCRtxData *data;
565 data = gst_rtp_rtx_send_get_ssrc_data (rtx, ssrc);
566 g_hash_table_remove (rtx->rtx_ssrcs,
567 GUINT_TO_POINTER (data->rtx_ssrc));
568 g_hash_table_remove (rtx->ssrc_data, GUINT_TO_POINTER (ssrc));
569 }
570
571 GST_OBJECT_UNLOCK (rtx);
572
573 /* forward event to payloader in case collided ssrc is
574 * master stream */
575 res = gst_pad_event_default (pad, parent, event);
576 }
577 } else {
578 res = gst_pad_event_default (pad, parent, event);
579 }
580 break;
581 }
582 default:
583 res = gst_pad_event_default (pad, parent, event);
584 break;
585 }
586 return res;
587 }
588
589 static gboolean
gst_rtp_rtx_send_sink_event(GstPad * pad,GstObject * parent,GstEvent * event)590 gst_rtp_rtx_send_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
591 {
592 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (parent);
593
594 switch (GST_EVENT_TYPE (event)) {
595 case GST_EVENT_FLUSH_START:
596 gst_pad_push_event (rtx->srcpad, event);
597 gst_rtp_rtx_send_set_flushing (rtx, TRUE);
598 gst_pad_pause_task (rtx->srcpad);
599 return TRUE;
600 case GST_EVENT_FLUSH_STOP:
601 gst_pad_push_event (rtx->srcpad, event);
602 gst_rtp_rtx_send_set_flushing (rtx, FALSE);
603 gst_pad_start_task (rtx->srcpad,
604 (GstTaskFunction) gst_rtp_rtx_send_src_loop, rtx, NULL);
605 return TRUE;
606 case GST_EVENT_EOS:
607 GST_INFO_OBJECT (rtx, "Got EOS - enqueueing it");
608 gst_rtp_rtx_send_push_out (rtx, event);
609 return TRUE;
610 case GST_EVENT_CAPS:
611 {
612 GstCaps *caps;
613 GstStructure *s;
614 guint ssrc;
615 gint payload;
616 gpointer rtx_payload;
617 SSRCRtxData *data;
618
619 gst_event_parse_caps (event, &caps);
620
621 s = gst_caps_get_structure (caps, 0);
622 if (!gst_structure_get_uint (s, "ssrc", &ssrc))
623 ssrc = -1;
624 if (!gst_structure_get_int (s, "payload", &payload))
625 payload = -1;
626
627 if (payload == -1)
628 GST_WARNING_OBJECT (rtx, "No payload in caps");
629
630 GST_OBJECT_LOCK (rtx);
631 data = gst_rtp_rtx_send_get_ssrc_data (rtx, ssrc);
632 if (!g_hash_table_lookup_extended (rtx->rtx_pt_map,
633 GUINT_TO_POINTER (payload), NULL, &rtx_payload))
634 rtx_payload = GINT_TO_POINTER (-1);
635
636 if (GPOINTER_TO_INT (rtx_payload) == -1 && payload != -1)
637 GST_WARNING_OBJECT (rtx, "Payload %d not in rtx-pt-map", payload);
638
639 GST_DEBUG_OBJECT (rtx,
640 "got caps for payload: %d->%d, ssrc: %u->%u : %" GST_PTR_FORMAT,
641 payload, GPOINTER_TO_INT (rtx_payload), ssrc, data->rtx_ssrc, caps);
642
643 gst_structure_get_int (s, "clock-rate", &data->clock_rate);
644
645 /* The session might need to know the RTX ssrc */
646 caps = gst_caps_copy (caps);
647 gst_caps_set_simple (caps, "rtx-ssrc", G_TYPE_UINT, data->rtx_ssrc,
648 "rtx-seqnum-offset", G_TYPE_UINT, data->seqnum_base, NULL);
649
650 if (GPOINTER_TO_INT (rtx_payload) != -1)
651 gst_caps_set_simple (caps, "rtx-payload", G_TYPE_INT,
652 GPOINTER_TO_INT (rtx_payload), NULL);
653
654 GST_DEBUG_OBJECT (rtx, "got clock-rate from caps: %d for ssrc: %u",
655 data->clock_rate, ssrc);
656 GST_OBJECT_UNLOCK (rtx);
657
658 gst_event_unref (event);
659 event = gst_event_new_caps (caps);
660 gst_caps_unref (caps);
661 break;
662 }
663 default:
664 break;
665 }
666 return gst_pad_event_default (pad, parent, event);
