Bumped version to 0.10.5

Change default data mid

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.7)
 project(libdatachannel
-	VERSION 0.10.2
+	VERSION 0.10.5
 	LANGUAGES CXX)
 set(PROJECT_DESCRIPTION "WebRTC Data Channels Library")
 
@@ -33,10 +33,11 @@ endif()
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/Modules)
+set(BUILD_SHARED_LIBS OFF) # to force usrsctp to be built static
 
 if(WIN32)
 	add_definitions(-DWIN32_LEAN_AND_MEAN)
-	if (MSVC)
+	if(MSVC)
 		add_definitions(-DNOMINMAX)
 		add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 		add_definitions(-D_SILENCE_CXX17_CODECVT_HEADER_DEPRECATION_WARNING)
@@ -163,8 +164,8 @@ target_link_libraries(datachannel-static PUBLIC Threads::Threads plog::plog)
 target_link_libraries(datachannel-static PRIVATE Usrsctp::Usrsctp)
 
 if(WIN32)
-	target_link_libraries(datachannel PRIVATE ws2_32) # winsock2
+	target_link_libraries(datachannel PUBLIC ws2_32) # winsock2
-	target_link_libraries(datachannel-static PRIVATE ws2_32) # winsock2
+	target_link_libraries(datachannel-static PUBLIC ws2_32) # winsock2
 endif()
 
 if(NO_MEDIA)
@@ -272,11 +273,7 @@ if(NOT NO_TESTS)
 		set_target_properties(datachannel-tests PROPERTIES OUTPUT_NAME tests)
 	endif()
 	target_include_directories(datachannel-tests PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
-	if(WIN32)
+	target_link_libraries(datachannel-tests datachannel)
-		target_link_libraries(datachannel-tests datachannel-static) # DLL exports only the C API
-	else()
-		target_link_libraries(datachannel-tests datachannel)
-	endif()
 
 	# Benchmark
 	add_executable(datachannel-benchmark test/benchmark.cpp)
@@ -288,11 +285,7 @@ if(NOT NO_TESTS)
 	endif()
 	target_compile_definitions(datachannel-benchmark PRIVATE BENCHMARK_MAIN=1)
 	target_include_directories(datachannel-benchmark PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
-	if(WIN32)
+	target_link_libraries(datachannel-benchmark datachannel)
-		target_link_libraries(datachannel-benchmark datachannel-static) # DLL exports only the C API
-	else()
-		target_link_libraries(datachannel-benchmark datachannel)
-	endif()
 endif()
 
 # Examples

Jamfile

@@ -15,9 +15,9 @@ lib libdatachannel
 	: # requirements
 	<cxxstd>17
 	<include>./include/rtc
-	<define>USE_NICE=0
 	<define>RTC_ENABLE_MEDIA=0
 	<define>RTC_ENABLE_WEBSOCKET=0
+	<define>USE_NICE=0
 	<toolset>msvc:<define>WIN32_LEAN_AND_MEAN
 	<toolset>msvc:<define>NOMINMAX
 	<toolset>msvc:<define>_CRT_SECURE_NO_WARNINGS
@@ -32,6 +32,8 @@ lib libdatachannel
 	<link>static
 	: # usage requirements
 	<include>./include
+	<define>RTC_ENABLE_MEDIA=0
+	<define>RTC_ENABLE_WEBSOCKET=0
 	<library>/libdatachannel//plog
 	<toolset>gcc:<cxxflags>"-pthread -Wno-pedantic -Wno-unused-parameter -Wno-unused-variable"
 	<toolset>clang:<cxxflags>"-pthread -Wno-pedantic -Wno-unused-parameter -Wno-unused-variable"
@@ -94,7 +96,7 @@ rule make_libusrsctp ( targets * : sources * : properties * )
 }
 actions make_libusrsctp
 {
-    (cd $(CWD)/deps/usrsctp && mkdir -p $(BUILD_DIR) && cd $(BUILD_DIR) && cmake -DCMAKE_BUILD_TYPE=$(VARIANT) -DCMAKE_C_FLAGS="-fPIC -Wno-unknown-warning-option -Wno-format-truncation" .. && make -j2 usrsctp-static)
+    (cd $(CWD)/deps/usrsctp && mkdir -p $(BUILD_DIR) && cd $(BUILD_DIR) && cmake -DCMAKE_BUILD_TYPE=$(VARIANT) -DCMAKE_C_FLAGS="-fPIC -Wno-unknown-warning-option -Wno-format-truncation" -Dsctp_build_shared_lib=0 -Dsctp_build_programs=0 .. && make -j2 usrsctp)
     cp $(CWD)/deps/usrsctp/$(BUILD_DIR)/usrsctplib/libusrsctp.a $(<)
 }
 rule make_libusrsctp_msvc ( targets * : sources * : properties * )
@@ -109,7 +111,7 @@ actions make_libusrsctp_msvc
     cd $(CWD)/deps/usrsctp
     mkdir $(BUILD_DIR)
     cd $(BUILD_DIR)
-    cmake -G "Visual Studio 16 2019" ..
+    cmake -G "Visual Studio 16 2019" -Dsctp_build_shared_lib=0 -Dsctp_build_programs=0 ..
     msbuild usrsctplib.sln /property:Configuration=$(VARIANT)
     cd %OLDD%
     cp $(CWD)/deps/usrsctp/$(BUILD_DIR)/usrsctplib/Release/usrsctp.lib $(<)

README.md

@@ -27,8 +27,9 @@ Features:
 - Full IPv6 support
 - Trickle ICE ([draft-ietf-ice-trickle-21](https://tools.ietf.org/html/draft-ietf-ice-trickle-21))
 - JSEP compatible ([draft-ietf-rtcweb-jsep-26](https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-26))
-- SRTP and SRTCP key derivation from DTLS ([RFC5764](https://tools.ietf.org/html/rfc5764))
 - Multicast DNS candidates ([draft-ietf-rtcweb-mdns-ice-candidates-04](https://tools.ietf.org/html/draft-ietf-rtcweb-mdns-ice-candidates-04))
+- SRTP and SRTCP key derivation from DTLS ([RFC5764](https://tools.ietf.org/html/rfc5764))
+- Differentiated Services QoS ([draft-ietf-tsvwg-rtcweb-qos-18](https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18))
 - TURN relaying ([RFC5766](https://tools.ietf.org/html/rfc5766)) with [libnice](https://github.com/libnice/libnice) as ICE backend
 
 Note only SDP BUNDLE mode is supported for media multiplexing ([draft-ietf-mmusic-sdp-bundle-negotiation-54](https://tools.ietf.org/html/draft-ietf-mmusic-sdp-bundle-negotiation-54)). The behavior is equivalent to the JSEP bundle-only policy: the library always negociates one unique network component, where SRTP media streams are multiplexed with SRTCP control packets ([RFC5761](https://tools.ietf.org/html/rfc5761)) and SCTP/DTLS data traffic ([RFC5764](https://tools.ietf.org/html/rfc5764)).

examples/client/CMakeLists.txt

@@ -9,14 +9,9 @@ target_compile_definitions(datachannel-client PUBLIC STATIC_GETOPT)
 else()
 add_executable(datachannel-client main.cpp parse_cl.cpp parse_cl.h)
 endif()
+
 set_target_properties(datachannel-client PROPERTIES
 	CXX_STANDARD 17
 	OUTPUT_NAME client)
-
-if(WIN32)
-	target_link_libraries(datachannel-client datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-client datachannel)
-endif()
 target_link_libraries(datachannel-client datachannel nlohmann_json)
 

examples/client/main.cpp

@@ -23,17 +23,18 @@
 
 #include "rtc/rtc.hpp"
 
+#include "parse_cl.h"
+
 #include <nlohmann/json.hpp>
 
 #include <algorithm>
+#include <future>
 #include <iostream>
 #include <memory>
 #include <random>
-#include <thread>
-#include <future>
 #include <stdexcept>
+#include <thread>
 #include <unordered_map>
-#include "parse_cl.h"
 
 using namespace rtc;
 using namespace std;
@@ -47,25 +48,23 @@ unordered_map<string, shared_ptr<PeerConnection>> peerConnectionMap;
 unordered_map<string, shared_ptr<DataChannel>> dataChannelMap;
 
 string localId;
-bool echoDataChannelMessages = false;
 
 shared_ptr<PeerConnection> createPeerConnection(const Configuration &config,
                                                 weak_ptr<WebSocket> wws, string id);
-void printReceived(bool echoed, string id, string type, size_t length);
 string randomId(size_t length);
 
-
 int main(int argc, char **argv) try {
 	auto params = std::make_unique<Cmdline>(argc, argv);
 
-	rtc::InitLogger(LogLevel::Debug);
+	rtc::InitLogger(LogLevel::Info);
 
 	Configuration config;
 	string stunServer = "";
 	if (params->noStun()) {
-		cout << "No STUN server is configured. Only local hosts and public IP addresses supported." << endl;
+		cout << "No STUN server is configured. Only local hosts and public IP addresses supported."
+		     << endl;
 	} else {
-		if (params->stunServer().substr(0,5).compare("stun:") != 0) {
+		if (params->stunServer().substr(0, 5).compare("stun:") != 0) {
 			stunServer = "stun:";
 		}
 		stunServer += params->stunServer() + ":" + to_string(params->stunPort());
@@ -76,27 +75,23 @@ int main(int argc, char **argv) try {
 	localId = randomId(4);
 	cout << "The local ID is: " << localId << endl;
 
-	echoDataChannelMessages = params->echoDataChannelMessages();
-	cout << "Received data channel messages will be "
-	     << (echoDataChannelMessages ? "echoed back to sender" : "printed to stdout") << endl;
-
 	auto ws = make_shared<WebSocket>();
 
 	std::promise<void> wsPromise;
 	auto wsFuture = wsPromise.get_future();
-	
+
-	ws->onOpen([&wsPromise]() { 
+	ws->onOpen([&wsPromise]() {
 		cout << "WebSocket connected, signaling ready" << endl;
 		wsPromise.set_value();
 	});
 
-	ws->onError([&wsPromise](string s) { 
+	ws->onError([&wsPromise](string s) {
 		cout << "WebSocket error" << endl;
 		wsPromise.set_exception(std::make_exception_ptr(std::runtime_error(s)));
 	});
-	
+
 	ws->onClosed([]() { cout << "WebSocket closed" << endl; });
-	
+
 	ws->onMessage([&](variant<binary, string> data) {
 		if (!holds_alternative<string>(data))
 			return;
@@ -134,14 +129,14 @@ int main(int argc, char **argv) try {
 	});
 
 	string wsPrefix = "";
-	if (params->webSocketServer().substr(0,5).compare("ws://") != 0) {
+	if (params->webSocketServer().substr(0, 5).compare("ws://") != 0) {
 		wsPrefix = "ws://";
 	}
 	const string url = wsPrefix + params->webSocketServer() + ":" +
-		to_string(params->webSocketPort()) + "/" + localId;
+	                   to_string(params->webSocketPort()) + "/" + localId;
 	cout << "Url is " << url << endl;
 	ws->open(url);
-	
+
 	cout << "Waiting for signaling to be connected..." << endl;
 	wsFuture.get();
 
