Support voice calls

CMakeLists.txt

@@ -227,6 +227,7 @@ configure_file(cmake/nheko.h config/nheko.h)
 #
 set(SRC_FILES
 	# Dialogs
+	src/dialogs/AcceptCall.cpp
 	src/dialogs/CreateRoom.cpp
 	src/dialogs/FallbackAuth.cpp
 	src/dialogs/ImageOverlay.cpp
@@ -235,6 +236,7 @@ set(SRC_FILES
 	src/dialogs/LeaveRoom.cpp
 	src/dialogs/Logout.cpp
 	src/dialogs/MemberList.cpp
+	src/dialogs/PlaceCall.cpp
 	src/dialogs/PreviewUploadOverlay.cpp
 	src/dialogs/ReCaptcha.cpp
 	src/dialogs/ReadReceipts.cpp
@@ -278,9 +280,11 @@ set(SRC_FILES
 	src/ui/Theme.cpp
 	src/ui/ThemeManager.cpp
 
+	src/ActiveCallBar.cpp
 	src/AvatarProvider.cpp
 	src/BlurhashProvider.cpp
 	src/Cache.cpp
+	src/CallManager.cpp
 	src/ChatPage.cpp
 	src/ColorImageProvider.cpp
 	src/CommunitiesList.cpp
@@ -306,6 +310,7 @@ set(SRC_FILES
 	src/UserInfoWidget.cpp
 	src/UserSettingsPage.cpp
 	src/Utils.cpp
+	src/WebRTCSession.cpp
 	src/WelcomePage.cpp
 	src/popups/PopupItem.cpp
 	src/popups/SuggestionsPopup.cpp
@@ -423,6 +428,10 @@ else()
 	find_package(Tweeny REQUIRED)
 endif()
 
+include(FindPkgConfig)
+pkg_check_modules(GST_SDP REQUIRED IMPORTED_TARGET gstreamer-sdp-1.0>=1.14) 
+pkg_check_modules(GST_WEBRTC REQUIRED IMPORTED_TARGET gstreamer-webrtc-1.0>=1.14) 
+
 # single instance functionality
 set(QAPPLICATION_CLASS QApplication CACHE STRING "Inheritance class for SingleApplication")
 add_subdirectory(third_party/SingleApplication-3.1.3.1/)
@@ -431,6 +440,7 @@ feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAG
 
 qt5_wrap_cpp(MOC_HEADERS
 	# Dialogs
+	src/dialogs/AcceptCall.h
 	src/dialogs/CreateRoom.h
 	src/dialogs/FallbackAuth.h
 	src/dialogs/ImageOverlay.h
@@ -439,6 +449,7 @@ qt5_wrap_cpp(MOC_HEADERS
 	src/dialogs/LeaveRoom.h
 	src/dialogs/Logout.h
 	src/dialogs/MemberList.h
+	src/dialogs/PlaceCall.h
 	src/dialogs/PreviewUploadOverlay.h
 	src/dialogs/RawMessage.h
 	src/dialogs/ReCaptcha.h
@@ -482,9 +493,11 @@ qt5_wrap_cpp(MOC_HEADERS
 
 	src/notifications/Manager.h
 
+	src/ActiveCallBar.h
 	src/AvatarProvider.h
 	src/BlurhashProvider.h
 	src/Cache_p.h
+	src/CallManager.h
 	src/ChatPage.h
 	src/CommunitiesList.h
 	src/CommunitiesListItem.h
@@ -504,6 +517,7 @@ qt5_wrap_cpp(MOC_HEADERS
 	src/TrayIcon.h
 	src/UserInfoWidget.h
 	src/UserSettingsPage.h
+	src/WebRTCSession.h
 	src/WelcomePage.h
 	src/popups/PopupItem.h
 	src/popups/SuggestionsPopup.h
@@ -583,6 +597,8 @@ target_link_libraries(nheko PRIVATE
 	lmdbxx::lmdbxx
 	liblmdb::lmdb
 	tweeny
+	PkgConfig::GST_SDP
+	PkgConfig::GST_WEBRTC
 	SingleApplication::SingleApplication)
 
 if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.16.0")

resources/langs/nheko_en.ts

@@ -404,6 +404,21 @@ Example: https://server.my:8787</translation>
         <source>%1 created and configured room: %2</source>
         <translation>%1 created and configured room: %2</translation>
     </message>
+    <message>
+        <location line="+6"/>
+        <source>%1 placed a voice call.</source>
+        <translation>%1 placed a voice call.</translation>
+    </message>
+    <message>
+        <location line="+6"/>
+        <source>%1 answered the call.</source>
+        <translation>%1 answered the call.</translation>
+    </message>
+    <message>
+        <location line="+6"/>
+        <source>%1 ended the call.</source>
+        <translation>%1 ended the call.</translation>
+    </message>
 </context>
 <context>
     <name>Placeholder</name>
@@ -1796,6 +1811,36 @@ Media size: %2
         <source>%1 sent an encrypted message</source>
         <translation>%1 sent an encrypted message</translation>
     </message>
+    <message>
+        <location line="+5"/>
+        <source>You placed a call</source>
+        <translation>You placed a call</translation>
+    </message>
+    <message>
+        <location line="+3"/>
+        <source>%1 placed a call</source>
+        <translation>%1 placed a call</translation>
+    </message>
+    <message>
+        <location line="+5"/>
+        <source>You answered a call</source>
+        <translation>You answered a call</translation>
+    </message>
+    <message>
+        <location line="+3"/>
+        <source>%1 answered a call</source>
+        <translation>%1 answered a call</translation>
+    </message>
+    <message>
+        <location line="+5"/>
+        <source>You ended a call</source>
+        <translation>You ended a call</translation>
+    </message>
+    <message>
+        <location line="+3"/>
+        <source>%1 ended a call</source>
+        <translation>%1 ended a call</translation>
+    </message>
 </context>
 <context>
     <name>popups::UserMentions</name>

resources/qml/delegates/MessageDelegate.qml

@@ -90,6 +90,24 @@ Item {
 				text: qsTr("%1 created and configured room: %2").arg(model.data.userName).arg(model.data.roomId)
 			}
 		}
+		DelegateChoice {
+			roleValue: MtxEvent.CallInvite
+			NoticeMessage {
+				text: qsTr("%1 placed a voice call.").arg(model.data.userName)
+			}
+		}
+		DelegateChoice {
+			roleValue: MtxEvent.CallAnswer
+			NoticeMessage {
+				text: qsTr("%1 answered the call.").arg(model.data.userName)
+			}
+		}
+		DelegateChoice {
+			roleValue: MtxEvent.CallHangUp
+			NoticeMessage {
+				text: qsTr("%1 ended the call.").arg(model.data.userName)
+			}
+		}
 		DelegateChoice {
 			// TODO: make a more complex formatter for the power levels.
 			roleValue: MtxEvent.PowerLevels

