ext/webrtc/transportreceivebin.c

   1 /* GStreamer
   2  * Copyright (C) 2017 Matthew Waters <matthew@centricular.com>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  17  * Boston, MA 02110-1301, USA.
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include "config.h"
  22 #endif
  23
  24 #include "transportreceivebin.h"
  25 #include "utils.h"
  26
  27 /*
  28  * ,----------------------------transport_receive_%u-----------------------------,
  29  * ;       (rtp)                                                                 ;
  30  * ;  ,---nicesrc----,  ,-capsfilter-,  ,----dtlssrtpdec----,      ,--funnel--,  ;
  31  * ;  ;          src o--o sink   src o--o sink      rtp_src o------o sink_0   ;  ;
  32  * ;  '--------------'  '------------'  ;                   ;      ;      src o--o rtp_src
  33  * ;                                    ;          rtcp_src o-, ,--o sink_1   ;  ;
  34  * ;                                    '-------------------' ; ;  '----------'  ;
  35  * ;                                                          ; ;  ,--funnel--,  ;
  36  * ;                                                          '-+--o sink_0   ;  ;
  37  * ;                                                          ,-'  ;      src o--o rtcp_src
  38  * ;       (rtcp)                                             ;  ,-o sink_1   ;  ;
  39  * ;  ,---nicesrc----,  ,-capsfilter-,  ,----dtlssrtpdec----, ;  ; '----------'  ;
  40  * ;  ;          src o--o sink   src o--o sink      rtp_src o-'  ;               ;
  41  * ;  '--------------'  '------------'  ;                   ;    ;               ;
  42  * ;                                    ;          rtcp_src o----'               ;
  43  * ;                                    '-------------------'                    ;
  44  * '-----------------------------------------------------------------------------'
  45  *
  46  * Do we really wnat to be *that* permissive in what we accept?
  47  *
  48  * FIXME: When and how do we want to clear the possibly stored buffers?
  49  */
  50
  51 #define GST_CAT_DEFAULT gst_webrtc_transport_receive_bin_debug
  52 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
  53
  54 #define transport_receive_bin_parent_class parent_class
  55 G_DEFINE_TYPE_WITH_CODE (TransportReceiveBin, transport_receive_bin,
  56     GST_TYPE_BIN,
  57     GST_DEBUG_CATEGORY_INIT (gst_webrtc_transport_receive_bin_debug,
  58         "webrtctransportreceivebin", 0, "webrtctransportreceivebin");
  59     );
  60
  61 static GstStaticPadTemplate rtp_sink_template =
  62 GST_STATIC_PAD_TEMPLATE ("rtp_src",
  63     GST_PAD_SINK,
  64     GST_PAD_ALWAYS,
  65     GST_STATIC_CAPS ("application/x-rtp"));
  66
  67 static GstStaticPadTemplate rtcp_sink_template =
  68 GST_STATIC_PAD_TEMPLATE ("rtcp_src",
  69     GST_PAD_SINK,
  70     GST_PAD_ALWAYS,
  71     GST_STATIC_CAPS ("application/x-rtp"));
  72
  73 enum
  74 {
  75   PROP_0,
  76   PROP_STREAM,
  77 };
  78
  79 static const gchar *
  80 _receive_state_to_string (ReceiveState state)
  81 {
  82   switch (state) {
  83     case RECEIVE_STATE_BLOCK:
  84       return "block";
  85     case RECEIVE_STATE_DROP:
  86       return "drop";
  87     case RECEIVE_STATE_PASS:
  88       return "pass";
  89     default:
  90       return "Unknown";
  91   }
  92 }
  93
  94 static GstPadProbeReturn
  95 pad_block (GstPad * pad, GstPadProbeInfo * info, TransportReceiveBin * receive)
  96 {
  97   GstPadProbeReturn ret;
  98
  99   g_mutex_lock (&receive->pad_block_lock);