@@ -171,20 +166,12 @@ int main(int argc, char **argv) try {
 
 		dc->onClosed([id]() { cout << "DataChannel from " << id << " closed" << endl; });
 
-		dc->onMessage([id, wdc = make_weak_ptr(dc)](const variant<binary, string> &message) {
+		dc->onMessage([id, wdc = make_weak_ptr(dc)](variant<binary, string> data) {
-			static bool firstMessage = true;
+			if (holds_alternative<string>(data))
-			if (holds_alternative<string>(message) && (!echoDataChannelMessages || firstMessage)) {
+				cout << "Message from " << id << " received: " << get<string>(data) << endl;
-				cout << "Message from " << id << " received: " << get<string>(message) << endl;
+			else
-				firstMessage = false;
+				cout << "Binary message from " << id
-			} else if (echoDataChannelMessages) {
+				     << " received, size=" << get<binary>(data).size() << endl;
-				bool echoed = false;
-				if (auto dc = wdc.lock()) {
-					dc->send(message);
-					echoed = true;
-				}
-				printReceived(echoed, id, (holds_alternative<string>(message) ? "text" : "binary"),
-				      get<string>(message).length());
-			}
 		});
 
 		dataChannelMap.emplace(id, dc);
@@ -237,20 +224,12 @@ shared_ptr<PeerConnection> createPeerConnection(const Configuration &config,
 
 		dc->onClosed([id]() { cout << "DataChannel from " << id << " closed" << endl; });
 
-		dc->onMessage([id, wdc = make_weak_ptr(dc)](const variant<binary, string> &message) {
+		dc->onMessage([id, wdc = make_weak_ptr(dc)](variant<binary, string> data) {
-			static bool firstMessage = true;
+			if (holds_alternative<string>(data))
-			if (holds_alternative<string>(message) && (!echoDataChannelMessages || firstMessage)) {
+				cout << "Message from " << id << " received: " << get<string>(data) << endl;
-				cout << "Message from " << id << " received: " << get<string>(message) << endl;
+			else
-				firstMessage = false;
+				cout << "Binary message from " << id
-			} else if (echoDataChannelMessages) {
+				     << " received, size=" << get<binary>(data).size() << endl;
-				bool echoed = false;
-				if (auto dc = wdc.lock()) {
-					dc->send(message);
-					echoed = true;
-				}
-				printReceived(echoed, id, (holds_alternative<string>(message) ? "text" : "binary"),
-						get<string>(message).length());
-			}
 		});
 
 		dc->send("Hello from " + localId);
@@ -262,20 +241,6 @@ shared_ptr<PeerConnection> createPeerConnection(const Configuration &config,
 	return pc;
 };
 
-// Helper function to print received pings
-void printReceived(bool echoed, string id, string type, size_t length) {
-	static long count = 0;
-	static long freq = 100;
-	if (!(++count%freq)) {
-		cout << "Received " << count << " pings in total from " << id << ", most recent of type "
-		     << type << " and " << (echoed ? "" : "un") << "successfully echoed most recent ping of size "
-		     << length << " back to " << id << endl;
-		if (count >= (freq * 10) && freq < 1000000) {
-			freq *= 10;
-		}
-	}
-}
-
 // Helper function to generate a random ID
 string randomId(size_t length) {
 	static const string characters(

examples/client/parse_cl.cpp

@@ -43,47 +43,39 @@ Cmdline::Cmdline (int argc, char *argv[]) // ISO C++17 not allowed: throw (std::
 
   static struct option long_options[] =
   {
-    {"echo", no_argument, NULL, 'e'},
     {"noStun", no_argument, NULL, 'n'},
     {"stunServer", required_argument, NULL, 's'},
     {"stunPort", required_argument, NULL, 't'},
     {"webSocketServer", required_argument, NULL, 'w'},
     {"webSocketPort", required_argument, NULL, 'x'},
     {"help", no_argument, NULL, 'h'},
-    {"version", no_argument, NULL, 'v'},
     {NULL, 0, NULL, 0}
   };
 
   _program_name += argv[0];
 
   /* default values */
-  _e = false;
   _n = false;
   _s = "stun.l.google.com";
   _t = 19302;
   _w = "localhost";
   _x = 8000;
   _h = false;
-  _v = false;
 
   optind = 0;
   while ((c = getopt_long (argc, argv, "s:t:w:x:enhv", long_options, &optind)) != - 1)
     {
       switch (c)
         {
-        case 'e': 
+        case 'n':
-          _e = true;
-          break;
-
-        case 'n': 
           _n = true;
           break;
 
-        case 's': 
+        case 's':
           _s = optarg;
           break;
 
-        case 't': 
+        case 't':
           _t = atoi (optarg);
           if (_t < 0)
             {
@@ -99,11 +91,11 @@ Cmdline::Cmdline (int argc, char *argv[]) // ISO C++17 not allowed: throw (std::
             }
           break;
 
-        case 'w': 
+        case 'w':
           _w = optarg;
           break;
 
-        case 'x': 
+        case 'x':
           _x = atoi (optarg);
           if (_x < 0)
             {
@@ -119,16 +111,11 @@ Cmdline::Cmdline (int argc, char *argv[]) // ISO C++17 not allowed: throw (std::
             }
           break;
 
-        case 'h': 
+        case 'h':
           _h = true;
           this->usage (EXIT_SUCCESS);
           break;
 
-        case 'v': 
-          _v = true;
-          this->version (EXIT_SUCCESS);
-          break;
-
         default:
           this->usage (EXIT_FAILURE);
 
@@ -155,8 +142,6 @@ void Cmdline::usage (int status)
       std::cout << "\
 usage: " << _program_name << " [ -enstwxhv ] \n\
 libdatachannel client implementing WebRTC Data Channels with WebSocket signaling\n\
-   [ -e ] [ --echo ] (type=FLAG)\n\
-          Echo data channel messages back to sender rather than putting to stdout.\n\
    [ -n ] [ --noStun ] (type=FLAG)\n\
           Do NOT use a stun server (overrides -s and -t).\n\
    [ -s ] [ --stunServer ] (type=STRING, default=stun.l.google.com)\n\
@@ -168,15 +153,8 @@ libdatachannel client implementing WebRTC Data Channels with WebSocket signaling
    [ -x ] [ --webSocketPort ] (type=INTEGER, range=0...65535, default=8000)\n\
           Web socket server port.\n\
    [ -h ] [ --help ] (type=FLAG)\n\
-          Display this help and exit.\n\
+          Display this help and exit.\n";
-   [ -v ] [ --version ] (type=FLAG)\n\
-          Output version information and exit.\n";
     }
   exit (status);
 }
 
-void Cmdline::version (int status)
-{
-  std::cout << _program_name << " v0.5\n";
-  exit (status);
-}

examples/client/parse_cl.h

@@ -34,14 +34,12 @@ class Cmdline
 {
 private:
   /* parameters */
-  bool _e;
   bool _n;
   std::string _s;
   int _t;
   std::string _w;
   int _x;
   bool _h;
-  bool _v;
 
   /* other stuff to keep track of */
   std::string _program_name;
@@ -55,20 +53,15 @@ public:
   /* usage function */
   void usage (int status);
 
-  /* version function */
-  void version (int status);
-
   /* return next (non-option) parameter */
   int next_param () { return _optind; }
 
-  bool echoDataChannelMessages () const { return _e; }
   bool noStun () const { return _n; }
   std::string stunServer () const { return _s; }
   int stunPort () const { return _t; }
   std::string webSocketServer () const { return _w; }
   int webSocketPort () const { return _x; }
   bool h () const { return _h; }
-  bool v () const { return _v; }
 };
 
 #endif

examples/copy-paste-capi/answerer.c

@@ -137,7 +137,7 @@ int main(int argc, char **argv) {
 			size_t candidate_size = 0;
 
 			if (getline(&candidate, &candidate_size, stdin)) {
-				rtcAddRemoteCandidate(peer->pc, candidate, "0");
+				rtcAddRemoteCandidate(peer->pc, candidate, NULL);
 				free(candidate);
 
 			} else {

examples/copy-paste-capi/offerer.c

@@ -140,7 +140,7 @@ int main(int argc, char **argv) {
 			char *candidate = NULL;
 			size_t candidate_size = 0;
 			if (getline(&candidate, &candidate_size, stdin)) {
-				rtcAddRemoteCandidate(peer->pc, candidate, "0");
+				rtcAddRemoteCandidate(peer->pc, candidate, NULL);
 				free(candidate);
 
 			} else {

examples/copy-paste/CMakeLists.txt

@@ -4,19 +4,11 @@ add_executable(datachannel-copy-paste-offerer offerer.cpp)
 set_target_properties(datachannel-copy-paste-offerer PROPERTIES
 	CXX_STANDARD 17
 	OUTPUT_NAME offerer)
-if(WIN32)
+target_link_libraries(datachannel-copy-paste-offerer datachannel)
-	target_link_libraries(datachannel-copy-paste-offerer datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-copy-paste-offerer datachannel)
-endif()
 
 add_executable(datachannel-copy-paste-answerer answerer.cpp)
 set_target_properties(datachannel-copy-paste-answerer PROPERTIES
 	CXX_STANDARD 17
 	OUTPUT_NAME answerer)
-if(WIN32)
+target_link_libraries(datachannel-copy-paste-answerer datachannel)
-	target_link_libraries(datachannel-copy-paste-answerer datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-copy-paste-answerer datachannel)
-endif()
 

examples/media/CMakeLists.txt

@@ -4,11 +4,5 @@ add_executable(datachannel-media main.cpp)
 set_target_properties(datachannel-media PROPERTIES
         CXX_STANDARD 17
         OUTPUT_NAME media)
+target_link_libraries(datachannel-media datachannel nlohmann_json)
 
-if(WIN32)
-    target_link_libraries(datachannel-media datachannel-static) # DLL exports only the C API
-else()
-    target_link_libraries(datachannel-media datachannel)
-endif()
-
-target_link_libraries(datachannel-media datachannel nlohmann_json)

examples/sfu-media/CMakeLists.txt

@@ -4,12 +4,5 @@ add_executable(datachannel-sfu-media main.cpp)
 set_target_properties(datachannel-sfu-media PROPERTIES
 		CXX_STANDARD 17
 		OUTPUT_NAME sfu-media)
-
-if(WIN32)
-	target_link_libraries(datachannel-sfu-media datachannel-static) # DLL exports only the C API
-else()
-	target_link_libraries(datachannel-sfu-media datachannel)
-endif()
-
 target_link_libraries(datachannel-sfu-media datachannel nlohmann_json)
 

examples/web/script.js

@@ -59,6 +59,7 @@ function openSignaling(url) {
     ws.onmessage = (e) => {
       if(typeof(e.data) != 'string') return;
       const message = JSON.parse(e.data);
+      console.log(message);
       const { id, type } = message;
 
       let pc = peerConnectionMap[id];

include/rtc/candidate.hpp

@@ -25,7 +25,7 @@
 
 namespace rtc {
 
-class Candidate {
+class RTC_CPP_EXPORT Candidate {
 public:
 	enum class Family { Unresolved, Ipv4, Ipv6 };
 	enum class Type { Unknown, Host, ServerReflexive, PeerReflexive, Relayed };
@@ -76,8 +76,8 @@ private:
 