resources/res.qrc

@@ -136,4 +136,9 @@
         <file>qml/delegates/Placeholder.qml</file>
         <file>qml/delegates/Reply.qml</file>
     </qresource>
+    <qresource prefix="/media">
+        <file>media/ring.ogg</file>
+        <file>media/ringback.ogg</file>
+        <file>media/callend.ogg</file>
+    </qresource>
 </RCC>

src/ActiveCallBar.cpp

@@ -0,0 +1,74 @@
+#include <QHBoxLayout>
+#include <QIcon>
+#include <QLabel>
+#include <QString>
+
+#include "ActiveCallBar.h"
+#include "WebRTCSession.h"
+#include "ui/FlatButton.h"
+
+ActiveCallBar::ActiveCallBar(QWidget *parent)
+  : QWidget(parent)
+{
+        setAutoFillBackground(true);
+        auto p = palette();
+        p.setColor(backgroundRole(), Qt::green);
+        setPalette(p);
+
+        QFont f;
+        f.setPointSizeF(f.pointSizeF());
+
+        const int fontHeight    = QFontMetrics(f).height();
+        const int widgetMargin  = fontHeight / 3;
+        const int contentHeight = fontHeight * 3;
+
+        setFixedHeight(contentHeight + widgetMargin);
+
+        topLayout_ = new QHBoxLayout(this);
+        topLayout_->setSpacing(widgetMargin);
+        topLayout_->setContentsMargins(
+          2 * widgetMargin, widgetMargin, 2 * widgetMargin, widgetMargin);
+        topLayout_->setSizeConstraint(QLayout::SetMinimumSize);
+
+        QFont labelFont;
+        labelFont.setPointSizeF(labelFont.pointSizeF() * 1.2);
+        labelFont.setWeight(QFont::Medium);
+
+        callPartyLabel_ = new QLabel(this);
+        callPartyLabel_->setFont(labelFont);
+
+        // TODO microphone mute/unmute icons
+        muteBtn_ = new FlatButton(this);
+        QIcon muteIcon;
+        muteIcon.addFile(":/icons/icons/ui/do-not-disturb-rounded-sign.png");
+        muteBtn_->setIcon(muteIcon);
+        muteBtn_->setIconSize(QSize(buttonSize_ / 2, buttonSize_ / 2));
+        muteBtn_->setToolTip(tr("Mute Mic"));
+        muteBtn_->setFixedSize(buttonSize_, buttonSize_);
+        muteBtn_->setCornerRadius(buttonSize_ / 2);
+        connect(muteBtn_, &FlatButton::clicked, this, [this]() {
+                if (WebRTCSession::instance().toggleMuteAudioSrc(muted_)) {
+                        QIcon icon;
+                        if (muted_) {
+                                muteBtn_->setToolTip("Unmute Mic");
+                                icon.addFile(":/icons/icons/ui/round-remove-button.png");
+                        } else {
+                                muteBtn_->setToolTip("Mute Mic");
+                                icon.addFile(":/icons/icons/ui/do-not-disturb-rounded-sign.png");
+                        }
+                        muteBtn_->setIcon(icon);
+                }
+        });
+
+        topLayout_->addWidget(callPartyLabel_, 0, Qt::AlignLeft);
+        topLayout_->addWidget(muteBtn_, 0, Qt::AlignRight);
+}
+
+void
+ActiveCallBar::setCallParty(const QString &userid, const QString &displayName)
+{
+        if (!displayName.isEmpty() && displayName != userid)
+                callPartyLabel_->setText("Active Call: " + displayName + " (" + userid + ")");
+        else
+                callPartyLabel_->setText("Active Call: " + userid);
+}

src/ActiveCallBar.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <QWidget>
+
+class QHBoxLayout;
+class QLabel;
+class QString;
+class FlatButton;
+
+class ActiveCallBar : public QWidget
+{
+        Q_OBJECT
+
+public:
+        ActiveCallBar(QWidget *parent = nullptr);
+
+public slots:
+        void setCallParty(const QString &userid, const QString &displayName);
+
+private:
+        QHBoxLayout *topLayout_ = nullptr;
+        QLabel *callPartyLabel_ = nullptr;
+        FlatButton *muteBtn_    = nullptr;
+        int buttonSize_         = 32;
+        bool muted_             = false;
+};

src/Cache.cpp

@@ -1364,6 +1364,9 @@ Cache::getLastMessageInfo(lmdb::txn &txn, const std::string &room_id)
 
                 if (!(obj["event"]["type"] == "m.room.message" ||
                       obj["event"]["type"] == "m.sticker" ||
+                      obj["event"]["type"] == "m.call.invite" ||
+                      obj["event"]["type"] == "m.call.answer" ||
+                      obj["event"]["type"] == "m.call.hangup" ||
                       obj["event"]["type"] == "m.room.encrypted"))
                         continue;
 