 100   while (receive->receive_state == RECEIVE_STATE_BLOCK) {
 101     g_cond_wait (&receive->pad_block_cond, &receive->pad_block_lock);
 102     GST_DEBUG_OBJECT (pad, "probe waited. new state %s",
 103         _receive_state_to_string (receive->receive_state));
 104   }
 105   ret = GST_PAD_PROBE_PASS;
 106
 107   if (receive->receive_state == RECEIVE_STATE_DROP) {
 108     ret = GST_PAD_PROBE_DROP;
 109   } else if (receive->receive_state == RECEIVE_STATE_PASS) {
 110     ret = GST_PAD_PROBE_OK;
 111   }
 112
 113   g_mutex_unlock (&receive->pad_block_lock);
 114
 115   return ret;
 116 }
 117
 118 void
 119 transport_receive_bin_set_receive_state (TransportReceiveBin * receive,
 120     ReceiveState state)
 121 {
 122   g_mutex_lock (&receive->pad_block_lock);
 123   receive->receive_state = state;
 124   GST_DEBUG_OBJECT (receive, "changing receive state to %s",
 125       _receive_state_to_string (state));
 126   g_cond_signal (&receive->pad_block_cond);
 127   g_mutex_unlock (&receive->pad_block_lock);
 128 }
 129
 130 static void
 131 transport_receive_bin_set_property (GObject * object, guint prop_id,
 132     const GValue * value, GParamSpec * pspec)
 133 {
 134   TransportReceiveBin *receive = TRANSPORT_RECEIVE_BIN (object);
 135
 136   GST_OBJECT_LOCK (receive);
 137   switch (prop_id) {
 138     case PROP_STREAM:
 139       /* XXX: weak-ref this? */
 140       receive->stream = TRANSPORT_STREAM (g_value_get_object (value));
 141       break;
 142     default:
 143       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 144       break;
 145   }
 146   GST_OBJECT_UNLOCK (receive);
 147 }
 148
 149 static void
 150 transport_receive_bin_get_property (GObject * object, guint prop_id,
 151     GValue * value, GParamSpec * pspec)
 152 {
 153   TransportReceiveBin *receive = TRANSPORT_RECEIVE_BIN (object);
 154
 155   GST_OBJECT_LOCK (receive);
 156   switch (prop_id) {
 157     case PROP_STREAM:
 158       g_value_set_object (value, receive->stream);
 159       break;
 160     default:
 161       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 162       break;
 163   }
 164   GST_OBJECT_UNLOCK (receive);
 165 }
 166
 167 static void
 168 transport_receive_bin_finalize (GObject * object)
 169 {
 170   TransportReceiveBin *receive = TRANSPORT_RECEIVE_BIN (object);
 171
 172   g_mutex_clear (&receive->pad_block_lock);
 173   g_cond_clear (&receive->pad_block_cond);
 174
 175   G_OBJECT_CLASS (parent_class)->finalize (object);
 176 }
 177
 178 static GstStateChangeReturn
 179 transport_receive_bin_change_state (GstElement * element,
 180     GstStateChange transition)
 181 {
 182   TransportReceiveBin *receive = TRANSPORT_RECEIVE_BIN (element);
 183   GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
 184
 185   GST_DEBUG ("changing state: %s => %s",
 186       gst_element_state_get_name (GST_STATE_TRANSITION_CURRENT (transition)),
 187       gst_element_state_get_name (GST_STATE_TRANSITION_NEXT (transition)));
 188
 189   switch (transition) {
 190     case GST_STATE_CHANGE_NULL_TO_READY:{
 191       GstElement *elem;
 192
 193       receive->rtp_block =
 194           _create_pad_block (GST_ELEMENT (receive), receive->rtp_src, 0, NULL,
 195           NULL);
 196       receive->rtp_block->block_id =
 197           gst_pad_add_probe (receive->rtp_src, GST_PAD_PROBE_TYPE_ALL_BOTH,
 198           (GstPadProbeCallback) pad_block, receive, NULL);
 199
 200       /* XXX: because nice needs the nicesrc internal main loop running in order