 } // namespace rtc
 
-std::ostream &operator<<(std::ostream &out, const rtc::Candidate &candidate);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Candidate &candidate);
-std::ostream &operator<<(std::ostream &out, const rtc::Candidate::Type &type);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Candidate::Type &type);
-std::ostream &operator<<(std::ostream &out, const rtc::Candidate::TransportType &transportType);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Candidate::TransportType &transportType);
 
 #endif

include/rtc/channel.hpp

@@ -28,13 +28,14 @@
 
 namespace rtc {
 
-class Channel {
+class RTC_CPP_EXPORT Channel {
 public:
 	Channel() = default;
 	virtual ~Channel() = default;
 
 	virtual void close() = 0;
 	virtual bool send(message_variant data) = 0; // returns false if buffered
+	virtual bool send(const byte *data, size_t size) = 0;
 
 	virtual bool isOpen() const = 0;
 	virtual bool isClosed() const = 0;

include/rtc/configuration.hpp

@@ -26,7 +26,7 @@
 
 namespace rtc {
 
-struct IceServer {
+struct RTC_CPP_EXPORT IceServer {
 	enum class Type { Stun, Turn };
 	enum class RelayType { TurnUdp, TurnTcp, TurnTls };
 
@@ -51,7 +51,7 @@ struct IceServer {
 	RelayType relayType;
 };
 
-struct ProxyServer {
+struct RTC_CPP_EXPORT ProxyServer {
 	enum class Type { None = 0, Socks5, Http, Last = Http };
 
 	ProxyServer(Type type_, string ip_, uint16_t port_, string username_ = "",
@@ -64,7 +64,7 @@ struct ProxyServer {
 	string password;
 };
 
-struct Configuration {
+struct RTC_CPP_EXPORT Configuration {
 	std::vector<IceServer> iceServers;
 	std::optional<ProxyServer> proxyServer;
 	bool enableIceTcp = false;

include/rtc/datachannel.hpp

@@ -36,7 +36,7 @@ namespace rtc {
 class SctpTransport;
 class PeerConnection;
 
-class DataChannel : public std::enable_shared_from_this<DataChannel>, public Channel {
+class RTC_CPP_EXPORT DataChannel : public std::enable_shared_from_this<DataChannel>, public Channel {
 public:
 	DataChannel(std::weak_ptr<PeerConnection> pc, uint16_t stream, string label, string protocol,
 	            Reliability reliability);
@@ -50,7 +50,7 @@ public:
 
 	void close(void) override;
 	bool send(message_variant data) override;
-	bool send(const byte *data, size_t size);
+	bool send(const byte *data, size_t size) override;
 	template <typename Buffer> bool sendBuffer(const Buffer &buf);
 	template <typename Iterator> bool sendBuffer(Iterator first, Iterator last);
 
@@ -87,7 +87,7 @@ private:
 	friend class PeerConnection;
 };
 
-class NegociatedDataChannel final : public DataChannel {
+class RTC_CPP_EXPORT NegociatedDataChannel final : public DataChannel {
 public:
 	NegociatedDataChannel(std::weak_ptr<PeerConnection> pc, uint16_t stream, string label,
 	                      string protocol, Reliability reliability);

include/rtc/description.hpp

@@ -32,7 +32,16 @@
 
 namespace rtc {
 
-class Description {
+const string DEFAULT_AUDIO_PROFILE =
+    "minptime=10;maxaveragebitrate=96000;stereo=1;sprop-stereo=1;useinbandfec=1";
+
+// Use Constrained Baseline profile Level 4.2 (necessary for Firefox)
+// https://developer.mozilla.org/en-US/docs/Web/Media/Formats/WebRTC_codecs#Supported_video_codecs
+// TODO: Should be 42E0 but 42C0 appears to be more compatible. Investigate this.
+const string DEFAULT_VIDEO_PROFILE =
+    "profile-level-id=42e01f;packetization-mode=1;level-asymmetry-allowed=1";
+
+class RTC_CPP_EXPORT Description {
 public:
 	enum class Type { Unspec, Offer, Answer, Pranswer, Rollback };
 	enum class Role { ActPass, Passive, Active };
@@ -63,7 +72,7 @@ public:
 	string generateSdp(string_view eol) const;
 	string generateApplicationSdp(string_view eol) const;
 
-	class Entry {
+	class RTC_CPP_EXPORT Entry {
 	public:
 		virtual ~Entry() = default;
 
@@ -95,7 +104,7 @@ public:
 		Direction mDirection;
 	};
 
-	struct Application : public Entry {
+	struct RTC_CPP_EXPORT Application : public Entry {
 	public:
 		Application(string mid = "data");
 		virtual ~Application() = default;
@@ -120,7 +129,7 @@ public:
 	};
 
 	// Media (non-data)
-	class Media : public Entry {
+	class RTC_CPP_EXPORT Media : public Entry {
 	public:
 		Media(const string &sdp);
 		Media(const string &mline, string mid, Direction dir = Direction::SendOnly);
@@ -131,9 +140,10 @@ public:
 
 		void removeFormat(const string &fmt);
 
-		void addSSRC(uint32_t ssrc, std::string name);
+		void addSSRC(uint32_t ssrc, std::optional<string> name,
-		void addSSRC(uint32_t ssrc);
+		             std::optional<string> msid = nullopt);
-		void replaceSSRC(uint32_t oldSSRC, uint32_t ssrc, string name);
+		void replaceSSRC(uint32_t oldSSRC, uint32_t ssrc, std::optional<string> name,
+		                 std::optional<string> msid = nullopt);
 		bool hasSSRC(uint32_t ssrc);
 		std::vector<uint32_t> getSSRCs();
 
@@ -142,6 +152,9 @@ public:
 
 		bool hasPayloadType(int payloadType) const;
 
+		void addRTXCodec(unsigned int payloadType, unsigned int originalPayloadType,
+		                 unsigned int clockRate);
+
 		virtual void parseSdpLine(string_view line) override;
 
 		struct RTPMap {
@@ -150,7 +163,7 @@ public:
 
 			void removeFB(const string &string);
 			void addFB(const string &string);
-			void addAttribute(std::string attr) { fmtps.emplace_back(attr); }
+			void addAttribute(string attr) { fmtps.emplace_back(std::move(attr)); }
 
 			int pt;
 			string format;
@@ -181,21 +194,27 @@ public:
 
 	public:
 		void addRTPMap(const RTPMap &map);
+
+		void removeSSRC(uint32_t oldSSRC);
 	};
 
-	class Audio : public Media {
+	class RTC_CPP_EXPORT Audio : public Media {
 	public:
 		Audio(string mid = "audio", Direction dir = Direction::SendOnly);
 
-		void addAudioCodec(int payloadType, const string &codec);
+		void addAudioCodec(int payloadType, string codec,
+		                   std::optional<string> profile = DEFAULT_AUDIO_PROFILE);
+
 		void addOpusCodec(int payloadType);
 	};
 
-	class Video : public Media {
+	class RTC_CPP_EXPORT Video : public Media {
 	public:
 		Video(string mid = "video", Direction dir = Direction::SendOnly);
 
-		void addVideoCodec(int payloadType, const string &codec);
+		void addVideoCodec(int payloadType, string codec,
+		                   std::optional<string> profile = DEFAULT_VIDEO_PROFILE);
+
 		void addH264Codec(int payloadType);
 		void addVP8Codec(int payloadType);
 		void addVP9Codec(int payloadType);
@@ -245,8 +264,8 @@ private:
 
 } // namespace rtc
 
-std::ostream &operator<<(std::ostream &out, const rtc::Description &description);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, const rtc::Description &description);
-std::ostream &operator<<(std::ostream &out, rtc::Description::Type type);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::Description::Type type);
-std::ostream &operator<<(std::ostream &out, rtc::Description::Role role);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::Description::Role role);
 
 #endif

include/rtc/include.hpp

@@ -28,9 +28,15 @@
 #endif
 
 #ifdef _WIN32
+#define RTC_CPP_EXPORT __declspec(dllexport)
 #ifndef _WIN32_WINNT
 #define _WIN32_WINNT 0x0602 // Windows 8
 #endif
+#ifdef _MSC_VER
+#pragma warning(disable:4251) // disable "X needs to have dll-interface..."
+#endif
+#else
+#define RTC_CPP_EXPORT
 #endif
 
 #include "log.hpp"

include/rtc/init.hpp

@@ -27,7 +27,7 @@ namespace rtc {
 
 using init_token = std::shared_ptr<void>;
 
-class Init {
+class RTC_CPP_EXPORT Init {
 public:
 	static init_token Token();
 	static void Preload();

include/rtc/log.hpp

@@ -35,6 +35,8 @@
 #pragma warning(pop)
 #endif
 
+#include "include.hpp"
+
 namespace rtc {
 
 enum class LogLevel { // Don't change, it must match plog severity
@@ -47,8 +49,8 @@ enum class LogLevel { // Don't change, it must match plog severity
 	Verbose = 6
 };
 
-void InitLogger(LogLevel level);
+RTC_CPP_EXPORT void InitLogger(LogLevel level);
-void InitLogger(plog::Severity severity, plog::IAppender *appender = nullptr);
+RTC_CPP_EXPORT void InitLogger(plog::Severity severity, plog::IAppender *appender = nullptr);
 } // namespace rtc
 
 #endif

include/rtc/message.hpp

@@ -29,7 +29,7 @@
 
 namespace rtc {
 
-struct Message : binary {
+struct RTC_CPP_EXPORT Message : binary {
 	enum Type { Binary, String, Control, Reset };
 
 	Message(const Message &message) = default;
@@ -42,7 +42,8 @@ struct Message : binary {
 	Message(binary &&data, Type type_ = Binary) : binary(std::move(data)), type(type_) {}
 
 	Type type;
-	unsigned int stream = 0;
+	unsigned int stream = 0; // Stream id (SCTP stream or SSRC)
+	unsigned int dscp = 0;   // Differentiated Services Code Point
 	std::shared_ptr<Reliability> reliability;
 };
 

include/rtc/peerconnection.hpp

@@ -50,14 +50,14 @@ class SctpTransport;
 using certificate_ptr = std::shared_ptr<Certificate>;
 using future_certificate_ptr = std::shared_future<certificate_ptr>;
 
-struct DataChannelInit {
+struct RTC_CPP_EXPORT DataChannelInit {
 	Reliability reliability = {};
 	bool negotiated = false;
 	std::optional<uint16_t> id = nullopt;
 	string protocol = "";
 };
 
-class PeerConnection final : public std::enable_shared_from_this<PeerConnection> {
+class RTC_CPP_EXPORT PeerConnection final : public std::enable_shared_from_this<PeerConnection> {
 public:
 	enum class State : int {
 		New = RTC_NEW,
@@ -157,6 +157,8 @@ private:
 	void processLocalCandidate(Candidate candidate);
 	void processRemoteDescription(Description description);
 	void processRemoteCandidate(Candidate candidate);
+	string localBundleMid() const;
+
 	void triggerDataChannel(std::weak_ptr<DataChannel> weakDataChannel);
 	void triggerTrack(std::shared_ptr<Track> track);
 	bool changeState(State state);
@@ -203,8 +205,8 @@ private:
 