src/CallManager.cpp

@@ -0,0 +1,315 @@
+#include <chrono>
+
+#include <QMediaPlaylist>
+#include <QUrl>
+
+#include "CallManager.h"
+#include "Cache.h"
+#include "ChatPage.h"
+#include "Logging.h"
+#include "MainWindow.h"
+#include "MatrixClient.h"
+#include "UserSettingsPage.h"
+#include "WebRTCSession.h"
+
+#include "dialogs/AcceptCall.h"
+
+Q_DECLARE_METATYPE(std::vector<mtx::events::msg::CallCandidates::Candidate>)
+Q_DECLARE_METATYPE(mtx::responses::TurnServer)
+
+using namespace mtx::events;
+using namespace mtx::events::msg;
+
+// TODO Allow altenative in settings
+#define STUN_SERVER "stun://turn.matrix.org:3478"
+
+CallManager::CallManager(QSharedPointer<UserSettings> userSettings)
+  : QObject(),
+    session_(WebRTCSession::instance()),
+    turnServerTimer_(this),
+    settings_(userSettings)
+{
+  qRegisterMetaType<std::vector<mtx::events::msg::CallCandidates::Candidate>>();
+  qRegisterMetaType<mtx::responses::TurnServer>();
+
+  connect(&session_, &WebRTCSession::offerCreated, this,
+      [this](const std::string &sdp,
+             const std::vector<mtx::events::msg::CallCandidates::Candidate>& candidates)
+            {
+              nhlog::ui()->debug("Offer created with callid_ and roomid_: {} {}", callid_, roomid_.toStdString());
+              emit newMessage(roomid_, CallInvite{callid_, sdp, 0, timeoutms_});
+              emit newMessage(roomid_, CallCandidates{callid_, candidates, 0});
+            });
+
+  connect(&session_, &WebRTCSession::answerCreated, this,
+      [this](const std::string &sdp,
+             const std::vector<mtx::events::msg::CallCandidates::Candidate>& candidates)
+            {
+              nhlog::ui()->debug("Answer created with callid_ and roomid_: {} {}", callid_, roomid_.toStdString());
+              emit newMessage(roomid_, CallAnswer{callid_, sdp, 0});
+              emit newMessage(roomid_, CallCandidates{callid_, candidates, 0});
+            });
+
+  connect(&turnServerTimer_, &QTimer::timeout, this, &CallManager::retrieveTurnServer);
+  turnServerTimer_.start(2000);
+
+  connect(this, &CallManager::turnServerRetrieved, this,
+      [this](const mtx::responses::TurnServer &res)
+            {
+              nhlog::net()->info("TURN server(s) retrieved from homeserver:");
+              nhlog::net()->info("username: {}", res.username);
+              nhlog::net()->info("ttl: {}", res.ttl);
+              for (const auto &u : res.uris)
+                nhlog::net()->info("uri: {}", u);
+
+              turnServer_ = res;
+              turnServerTimer_.setInterval(res.ttl * 1000 * 0.9);
+      });
+
+  connect(&session_, &WebRTCSession::pipelineChanged, this,
+      [this](bool started) {
+        if (!started)
+          playRingtone("qrc:/media/media/callend.ogg", false);
+        });
+
+  connect(&player_, &QMediaPlayer::mediaStatusChanged, this,
+      [this](QMediaPlayer::MediaStatus status) {
+       if (status == QMediaPlayer::LoadedMedia)
+         player_.play();
+       });
+}
+
+void
+CallManager::sendInvite(const QString &roomid)
+{
+    if (onActiveCall())
+      return;
+
+    std::vector<RoomMember> members(cache::getMembers(roomid.toStdString()));
+    if (members.size() != 2) {
+      emit ChatPage::instance()->showNotification("Voice/Video calls are limited to 1:1 rooms");
+      return;
+    }
+
+    std::string errorMessage;
+    if (!session_.init(&errorMessage)) {
+      emit ChatPage::instance()->showNotification(QString::fromStdString(errorMessage));
+      return;
+    }
+
+    roomid_ = roomid;
+    setTurnServers();
+    session_.setStunServer(settings_->useStunServer() ? STUN_SERVER : "");
+
+    // TODO Add invite timeout
+    generateCallID();
+    const RoomMember &callee = members.front().user_id == utils::localUser() ? members.back() : members.front();
+    emit newCallParty(callee.user_id, callee.display_name);
+    playRingtone("qrc:/media/media/ringback.ogg", true);
+    if (!session_.createOffer()) {
+      emit ChatPage::instance()->showNotification("Problem setting up call");
+      endCall();
+    }
+}
+
+void
+CallManager::hangUp()
+{
+  nhlog::ui()->debug("CallManager::hangUp: roomid_: {}", roomid_.toStdString());
+  if (!callid_.empty()) {
+    emit newMessage(roomid_, CallHangUp{callid_, 0, CallHangUp::Reason::User});
+    endCall();
+  }
+}
+
+bool
+CallManager::onActiveCall()
+{
+  return session_.isActive();
+}
+
+void CallManager::syncEvent(const mtx::events::collections::TimelineEvents &event)
+{
+  if (handleEvent_<CallInvite>(event) || handleEvent_<CallCandidates>(event)
+      || handleEvent_<CallAnswer>(event) || handleEvent_<CallHangUp>(event))
+    return;
+}
+
+template<typename T>
+bool
+CallManager::handleEvent_(const mtx::events::collections::TimelineEvents &event)
+{
+  if (std::holds_alternative<RoomEvent<T>>(event)) {
+    handleEvent(std::get<RoomEvent<T>>(event));
+    return true;
+  }
+  return false;
+}
+
+void
+CallManager::handleEvent(const RoomEvent<CallInvite> &callInviteEvent)
+{
+  nhlog::ui()->debug("CallManager::incoming CallInvite from {} with id {}", callInviteEvent.sender, callInviteEvent.content.call_id);
+
+  if (callInviteEvent.content.call_id.empty())
+    return;
+
+  std::vector<RoomMember> members(cache::getMembers(callInviteEvent.room_id));
+  if (onActiveCall() || members.size() != 2) {
+    emit newMessage(QString::fromStdString(callInviteEvent.room_id),
+        CallHangUp{callInviteEvent.content.call_id, 0, CallHangUp::Reason::InviteTimeOut});
+    return;
+  }
+
+  playRingtone("qrc:/media/media/ring.ogg", true);
+  roomid_ = QString::fromStdString(callInviteEvent.room_id);
+  callid_ = callInviteEvent.content.call_id;
+  remoteICECandidates_.clear();
+
+  const RoomMember &caller = members.front().user_id == utils::localUser() ? members.back() : members.front();
+  emit newCallParty(caller.user_id, caller.display_name);
+
+  auto dialog = new dialogs::AcceptCall(caller.user_id, caller.display_name, MainWindow::instance());
+  connect(dialog, &dialogs::AcceptCall::accept, this,
+      [this, callInviteEvent](){
+        MainWindow::instance()->hideOverlay();
+        answerInvite(callInviteEvent.content);});
+  connect(dialog, &dialogs::AcceptCall::reject, this,
+      [this](){
+        MainWindow::instance()->hideOverlay();
+        hangUp();});
+  MainWindow::instance()->showSolidOverlayModal(dialog);
+}
+
+void
+CallManager::answerInvite(const CallInvite &invite)
+{
+  stopRingtone();
+  std::string errorMessage;
+  if (!session_.init(&errorMessage)) {
+    emit ChatPage::instance()->showNotification(QString::fromStdString(errorMessage));
+    hangUp();
+    return;
+  }
+
+  setTurnServers();
+  session_.setStunServer(settings_->useStunServer() ? STUN_SERVER : "");
+
+  if (!session_.acceptOffer(invite.sdp)) {
+    emit ChatPage::instance()->showNotification("Problem setting up call");
+    hangUp();
+    return;
+  }
+  session_.acceptICECandidates(remoteICECandidates_);
+  remoteICECandidates_.clear();
+}
+
+void
+CallManager::handleEvent(const RoomEvent<CallCandidates> &callCandidatesEvent)
+{
+  nhlog::ui()->debug("CallManager::incoming CallCandidates from {} with id {}", callCandidatesEvent.sender, callCandidatesEvent.content.call_id);
+  if (callid_ == callCandidatesEvent.content.call_id) {
+    if (onActiveCall())
+      session_.acceptICECandidates(callCandidatesEvent.content.candidates);
+    else {
+      // CallInvite has been received and we're awaiting localUser to accept or reject the call
+      for (const auto &c : callCandidatesEvent.content.candidates)
+        remoteICECandidates_.push_back(c);
+    }
+  }
+}
+
+void
+CallManager::handleEvent(const RoomEvent<CallAnswer> &callAnswerEvent)
+{
+  nhlog::ui()->debug("CallManager::incoming CallAnswer from {} with id {}", callAnswerEvent.sender, callAnswerEvent.content.call_id);
+  if (onActiveCall() && callid_ == callAnswerEvent.content.call_id) {
+    stopRingtone();
+    if (!session_.acceptAnswer(callAnswerEvent.content.sdp)) {
+      emit ChatPage::instance()->showNotification("Problem setting up call");
+      hangUp();
+    }
+  }
+}
+
+void
+CallManager::handleEvent(const RoomEvent<CallHangUp> &callHangUpEvent)
+{
+  nhlog::ui()->debug("CallManager::incoming CallHangUp from {} with id {}", callHangUpEvent.sender, callHangUpEvent.content.call_id);
+  if (onActiveCall() && callid_ == callHangUpEvent.content.call_id)
+    endCall();
+}
+
+void
+CallManager::generateCallID()
+{
+  using namespace std::chrono;
+  uint64_t ms = duration_cast<milliseconds>(system_clock::now().time_since_epoch()).count();
+  callid_ = "c" + std::to_string(ms);
+}
+
+void
+CallManager::endCall()
+{
+  stopRingtone();
+  session_.end();
+  roomid_.clear();
+  callid_.clear();
+  remoteICECandidates_.clear();
+}
+
+void
+CallManager::retrieveTurnServer()
+{
+  http::client()->get_turn_server(
+    [this](const mtx::responses::TurnServer &res, mtx::http::RequestErr err) {
+        if (err) {
+            turnServerTimer_.setInterval(5000);
+            return;
+        }
+        emit turnServerRetrieved(res);
+  });
+}
+
+void
+CallManager::setTurnServers()
+{
+  // gstreamer expects (percent-encoded): turn(s)://username:password@host:port?transport=udp(tcp)
+  std::vector<std::string> uris;
+  for (const auto &uri : turnServer_.uris) {
+    if (auto c = uri.find(':'); c == std::string::npos) {
+      nhlog::ui()->error("Invalid TURN server uri: {}", uri);
+      continue;
+    }
+    else {
+      std::string scheme = std::string(uri, 0, c);
+      if (scheme != "turn" && scheme != "turns") {
+        nhlog::ui()->error("Invalid TURN server uri: {}", uri);
+        continue;
+      }
+      std::string res = scheme + "://" + turnServer_.username + ":" + turnServer_.password
+        + "@" + std::string(uri, ++c);
+      QString encodedUri = QUrl::toPercentEncoding(QString::fromStdString(res));
+      uris.push_back(encodedUri.toStdString());
+    }
+  }
+  if (!uris.empty())
+    session_.setTurnServers(uris);
+}
+
+void
+CallManager::playRingtone(const QString &ringtone, bool repeat)
+{
+  static QMediaPlaylist playlist;
+  playlist.clear();
+  playlist.setPlaybackMode(repeat ? QMediaPlaylist::CurrentItemInLoop : QMediaPlaylist::CurrentItemOnce);
+  playlist.addMedia(QUrl(ringtone));
+  player_.setVolume(100);
+  player_.setPlaylist(&playlist);
+}
+
+void
+CallManager::stopRingtone()
+{
+  player_.setPlaylist(nullptr);
+}