667 }
668
669 /* like rtp_jitter_buffer_get_ts_diff() */
670 static guint32
gst_rtp_rtx_send_get_ts_diff(SSRCRtxData * data)671 gst_rtp_rtx_send_get_ts_diff (SSRCRtxData * data)
672 {
673 guint64 high_ts, low_ts;
674 BufferQueueItem *high_buf, *low_buf;
675 guint32 result;
676
677 high_buf =
678 g_sequence_get (g_sequence_iter_prev (g_sequence_get_end_iter
679 (data->queue)));
680 low_buf = g_sequence_get (g_sequence_get_begin_iter (data->queue));
681
682 if (!high_buf || !low_buf || high_buf == low_buf)
683 return 0;
684
685 high_ts = high_buf->timestamp;
686 low_ts = low_buf->timestamp;
687
688 /* it needs to work if ts wraps */
689 if (high_ts >= low_ts) {
690 result = (guint32) (high_ts - low_ts);
691 } else {
692 result = (guint32) (high_ts + G_MAXUINT32 + 1 - low_ts);
693 }
694
695 /* return value in ms instead of clock ticks */
696 return (guint32) gst_util_uint64_scale_int (result, 1000, data->clock_rate);
697 }
698
699 /* Must be called with lock */
700 static void
process_buffer(GstRtpRtxSend * rtx,GstBuffer * buffer)701 process_buffer (GstRtpRtxSend * rtx, GstBuffer * buffer)
702 {
703 GstRTPBuffer rtp = GST_RTP_BUFFER_INIT;
704 BufferQueueItem *item;
705 SSRCRtxData *data;
706 guint16 seqnum;
707 guint8 payload_type;
708 guint32 ssrc, rtptime;
709
710 /* read the information we want from the buffer */
711 gst_rtp_buffer_map (buffer, GST_MAP_READ, &rtp);
712 seqnum = gst_rtp_buffer_get_seq (&rtp);
713 payload_type = gst_rtp_buffer_get_payload_type (&rtp);
714 ssrc = gst_rtp_buffer_get_ssrc (&rtp);
715 rtptime = gst_rtp_buffer_get_timestamp (&rtp);
716 gst_rtp_buffer_unmap (&rtp);
717
718 GST_TRACE_OBJECT (rtx, "Processing buffer seqnum: %u, ssrc: %X", seqnum,
719 ssrc);
720
721 /* do not store the buffer if it's payload type is unknown */
722 if (g_hash_table_contains (rtx->rtx_pt_map, GUINT_TO_POINTER (payload_type))) {
723 data = gst_rtp_rtx_send_get_ssrc_data (rtx, ssrc);
724
725 /* add current rtp buffer to queue history */
726 item = g_slice_new0 (BufferQueueItem);
727 item->seqnum = seqnum;
728 item->timestamp = rtptime;
729 item->buffer = gst_buffer_ref (buffer);
730 g_sequence_append (data->queue, item);
731
732 /* remove oldest packets from history if they are too many */
733 if (rtx->max_size_packets) {
734 while (g_sequence_get_length (data->queue) > rtx->max_size_packets)
735 g_sequence_remove (g_sequence_get_begin_iter (data->queue));
736 }
737 if (rtx->max_size_time) {
738 while (gst_rtp_rtx_send_get_ts_diff (data) > rtx->max_size_time)
739 g_sequence_remove (g_sequence_get_begin_iter (data->queue));
740 }
741 }
742 }
743
744 static GstFlowReturn
gst_rtp_rtx_send_chain(GstPad * pad,GstObject * parent,GstBuffer * buffer)745 gst_rtp_rtx_send_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
746 {
747 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (parent);
748 GstFlowReturn ret;
749
750 GST_OBJECT_LOCK (rtx);
751 process_buffer (rtx, buffer);
752 GST_OBJECT_UNLOCK (rtx);
753 ret = gst_pad_push (rtx->srcpad, buffer);
754
755 return ret;
756 }
757
758 static gboolean
process_buffer_from_list(GstBuffer ** buffer,guint idx,gpointer user_data)759 process_buffer_from_list (GstBuffer ** buffer, guint idx, gpointer user_data)