 201        * correctly STUN... */
 202       /* FIXME: this races with the pad exposure later and may get not-linked */
 203       elem = receive->stream->transport->transport->src;
 204       gst_element_set_locked_state (elem, TRUE);
 205       gst_element_set_state (elem, GST_STATE_PLAYING);
 206       elem = receive->stream->rtcp_transport->transport->src;
 207       gst_element_set_locked_state (elem, TRUE);
 208       gst_element_set_state (elem, GST_STATE_PLAYING);
 209       break;
 210     }
 211     default:
 212       break;
 213   }
 214
 215   ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
 216   if (ret == GST_STATE_CHANGE_FAILURE)
 217     return ret;
 218
 219   switch (transition) {
 220     case GST_STATE_CHANGE_READY_TO_NULL:{
 221       GstElement *elem;
 222
 223       elem = receive->stream->transport->transport->src;
 224       gst_element_set_locked_state (elem, FALSE);
 225       gst_element_set_state (elem, GST_STATE_NULL);
 226       elem = receive->stream->rtcp_transport->transport->src;
 227       gst_element_set_locked_state (elem, FALSE);
 228       gst_element_set_state (elem, GST_STATE_NULL);
 229
 230       if (receive->rtp_block)
 231         _free_pad_block (receive->rtp_block);
 232       receive->rtp_block = NULL;
 233       break;
 234     }
 235     default:
 236       break;
 237   }
 238
 239   return ret;
 240 }
 241
 242 static void
 243 rtp_queue_overrun (GstElement * queue, TransportReceiveBin * receive)
 244 {
 245   GST_WARNING_OBJECT (receive, "Internal receive queue overrun. Dropping data");
 246 }
 247
 248 static void
 249 transport_receive_bin_constructed (GObject * object)
 250 {
 251   TransportReceiveBin *receive = TRANSPORT_RECEIVE_BIN (object);
 252   GstWebRTCDTLSTransport *transport;
 253   GstPad *ghost, *pad;
 254   GstElement *capsfilter, *funnel, *queue;
 255   GstCaps *caps;
 256
 257   g_return_if_fail (receive->stream);
 258
 259   /* link ice src, dtlsrtp together for rtp */
 260   transport = receive->stream->transport;
 261   gst_bin_add (GST_BIN (receive), GST_ELEMENT (transport->dtlssrtpdec));
 262
 263   capsfilter = gst_element_factory_make ("capsfilter", NULL);
 264   caps = gst_caps_new_empty_simple ("application/x-rtp");
 265   g_object_set (capsfilter, "caps", caps, NULL);
 266   gst_caps_unref (caps);
 267
 268   gst_bin_add (GST_BIN (receive), GST_ELEMENT (capsfilter));
 269   if (!gst_element_link_pads (capsfilter, "src", transport->dtlssrtpdec,
 270           "sink"))
 271     g_warn_if_reached ();
 272
 273   gst_bin_add (GST_BIN (receive), GST_ELEMENT (transport->transport->src));
 274
 275   if (!gst_element_link_pads (GST_ELEMENT (transport->transport->src), "src",
 276           GST_ELEMENT (capsfilter), "sink"))
 277     g_warn_if_reached ();
 278
 279   /* link ice src, dtlsrtp together for rtcp */
 280   transport = receive->stream->rtcp_transport;
 281   gst_bin_add (GST_BIN (receive), GST_ELEMENT (transport->dtlssrtpdec));
 282
 283   capsfilter = gst_element_factory_make ("capsfilter", NULL);
 284   caps = gst_caps_new_empty_simple ("application/x-rtcp");
 285   g_object_set (capsfilter, "caps", caps, NULL);
 286   gst_caps_unref (caps);
 287
 288   gst_bin_add (GST_BIN (receive), GST_ELEMENT (capsfilter));
 289   if (!gst_element_link_pads (capsfilter, "src", transport->dtlssrtpdec,
 290           "sink"))
 291     g_warn_if_reached ();
 292
 293   gst_bin_add (GST_BIN (receive), GST_ELEMENT (transport->transport->src));
 294
 295   if (!gst_element_link_pads (GST_ELEMENT (transport->transport->src), "src",