 } // namespace rtc
 
-std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::State state);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::State state);
-std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::GatheringState state);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::GatheringState state);
-std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::SignalingState state);
+RTC_CPP_EXPORT std::ostream &operator<<(std::ostream &out, rtc::PeerConnection::SignalingState state);
 
 #endif

include/rtc/rtcp.hpp

@@ -29,7 +29,7 @@
 
 namespace rtc {
 
-class RtcpHandler {
+class RTC_CPP_EXPORT RtcpHandler {
 protected:
 	/**
 	 * Use this callback when trying to send custom data (such as RTCP) to the client.
@@ -64,7 +64,7 @@ public:
 class Track;
 
 // An RtcpSession can be plugged into a Track to handle the whole RTCP session
-class RtcpReceivingSession : public RtcpHandler {
+class RTC_CPP_EXPORT RtcpReceivingSession : public RtcpHandler {
 public:
 	rtc::message_ptr incoming(rtc::message_ptr ptr) override;
 	rtc::message_ptr outgoing(rtc::message_ptr ptr) override;

include/rtc/rtp.hpp

@@ -20,7 +20,7 @@
 #ifndef RTC_RTP_HPP
 #define RTC_RTP_HPP
 
-#include <rtc/log.hpp>
+#include "log.hpp"
 
 #include <cmath>
 
@@ -66,28 +66,31 @@ public:
 	inline uint32_t ssrc() const { return ntohl(_ssrc); }
 
 	inline size_t getSize() const {
-		return ((char *)&csrc) - ((char *)this) + sizeof(SSRC) * csrcCount();
+		return reinterpret_cast<const char *>(&csrc) - reinterpret_cast<const char *>(this) +
+		       sizeof(SSRC) * csrcCount();
 	}
 
-	char *getBody() const { return ((char *)&csrc) + sizeof(SSRC) * csrcCount(); }
+	[[nodiscard]] char *getBody() {
+		return reinterpret_cast<char *>(&csrc) + sizeof(SSRC) * csrcCount();
+	}
+
+	[[nodiscard]] const char *getBody() const {
+		return reinterpret_cast<const char *>(&csrc) + sizeof(SSRC) * csrcCount();
+	}
 
 	inline void setSeqNumber(uint16_t newSeqNo) { _seqNumber = htons(newSeqNo); }
 	inline void setPayloadType(uint8_t newPayloadType) {
 		_payloadType = (_payloadType & 0b10000000u) | (0b01111111u & newPayloadType);
 	}
-	inline void setSsrc(uint32_t ssrc) { _ssrc = htonl(ssrc); }
+	inline void setSsrc(uint32_t in_ssrc) { _ssrc = htonl(in_ssrc); }
 
 	void setTimestamp(uint32_t i) { _timestamp = htonl(i); }
 
 	void log() {
-		PLOG_VERBOSE  << "RTP V: " << (int) version()
+		PLOG_VERBOSE << "RTP V: " << (int)version() << " P: " << (padding() ? "P" : " ")
-		            << " P: " << (padding() ? "P" : " ")
+		             << " X: " << (extension() ? "X" : " ") << " CC: " << (int)csrcCount()
-		            << " X: " << (extension() ? "X" : " ")
+		             << " M: " << (marker() ? "M" : " ") << " PT: " << (int)payloadType()
-		            << " CC: "  << (int) csrcCount()
+		             << " SEQNO: " << seqNumber() << " TS: " << timestamp();
-		            << " M: " << (marker() ? "M" : " ")
-		            << " PT: " << (int) payloadType()
-		            << " SEQNO: " << seqNumber()
-		            << " TS: " << timestamp();
 	}
 };
 
@@ -103,13 +106,13 @@ private:
 	uint32_t _delaySinceLastReport;
 
 public:
-	inline void preparePacket(SSRC ssrc, [[maybe_unused]] unsigned int packetsLost,
+	inline void preparePacket(SSRC in_ssrc, [[maybe_unused]] unsigned int packetsLost,
 	                          [[maybe_unused]] unsigned int totalPackets, uint16_t highestSeqNo,
 	                          uint16_t seqNoCycles, uint32_t jitter, uint64_t lastSR_NTP,
 	                          uint64_t lastSR_DELAY) {
 		setSeqNo(highestSeqNo, seqNoCycles);
 		setJitter(jitter);
-		setSSRC(ssrc);
+		setSSRC(in_ssrc);
 
 		// Middle 32 bits of NTP Timestamp
 		//		  this->lastReport = lastSR_NTP >> 16u;
@@ -117,22 +120,23 @@ public:
 		setDelaySinceSR(uint32_t(lastSR_DELAY));
 
 		// The delay, expressed in units of 1/65536 seconds
-		//		  this->delaySinceLastReport = lastSR_DELAY;
+		// this->delaySinceLastReport = lastSR_DELAY;
 	}
 
-	inline void setSSRC(SSRC ssrc) { this->ssrc = htonl(ssrc); }
+	inline void setSSRC(SSRC in_ssrc) { this->ssrc = htonl(in_ssrc); }
-	inline SSRC getSSRC() const { return ntohl(ssrc); }
+	[[nodiscard]] inline SSRC getSSRC() const { return ntohl(ssrc); }
 
 	inline void setPacketsLost([[maybe_unused]] unsigned int packetsLost,
 	                           [[maybe_unused]] unsigned int totalPackets) {
 		// TODO Implement loss percentages.
 		_fractionLostAndPacketsLost = 0;
 	}
-	inline unsigned int getLossPercentage() const {
+
+	[[nodiscard]] inline unsigned int getLossPercentage() const {
 		// TODO Implement loss percentages.
 		return 0;
 	}
-	inline unsigned int getPacketLostCount() const {
+	[[nodiscard]] inline unsigned int getPacketLostCount() const {
 		// TODO Implement total packets lost.
 		return 0;
 	}
@@ -149,13 +153,13 @@ public:
 	inline void setJitter(uint32_t jitter) { _jitter = htonl(jitter); }
 
 	inline void setNTPOfSR(uint64_t ntp) { _lastReport = htonll(ntp >> 16u); }
-	inline uint32_t getNTPOfSR() const { return ntohl(_lastReport) << 16u; }
+	[[nodiscard]] inline uint32_t getNTPOfSR() const { return ntohl(_lastReport) << 16u; }
 
 	inline void setDelaySinceSR(uint32_t sr) {
 		// The delay, expressed in units of 1/65536 seconds
 		_delaySinceLastReport = htonl(sr);
 	}
-	inline uint32_t getDelaySinceSR() const { return ntohl(_delaySinceLastReport); }
+	[[nodiscard]] inline uint32_t getDelaySinceSR() const { return ntohl(_delaySinceLastReport); }
 
 	inline void log() const {
 		PLOG_VERBOSE << "RTCP report block: "
@@ -199,9 +203,9 @@ public:
 
 	inline void log() const {
 		PLOG_VERBOSE << "RTCP header: "
-		          << "version=" << unsigned(version()) << ", padding=" << padding()
+		             << "version=" << unsigned(version()) << ", padding=" << padding()
-		          << ", reportCount=" << unsigned(reportCount())
+		             << ", reportCount=" << unsigned(reportCount())
-		          << ", payloadType=" << unsigned(payloadType()) << ", length=" << length();
+		             << ", payloadType=" << unsigned(payloadType()) << ", length=" << length();
 	}
 };
 
@@ -246,8 +250,10 @@ public:
 		this->_senderSSRC = htonl(senderSSRC);
 	}
 
-	inline RTCP_ReportBlock *getReportBlock(int num) { return &_reportBlocks + num; }
+	[[nodiscard]] inline RTCP_ReportBlock *getReportBlock(int num) { return &_reportBlocks + num; }
-	inline const RTCP_ReportBlock *getReportBlock(int num) const { return &_reportBlocks + num; }
+	[[nodiscard]] inline const RTCP_ReportBlock *getReportBlock(int num) const {
+		return &_reportBlocks + num;
+	}
 
 	[[nodiscard]] inline size_t getSize() const {
 		// "length" in packet is one less than the number of 32 bit words in the packet.
@@ -284,8 +290,10 @@ private:
 	RTCP_ReportBlock _reportBlocks;
 
 public:
-	inline RTCP_ReportBlock *getReportBlock(int num) { return &_reportBlocks + num; }
+	[[nodiscard]] inline RTCP_ReportBlock *getReportBlock(int num) { return &_reportBlocks + num; }
-	inline const RTCP_ReportBlock *getReportBlock(int num) const { return &_reportBlocks + num; }
+	[[nodiscard]] inline const RTCP_ReportBlock *getReportBlock(int num) const {
+		return &_reportBlocks + num;
+	}
 
 	inline SSRC senderSSRC() const { return ntohl(_senderSSRC); }
 	inline void setSenderSSRC(SSRC ssrc) { this->_senderSSRC = htonl(ssrc); }
@@ -337,7 +345,7 @@ struct RTCP_REMB {
 		return sizeof(uint32_t) * (1 + header.header.length());
 	}
 
-	void preparePacket(SSRC senderSSRC, unsigned int numSSRC, unsigned int bitrate) {
+	void preparePacket(SSRC senderSSRC, unsigned int numSSRC, unsigned int in_bitrate) {
 
 		// Report Count becomes the format here.
 		header.header.prepareHeader(206, 15, 0);
@@ -352,21 +360,21 @@ struct RTCP_REMB {
 		id[2] = 'M';
 		id[3] = 'B';
 
-		setBitrate(numSSRC, bitrate);
+		setBitrate(numSSRC, in_bitrate);
 	}
 
-	void setBitrate(unsigned int numSSRC, unsigned int bitrate) {
+	void setBitrate(unsigned int numSSRC, unsigned int in_bitrate) {
 		unsigned int exp = 0;
-		while (bitrate > pow(2, 18) - 1) {
+		while (in_bitrate > pow(2, 18) - 1) {
 			exp++;
-			bitrate /= 2;
+			in_bitrate /= 2;
 		}
 
 		// "length" in packet is one less than the number of 32 bit words in the packet.
 		header.header.setLength(
 		    uint16_t((offsetof(RTCP_REMB, ssrc) / sizeof(uint32_t)) - 1 + numSSRC));
 
-		this->bitrate = htonl((numSSRC << (32u - 8u)) | (exp << (32u - 8u - 6u)) | bitrate);
+		this->bitrate = htonl((numSSRC << (32u - 8u)) | (exp << (32u - 8u - 6u)) | in_bitrate);
 	}
 
 	void setSsrc(int iterator, SSRC newSssrc) { ssrc[iterator] = htonl(newSssrc); }
@@ -428,7 +436,7 @@ public:
 
 public:
 	void preparePacket(SSRC ssrc, unsigned int discreteSeqNoCount) {
-		header.header.prepareHeader(205, 1, 2 + discreteSeqNoCount);
+		header.header.prepareHeader(205, 1, 2 + uint16_t(discreteSeqNoCount));
 		header.setMediaSourceSSRC(ssrc);
 		header.setPacketSenderSSRC(ssrc);
 	}
@@ -481,11 +489,15 @@ public:
 		return ntohs(*(uint16_t *)(header.getBody()));
 	}
 