src/CallManager.h

@@ -0,0 +1,67 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include <QObject>
+#include <QMediaPlayer>
+#include <QSharedPointer>
+#include <QString>
+#include <QTimer>
+
+#include "mtx/events/collections.hpp"
+#include "mtx/events/voip.hpp"
+#include "mtx/responses/turn_server.hpp"
+
+class UserSettings;
+class WebRTCSession;
+
+class CallManager : public QObject
+{
+        Q_OBJECT
+
+public:
+        CallManager(QSharedPointer<UserSettings>);
+
+        void sendInvite(const QString &roomid);
+        void hangUp();
+        bool onActiveCall();
+
+public slots:
+        void syncEvent(const mtx::events::collections::TimelineEvents &event);
+
+signals:
+        void newMessage(const QString &roomid, const mtx::events::msg::CallInvite&);
+        void newMessage(const QString &roomid, const mtx::events::msg::CallCandidates&);
+        void newMessage(const QString &roomid, const mtx::events::msg::CallAnswer&);
+        void newMessage(const QString &roomid, const mtx::events::msg::CallHangUp&);
+        void turnServerRetrieved(const mtx::responses::TurnServer&);
+        void newCallParty(const QString &userid, const QString& displayName);
+
+private slots:
+        void retrieveTurnServer();
+
+private:
+        WebRTCSession& session_;
+        QString roomid_;
+        std::string callid_;
+        const uint32_t timeoutms_ = 120000;
+        std::vector<mtx::events::msg::CallCandidates::Candidate> remoteICECandidates_;
+        mtx::responses::TurnServer turnServer_;
+        QTimer turnServerTimer_;
+        QSharedPointer<UserSettings> settings_;
+        QMediaPlayer player_;
+
+        template<typename T>
+        bool handleEvent_(const mtx::events::collections::TimelineEvents &event);
+        void handleEvent(const mtx::events::RoomEvent<mtx::events::msg::CallInvite>&);
+        void handleEvent(const mtx::events::RoomEvent<mtx::events::msg::CallCandidates>&);
+        void handleEvent(const mtx::events::RoomEvent<mtx::events::msg::CallAnswer>&);
+        void handleEvent(const mtx::events::RoomEvent<mtx::events::msg::CallHangUp>&);
+        void answerInvite(const mtx::events::msg::CallInvite&);
+        void generateCallID();
+        void endCall();
+        void setTurnServers();
+        void playRingtone(const QString &ringtone, bool repeat);
+        void stopRingtone();
+};

src/ChatPage.cpp

@@ -22,6 +22,7 @@
 #include <QShortcut>
 #include <QtConcurrent>
 
+#include "ActiveCallBar.h"
 #include "AvatarProvider.h"
 #include "Cache.h"
 #include "Cache_p.h"
@@ -40,11 +41,13 @@
 #include "UserInfoWidget.h"
 #include "UserSettingsPage.h"
 #include "Utils.h"
+#include "WebRTCSession.h"
 #include "ui/OverlayModal.h"
 #include "ui/Theme.h"
 