 296           GST_ELEMENT (capsfilter), "sink"))
 297     g_warn_if_reached ();
 298
 299   /* create funnel for rtp_src */
 300   funnel = gst_element_factory_make ("funnel", NULL);
 301   gst_bin_add (GST_BIN (receive), funnel);
 302   if (!gst_element_link_pads (receive->stream->transport->dtlssrtpdec,
 303           "rtp_src", funnel, "sink_0"))
 304     g_warn_if_reached ();
 305   if (!gst_element_link_pads (receive->stream->rtcp_transport->dtlssrtpdec,
 306           "rtp_src", funnel, "sink_1"))
 307     g_warn_if_reached ();
 308
 309   queue = gst_element_factory_make ("queue", NULL);
 310   /* FIXME: make this configurable? */
 311   g_object_set (queue, "leaky", 2, "max-size-time", (guint64) 0,
 312       "max-size-buffers", 0, "max-size-bytes", 5 * 1024 * 1024, NULL);
 313   g_signal_connect (queue, "overrun", G_CALLBACK (rtp_queue_overrun), receive);
 314   gst_bin_add (GST_BIN (receive), queue);
 315   if (!gst_element_link_pads (funnel, "src", queue, "sink"))
 316     g_warn_if_reached ();
 317
 318   pad = gst_element_get_static_pad (queue, "src");
 319   receive->rtp_src = gst_ghost_pad_new ("rtp_src", pad);
 320
 321   gst_element_add_pad (GST_ELEMENT (receive), receive->rtp_src);
 322   gst_object_unref (pad);
 323
 324   /* create funnel for rtcp_src */
 325   funnel = gst_element_factory_make ("funnel", NULL);
 326   gst_bin_add (GST_BIN (receive), funnel);
 327   if (!gst_element_link_pads (receive->stream->transport->dtlssrtpdec,
 328           "rtcp_src", funnel, "sink_0"))
 329     g_warn_if_reached ();
 330   if (!gst_element_link_pads (receive->stream->rtcp_transport->dtlssrtpdec,
 331           "rtcp_src", funnel, "sink_1"))
 332     g_warn_if_reached ();
 333
 334   pad = gst_element_get_static_pad (funnel, "src");
 335   ghost = gst_ghost_pad_new ("rtcp_src", pad);
 336   gst_element_add_pad (GST_ELEMENT (receive), ghost);
 337   gst_object_unref (pad);
 338
 339   G_OBJECT_CLASS (parent_class)->constructed (object);
 340 }
 341
 342 static void
 343 transport_receive_bin_class_init (TransportReceiveBinClass * klass)
 344 {
 345   GObjectClass *gobject_class = (GObjectClass *) klass;
 346   GstElementClass *element_class = (GstElementClass *) klass;
 347
 348   element_class->change_state = transport_receive_bin_change_state;
 349
 350   gst_element_class_add_static_pad_template (element_class, &rtp_sink_template);
 351   gst_element_class_add_static_pad_template (element_class,
 352       &rtcp_sink_template);
 353
 354   gst_element_class_set_metadata (element_class, "WebRTC Transport Receive Bin",
 355       "Filter/Network/WebRTC", "A bin for webrtc connections",
 356       "Matthew Waters <matthew@centricular.com>");
 357
 358   gobject_class->constructed = transport_receive_bin_constructed;
 359   gobject_class->get_property = transport_receive_bin_get_property;
 360   gobject_class->set_property = transport_receive_bin_set_property;
 361   gobject_class->finalize = transport_receive_bin_finalize;
 362
 363   g_object_class_install_property (gobject_class,
 364       PROP_STREAM,
 365       g_param_spec_object ("stream", "Stream",
 366           "The TransportStream for this receiveing bin",
 367           transport_stream_get_type (),
 368           G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
 369 }
 370
 371 static void
 372 transport_receive_bin_init (TransportReceiveBin * receive)
 373 {
 374   g_mutex_init (&receive->pad_block_lock);
 375   g_cond_init (&receive->pad_block_cond);
 376 }