/* * Demo gstreamer app for negotiating and streaming a sendrecv webrtc stream * with a browser JS app. * * Build by running: `make webrtc-sendrecv`, or build the gstreamer monorepo. * * Author: Nirbheek Chauhan */ #include #include #include #include #include #include "custom_agent.h" /* For signalling */ #include #include #include enum AppState { APP_STATE_UNKNOWN = 0, APP_STATE_ERROR = 1, /* generic error */ SERVER_CONNECTING = 1000, SERVER_CONNECTION_ERROR, SERVER_CONNECTED, /* Ready to register */ SERVER_REGISTERING = 2000, SERVER_REGISTRATION_ERROR, SERVER_REGISTERED, /* Ready to call a peer */ SERVER_CLOSED, /* server connection closed by us or the server */ PEER_CONNECTING = 3000, PEER_CONNECTION_ERROR, PEER_CONNECTED, PEER_CALL_NEGOTIATING = 4000, PEER_CALL_STARTED, PEER_CALL_STOPPING, PEER_CALL_STOPPED, PEER_CALL_ERROR, }; #define GST_CAT_DEFAULT webrtc_sendrecv_debug GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT); static GMainLoop *loop; static GstElement *pipe1, *webrtc1, *audio_bin, *video_bin = NULL; static GObject *send_channel, *receive_channel; static SoupWebsocketConnection *ws_conn = NULL; static enum AppState app_state = 0; static gchar *peer_id = NULL; static gchar *our_id = NULL; static const gchar *server_url = "wss://webrtc.nirbheek.in:8443"; static gboolean disable_ssl = FALSE; static gboolean remote_is_offerer = FALSE; static gboolean custom_ice = FALSE; static GOptionEntry entries[] = { {"peer-id", 0, 0, G_OPTION_ARG_STRING, &peer_id, "String ID of the peer to connect to", "ID"}, {"our-id", 0, 0, G_OPTION_ARG_STRING, &our_id, "String ID that the peer can use to connect to us", "ID"}, {"server", 0, 0, G_OPTION_ARG_STRING, &server_url, "Signalling server to connect to", "URL"}, {"disable-ssl", 0, 0, G_OPTION_ARG_NONE, &disable_ssl, "Disable ssl", NULL}, {"remote-offerer", 0, 0, G_OPTION_ARG_NONE, &remote_is_offerer, "Request that the peer generate the offer and we'll answer", NULL}, {"custom-ice", 0, 0, G_OPTION_ARG_NONE, &custom_ice, "Use a custom ice agent", NULL}, {NULL}, }; static gboolean cleanup_and_quit_loop (const gchar * msg, enum AppState state) { if (msg) gst_printerr ("%s\n", msg); if (state > 0) app_state = state; if (ws_conn) { if (soup_websocket_connection_get_state (ws_conn) == SOUP_WEBSOCKET_STATE_OPEN) /* This will call us again */ soup_websocket_connection_close (ws_conn, 1000, ""); else g_clear_object (&ws_conn); } if (loop) { g_main_loop_quit (loop); g_clear_pointer (&loop, g_main_loop_unref); } /* To allow usage as a GSourceFunc */ return G_SOURCE_REMOVE; } static gchar * get_string_from_json_object (JsonObject * object) { JsonNode *root; JsonGenerator *generator; gchar *text; /* Make it the root node */ root = json_node_init_object (json_node_alloc (), object); generator = json_generator_new (); json_generator_set_root (generator, root); text = json_generator_to_data (generator, NULL); /* Release everything */ g_object_unref (generator); json_node_free (root); return text; } static void handle_media_stream (GstPad * pad, GstElement * pipe, const char *convert_name, const char *sink_name) { GstPad *qpad; GstElement *q, *conv, *resample, *sink; GstPadLinkReturn ret; gst_println ("Trying to handle stream with %s ! %s", convert_name, sink_name); q = gst_element_factory_make ("queue", NULL); g_assert_nonnull (q); conv = gst_element_factory_make (convert_name, NULL); g_assert_nonnull (conv); sink = gst_element_factory_make (sink_name, NULL); g_assert_nonnull (sink); if (g_strcmp0 (convert_name, "audioconvert") == 0) { /* Might also need to resample, so add it just in case. * Will be a no-op if it's not required. */ resample = gst_element_factory_make ("audioresample", NULL); g_assert_nonnull (resample); gst_bin_add_many (GST_BIN (pipe), q, conv, resample, sink, NULL); gst_element_sync_state_with_parent (q); gst_element_sync_state_with_parent (conv); gst_element_sync_state_with_parent (resample); gst_element_sync_state_with_parent (sink); gst_element_link_many (q, conv, resample, sink, NULL); } else { gst_bin_add_many (GST_BIN (pipe), q, conv, sink, NULL); gst_element_sync_state_with_parent (q); gst_element_sync_state_with_parent (conv); gst_element_sync_state_with_parent (sink); gst_element_link_many (q, conv, sink, NULL); } qpad = gst_element_get_static_pad (q, "sink"); ret = gst_pad_link (pad, qpad); g_assert_cmphex (ret, ==, GST_PAD_LINK_OK); } static void on_incoming_decodebin_stream (GstElement * decodebin, GstPad * pad, GstElement * pipe) { GstCaps *caps; const gchar *name; if (!gst_pad_has_current_caps (pad)) { gst_printerr ("Pad '%s' has no caps, can't do anything, ignoring\n", GST_PAD_NAME (pad)); return; } caps = gst_pad_get_current_caps (pad); name = gst_structure_get_name (gst_caps_get_structure (caps, 0)); if (g_str_has_prefix (name, "video")) { handle_media_stream (pad, pipe, "videoconvert", "autovideosink"); } else if (g_str_has_prefix (name, "audio")) { handle_media_stream (pad, pipe, "audioconvert", "autoaudiosink"); } else { gst_printerr ("Unknown pad %s, ignoring", GST_PAD_NAME (pad)); } } static void on_incoming_stream (GstElement * webrtc, GstPad * pad, GstElement * pipe) { GstElement *decodebin; GstPad *sinkpad; if (GST_PAD_DIRECTION (pad) != GST_PAD_SRC) return; decodebin = gst_element_factory_make ("decodebin", NULL); g_signal_connect (decodebin, "pad-added", G_CALLBACK (on_incoming_decodebin_stream), pipe); gst_bin_add (GST_BIN (pipe), decodebin); gst_element_sync_state_with_parent (decodebin); sinkpad = gst_element_get_static_pad (decodebin, "sink"); gst_pad_link (pad, sinkpad); gst_object_unref (sinkpad); } static void send_ice_candidate_message (GstElement * webrtc G_GNUC_UNUSED, guint mlineindex, gchar * candidate, gpointer user_data G_GNUC_UNUSED) { gchar *text; JsonObject *ice, *msg; if (app_state < PEER_CALL_NEGOTIATING) { cleanup_and_quit_loop ("Can't send ICE, not in call", APP_STATE_ERROR); return; } ice = json_object_new (); json_object_set_string_member (ice, "candidate", candidate); json_object_set_int_member (ice, "sdpMLineIndex", mlineindex); msg = json_object_new (); json_object_set_object_member (msg, "ice", ice); text = get_string_from_json_object (msg); json_object_unref (msg); soup_websocket_connection_send_text (ws_conn, text); g_free (text); } static void send_sdp_to_peer (GstWebRTCSessionDescription * desc) { gchar *text; JsonObject *msg, *sdp; if (app_state < PEER_CALL_NEGOTIATING) { cleanup_and_quit_loop ("Can't send SDP to peer, not in call", APP_STATE_ERROR); return; } text = gst_sdp_message_as_text (desc->sdp); sdp = json_object_new (); if (desc->type == GST_WEBRTC_SDP_TYPE_OFFER) { gst_print ("Sending offer:\n%s\n", text); json_object_set_string_member (sdp, "type", "offer"); } else if (desc->type == GST_WEBRTC_SDP_TYPE_ANSWER) { gst_print ("Sending answer:\n%s\n", text); json_object_set_string_member (sdp, "type", "answer"); } else { g_assert_not_reached (); } json_object_set_string_member (sdp, "sdp", text); g_free (text); msg = json_object_new (); json_object_set_object_member (msg, "sdp", sdp); text = get_string_from_json_object (msg); json_object_unref (msg); soup_websocket_connection_send_text (ws_conn, text); g_free (text); } /* Offer created by our pipeline, to be sent to the peer */ static void on_offer_created (GstPromise * promise, gpointer user_data) { GstWebRTCSessionDescription *offer = NULL; const GstStructure *reply; g_assert_cmphex (app_state, ==, PEER_CALL_NEGOTIATING); g_assert_cmphex (gst_promise_wait (promise), ==, GST_PROMISE_RESULT_REPLIED); reply = gst_promise_get_reply (promise); gst_structure_get (reply, "offer", GST_TYPE_WEBRTC_SESSION_DESCRIPTION, &offer, NULL); gst_promise_unref (promise); promise = gst_promise_new (); g_signal_emit_by_name (webrtc1, "set-local-description", offer, promise); gst_promise_interrupt (promise); gst_promise_unref (promise); /* Send offer to peer */ send_sdp_to_peer (offer); gst_webrtc_session_description_free (offer); } static void on_negotiation_needed (GstElement * element, gpointer user_data) { gboolean create_offer = GPOINTER_TO_INT (user_data); app_state = PEER_CALL_NEGOTIATING; if (remote_is_offerer) { soup_websocket_connection_send_text (ws_conn, "OFFER_REQUEST"); } else if (create_offer) { GstPromise *promise = gst_promise_new_with_change_func (on_offer_created, NULL, NULL); g_signal_emit_by_name (webrtc1, "create-offer", NULL, promise); } } static void data_channel_on_error (GObject * dc, gpointer user_data) { cleanup_and_quit_loop ("Data channel error", 0); } static void data_channel_on_open (GObject * dc, gpointer user_data) { GBytes *bytes = g_bytes_new ("data", strlen ("data")); gst_print ("data channel opened\n"); g_signal_emit_by_name (dc, "send-string", "Hi! from GStreamer"); g_signal_emit_by_name (dc, "send-data", bytes); g_bytes_unref (bytes); } static void data_channel_on_close (GObject * dc, gpointer user_data) { cleanup_and_quit_loop ("Data channel closed", 0); } static void data_channel_on_message_string (GObject * dc, gchar * str, gpointer user_data) { gst_print ("Received data channel message: %s\n", str); } static void connect_data_channel_signals (GObject * data_channel) { g_signal_connect (data_channel, "on-error", G_CALLBACK (data_channel_on_error), NULL); g_signal_connect (data_channel, "on-open", G_CALLBACK (data_channel_on_open), NULL); g_signal_connect (data_channel, "on-close", G_CALLBACK (data_channel_on_close), NULL); g_signal_connect (data_channel, "on-message-string", G_CALLBACK (data_channel_on_message_string), NULL); } static void on_data_channel (GstElement * webrtc, GObject * data_channel, gpointer user_data) { connect_data_channel_signals (data_channel); receive_channel = data_channel; } static void on_ice_gathering_state_notify (GstElement * webrtcbin, GParamSpec * pspec, gpointer user_data) { GstWebRTCICEGatheringState ice_gather_state; const gchar *new_state = "unknown"; g_object_get (webrtcbin, "ice-gathering-state", &ice_gather_state, NULL); switch (ice_gather_state) { case GST_WEBRTC_ICE_GATHERING_STATE_NEW: new_state = "new"; break; case GST_WEBRTC_ICE_GATHERING_STATE_GATHERING: new_state = "gathering"; break; case GST_WEBRTC_ICE_GATHERING_STATE_COMPLETE: new_state = "complete"; break; } gst_print ("ICE gathering state changed to %s\n", new_state); } static gboolean webrtcbin_get_stats (GstElement * webrtcbin); static gboolean on_webrtcbin_stat (GQuark field_id, const GValue * value, gpointer unused) { if (GST_VALUE_HOLDS_STRUCTURE (value)) { GST_DEBUG ("stat: \'%s\': %" GST_PTR_FORMAT, g_quark_to_string (field_id), gst_value_get_structure (value)); } else { GST_FIXME ("unknown field \'%s\' value type: \'%s\'", g_quark_to_string (field_id), g_type_name (G_VALUE_TYPE (value))); } return TRUE; } static void on_webrtcbin_get_stats (GstPromise * promise, GstElement * webrtcbin) { const GstStructure *stats; g_return_if_fail (gst_promise_wait (promise) == GST_PROMISE_RESULT_REPLIED); stats = gst_promise_get_reply (promise); gst_structure_foreach (stats, on_webrtcbin_stat, NULL); g_timeout_add (100, (GSourceFunc) webrtcbin_get_stats, webrtcbin); } static gboolean webrtcbin_get_stats (GstElement * webrtcbin) { GstPromise *promise; promise = gst_promise_new_with_change_func ( (GstPromiseChangeFunc) on_webrtcbin_get_stats, webrtcbin, NULL); GST_TRACE ("emitting get-stats on %" GST_PTR_FORMAT, webrtcbin); g_signal_emit_by_name (webrtcbin, "get-stats", NULL, promise); gst_promise_unref (promise); return G_SOURCE_REMOVE; } #define STUN_SERVER "stun://stun.l.google.com:19302" #define RTP_TWCC_URI "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01" #define RTP_OPUS_DEFAULT_PT 97 #define RTP_VP8_DEFAULT_PT 96 static gboolean start_pipeline (gboolean create_offer, guint opus_pt, guint vp8_pt) { char *audio_desc, *video_desc; GstStateChangeReturn ret; GstWebRTCICE *custom_agent; GError *audio_error = NULL; GError *video_error = NULL; pipe1 = gst_pipeline_new ("webrtc-pipeline"); audio_desc = g_strdup_printf ("audiotestsrc is-live=true wave=red-noise ! audioconvert ! audioresample" "! queue ! opusenc ! rtpopuspay name=audiopay ! queue"); audio_bin = gst_parse_bin_from_description (audio_desc, TRUE, &audio_error); g_free (audio_desc); if (audio_error) { gst_printerr ("Failed to parse audio_bin: %s\n", audio_error->message); g_error_free (audio_error); goto err; } video_desc = g_strdup_printf ("videotestsrc is-live=true pattern=ball ! videoconvert ! queue ! " /* increase the default keyframe distance, browsers have really long * periods between keyframes and rely on PLI events on packet loss to * fix corrupted video. */ "vp8enc deadline=1 keyframe-max-dist=2000 ! " /* picture-id-mode=15-bit seems to make TWCC stats behave better, and * fixes stuttery video playback in Chrome */ "rtpvp8pay name=videopay picture-id-mode=15-bit ! queue"); video_bin = gst_parse_bin_from_description (video_desc, TRUE, &video_error); g_free (video_desc); if (video_error) { gst_printerr ("Failed to parse video_bin: %s\n", video_error->message); g_error_free (video_error); goto err; } if (custom_ice) { custom_agent = GST_WEBRTC_ICE (customice_agent_new ("custom")); webrtc1 = gst_element_factory_make_full ("webrtcbin", "name", "sendrecv", "bundle-policy", "max-bundle", "stun-server", STUN_SERVER, "ice-agent", custom_agent, NULL); } else { webrtc1 = gst_element_factory_make_full ("webrtcbin", "name", "sendrecv", "bundle-policy", "max-bundle", "stun-server", STUN_SERVER, NULL); } g_assert_nonnull (webrtc1); gst_bin_add_many (GST_BIN (pipe1), audio_bin, video_bin, webrtc1, NULL); if (!gst_element_link (audio_bin, webrtc1)) { gst_printerr ("Failed to link audio_bin \n"); } if (!gst_element_link (video_bin, webrtc1)) { gst_printerr ("Failed to link video_bin \n"); } if (!create_offer) { /* XXX: this will fail when the remote offers twcc as the extension id * cannot currently be negotiated when receiving an offer. */ GST_FIXME ("Need to implement header extension negotiation when " "reciving a remote offers"); } else { GstElement *videopay, *audiopay; GstRTPHeaderExtension *video_twcc, *audio_twcc; videopay = gst_bin_get_by_name (GST_BIN (pipe1), "videopay"); g_assert_nonnull (videopay); video_twcc = gst_rtp_header_extension_create_from_uri (RTP_TWCC_URI); g_assert_nonnull (video_twcc); gst_rtp_header_extension_set_id (video_twcc, 1); g_signal_emit_by_name (videopay, "add-extension", video_twcc); g_clear_object (&video_twcc); g_clear_object (&videopay); audiopay = gst_bin_get_by_name (GST_BIN (pipe1), "audiopay"); g_assert_nonnull (audiopay); audio_twcc = gst_rtp_header_extension_create_from_uri (RTP_TWCC_URI); g_assert_nonnull (audio_twcc); gst_rtp_header_extension_set_id (audio_twcc, 1); g_signal_emit_by_name (audiopay, "add-extension", audio_twcc); g_clear_object (&audio_twcc); g_clear_object (&audiopay); } /* This is the gstwebrtc entry point where we create the offer and so on. It * will be called when the pipeline goes to PLAYING. */ g_signal_connect (webrtc1, "on-negotiation-needed", G_CALLBACK (on_negotiation_needed), GINT_TO_POINTER (create_offer)); /* We need to transmit this ICE candidate to the browser via the websockets * signalling server. Incoming ice candidates from the browser need to be * added by us too, see on_server_message() */ g_signal_connect (webrtc1, "on-ice-candidate", G_CALLBACK (send_ice_candidate_message), NULL); g_signal_connect (webrtc1, "notify::ice-gathering-state", G_CALLBACK (on_ice_gathering_state_notify), NULL); gst_element_set_state (pipe1, GST_STATE_READY); g_signal_emit_by_name (webrtc1, "create-data-channel", "channel", NULL, &send_channel); if (send_channel) { gst_print ("Created data channel\n"); connect_data_channel_signals (send_channel); } else { gst_print ("Could not create data channel, is usrsctp available?\n"); } g_signal_connect (webrtc1, "on-data-channel", G_CALLBACK (on_data_channel), NULL); /* Incoming streams will be exposed via this signal */ g_signal_connect (webrtc1, "pad-added", G_CALLBACK (on_incoming_stream), pipe1); /* Lifetime is the same as the pipeline itself */ gst_object_unref (webrtc1); g_timeout_add (100, (GSourceFunc) webrtcbin_get_stats, webrtc1); gst_print ("Starting pipeline\n"); ret = gst_element_set_state (GST_ELEMENT (pipe1), GST_STATE_PLAYING); if (ret == GST_STATE_CHANGE_FAILURE) goto err; return TRUE; err: if (pipe1) g_clear_object (&pipe1); if (webrtc1) webrtc1 = NULL; return FALSE; } static gboolean setup_call (void) { gchar *msg; if (soup_websocket_connection_get_state (ws_conn) != SOUP_WEBSOCKET_STATE_OPEN) return FALSE; if (!peer_id) return FALSE; gst_print ("Setting up signalling server call with %s\n", peer_id); app_state = PEER_CONNECTING; msg = g_strdup_printf ("SESSION %s", peer_id); soup_websocket_connection_send_text (ws_conn, msg); g_free (msg); return TRUE; } static gboolean register_with_server (void) { gchar *hello; if (soup_websocket_connection_get_state (ws_conn) != SOUP_WEBSOCKET_STATE_OPEN) return FALSE; if (!our_id) { gint32 id; id = g_random_int_range (10, 10000); gst_print ("Registering id %i with server\n", id); hello = g_strdup_printf ("HELLO %i", id); } else { gst_print ("Registering id %s with server\n", our_id); hello = g_strdup_printf ("HELLO %s", our_id); } app_state = SERVER_REGISTERING; /* Register with the server with a random integer id. Reply will be received * by on_server_message() */ soup_websocket_connection_send_text (ws_conn, hello); g_free (hello); return TRUE; } static void on_server_closed (SoupWebsocketConnection * conn G_GNUC_UNUSED, gpointer user_data G_GNUC_UNUSED) { app_state = SERVER_CLOSED; cleanup_and_quit_loop ("Server connection closed", 0); } /* Answer created by our pipeline, to be sent to the peer */ static void on_answer_created (GstPromise * promise, gpointer user_data) { GstWebRTCSessionDescription *answer = NULL; const GstStructure *reply; g_assert_cmphex (app_state, ==, PEER_CALL_NEGOTIATING); g_assert_cmphex (gst_promise_wait (promise), ==, GST_PROMISE_RESULT_REPLIED); reply = gst_promise_get_reply (promise); gst_structure_get (reply, "answer", GST_TYPE_WEBRTC_SESSION_DESCRIPTION, &answer, NULL); gst_promise_unref (promise); promise = gst_promise_new (); g_signal_emit_by_name (webrtc1, "set-local-description", answer, promise); gst_promise_interrupt (promise); gst_promise_unref (promise); /* Send answer to peer */ send_sdp_to_peer (answer); gst_webrtc_session_description_free (answer); } static void on_offer_set (GstPromise * promise, gpointer user_data) { gst_promise_unref (promise); promise = gst_promise_new_with_change_func (on_answer_created, NULL, NULL); g_signal_emit_by_name (webrtc1, "create-answer", NULL, promise); } static void on_offer_received (GstSDPMessage * sdp) { GstWebRTCSessionDescription *offer = NULL; GstPromise *promise; /* If we got an offer and we have no webrtcbin, we need to parse the SDP, * get the payload types, then start the pipeline */ if (!webrtc1 && our_id) { guint medias_len, formats_len; guint opus_pt = 0, vp8_pt = 0; gst_println ("Parsing offer to find payload types"); medias_len = gst_sdp_message_medias_len (sdp); for (int i = 0; i < medias_len; i++) { const GstSDPMedia *media = gst_sdp_message_get_media (sdp, i); formats_len = gst_sdp_media_formats_len (media); for (int j = 0; j < formats_len; j++) { guint pt; GstCaps *caps; GstStructure *s; const char *fmt, *encoding_name; fmt = gst_sdp_media_get_format (media, j); if (g_strcmp0 (fmt, "webrtc-datachannel") == 0) continue; pt = atoi (fmt); caps = gst_sdp_media_get_caps_from_media (media, pt); s = gst_caps_get_structure (caps, 0); encoding_name = gst_structure_get_string (s, "encoding-name"); if (vp8_pt == 0 && g_strcmp0 (encoding_name, "VP8") == 0) vp8_pt = pt; if (opus_pt == 0 && g_strcmp0 (encoding_name, "OPUS") == 0) opus_pt = pt; } } g_assert_cmpint (opus_pt, !=, 0); g_assert_cmpint (vp8_pt, !=, 0); gst_println ("Starting pipeline with opus pt: %u vp8 pt: %u", opus_pt, vp8_pt); if (!start_pipeline (FALSE, opus_pt, vp8_pt)) { cleanup_and_quit_loop ("ERROR: failed to start pipeline", PEER_CALL_ERROR); } } offer = gst_webrtc_session_description_new (GST_WEBRTC_SDP_TYPE_OFFER, sdp); g_assert_nonnull (offer); /* Set remote description on our pipeline */ { promise = gst_promise_new_with_change_func (on_offer_set, NULL, NULL); g_signal_emit_by_name (webrtc1, "set-remote-description", offer, promise); } gst_webrtc_session_description_free (offer); } /* One mega message handler for our asynchronous calling mechanism */ static void on_server_message (SoupWebsocketConnection * conn, SoupWebsocketDataType type, GBytes * message, gpointer user_data) { gchar *text; switch (type) { case SOUP_WEBSOCKET_DATA_BINARY: gst_printerr ("Received unknown binary message, ignoring\n"); return; case SOUP_WEBSOCKET_DATA_TEXT:{ gsize size; const gchar *data = g_bytes_get_data (message, &size); /* Convert to NULL-terminated string */ text = g_strndup (data, size); break; } default: g_assert_not_reached (); } if (g_strcmp0 (text, "HELLO") == 0) { /* Server has accepted our registration, we are ready to send commands */ if (app_state != SERVER_REGISTERING) { cleanup_and_quit_loop ("ERROR: Received HELLO when not registering", APP_STATE_ERROR); goto out; } app_state = SERVER_REGISTERED; gst_print ("Registered with server\n"); if (!our_id) { /* Ask signalling server to connect us with a specific peer */ if (!setup_call ()) { cleanup_and_quit_loop ("ERROR: Failed to setup call", PEER_CALL_ERROR); goto out; } } else { gst_println ("Waiting for connection from peer (our-id: %s)", our_id); } } else if (g_strcmp0 (text, "SESSION_OK") == 0) { /* The call initiated by us has been setup by the server; now we can start * negotiation */ if (app_state != PEER_CONNECTING) { cleanup_and_quit_loop ("ERROR: Received SESSION_OK when not calling", PEER_CONNECTION_ERROR); goto out; } app_state = PEER_CONNECTED; /* Start negotiation (exchange SDP and ICE