 #include "notifications/Manager.h"
 
+#include "dialogs/PlaceCall.h"
 #include "dialogs/ReadReceipts.h"
 #include "popups/UserMentions.h"
 #include "timeline/TimelineViewManager.h"
@@ -68,6 +71,7 @@ ChatPage::ChatPage(QSharedPointer<UserSettings> userSettings, QWidget *parent)
   , isConnected_(true)
   , userSettings_{userSettings}
   , notificationsManager(this)
+  , callManager_(userSettings)
 {
         setObjectName("chatPage");
 
@@ -123,11 +127,26 @@ ChatPage::ChatPage(QSharedPointer<UserSettings> userSettings, QWidget *parent)
         contentLayout_->setMargin(0);
 
         top_bar_      = new TopRoomBar(this);
-        view_manager_ = new TimelineViewManager(userSettings_, this);
+        view_manager_ = new TimelineViewManager(userSettings_, &callManager_, this);
 
         contentLayout_->addWidget(top_bar_);
         contentLayout_->addWidget(view_manager_->getWidget());
 
+        activeCallBar_ = new ActiveCallBar(this);
+        contentLayout_->addWidget(activeCallBar_);
+        activeCallBar_->hide();
+        connect(
+          &callManager_, &CallManager::newCallParty, activeCallBar_, &ActiveCallBar::setCallParty);
+        connect(&WebRTCSession::instance(),
+                &WebRTCSession::pipelineChanged,
+                this,
+                [this](bool callStarted) {
+                        if (callStarted)
+                                activeCallBar_->show();
+                        else
+                                activeCallBar_->hide();
+                });
+
         // Splitter
         splitter->addWidget(sideBar_);
         splitter->addWidget(content_);
@@ -446,6 +465,31 @@ ChatPage::ChatPage(QSharedPointer<UserSettings> userSettings, QWidget *parent)
                                   roomid, filename, encryptedFile, url, mime, dsize);
                 });
 
+        connect(text_input_, &TextInputWidget::callButtonPress, this, [this]() {
+                if (callManager_.onActiveCall()) {
+                        callManager_.hangUp();
+                } else {
+                        if (cache::singleRoomInfo(current_room_.toStdString()).member_count != 2) {
+                                showNotification("Voice/Video calls are limited to 1:1 rooms");
+                        } else {
+                                std::vector<RoomMember> members(
+                                  cache::getMembers(current_room_.toStdString()));
+                                const RoomMember &callee =
+                                  members.front().user_id == utils::localUser() ? members.back()
+                                                                                : members.front();
+                                auto dialog =
+                                  new dialogs::PlaceCall(callee.user_id, callee.display_name, this);
+                                connect(dialog, &dialogs::PlaceCall::voice, this, [this]() {
+                                        callManager_.sendInvite(current_room_);
+                                });
+                                connect(dialog, &dialogs::PlaceCall::video, this, [this]() {
+                                        showNotification("Video calls not yet implemented");
+                                });
+                                dialog->show();
+                        }
+                }
+        });
+
         connect(room_list_, &RoomList::roomAvatarChanged, this, &ChatPage::updateTopBarAvatar);
 
         connect(
@@ -569,6 +613,11 @@ ChatPage::ChatPage(QSharedPointer<UserSettings> userSettings, QWidget *parent)
 
         connect(this, &ChatPage::dropToLoginPageCb, this, &ChatPage::dropToLoginPage);
 
+        connectCallMessage<mtx::events::msg::CallInvite>();
+        connectCallMessage<mtx::events::msg::CallCandidates>();
+        connectCallMessage<mtx::events::msg::CallAnswer>();
+        connectCallMessage<mtx::events::msg::CallHangUp>();
+
         instance_ = this;
 }
 
@@ -1430,3 +1479,13 @@ ChatPage::initiateLogout()
 
         emit showOverlayProgressBar();
 }
+
+template<typename T>
+void
+ChatPage::connectCallMessage()
+{
+        connect(&callManager_,
+                qOverload<const QString &, const T &>(&CallManager::newMessage),
+                view_manager_,
+                qOverload<const QString &, const T &>(&TimelineViewManager::queueCallMessage));
+}

src/ChatPage.h

@@ -35,11 +35,13 @@
 #include <QWidget>
 
 #include "CacheStructs.h"
+#include "CallManager.h"
 #include "CommunitiesList.h"
 #include "Utils.h"
 #include "notifications/Manager.h"
 #include "popups/UserMentions.h"
 
+class ActiveCallBar;
 class OverlayModal;
 class QuickSwitcher;
 class RoomList;
@@ -50,7 +52,6 @@ class TimelineViewManager;
 class TopRoomBar;
 class UserInfoWidget;
 class UserSettings;
-class NotificationsManager;
 
 constexpr int CONSENSUS_TIMEOUT      = 1000;
 constexpr int SHOW_CONTENT_TIMEOUT   = 3000;
@@ -216,6 +217,9 @@ private:
 
         void showNotificationsDialog(const QPoint &point);
 
+        template<typename T>
+        void connectCallMessage();
+
         QHBoxLayout *topLayout_;
         Splitter *splitter;
 
@@ -235,6 +239,7 @@ private:
 
         TopRoomBar *top_bar_;
         TextInputWidget *text_input_;
+        ActiveCallBar *activeCallBar_;
 
         QTimer connectivityTimer_;
         std::atomic_bool isConnected_;
@@ -252,6 +257,7 @@ private:
         QSharedPointer<UserSettings> userSettings_;
 
         NotificationsManager notificationsManager;
+        CallManager callManager_;
 };
 
 template<class Collection>

src/TextInputWidget.cpp

@@ -31,6 +31,7 @@
 #include "Logging.h"
 #include "TextInputWidget.h"
 #include "Utils.h"
+#include "WebRTCSession.h"
 #include "ui/FlatButton.h"
 #include "ui/LoadingIndicator.h"
 