-	char *getBody() { return header.getBody() + sizeof(uint16_t); }
+	[[nodiscard]] char *getBody() { return header.getBody() + sizeof(uint16_t); }
 
-	size_t getBodySize(size_t totalSize) { return totalSize - ((char *)getBody() - (char *)this); }
+	[[nodiscard]] const char *getBody() const { return header.getBody() + sizeof(uint16_t); }
 
-	RTP &getHeader() { return header; }
+	[[nodiscard]] size_t getBodySize(size_t totalSize) {
+		return totalSize - (getBody() - reinterpret_cast<char *>(this));
+	}
+
+	[[nodiscard]] RTP &getHeader() { return header; }
 
 	size_t normalizePacket(size_t totalSize, SSRC originalSSRC, uint8_t originalPayloadType) {
 		header.setSeqNumber(getOriginalSeqNo());

include/rtc/track.hpp

@@ -35,7 +35,7 @@ namespace rtc {
 class DtlsSrtpTransport;
 #endif
 
-class Track final : public std::enable_shared_from_this<Track>, public Channel {
+class RTC_CPP_EXPORT Track final : public std::enable_shared_from_this<Track>, public Channel {
 public:
 	Track(Description::Media description);
 	~Track() = default;
@@ -47,7 +47,7 @@ public:
 
 	void close(void) override;
 	bool send(message_variant data) override;
-	bool send(const byte *data, size_t size);
+	bool send(const byte *data, size_t size) override;
 
 	bool isOpen(void) const override;
 	bool isClosed(void) const override;
@@ -70,8 +70,8 @@ private:
 	std::weak_ptr<DtlsSrtpTransport> mDtlsSrtpTransport;
 #endif
 
-	bool outgoing(message_ptr message);
 	void incoming(message_ptr message);
+	bool outgoing(message_ptr message);
 
 	Description::Media mMediaDescription;
 	std::atomic<bool> mIsClosed = false;

include/rtc/websocket.hpp

@@ -38,7 +38,7 @@ class TcpTransport;
 class TlsTransport;
 class WsTransport;
 
-class WebSocket final : public Channel, public std::enable_shared_from_this<WebSocket> {
+class RTC_CPP_EXPORT WebSocket final : public Channel, public std::enable_shared_from_this<WebSocket> {
 public:
 	enum class State : int {
 		Connecting = 0,
@@ -49,6 +49,7 @@ public:
 
 	struct Configuration {
 		bool disableTlsVerification = false; // if true, don't verify the TLS certificate
+		std::vector<string> protocols;
 	};
 
 	WebSocket(std::optional<Configuration> config = nullopt);
@@ -59,6 +60,7 @@ public:
 	void open(const string &url);
 	void close() override;
 	bool send(const message_variant data) override;
+	bool send(const byte *data, size_t size) override;
 
 	bool isOpen() const override;
 	bool isClosed() const override;

src/candidate.cpp

@@ -117,9 +117,9 @@ void Candidate::parse(string candidate) {
 		mTransportType = TransportType::Udp;
 	} else if (transport == "TCP" || transport == "tcp") {
 		// Peek tail to find TCP type
-		std::istringstream iss(mTail);
+		std::istringstream tiss(mTail);
 		string tcptype_, tcptype;
-		if (iss >> tcptype_ >> tcptype && tcptype_ == "tcptype") {
+		if (tiss >> tcptype_ >> tcptype && tcptype_ == "tcptype") {
 			if (auto it = TcpTypeMap.find(tcptype); it != TcpTypeMap.end())
 				mTransportType = it->second;
 			else

src/description.cpp

@@ -29,13 +29,13 @@
 #include <unordered_map>
 
 using std::shared_ptr;
-using std::size_t;
-using std::string;
-using std::string_view;
 using std::chrono::system_clock;
 
 namespace {
 
+using std::string;
+using std::string_view;
+
 inline bool match_prefix(string_view str, string_view prefix) {
 	return str.size() >= prefix.size() &&
 	       std::mismatch(prefix.begin(), prefix.end(), str.begin()).first == prefix.end();
@@ -483,8 +483,7 @@ string Description::Entry::generateSdpLines(string_view eol) const {
 	}
 
 	for (const auto &attr : mAttributes) {
-		if (attr.find("extmap") == std::string::npos &&
+		if (attr.find("extmap") == string::npos && attr.find("rtcp-rsize") == string::npos)
-		    attr.find("rtcp-rsize") == std::string::npos)
 			sdp << "a=" << attr << eol;
 	}
 
@@ -519,12 +518,21 @@ Description::Entry::removeAttribute(std::vector<string>::iterator it) {
 	return mAttributes.erase(it);
 }
 
-void Description::Media::addSSRC(uint32_t ssrc, std::string name) {
+void Description::Media::addSSRC(uint32_t ssrc, std::optional<string> name,
-	mAttributes.emplace_back("ssrc:" + std::to_string(ssrc) + " cname:" + name);
+                                 std::optional<string> msid) {
+	if (name)
+		mAttributes.emplace_back("ssrc:" + std::to_string(ssrc) + " cname:" + *name);
+	else
+		mAttributes.emplace_back("ssrc:" + std::to_string(ssrc));
+
+	if (msid)
+		mAttributes.emplace_back("ssrc:" + std::to_string(ssrc) + " msid:" + *msid + " " + *msid);
+
 	mSsrcs.emplace_back(ssrc);
 }
 
-void Description::Media::replaceSSRC(uint32_t oldSSRC, uint32_t ssrc, std::string name) {
+void Description::Media::replaceSSRC(uint32_t oldSSRC, uint32_t ssrc, std::optional<string> name,
+                                     std::optional<string> msid) {
 	auto it = mAttributes.begin();
 	while (it != mAttributes.end()) {
 		if (it->find("ssrc:" + std::to_string(oldSSRC)) == 0) {
@@ -532,11 +540,17 @@ void Description::Media::replaceSSRC(uint32_t oldSSRC, uint32_t ssrc, std::strin
 		} else
 			it++;
 	}
-	mAttributes.emplace_back("ssrc:" + std::to_string(ssrc) + " cname:" + name);
+	addSSRC(ssrc, std::move(name), std::move(msid));
 }
 
-void Description::Media::addSSRC(uint32_t ssrc) {
+void Description::Media::removeSSRC(uint32_t oldSSRC) {
-	mAttributes.emplace_back("ssrc:" + std::to_string(ssrc));
+	auto it = mAttributes.begin();
+	while (it != mAttributes.end()) {
+		if (it->find("ssrc:" + std::to_string(oldSSRC)) == 0) {
+			it = mAttributes.erase(it);
+		} else
+			it++;
+	}
 }
 
 bool Description::Media::hasSSRC(uint32_t ssrc) {
@@ -689,32 +703,17 @@ void Description::Media::removeFormat(const string &fmt) {
 	}
 }
 
-void Description::Video::addVideoCodec(int payloadType, const string &codec) {
+void Description::Video::addVideoCodec(int payloadType, string codec,
+                                       std::optional<string> profile) {
 	RTPMap map(std::to_string(payloadType) + ' ' + codec + "/90000");
 	map.addFB("nack");
 	map.addFB("nack pli");
-	//    map.addFB("nack fir");
+	//    map.addFB("ccm fir");
 	map.addFB("goog-remb");
-	if (codec == "H264") {
+	if (profile)
-		// Use Constrained Baseline profile Level 4.2 (necessary for Firefox)
+		map.fmtps.emplace_back(*profile);
-		// https://developer.mozilla.org/en-US/docs/Web/Media/Formats/WebRTC_codecs#Supported_video_codecs
-		// TODO: Should be 42E0 but 42C0 appears to be more compatible. Investigate this.
-		map.fmtps.emplace_back(
-		    "profile-level-id=4de01f;packetization-mode=1;level-asymmetry-allowed=1");
-
-		// Because certain Android devices don't like me, let us just negotiate some random
-		{
-			RTPMap map(std::to_string(payloadType + 1) + ' ' + codec + "/90000");
-			map.addFB("nack");
-			map.addFB("nack pli");
-			//            map.addFB("nack fir");
-			map.addFB("goog-remb");
-			addRTPMap(map);
-		}
-	}
 	addRTPMap(map);
 
-	//	// RTX Packets
 	/* TODO
 	 *  TIL that Firefox does not properly support the negotiation of RTX! It works, but doesn't
 	 * negotiate the SSRC so we have no idea what SSRC is RTX going to be. Three solutions: One) we
@@ -722,24 +721,34 @@ void Description::Video::addVideoCodec(int payloadType, const string &codec) {
 	 * rebuild the original packet before we send it distribute it to each track. Three) we complain
 	 * to mozilla. This one probably won't do much.
 	 */
-	//    RTPMap rtx(std::to_string(payloadType+1) + " rtx/90000");
+	// RTX Packets
-	//    // TODO rtx-time is how long can a request be stashed for before needing to resend it.
+	// RTPMap rtx(std::to_string(payloadType+1) + " rtx/90000");
-	//    Needs to be parameterized rtx.addAttribute("apt=" + std::to_string(payloadType) +
+	// // TODO rtx-time is how long can a request be stashed for before needing to resend it.
-	//    ";rtx-time=3000"); addRTPMap(rtx);
+	// Needs to be parameterized rtx.addAttribute("apt=" + std::to_string(payloadType) +
+	// ";rtx-time=3000"); addRTPMap(rtx);
 }
 
-void Description::Audio::addAudioCodec(int payloadType, const string &codec) {
+void Description::Audio::addAudioCodec(int payloadType, string codec,
+                                       std::optional<string> profile) {
 	// TODO This 48000/2 should be parameterized
 	RTPMap map(std::to_string(payloadType) + ' ' + codec + "/48000/2");
-	map.fmtps.emplace_back("maxaveragebitrate=96000; stereo=1; sprop-stereo=1; useinbandfec=1");
+	if (profile)
+		map.fmtps.emplace_back(*profile);
+	addRTPMap(map);
+}
+
+void Description::Media::addRTXCodec(unsigned int payloadType, unsigned int originalPayloadType,
+                                     unsigned int clockRate) {
+	RTPMap map(std::to_string(payloadType) + " RTX/" + std::to_string(clockRate));
+	map.fmtps.emplace_back("apt=" + std::to_string(originalPayloadType));
 	addRTPMap(map);
 }
 
 void Description::Video::addH264Codec(int pt) { addVideoCodec(pt, "H264"); }
 
-void Description::Video::addVP8Codec(int payloadType) { addVideoCodec(payloadType, "VP8"); }
+void Description::Video::addVP8Codec(int payloadType) { addVideoCodec(payloadType, "VP8", nullopt); }
 