760 {
761 process_buffer (user_data, *buffer);
762 return TRUE;
763 }
764
765 static GstFlowReturn
gst_rtp_rtx_send_chain_list(GstPad * pad,GstObject * parent,GstBufferList * list)766 gst_rtp_rtx_send_chain_list (GstPad * pad, GstObject * parent,
767 GstBufferList * list)
768 {
769 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (parent);
770 GstFlowReturn ret;
771
772 GST_OBJECT_LOCK (rtx);
773 gst_buffer_list_foreach (list, process_buffer_from_list, rtx);
774 GST_OBJECT_UNLOCK (rtx);
775
776 ret = gst_pad_push_list (rtx->srcpad, list);
777
778 return ret;
779 }
780
781 static void
gst_rtp_rtx_send_src_loop(GstRtpRtxSend * rtx)782 gst_rtp_rtx_send_src_loop (GstRtpRtxSend * rtx)
783 {
784 GstDataQueueItem *data;
785
786 if (gst_data_queue_pop (rtx->queue, &data)) {
787 GST_LOG_OBJECT (rtx, "pushing rtx buffer %p", data->object);
788
789 if (G_LIKELY (GST_IS_BUFFER (data->object))) {
790 GST_OBJECT_LOCK (rtx);
791 /* Update statistics just before pushing. */
792 rtx->num_rtx_packets++;
793 GST_OBJECT_UNLOCK (rtx);
794
795 gst_pad_push (rtx->srcpad, GST_BUFFER (data->object));
796 } else if (GST_IS_EVENT (data->object)) {
797 gst_pad_push_event (rtx->srcpad, GST_EVENT (data->object));
798
799 /* after EOS, we should not send any more buffers,
800 * even if there are more requests coming in */
801 if (GST_EVENT_TYPE (data->object) == GST_EVENT_EOS) {
802 gst_rtp_rtx_send_set_flushing (rtx, TRUE);
803 }
804 } else {
805 g_assert_not_reached ();
806 }
807
808 data->object = NULL; /* we no longer own that object */
809 data->destroy (data);
810 } else {
811 GST_LOG_OBJECT (rtx, "flushing");
812 gst_pad_pause_task (rtx->srcpad);
813 }
814 }
815
816 static gboolean
gst_rtp_rtx_send_activate_mode(GstPad * pad,GstObject * parent,GstPadMode mode,gboolean active)817 gst_rtp_rtx_send_activate_mode (GstPad * pad, GstObject * parent,
818 GstPadMode mode, gboolean active)
819 {
820 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (parent);
821 gboolean ret = FALSE;
822
823 switch (mode) {
824 case GST_PAD_MODE_PUSH:
825 if (active) {
826 gst_rtp_rtx_send_set_flushing (rtx, FALSE);
827 ret = gst_pad_start_task (rtx->srcpad,
828 (GstTaskFunction) gst_rtp_rtx_send_src_loop, rtx, NULL);
829 } else {
830 gst_rtp_rtx_send_set_flushing (rtx, TRUE);
831 ret = gst_pad_stop_task (rtx->srcpad);
832 }
833 GST_INFO_OBJECT (rtx, "activate_mode: active %d, ret %d", active, ret);
834 break;
835 default:
836 break;
837 }
838 return ret;
839 }
840
841 static void
gst_rtp_rtx_send_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)842 gst_rtp_rtx_send_get_property (GObject * object,
843 guint prop_id, GValue * value, GParamSpec * pspec)
844 {
845 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (object);
846
847 switch (prop_id) {
848 case PROP_PAYLOAD_TYPE_MAP:
849 GST_OBJECT_LOCK (rtx);
850 g_value_set_boxed (value, rtx->rtx_pt_map_structure);
851 GST_OBJECT_UNLOCK (rtx);
852 break;
853 case PROP_MAX_SIZE_TIME:
854 GST_OBJECT_LOCK (rtx);
855 g_value_set_uint (value, rtx->max_size_time);
856 GST_OBJECT_UNLOCK (rtx);
857 break;
858 case PROP_MAX_SIZE_PACKETS:
859 GST_OBJECT_LOCK (rtx);
860 g_value_set_uint (value, rtx->max_size_packets);
861 GST_OBJECT_UNLOCK (rtx);