@@ -453,6 +454,13 @@ TextInputWidget::TextInputWidget(QWidget *parent)
         topLayout_->setSpacing(0);
         topLayout_->setContentsMargins(13, 1, 13, 0);
 
+        callBtn_ = new FlatButton(this);
+        changeCallButtonState(false);
+        connect(&WebRTCSession::instance(),
+                &WebRTCSession::pipelineChanged,
+                this,
+                &TextInputWidget::changeCallButtonState);
+
         QIcon send_file_icon;
         send_file_icon.addFile(":/icons/icons/ui/paper-clip-outline.png");
 
@@ -521,6 +529,7 @@ TextInputWidget::TextInputWidget(QWidget *parent)
         emojiBtn_->setIcon(emoji_icon);
         emojiBtn_->setIconSize(QSize(ButtonHeight, ButtonHeight));
 
+        topLayout_->addWidget(callBtn_);
         topLayout_->addWidget(sendFileBtn_);
         topLayout_->addWidget(input_);
         topLayout_->addWidget(emojiBtn_);
@@ -528,6 +537,7 @@ TextInputWidget::TextInputWidget(QWidget *parent)
 
         setLayout(topLayout_);
 
+        connect(callBtn_, &FlatButton::clicked, this, &TextInputWidget::callButtonPress);
         connect(sendMessageBtn_, &FlatButton::clicked, input_, &FilteredTextEdit::submit);
         connect(sendFileBtn_, SIGNAL(clicked()), this, SLOT(openFileSelection()));
         connect(input_, &FilteredTextEdit::message, this, &TextInputWidget::sendTextMessage);
@@ -652,3 +662,19 @@ TextInputWidget::paintEvent(QPaintEvent *)
 
         style()->drawPrimitive(QStyle::PE_Widget, &opt, &p, this);
 }
+
+void
+TextInputWidget::changeCallButtonState(bool callStarted)
+{
+        // TODO Telephone and HangUp icons - co-opt the ones below for now
+        QIcon icon;
+        if (callStarted) {
+                callBtn_->setToolTip(tr("Hang up"));
+                icon.addFile(":/icons/icons/ui/remove-symbol.png");
+        } else {
+                callBtn_->setToolTip(tr("Place a call"));
+                icon.addFile(":/icons/icons/ui/speech-bubbles-comment-option.png");
+        }
+        callBtn_->setIcon(icon);
+        callBtn_->setIconSize(QSize(ButtonHeight, ButtonHeight));
+}

src/TextInputWidget.h

@@ -149,6 +149,7 @@ public slots:
         void openFileSelection();
         void hideUploadSpinner();
         void focusLineEdit() { input_->setFocus(); }
+        void changeCallButtonState(bool callStarted);
 
 private slots:
         void addSelectedEmoji(const QString &emoji);
@@ -161,6 +162,7 @@ signals:
         void uploadMedia(const QSharedPointer<QIODevice> data,
                          QString mimeClass,
                          const QString &filename);
+        void callButtonPress();
 
         void sendJoinRoomRequest(const QString &room);
         void sendInviteRoomRequest(const QString &userid, const QString &reason);
@@ -185,6 +187,7 @@ private:
 
         LoadingIndicator *spinner_;
 
+        FlatButton *callBtn_;
         FlatButton *sendFileBtn_;
         FlatButton *sendMessageBtn_;
         emoji::PickButton *emojiBtn_;

src/UserSettingsPage.cpp

@@ -77,6 +77,7 @@ UserSettings::load()
         presence_ =
           settings.value("user/presence", QVariant::fromValue(Presence::AutomaticPresence))
             .value<Presence>();
+        useStunServer_ = settings.value("user/use_stun_server", false).toBool();
 
         applyTheme();
 }
@@ -279,6 +280,16 @@ UserSettings::setTheme(QString theme)
         emit themeChanged(theme);
 }
 
+void
+UserSettings::setUseStunServer(bool useStunServer)
+{
+        if (useStunServer == useStunServer_)
+                return;
+        useStunServer_ = useStunServer;
+        emit useStunServerChanged(useStunServer);
+        save();
+}
+
 void
 UserSettings::applyTheme()
 {
@@ -364,6 +375,7 @@ UserSettings::save()
         settings.setValue("font_family", font_);
         settings.setValue("emoji_font_family", emojiFont_);
         settings.setValue("presence", QVariant::fromValue(presence_));
+        settings.setValue("use_stun_server", useStunServer_);
 
         settings.endGroup();
 
@@ -429,6 +441,7 @@ UserSettingsPage::UserSettingsPage(QSharedPointer<UserSettings> settings, QWidge
         markdown_                 = new Toggle{this};
         desktopNotifications_     = new Toggle{this};
         alertOnNotification_      = new Toggle{this};
+        useStunServer_            = new Toggle{this};
         scaleFactorCombo_         = new QComboBox{this};
         fontSizeCombo_            = new QComboBox{this};
         fontSelectionCombo_       = new QComboBox{this};
@@ -482,6 +495,12 @@ UserSettingsPage::UserSettingsPage(QSharedPointer<UserSettings> settings, QWidge
         timelineMaxWidthSpin_->setMaximum(100'000'000);
         timelineMaxWidthSpin_->setSingleStep(10);
 
+        auto callsLabel = new QLabel{tr("CALLS"), this};
+        callsLabel->setFixedHeight(callsLabel->minimumHeight() + LayoutTopMargin);
+        callsLabel->setAlignment(Qt::AlignBottom);
+        callsLabel->setFont(font);
+        useStunServer_ = new Toggle{this};
+
         auto encryptionLabel_ = new QLabel{tr("ENCRYPTION"), this};
         encryptionLabel_->setFixedHeight(encryptionLabel_->minimumHeight() + LayoutTopMargin);
         encryptionLabel_->setAlignment(Qt::AlignBottom);
@@ -612,6 +631,13 @@ UserSettingsPage::UserSettingsPage(QSharedPointer<UserSettings> settings, QWidge
 #endif
 
         boxWrap(tr("Theme"), themeCombo_);
+
+        formLayout_->addRow(callsLabel);
+        formLayout_->addRow(new HorizontalLine{this});
+        boxWrap(tr("Allow Fallback Call Assist Server"),
+                useStunServer_,
+                tr("Will use turn.matrix.org as assist when your home server does not offer one."));
+
         formLayout_->addRow(encryptionLabel_);
         formLayout_->addRow(new HorizontalLine{this});
         boxWrap(tr("Device ID"), deviceIdValue_);
@@ -724,6 +750,10 @@ UserSettingsPage::UserSettingsPage(QSharedPointer<UserSettings> settings, QWidge
                 settings_->setEnlargeEmojiOnlyMessages(!disabled);
         });
 