-void Description::Video::addVP9Codec(int payloadType) { addVideoCodec(payloadType, "VP9"); }
+void Description::Video::addVP9Codec(int payloadType) { addVideoCodec(payloadType, "VP9", nullopt); }
 
 void Description::Media::setBitrate(int bitrate) { mBas = bitrate; }
 
@@ -808,7 +817,7 @@ void Description::Media::parseSdpLine(string_view line) {
 		} else if (key == "rtcp-mux") {
 			// always added
 		} else if (key == "ssrc") {
-			mSsrcs.emplace_back(std::stoul((std::string)value));
+			mSsrcs.emplace_back(std::stoul(string(value)));
 		} else {
 			Entry::parseSdpLine(line);
 		}
@@ -828,7 +837,7 @@ std::vector<uint32_t> Description::Media::getSSRCs() {
 	for (auto &val : mAttributes) {
 		PLOG_DEBUG << val;
 		if (val.find("ssrc:") == 0) {
-			vec.emplace_back(std::stoul((std::string)val.substr(5, val.find(" "))));
+			vec.emplace_back(std::stoul(string(val.substr(5, val.find(" ")))));
 		}
 	}
 	return vec;
@@ -852,7 +861,7 @@ Description::Media::RTPMap::RTPMap(string_view mline) { setMLine(mline); }
 void Description::Media::RTPMap::removeFB(const string &str) {
 	auto it = rtcpFbs.begin();
 	while (it != rtcpFbs.end()) {
-		if (it->find(str) != std::string::npos) {
+		if (it->find(str) != string::npos) {
 			it = rtcpFbs.erase(it);
 		} else
 			it++;

src/dtlssrtptransport.cpp

@@ -110,7 +110,7 @@ bool DtlsSrtpTransport::sendMedia(message_ptr message) {
 			if (err == srtp_err_status_replay_fail)
 				throw std::runtime_error("SRTCP packet is a replay");
 			else if (err == srtp_err_status_no_ctx) {
-				auto ssrc = ((RTCP_SR *)message->data())->senderSSRC();
+				auto ssrc = reinterpret_cast<RTCP_SR *>(message->data())->senderSSRC();
 				PLOG_INFO << "Adding SSRC to SRTCP: " << ssrc;
 				addSSRC(ssrc);
 				if ((err = srtp_protect_rtcp(mSrtpOut, message->data(), &size)))
@@ -127,11 +127,11 @@ bool DtlsSrtpTransport::sendMedia(message_ptr message) {
 			if (err == srtp_err_status_replay_fail)
 				throw std::runtime_error("Outgoing SRTP packet is a replay");
 			else if (err == srtp_err_status_no_ctx) {
-				auto ssrc = ((RTP *)message->data())->ssrc();
+				auto ssrc = reinterpret_cast<RTP *>(message->data())->ssrc();
 				PLOG_INFO << "Adding SSRC to RTP: " << ssrc;
 				addSSRC(ssrc);
-				if ((err = srtp_protect_rtcp(mSrtpOut, message->data(), &size)))
+				if ((err = srtp_protect(mSrtpOut, message->data(), &size)))
-					throw std::runtime_error("SRTCP protect error, status=" +
+					throw std::runtime_error("SRTP protect error, status=" +
 					                         to_string(static_cast<int>(err)));
 			} else
 				throw std::runtime_error("SRTP protect error, status=" +
@@ -141,7 +141,14 @@ bool DtlsSrtpTransport::sendMedia(message_ptr message) {
 	}
 
 	message->resize(size);
-	return outgoing(message);
+
+	if (message->dscp == 0) { // Track might override the value
+		// Set recommended medium-priority DSCP value
+		// See https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18
+		message->dscp = 36; // AF42: Assured Forwarding class 4, medium drop probability
+	}
+
+	return Transport::outgoing(message); // bypass DTLS DSCP marking
 }
 
 void DtlsSrtpTransport::incoming(message_ptr message) {
@@ -189,7 +196,7 @@ void DtlsSrtpTransport::incoming(message_ptr message) {
 				else if (err == srtp_err_status_auth_fail)
 					PLOG_WARNING << "Incoming SRTCP packet failed authentication check";
 				else if (err == srtp_err_status_no_ctx) {
-					auto ssrc = ((RTCP_SR *)message->data())->senderSSRC();
+					auto ssrc = reinterpret_cast<RTCP_SR *>(message->data())->senderSSRC();
 					PLOG_INFO << "Adding SSRC to RTCP: " << ssrc;
 					addSSRC(ssrc);
 					if ((err = srtp_unprotect_rtcp(mSrtpIn, message->data(), &size)))
@@ -203,8 +210,7 @@ void DtlsSrtpTransport::incoming(message_ptr message) {
 			}
 			PLOG_VERBOSE << "Unprotected SRTCP packet, size=" << size;
 			message->type = Message::Type::Control;
-			auto rtp = (RTCP_SR *)message->data();
+			message->stream = reinterpret_cast<RTCP_SR *>(message->data())->senderSSRC();
-			message->stream = rtp->senderSSRC();
 		} else {
 			PLOG_VERBOSE << "Incoming SRTP packet, size=" << size;
 			if (srtp_err_status_t err = srtp_unprotect(mSrtpIn, message->data(), &size)) {
@@ -213,21 +219,20 @@ void DtlsSrtpTransport::incoming(message_ptr message) {
 				else if (err == srtp_err_status_auth_fail)
 					PLOG_WARNING << "Incoming SRTP packet failed authentication check";
 				else if (err == srtp_err_status_no_ctx) {
-					auto ssrc = ((RTP *)message->data())->ssrc();
+					auto ssrc = reinterpret_cast<RTP *>(message->data())->ssrc();
 					PLOG_INFO << "Adding SSRC to RTP: " << ssrc;
 					addSSRC(ssrc);
 					if ((err = srtp_unprotect(mSrtpIn, message->data(), &size)))
-						throw std::runtime_error("SRTCP unprotect error, status=" +
+						throw std::runtime_error("SRTP unprotect error, status=" +
 						                         to_string(static_cast<int>(err)));
 				} else
 					PLOG_WARNING << "SRTP unprotect error, status=" << err
-					             << " SSRC=" << ((RTP *)message->data())->ssrc();
+					             << " SSRC=" << reinterpret_cast<RTP *>(message->data())->ssrc();
 				return;
 			}
 			PLOG_VERBOSE << "Unprotected SRTP packet, size=" << size;
 			message->type = Message::Type::Binary;
-			auto rtp = (RTP *)message->data();
+			message->stream = reinterpret_cast<RTP *>(message->data())->ssrc();
-			message->stream = rtp->ssrc();
 		}
 
 		message->resize(size);

src/dtlstransport.cpp

@@ -53,7 +53,7 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, certificate_ptr cer
                              verifier_callback verifierCallback, state_callback stateChangeCallback)
     : Transport(lower, std::move(stateChangeCallback)), mCertificate(certificate),
       mVerifierCallback(std::move(verifierCallback)),
-      mIsClient(lower->role() == Description::Role::Active) {
+      mIsClient(lower->role() == Description::Role::Active), mCurrentDscp(0) {
 
 	PLOG_DEBUG << "Initializing DTLS transport (GnuTLS)";
 
@@ -122,6 +122,7 @@ bool DtlsTransport::send(message_ptr message) {
 
 	PLOG_VERBOSE << "Send size=" << message->size();
 
+	mCurrentDscp = message->dscp;
 	ssize_t ret;
 	do {
 		ret = gnutls_record_send(mSession, message->data(), message->size());
@@ -143,6 +144,13 @@ void DtlsTransport::incoming(message_ptr message) {
 	mIncomingQueue.push(message);
 }
 
+bool DtlsTransport::outgoing(message_ptr message) {
+	if (message->dscp == 0)
+		message->dscp = mCurrentDscp;
+
+	return Transport::outgoing(std::move(message));
+}
+
 void DtlsTransport::postHandshake() {
 	// Dummy
 }
@@ -309,7 +317,7 @@ DtlsTransport::DtlsTransport(shared_ptr<IceTransport> lower, shared_ptr<Certific
                              verifier_callback verifierCallback, state_callback stateChangeCallback)
     : Transport(lower, std::move(stateChangeCallback)), mCertificate(certificate),
       mVerifierCallback(std::move(verifierCallback)),
-      mIsClient(lower->role() == Description::Role::Active) {
+      mIsClient(lower->role() == Description::Role::Active), mCurrentDscp(0) {
 	PLOG_DEBUG << "Initializing DTLS transport (OpenSSL)";
 
 	try {
@@ -405,6 +413,7 @@ bool DtlsTransport::send(message_ptr message) {
 
 	PLOG_VERBOSE << "Send size=" << message->size();
 
+	mCurrentDscp = message->dscp;
 	int ret = SSL_write(mSsl, message->data(), int(message->size()));
 	return openssl::check(mSsl, ret);
 }
@@ -419,6 +428,13 @@ void DtlsTransport::incoming(message_ptr message) {
 	mIncomingQueue.push(message);
 }
 
+bool DtlsTransport::outgoing(message_ptr message) {
+	if (message->dscp == 0)
+		message->dscp = mCurrentDscp;
+
+	return Transport::outgoing(std::move(message));
+}
+
 void DtlsTransport::postHandshake() {
 	// Dummy
 }

src/dtlstransport.hpp

@@ -53,6 +53,7 @@ public:
 
 protected:
 	virtual void incoming(message_ptr message) override;
+	virtual bool outgoing(message_ptr message) override;
 	virtual void postHandshake();
 	void runRecvLoop();
 
@@ -62,6 +63,7 @@ protected:
 
 	Queue<message_ptr> mIncomingQueue;
 	std::thread mRecvThread;
+	std::atomic<unsigned int> mCurrentDscp;
 
 #if USE_GNUTLS
 	gnutls_session_t mSession;

src/icetransport.cpp

@@ -168,7 +168,9 @@ bool IceTransport::addRemoteCandidate(const Candidate &candidate) {
 	return juice_add_remote_candidate(mAgent.get(), string(candidate).c_str()) >= 0;
 }
 
-void IceTransport::gatherLocalCandidates() {
+void IceTransport::gatherLocalCandidates(string mid) {
+	mMid = std::move(mid);
+
 	// Change state now as candidates calls can be synchronous
 	changeGatheringState(GatheringState::InProgress);
 
@@ -222,8 +224,10 @@ bool IceTransport::send(message_ptr message) {
 }
 
 bool IceTransport::outgoing(message_ptr message) {
-	return juice_send(mAgent.get(), reinterpret_cast<const char *>(message->data()),
+	// Explicit Congestion Notification takes the least-significant 2 bits of the DS field
-	                  message->size()) >= 0;
+	int ds = int(message->dscp << 2);
+	return juice_send_diffserv(mAgent.get(), reinterpret_cast<const char *>(message->data()),
+	                           message->size(), ds) >= 0;
 }
 
 void IceTransport::changeGatheringState(GatheringState state) {
@@ -330,7 +334,7 @@ IceTransport::IceTransport(const Configuration &config, candidate_callback candi
       mMid("0"), mGatheringState(GatheringState::New),
       mCandidateCallback(std::move(candidateCallback)),
       mGatheringStateChangeCallback(std::move(gatheringStateChangeCallback)),
-      mNiceAgent(nullptr, nullptr), mMainLoop(nullptr, nullptr) {
+      mNiceAgent(nullptr, nullptr), mMainLoop(nullptr, nullptr), mOutgoingDscp(0) {
 