candidates) */ if (!start_pipeline (TRUE, RTP_OPUS_DEFAULT_PT, RTP_VP8_DEFAULT_PT)) cleanup_and_quit_loop ("ERROR: failed to start pipeline", PEER_CALL_ERROR); } else if (g_strcmp0 (text, "OFFER_REQUEST") == 0) { if (app_state != SERVER_REGISTERED) { gst_printerr ("Received OFFER_REQUEST at a strange time, ignoring\n"); goto out; } gst_print ("Received OFFER_REQUEST, sending offer\n"); /* Peer wants us to start negotiation (exchange SDP and ICE candidates) */ if (!start_pipeline (TRUE, RTP_OPUS_DEFAULT_PT, RTP_VP8_DEFAULT_PT)) cleanup_and_quit_loop ("ERROR: failed to start pipeline", PEER_CALL_ERROR); } else if (g_str_has_prefix (text, "ERROR")) { /* Handle errors */ switch (app_state) { case SERVER_CONNECTING: app_state = SERVER_CONNECTION_ERROR; break; case SERVER_REGISTERING: app_state = SERVER_REGISTRATION_ERROR; break; case PEER_CONNECTING: app_state = PEER_CONNECTION_ERROR; break; case PEER_CONNECTED: case PEER_CALL_NEGOTIATING: app_state = PEER_CALL_ERROR; break; default: app_state = APP_STATE_ERROR; } cleanup_and_quit_loop (text, 0); } else { /* Look for JSON messages containing SDP and ICE candidates */ JsonNode *root; JsonObject *object, *child; JsonParser *parser = json_parser_new (); if (!json_parser_load_from_data (parser, text, -1, NULL)) { gst_printerr ("Unknown message '%s', ignoring\n", text); g_object_unref (parser); goto out; } root = json_parser_get_root (parser); if (!JSON_NODE_HOLDS_OBJECT (root)) { gst_printerr ("Unknown json message '%s', ignoring\n", text); g_object_unref (parser); goto out; } object = json_node_get_object (root); /* Check type of JSON message */ if (json_object_has_member (object, "sdp")) { int ret; GstSDPMessage *sdp; const gchar *text, *sdptype; GstWebRTCSessionDescription *answer; app_state = PEER_CALL_NEGOTIATING; child = json_object_get_object_member (object, "sdp"); if (!json_object_has_member (child, "type")) { cleanup_and_quit_loop ("ERROR: received SDP without 'type'", PEER_CALL_ERROR); goto out; } sdptype = json_object_get_string_member (child, "type"); /* In this example, we create the offer and receive one answer by default, * but it's possible to comment out the offer creation and wait for an offer * instead, so we handle either here. * * See tests/examples/webrtcbidirectional.c in gst-plugins-bad for another * example how to handle offers from peers and reply with answers using webrtcbin. */ text = json_object_get_string_member (child, "sdp"); ret = gst_sdp_message_new (&sdp); g_assert_cmphex (ret, ==, GST_SDP_OK); ret = gst_sdp_message_parse_buffer ((guint8 *) text, strlen (text), sdp); g_assert_cmphex (ret, ==, GST_SDP_OK); if (g_str_equal (sdptype, "answer")) { gst_print ("Received answer:\n%s\n", text); answer = gst_webrtc_session_description_new (GST_WEBRTC_SDP_TYPE_ANSWER, sdp); g_assert_nonnull (answer); /* Set remote description on our pipeline */ { GstPromise *promise = gst_promise_new (); g_signal_emit_by_name (webrtc1, "set-remote-description", answer, promise); gst_promise_interrupt (promise); gst_promise_unref (promise); } app_state = PEER_CALL_STARTED; } else { gst_print ("Received offer:\n%s\n", text); on_offer_received (sdp); } } else if (json_object_has_member (object, "ice")) { const gchar *candidate; gint sdpmlineindex; child = json_object_get_object_member (object, "ice"); candidate = json_object_get_string_member (child, "candidate"); sdpmlineindex = json_object_get_int_member (child, "sdpMLineIndex"); /* Add ice candidate sent by remote peer */ g_signal_emit_by_name (webrtc1, "add-ice-candidate", sdpmlineindex, candidate); } else { gst_printerr ("Ignoring unknown JSON message:\n%s\n", text); } g_object_unref (parser); } out: g_free (text); } static void on_server_connected (SoupSession * session, GAsyncResult * res, SoupMessage * msg) { GError *error = NULL; ws_conn = soup_session_websocket_connect_finish (session, res, &error); if (error) { cleanup_and_quit_loop (error->message, SERVER_CONNECTION_ERROR); g_error_free (error); return; } g_assert_nonnull (ws_conn); app_state = SERVER_CONNECTED; gst_print ("Connected to signalling server\n"); g_signal_connect (ws_conn, "closed", G_CALLBACK (on_server_closed), NULL); g_signal_connect (ws_conn, "message", G_CALLBACK (on_server_message), NULL); /* Register with the server so it knows about us and can accept commands */ register_with_server (); } /* * Connect to the signalling server. This is the entrypoint for everything else. */ static void connect_to_websocket_server_async (void) { SoupLogger *logger; SoupMessage *message; SoupSession *session; const char *https_aliases[] = { "wss", NULL }; session = soup_session_new_with_options (SOUP_SESSION_SSL_STRICT, !disable_ssl, SOUP_SESSION_SSL_USE_SYSTEM_CA_FILE, TRUE, //SOUP_SESSION_SSL_CA_FILE, "/etc/ssl/certs/ca-bundle.crt", SOUP_SESSION_HTTPS_ALIASES, https_aliases, NULL); logger = soup_logger_new (SOUP_LOGGER_LOG_BODY, -1); soup_session_add_feature (session, SOUP_SESSION_FEATURE (logger)); g_object_unref (logger); message = soup_message_new (SOUP_METHOD_GET, server_url); gst_print ("Connecting to server...\n"); /* Once connected, we will register */ soup_session_websocket_connect_async (session, message, NULL, NULL, NULL, (GAsyncReadyCallback) on_server_connected, message); app_state = SERVER_CONNECTING; } static gboolean check_plugins (void) { int i; gboolean ret; GstPlugin *plugin; GstRegistry *registry; const gchar *needed[] = { "opus", "vpx", "nice", "webrtc", "dtls", "srtp", "rtpmanager", "videotestsrc", "audiotestsrc", NULL }; registry = gst_registry_get (); ret = TRUE; for (i = 0; i < g_strv_length ((gchar **) needed); i++) { plugin = gst_registry_find_plugin (registry, needed[i]); if (!plugin) { gst_print ("Required gstreamer plugin '%s' not found\n", needed[i]); ret = FALSE; continue; } gst_object_unref (plugin); } return ret; } int main (int argc, char *argv[]) { GOptionContext *context; GError *error = NULL; int ret_code = -1; context = g_option_context_new ("- gstreamer webrtc sendrecv demo"); g_option_context_add_main_entries (context, entries, NULL); g_option_context_add_group (context, gst_init_get_option_group ()); if (!g_option_context_parse (context, &argc, &argv, &error)) { gst_printerr ("Error initializing: %s\n", error->message); return -1; } GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "webrtc-sendrecv", 0, "WebRTC Sending and Receiving example"); if (!check_plugins ()) { goto out; } if (!peer_id && !our_id) { gst_printerr ("--peer-id or --our-id is a required argument\n"); goto out; } if (peer_id && our_id) { gst_printerr ("specify only --peer-id or --our-id\n"); goto out; } ret_code = 0; /* Disable ssl when running a localhost server, because * it's probably a test server with a self-signed certificate */ { GstUri *uri = gst_uri_from_string (server_url); if (g_strcmp0 ("localhost", gst_uri_get_host (uri)) == 0 || g_strcmp0 ("127.0.0.1", gst_uri_get_host (uri)) == 0) disable_ssl = TRUE; gst_uri_unref (uri); } loop = g_main_loop_new (NULL, FALSE); connect_to_websocket_server_async (); g_main_loop_run (loop); if (loop) g_main_loop_unref (loop); if (pipe1) { gst_element_set_state (GST_ELEMENT (pipe1), GST_STATE_NULL); gst_print ("Pipeline stopped\n"); gst_object_unref (pipe1); } out: g_free (peer_id); g_free (our_id); return ret_code; }