+        connect(useStunServer_, &Toggle::toggled, this, [this](bool disabled) {
+                settings_->setUseStunServer(!disabled);
+        });
+
         connect(timelineMaxWidthSpin_,
                 qOverload<int>(&QSpinBox::valueChanged),
                 this,
@@ -766,6 +796,7 @@ UserSettingsPage::showEvent(QShowEvent *)
         enlargeEmojiOnlyMessages_->setState(!settings_->enlargeEmojiOnlyMessages());
         deviceIdValue_->setText(QString::fromStdString(http::client()->device_id()));
         timelineMaxWidthSpin_->setValue(settings_->timelineMaxWidth());
+        useStunServer_->setState(!settings_->useStunServer());
 
         deviceFingerprintValue_->setText(
           utils::humanReadableFingerprint(olm::client()->identity_keys().ed25519));

src/UserSettingsPage.h

@@ -71,6 +71,8 @@ class UserSettings : public QObject
         Q_PROPERTY(
           QString emojiFont READ emojiFont WRITE setEmojiFontFamily NOTIFY emojiFontChanged)
         Q_PROPERTY(Presence presence READ presence WRITE setPresence NOTIFY presenceChanged)
+        Q_PROPERTY(
+          bool useStunServer READ useStunServer WRITE setUseStunServer NOTIFY useStunServerChanged)
 
 public:
         UserSettings();
@@ -107,6 +109,7 @@ public:
         void setAvatarCircles(bool state);
         void setDecryptSidebar(bool state);
         void setPresence(Presence state);
+        void setUseStunServer(bool state);
 
         QString theme() const { return !theme_.isEmpty() ? theme_ : defaultTheme_; }
         bool messageHoverHighlight() const { return messageHoverHighlight_; }
@@ -132,6 +135,7 @@ public:
         QString font() const { return font_; }
         QString emojiFont() const { return emojiFont_; }
         Presence presence() const { return presence_; }
+        bool useStunServer() const { return useStunServer_; }
 
 signals:
         void groupViewStateChanged(bool state);
@@ -154,6 +158,7 @@ signals:
         void fontChanged(QString state);
         void emojiFontChanged(QString state);
         void presenceChanged(Presence state);
+        void useStunServerChanged(bool state);
 
 private:
         // Default to system theme if QT_QPA_PLATFORMTHEME var is set.
@@ -181,6 +186,7 @@ private:
         QString font_;
         QString emojiFont_;
         Presence presence_;
+        bool useStunServer_;
 };
 
 class HorizontalLine : public QFrame
@@ -234,6 +240,7 @@ private:
         Toggle *desktopNotifications_;
         Toggle *alertOnNotification_;
         Toggle *avatarCircles_;
+        Toggle *useStunServer_;
         Toggle *decryptSidebar_;
         QLabel *deviceFingerprintValue_;
         QLabel *deviceIdValue_;

src/Utils.cpp

@@ -35,14 +35,13 @@ createDescriptionInfo(const Event &event, const QString &localUser, const QStrin
         const auto username = cache::displayName(room_id, sender);
         const auto ts       = QDateTime::fromMSecsSinceEpoch(msg.origin_server_ts);
 
-        return DescInfo{
+        return DescInfo{QString::fromStdString(msg.event_id),
-          QString::fromStdString(msg.event_id),
+                        sender,
-          sender,
+                        utils::messageDescription<T>(
-          utils::messageDescription<T>(
+                          username, utils::event_body(event).trimmed(), sender == localUser),
-            username, QString::fromStdString(msg.content.body).trimmed(), sender == localUser),
+                        utils::descriptiveTime(ts),
-          utils::descriptiveTime(ts),
+                        msg.origin_server_ts,
-          msg.origin_server_ts,
+                        ts};
-          ts};
 }
 
 QString
@@ -156,14 +155,17 @@ utils::getMessageDescription(const TimelineEvent &event,
                              const QString &localUser,
                              const QString &room_id)
 {
-        using Audio     = mtx::events::RoomEvent<mtx::events::msg::Audio>;
+        using Audio      = mtx::events::RoomEvent<mtx::events::msg::Audio>;
-        using Emote     = mtx::events::RoomEvent<mtx::events::msg::Emote>;
+        using Emote      = mtx::events::RoomEvent<mtx::events::msg::Emote>;
-        using File      = mtx::events::RoomEvent<mtx::events::msg::File>;
+        using File       = mtx::events::RoomEvent<mtx::events::msg::File>;
-        using Image     = mtx::events::RoomEvent<mtx::events::msg::Image>;
+        using Image      = mtx::events::RoomEvent<mtx::events::msg::Image>;
-        using Notice    = mtx::events::RoomEvent<mtx::events::msg::Notice>;
+        using Notice     = mtx::events::RoomEvent<mtx::events::msg::Notice>;
-        using Text      = mtx::events::RoomEvent<mtx::events::msg::Text>;
+        using Text       = mtx::events::RoomEvent<mtx::events::msg::Text>;
-        using Video     = mtx::events::RoomEvent<mtx::events::msg::Video>;
+        using Video      = mtx::events::RoomEvent<mtx::events::msg::Video>;
-        using Encrypted = mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>;
+        using CallInvite = mtx::events::RoomEvent<mtx::events::msg::CallInvite>;
+        using CallAnswer = mtx::events::RoomEvent<mtx::events::msg::CallAnswer>;
+        using CallHangUp = mtx::events::RoomEvent<mtx::events::msg::CallHangUp>;
+        using Encrypted  = mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>;
 
         if (std::holds_alternative<Audio>(event)) {
                 return createDescriptionInfo<Audio>(event, localUser, room_id);
@@ -179,6 +181,12 @@ utils::getMessageDescription(const TimelineEvent &event,
                 return createDescriptionInfo<Text>(event, localUser, room_id);
         } else if (std::holds_alternative<Video>(event)) {
                 return createDescriptionInfo<Video>(event, localUser, room_id);
+        } else if (std::holds_alternative<CallInvite>(event)) {
+                return createDescriptionInfo<CallInvite>(event, localUser, room_id);
+        } else if (std::holds_alternative<CallAnswer>(event)) {
+                return createDescriptionInfo<CallAnswer>(event, localUser, room_id);
+        } else if (std::holds_alternative<CallHangUp>(event)) {
+                return createDescriptionInfo<CallHangUp>(event, localUser, room_id);
         } else if (std::holds_alternative<mtx::events::Sticker>(event)) {
                 return createDescriptionInfo<mtx::events::Sticker>(event, localUser, room_id);
         } else if (auto msg = std::get_if<Encrypted>(&event); msg != nullptr) {