 	PLOG_DEBUG << "Initializing ICE transport (libnice)";
 
@@ -580,7 +584,9 @@ bool IceTransport::addRemoteCandidate(const Candidate &candidate) {
 	return ret > 0;
 }
 
-void IceTransport::gatherLocalCandidates() {
+void IceTransport::gatherLocalCandidates(string mid) {
+	mMid = std::move(mid);
+
 	// Change state now as candidates calls can be synchronous
 	changeGatheringState(GatheringState::InProgress);
 
@@ -617,6 +623,13 @@ bool IceTransport::send(message_ptr message) {
 }
 
 bool IceTransport::outgoing(message_ptr message) {
+	std::lock_guard lock(mOutgoingMutex);
+	if (mOutgoingDscp != message->dscp) {
+		mOutgoingDscp = message->dscp;
+		// Explicit Congestion Notification takes the least-significant 2 bits of the DS field
+		int ds = int(message->dscp << 2);
+		nice_agent_set_stream_tos(mNiceAgent.get(), mStreamId, ds); // ToS is the legacy name for DS
+	}
 	return nice_agent_send(mNiceAgent.get(), mStreamId, 1, message->size(),
 	                       reinterpret_cast<const char *>(message->data())) >= 0;
 }

src/icetransport.hpp

@@ -35,6 +35,7 @@
 #include <atomic>
 #include <chrono>
 #include <thread>
+#include <mutex>
 
 namespace rtc {
 
@@ -55,7 +56,7 @@ public:
 	Description getLocalDescription(Description::Type type) const;
 	void setRemoteDescription(const Description &description);
 	bool addRemoteCandidate(const Candidate &candidate);
-	void gatherLocalCandidates();
+	void gatherLocalCandidates(string mid);
 
 	std::optional<string> getLocalAddress() const;
 	std::optional<string> getRemoteAddress() const;
@@ -99,6 +100,8 @@ private:
 	std::unique_ptr<GMainLoop, void (*)(GMainLoop *)> mMainLoop;
 	std::thread mMainLoopThread;
 	guint mTimeoutId = 0;
+	std::mutex mOutgoingMutex;
+	unsigned int mOutgoingDscp;
 
 	static string AddressToString(const NiceAddress &addr);
 

src/peerconnection.cpp

@@ -189,13 +189,14 @@ void PeerConnection::setLocalDescription(Description::Type type) {
 
 	auto iceTransport = initIceTransport();
 
-	Description localDescription = iceTransport->getLocalDescription(type);
+	Description local = iceTransport->getLocalDescription(type);
-	processLocalDescription(std::move(localDescription));
+	processLocalDescription(std::move(local));
 
 	changeSignalingState(newSignalingState);
 
-	if (mGatheringState == GatheringState::New)
+	if (mGatheringState == GatheringState::New) {
-		iceTransport->gatherLocalCandidates();
+		iceTransport->gatherLocalCandidates(localBundleMid());
+	}
 }
 
 void PeerConnection::setRemoteDescription(Description description) {
@@ -369,7 +370,7 @@ void PeerConnection::onSignalingStateChange(std::function<void(SignalingState st
 std::shared_ptr<Track> PeerConnection::addTrack(Description::Media description) {
 #if !RTC_ENABLE_MEDIA
 	if (mTracks.empty()) {
-		PLOG_WARNING << "Tracks will be inative (not compiled with SRTP support)";
+		PLOG_WARNING << "Tracks will be inative (not compiled with media support)";
 	}
 #endif
 
@@ -503,7 +504,7 @@ shared_ptr<DtlsTransport> PeerConnection::initDtlsTransport() {
 			    lower, certificate, verifierCallback,
 			    std::bind(&PeerConnection::forwardMedia, this, _1), stateChangeCallback);
 #else
-			PLOG_WARNING << "Ignoring media support (not compiled with SRTP support)";
+			PLOG_WARNING << "Ignoring media support (not compiled with media support)";
 #endif
 		}
 
@@ -648,10 +649,10 @@ void PeerConnection::forwardMessage(message_ptr message) {
 		    stream % 2 == remoteParity) {
 
 			channel = std::make_shared<NegociatedDataChannel>(shared_from_this(), sctpTransport,
-			                                                  message->stream);
+			                                                  stream);
 			channel->onOpen(weak_bind(&PeerConnection::triggerDataChannel, this,
 			                          weak_ptr<DataChannel>{channel}));
-			mDataChannels.emplace(message->stream, channel);
+			mDataChannels.emplace(stream, channel);
 		} else {
 			// Invalid, close the DataChannel
 			sctpTransport->closeStream(message->stream);
@@ -872,7 +873,7 @@ void PeerConnection::incomingTrack(Description::Media description) {
 	std::unique_lock lock(mTracksMutex); // we are going to emplace
 #if !RTC_ENABLE_MEDIA
 	if (mTracks.empty()) {
-		PLOG_WARNING << "Tracks will be inative (not compiled with SRTP support)";
+		PLOG_WARNING << "Tracks will be inative (not compiled with media support)";
 	}
 #endif
 	if (mTracks.find(description.mid()) == mTracks.end()) {
@@ -1013,7 +1014,10 @@ void PeerConnection::processLocalDescription(Description description) {
 		if (!description.hasApplication()) {
 			std::shared_lock lock(mDataChannelsMutex);
 			if (!mDataChannels.empty()) {
-				Description::Application app("data");
+				unsigned int m = 0;
+				while (description.hasMid(std::to_string(m)))
+					++m;
+				Description::Application app(std::to_string(m));
 				app.setSctpPort(DEFAULT_SCTP_PORT);
 				app.setMaxMessageSize(LOCAL_MAX_MESSAGE_SIZE);
 
@@ -1133,7 +1137,7 @@ void PeerConnection::processRemoteCandidate(Candidate candidate) {
 	} else {
 		// We might need a lookup, do it asynchronously
 		// We don't use the thread pool because we have no control on the timeout
-		if (auto iceTransport = std::atomic_load(&mIceTransport)) {
+		if ((iceTransport = std::atomic_load(&mIceTransport))) {
 			weak_ptr<IceTransport> weakIceTransport{iceTransport};
 			std::thread t([weakIceTransport, candidate = std::move(candidate)]() mutable {
 				if (candidate.resolve(Candidate::ResolveMode::Lookup))
@@ -1145,6 +1149,11 @@ void PeerConnection::processRemoteCandidate(Candidate candidate) {
 	}
 }
 
+string PeerConnection::localBundleMid() const {
+	std::lock_guard lock(mLocalDescriptionMutex);
+	return mLocalDescription ? mLocalDescription->bundleMid() : "0";
+}
+
 void PeerConnection::triggerDataChannel(weak_ptr<DataChannel> weakDataChannel) {
 	auto dataChannel = weakDataChannel.lock();
 	if (!dataChannel)

src/rtcp.cpp

@@ -126,7 +126,7 @@ bool RtcpReceivingSession::requestKeyframe() {
 
 void RtcpReceivingSession::pushPLI() {
 	auto msg = rtc::make_message(rtc::RTCP_PLI::size(), rtc::Message::Type::Control);
-	auto *pli = (rtc::RTCP_PLI *)msg->data();
+	auto *pli = reinterpret_cast<rtc::RTCP_PLI *>(msg->data());
 	pli->preparePacket(mSsrc);
 	send(msg);
 }

src/sctptransport.cpp

@@ -325,6 +325,13 @@ void SctpTransport::incoming(message_ptr message) {
 	usrsctp_conninput(this, message->data(), message->size(), 0);
 }
 
+bool SctpTransport::outgoing(message_ptr message) {
+	// Set recommended medium-priority DSCP value
+	// See https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18
+	message->dscp = 10; // AF11: Assured Forwarding class 1, low drop probability
+	return Transport::outgoing(std::move(message));
+}
+
 void SctpTransport::doRecv() {
 	std::lock_guard lock(mRecvMutex);
 	--mPendingRecvCount;
@@ -554,6 +561,7 @@ int SctpTransport::handleWrite(byte *data, size_t len, uint8_t /*tos*/, uint8_t
 		std::unique_lock lock(mWriteMutex);
 		PLOG_VERBOSE << "Handle write, len=" << len;
 
+		auto message = make_message(data, data + len);
 		if (!outgoing(make_message(data, data + len)))
 			return -1;
 

src/sctptransport.hpp

@@ -77,6 +77,7 @@ private:
 	void shutdown();
 	void close();
 	void incoming(message_ptr message) override;
+	bool outgoing(message_ptr message) override;
 
 	void doRecv();
 	bool trySendQueue();

src/threadpool.cpp

@@ -18,15 +18,26 @@
 
 #include "threadpool.hpp"
 
+#include <cstdlib>
+
+namespace {
+	void joinThreadPoolInstance() {
+		rtc::ThreadPool::Instance().join();
+	}
+}
+
 namespace rtc {
 
 ThreadPool &ThreadPool::Instance() {
-	// Init handles joining on cleanup
 	static ThreadPool *instance = new ThreadPool;
 	return *instance;
 }
 
-ThreadPool::~ThreadPool() { join(); }
+ThreadPool::ThreadPool() {
+	std::atexit(joinThreadPoolInstance);
+}
+
+ThreadPool::~ThreadPool() {}
 
 int ThreadPool::count() const {
 	std::unique_lock lock(mWorkersMutex);

src/threadpool.hpp

@@ -56,7 +56,7 @@ public:
 	auto enqueue(F &&f, Args &&... args) -> invoke_future_t<F, Args...>;
 
 protected:
-	ThreadPool() = default;
+	ThreadPool();
 	~ThreadPool();
 
 	std::function<void()> dequeue(); // returns null function if joining

src/track.cpp

@@ -45,12 +45,30 @@ void Track::close() {
 	setRtcpHandler(nullptr);
 }
 
-bool Track::send(message_variant data) { return outgoing(make_message(std::move(data))); }
+bool Track::send(message_variant data) {
+	if (mIsClosed)
+		throw std::runtime_error("Track is closed");
 
-bool Track::send(const byte *data, size_t size) {
+	auto direction = mMediaDescription.direction();
-	return outgoing(std::make_shared<Message>(data, data + size, Message::Binary));
+	if ((direction == Description::Direction::RecvOnly ||
+	     direction == Description::Direction::Inactive)) {
+		PLOG_WARNING << "Track media direction does not allow transmission, dropping";
+		return false;
+	}
+
+	auto message = make_message(std::move(data));
+
+	if (mRtcpHandler) {
+		message = mRtcpHandler->outgoing(message);
+		if (!message)
+			return false;
+	}
+
+	return outgoing(std::move(message));
 }
 
+bool Track::send(const byte *data, size_t size) { return send(binary(data, data + size)); }
+
 std::optional<message_variant> Track::receive() {
 	if (auto next = mRecvQueue.tryPop())
 		return to_variant(std::move(**next));
@@ -88,50 +106,10 @@ void Track::open(shared_ptr<DtlsSrtpTransport> transport) {
 }
 #endif
 