862 break;
863 case PROP_NUM_RTX_REQUESTS:
864 GST_OBJECT_LOCK (rtx);
865 g_value_set_uint (value, rtx->num_rtx_requests);
866 GST_OBJECT_UNLOCK (rtx);
867 break;
868 case PROP_NUM_RTX_PACKETS:
869 GST_OBJECT_LOCK (rtx);
870 g_value_set_uint (value, rtx->num_rtx_packets);
871 GST_OBJECT_UNLOCK (rtx);
872 break;
873 default:
874 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
875 break;
876 }
877 }
878
879 static gboolean
structure_to_hash_table(GQuark field_id,const GValue * value,gpointer hash)880 structure_to_hash_table (GQuark field_id, const GValue * value, gpointer hash)
881 {
882 const gchar *field_str;
883 guint field_uint;
884 guint value_uint;
885
886 field_str = g_quark_to_string (field_id);
887 field_uint = atoi (field_str);
888 value_uint = g_value_get_uint (value);
889 g_hash_table_insert ((GHashTable *) hash, GUINT_TO_POINTER (field_uint),
890 GUINT_TO_POINTER (value_uint));
891
892 return TRUE;
893 }
894
895 static void
gst_rtp_rtx_send_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)896 gst_rtp_rtx_send_set_property (GObject * object,
897 guint prop_id, const GValue * value, GParamSpec * pspec)
898 {
899 GstRtpRtxSend *rtx = GST_RTP_RTX_SEND (object);
900
901 switch (prop_id) {
902 case PROP_SSRC_MAP:
903 GST_OBJECT_LOCK (rtx);
904 if (rtx->external_ssrc_map)
905 gst_structure_free (rtx->external_ssrc_map);
906 rtx->external_ssrc_map = g_value_dup_boxed (value);
907 GST_OBJECT_UNLOCK (rtx);
908 break;
909 case PROP_PAYLOAD_TYPE_MAP:
910 GST_OBJECT_LOCK (rtx);
911 if (rtx->rtx_pt_map_structure)
912 gst_structure_free (rtx->rtx_pt_map_structure);
913 rtx->rtx_pt_map_structure = g_value_dup_boxed (value);
914 g_hash_table_remove_all (rtx->rtx_pt_map);
915 gst_structure_foreach (rtx->rtx_pt_map_structure, structure_to_hash_table,
916 rtx->rtx_pt_map);
917 GST_OBJECT_UNLOCK (rtx);
918 break;
919 case PROP_MAX_SIZE_TIME:
920 GST_OBJECT_LOCK (rtx);
921 rtx->max_size_time = g_value_get_uint (value);
922 GST_OBJECT_UNLOCK (rtx);
923 break;
924 case PROP_MAX_SIZE_PACKETS:
925 GST_OBJECT_LOCK (rtx);
926 rtx->max_size_packets = g_value_get_uint (value);
927 GST_OBJECT_UNLOCK (rtx);
928 break;
929 default:
930 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
931 break;
932 }
933 }
934
935 static GstStateChangeReturn
gst_rtp_rtx_send_change_state(GstElement * element,GstStateChange transition)936 gst_rtp_rtx_send_change_state (GstElement * element, GstStateChange transition)
937 {
938 GstStateChangeReturn ret;
939 GstRtpRtxSend *rtx;
940
941 rtx = GST_RTP_RTX_SEND (element);
942
943 switch (transition) {
944 default:
945 break;
946 }
947
948 ret =
949 GST_ELEMENT_CLASS (gst_rtp_rtx_send_parent_class)->change_state (element,
950 transition);
951
952 switch (transition) {
953 case GST_STATE_CHANGE_PAUSED_TO_READY:
954 gst_rtp_rtx_send_reset (rtx);
955 break;
956 default:
957 break;
958 }
959
960 return ret;
961 }
962
963 gboolean
gst_rtp_rtx_send_plugin_init(GstPlugin * plugin)964 gst_rtp_rtx_send_plugin_init (GstPlugin * plugin)
965 {
966 GST_DEBUG_CATEGORY_INIT (gst_rtp_rtx_send_debug, "rtprtxsend", 0,
967 "rtp retransmission sender");
968
969 return gst_element_register (plugin, "rtprtxsend", GST_RANK_NONE,
970 GST_TYPE_RTP_RTX_SEND);
971 }
972