-bool Track::outgoing(message_ptr message) {
-
-	if (mRtcpHandler) {
-		message = mRtcpHandler->outgoing(message);
-		if (!message)
-			return false;
-	}
-
-	auto direction = mMediaDescription.direction();
-	if ((direction == Description::Direction::RecvOnly ||
-	     direction == Description::Direction::Inactive) &&
-	    message->type != Message::Control) {
-		PLOG_WARNING << "Track media direction does not allow transmission, dropping";
-		return false;
-	}
-
-	if (mIsClosed)
-		throw std::runtime_error("Track is closed");
-
-	if (message->size() > maxMessageSize())
-		throw std::runtime_error("Message size exceeds limit");
-
-#if RTC_ENABLE_MEDIA
-	auto transport = mDtlsSrtpTransport.lock();
-	if (!transport)
-		throw std::runtime_error("Track transport is not open");
-
-	return transport->sendMedia(message);
-#else
-	PLOG_WARNING << "Ignoring track send (not compiled with SRTP support)";
-	return false;
-#endif
-}
-
 void Track::incoming(message_ptr message) {
 	if (!message)
 		return;
 
-	if (mRtcpHandler) {
-		message = mRtcpHandler->incoming(message);
-		if (!message)
-			return;
-	}
-
 	auto direction = mMediaDescription.direction();
 	if ((direction == Description::Direction::SendOnly ||
 	     direction == Description::Direction::Inactive) &&
@@ -140,30 +118,46 @@ void Track::incoming(message_ptr message) {
 		return;
 	}
 
+	if (mRtcpHandler) {
+		message = mRtcpHandler->incoming(message);
+		if (!message)
+			return;
+	}
+
 	// Tail drop if queue is full
-	if (mRecvQueue.full())
+	if (mRecvQueue.full()) {
+		PLOG_WARNING << "Track incoming queue is full, dropping";
 		return;
+	}
 
 	mRecvQueue.push(message);
 	triggerAvailable(mRecvQueue.size());
 }
 
+bool Track::outgoing([[maybe_unused]] message_ptr message) {
+#if RTC_ENABLE_MEDIA
+	auto transport = mDtlsSrtpTransport.lock();
+	if (!transport)
+		throw std::runtime_error("Track transport is not open");
+
+	// Set recommended medium-priority DSCP value
+	// See https://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-18
+	if (mMediaDescription.type() == "audio")
+		message->dscp = 46; // EF: Expedited Forwarding
+	else
+		message->dscp = 36; // AF42: Assured Forwarding class 4, medium drop probability
+
+	return transport->sendMedia(message);
+#else
+	PLOG_WARNING << "Ignoring track send (not compiled with media support)";
+	return false;
+#endif
+}
+
 void Track::setRtcpHandler(std::shared_ptr<RtcpHandler> handler) {
 	mRtcpHandler = std::move(handler);
-	if (mRtcpHandler) {
+	if (mRtcpHandler)
-		mRtcpHandler->onOutgoing([&]([[maybe_unused]] const rtc::message_ptr &message) {
+		mRtcpHandler->onOutgoing(std::bind(&Track::outgoing, this, std::placeholders::_1));
-#if RTC_ENABLE_MEDIA
-			auto transport = mDtlsSrtpTransport.lock();
-			if (!transport)
-				throw std::runtime_error("Track transport is not open");
-
-			return transport->sendMedia(message);
-#else
-			PLOG_WARNING << "Ignoring track send (not compiled with SRTP support)";
-			return false;
-#endif
-		});
-	}
 }
 
 bool Track::requestKeyframe() {

src/transport.hpp

@@ -28,8 +28,6 @@
 
 namespace rtc {
 
-using namespace std::placeholders;
-
 class Transport {
 public:
 	enum class State { Disconnected, Connecting, Connected, Completed, Failed };
@@ -57,7 +55,7 @@ public:
 	void registerIncoming() {
 		if (mLower) {
 			PLOG_VERBOSE << "Registering incoming callback";
-			mLower->onRecv(std::bind(&Transport::incoming, this, _1));
+			mLower->onRecv(std::bind(&Transport::incoming, this, std::placeholders::_1));
 		}
 	}
 

src/websocket.cpp

@@ -36,6 +36,7 @@
 namespace rtc {
 
 using std::shared_ptr;
+using namespace std::placeholders;
 
 WebSocket::WebSocket(std::optional<Configuration> config)
     : mConfig(config ? std::move(*config) : Configuration()),
@@ -117,6 +118,10 @@ void WebSocket::remoteClose() {
 
 bool WebSocket::send(message_variant data) { return outgoing(make_message(std::move(data))); }
 
+bool WebSocket::send(const byte *data, size_t size) {
+	return outgoing(make_message(data, data + size));
+}
+
 bool WebSocket::isOpen() const { return mState == State::Open; }
 
 bool WebSocket::isClosed() const { return mState == State::Closed; }
@@ -286,8 +291,14 @@ shared_ptr<WsTransport> WebSocket::initWsTransport() {
 		shared_ptr<Transport> lower = std::atomic_load(&mTlsTransport);
 		if (!lower)
 			lower = std::atomic_load(&mTcpTransport);
+
+		WsTransport::Configuration wsConfig = {};
+		wsConfig.host = mHost;
+		wsConfig.path = mPath;
+		wsConfig.protocols = mConfig.protocols;
+
 		auto transport = std::make_shared<WsTransport>(
-		    lower, mHost, mPath, weak_bind(&WebSocket::incoming, this, _1),
+			lower, wsConfig, weak_bind(&WebSocket::incoming, this, _1),
 		    [this, weak_this = weak_from_this()](State state) {
 			    auto shared_this = weak_this.lock();
 			    if (!shared_this)

src/wstransport.cpp

@@ -24,8 +24,10 @@
 #if RTC_ENABLE_WEBSOCKET
 
 #include <chrono>
+#include <iterator>
 #include <list>
 #include <map>
+#include <numeric>
 #include <random>
 #include <regex>
 
@@ -52,17 +54,17 @@ using std::to_string;
 using random_bytes_engine =
     std::independent_bits_engine<std::default_random_engine, CHAR_BIT, unsigned short>;
 
-WsTransport::WsTransport(std::shared_ptr<Transport> lower, string host, string path,
+WsTransport::WsTransport(std::shared_ptr<Transport> lower, Configuration config,
                          message_callback recvCallback, state_callback stateCallback)
-    : Transport(lower, std::move(stateCallback)), mHost(std::move(host)), mPath(std::move(path)) {
+    : Transport(lower, std::move(stateCallback)), mConfig(std::move(config)) {
 	onRecv(recvCallback);
 
 	PLOG_DEBUG << "Initializing WebSocket transport";
 
-	if (mHost.empty())
+	if (mConfig.host.empty())
 		throw std::invalid_argument("WebSocket HTTP host cannot be empty");
 
-	if (mPath.empty())
+	if (mConfig.path.empty())
 		throw std::invalid_argument("WebSocket HTTP path cannot be empty");
 }
 
@@ -153,7 +155,7 @@ void WsTransport::close() {
 }
 
 bool WsTransport::sendHttpRequest() {
-	PLOG_DEBUG << "Sending WebSocket HTTP request for path " << mPath;
+	PLOG_DEBUG << "Sending WebSocket HTTP request for path " << mConfig.path;
 	changeState(State::Connecting);
 
 	auto seed = static_cast<unsigned int>(system_clock::now().time_since_epoch().count());
@@ -163,18 +165,27 @@ bool WsTransport::sendHttpRequest() {
 	auto k = reinterpret_cast<uint8_t *>(key.data());
 	std::generate(k, k + key.size(), [&]() { return uint8_t(generator()); });
 
-	const string request = "GET " + mPath +
+	string appendHeader = "";
+	if (mConfig.protocols.size() > 0) {
+		appendHeader +=
+		    "Sec-WebSocket-Protocol: " +
+		    std::accumulate(mConfig.protocols.begin(), mConfig.protocols.end(), string(),
+		                    [](const string &a, const string &b) -> string {
+			                    return a + (a.length() > 0 ? "," : "") + b;
+		                    }) +
+		    "\r\n";
+	}
+
+	const string request = "GET " + mConfig.path +
 	                       " HTTP/1.1\r\n"
 	                       "Host: " +
-	                       mHost +
+	                       mConfig.host +
 	                       "\r\n"
 	                       "Connection: Upgrade\r\n"
 	                       "Upgrade: websocket\r\n"
 	                       "Sec-WebSocket-Version: 13\r\n"
 	                       "Sec-WebSocket-Key: " +
-	                       to_base64(key) +
+	                       to_base64(key) + "\r\n" + std::move(appendHeader) + "\r\n";
-	                       "\r\n"
-	                       "\r\n";
 
 	auto data = reinterpret_cast<const byte *>(request.data());
 	auto size = request.size();
@@ -227,8 +238,14 @@ size_t WsTransport::readHttpResponse(const byte *buffer, size_t size) {
 	}
 
 	auto h = headers.find("upgrade");
-	if (h == headers.end() || h->second != "websocket")
+	if (h == headers.end())
-		throw std::runtime_error("WebSocket update header missing or mismatching");
+		throw std::runtime_error("WebSocket update header missing");
+
+	string upgrade;
+	std::transform(h->second.begin(), h->second.end(), std::back_inserter(upgrade),
+	               [](char c) { return std::tolower(c); });
+	if (upgrade != "websocket")
+		throw std::runtime_error("WebSocket update header mismatching: " + h->second);
 
 	h = headers.find("sec-websocket-accept");
 	if (h == headers.end())

src/wstransport.hpp

@@ -31,7 +31,13 @@ class TlsTransport;
 
 class WsTransport : public Transport {
 public:
-	WsTransport(std::shared_ptr<Transport> lower, string host, string path,
+	struct Configuration {
+		string host;
+		string path = "/";
+		std::vector<string> protocols;
+	};
+
+	WsTransport(std::shared_ptr<Transport> lower, Configuration config,
 	            message_callback recvCallback, state_callback stateCallback);
 	~WsTransport();
 
@@ -68,12 +74,12 @@ private:
 	void recvFrame(const Frame &frame);
 	bool sendFrame(const Frame &frame);
 
-	const string mHost;
+	const Configuration mConfig;
-	const string mPath;
 
 	binary mBuffer;
 	binary mPartial;
 	Opcode mPartialOpcode;
+
 };
 
 } // namespace rtc

test/capi_connectivity.cpp

@@ -161,6 +161,7 @@ static Peer *createPeer(const rtcConfiguration *config) {
 	rtcSetLocalCandidateCallback(peer->pc, candidateCallback);
 	rtcSetStateChangeCallback(peer->pc, stateChangeCallback);
 	rtcSetGatheringStateChangeCallback(peer->pc, gatheringStateCallback);
+	rtcSetSignalingStateChangeCallback(peer->pc, signalingStateCallback);
 
 	return peer;
 }
@@ -226,12 +227,6 @@ int test_capi_connectivity_main() {
 		goto error;
 	}
 
-	if (peer1->signalingState != RTC_SIGNALING_STABLE ||
-	    peer2->signalingState != RTC_SIGNALING_STABLE) {
-		fprintf(stderr, "Signaling state is not stable\n");
-		goto error;
-	}
-
 	if (!peer1->connected || !peer2->connected) {
 		fprintf(stderr, "DataChannel is not connected\n");
 		goto error;