src/Utils.h

@@ -88,15 +88,18 @@ messageDescription(const QString &username = "",
                    const QString &body     = "",
                    const bool isLocal      = false)
 {
-        using Audio     = mtx::events::RoomEvent<mtx::events::msg::Audio>;
+        using Audio      = mtx::events::RoomEvent<mtx::events::msg::Audio>;
-        using Emote     = mtx::events::RoomEvent<mtx::events::msg::Emote>;
+        using Emote      = mtx::events::RoomEvent<mtx::events::msg::Emote>;
-        using File      = mtx::events::RoomEvent<mtx::events::msg::File>;
+        using File       = mtx::events::RoomEvent<mtx::events::msg::File>;
-        using Image     = mtx::events::RoomEvent<mtx::events::msg::Image>;
+        using Image      = mtx::events::RoomEvent<mtx::events::msg::Image>;
-        using Notice    = mtx::events::RoomEvent<mtx::events::msg::Notice>;
+        using Notice     = mtx::events::RoomEvent<mtx::events::msg::Notice>;
-        using Sticker   = mtx::events::Sticker;
+        using Sticker    = mtx::events::Sticker;
-        using Text      = mtx::events::RoomEvent<mtx::events::msg::Text>;
+        using Text       = mtx::events::RoomEvent<mtx::events::msg::Text>;
-        using Video     = mtx::events::RoomEvent<mtx::events::msg::Video>;
+        using Video      = mtx::events::RoomEvent<mtx::events::msg::Video>;
-        using Encrypted = mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>;
+        using CallInvite = mtx::events::RoomEvent<mtx::events::msg::CallInvite>;
+        using CallAnswer = mtx::events::RoomEvent<mtx::events::msg::CallAnswer>;
+        using CallHangUp = mtx::events::RoomEvent<mtx::events::msg::CallHangUp>;
+        using Encrypted  = mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>;
 
         if (std::is_same<T, Audio>::value) {
                 if (isLocal)
@@ -164,6 +167,30 @@ messageDescription(const QString &username = "",
                         return QCoreApplication::translate("message-description sent:",
                                                            "%1 sent an encrypted message")
                           .arg(username);
+        } else if (std::is_same<T, CallInvite>::value) {
+                if (isLocal)
+                        return QCoreApplication::translate("message-description sent:",
+                                                           "You placed a call");
+                else
+                        return QCoreApplication::translate("message-description sent:",
+                                                           "%1 placed a call")
+                          .arg(username);
+        } else if (std::is_same<T, CallAnswer>::value) {
+                if (isLocal)
+                        return QCoreApplication::translate("message-description sent:",
+                                                           "You answered a call");
+                else
+                        return QCoreApplication::translate("message-description sent:",
+                                                           "%1 answered a call")
+                          .arg(username);
+        } else if (std::is_same<T, CallHangUp>::value) {
+                if (isLocal)
+                        return QCoreApplication::translate("message-description sent:",
+                                                           "You ended a call");
+                else
+                        return QCoreApplication::translate("message-description sent:",
+                                                           "%1 ended a call")
+                          .arg(username);
         } else {
                 return QCoreApplication::translate("utils", "Unknown Message Type");
         }

src/WebRTCSession.cpp

@@ -0,0 +1,438 @@
+#include "WebRTCSession.h"
+#include "Logging.h"
+
+extern "C" {
+#include "gst/gst.h"
+#include "gst/sdp/sdp.h"
+
+#define GST_USE_UNSTABLE_API
+#include "gst/webrtc/webrtc.h"
+}
+
+namespace {
+bool gisoffer;
+std::string glocalsdp;
+std::vector<mtx::events::msg::CallCandidates::Candidate> gcandidates;
+
+gboolean newBusMessage(GstBus *bus G_GNUC_UNUSED, GstMessage *msg, gpointer user_data);
+GstWebRTCSessionDescription* parseSDP(const std::string &sdp, GstWebRTCSDPType type);
+void generateOffer(GstElement *webrtc);
+void setLocalDescription(GstPromise *promise, gpointer webrtc);
+void addLocalICECandidate(GstElement *webrtc G_GNUC_UNUSED, guint mlineIndex, gchar *candidate, gpointer G_GNUC_UNUSED);
+gboolean onICEGatheringCompletion(gpointer timerid);
+void createAnswer(GstPromise *promise, gpointer webrtc);
+void addDecodeBin(GstElement *webrtc G_GNUC_UNUSED, GstPad *newpad, GstElement *pipe);
+void linkNewPad(GstElement *decodebin G_GNUC_UNUSED, GstPad *newpad, GstElement *pipe);
+}
+
+bool
+WebRTCSession::init(std::string *errorMessage)
+{
+  if (initialised_)
+    return true;
+
+  GError *error = nullptr;
+  if (!gst_init_check(nullptr, nullptr, &error)) {
+    std::string strError = std::string("Failed to initialise GStreamer: ");
+    if (error) {
+      strError += error->message;
+      g_error_free(error);
+    }
+    nhlog::ui()->error(strError);
+    if (errorMessage)
+      *errorMessage = strError;
+    return false;
+  }
+
+  gchar *version = gst_version_string();
+  std::string gstVersion(version); 
+  g_free(version);
+  nhlog::ui()->info("Initialised " + gstVersion);
+
+  // GStreamer Plugins:
+  // Base:            audioconvert, audioresample, opus, playback, videoconvert, volume
+  // Good:            autodetect, rtpmanager, vpx
+  // Bad:             dtls, srtp, webrtc
+  // libnice [GLib]:  nice
+  initialised_ = true;
+  std::string strError = gstVersion + ": Missing plugins: ";
+  const gchar *needed[] = {"audioconvert", "audioresample", "autodetect", "dtls", "nice",
+    "opus", "playback", "rtpmanager", "srtp", "videoconvert", "vpx", "volume", "webrtc", nullptr};
+  GstRegistry *registry = gst_registry_get();
+  for (guint i = 0; i < g_strv_length((gchar**)needed); i++) {
+    GstPlugin *plugin = gst_registry_find_plugin(registry, needed[i]);
+    if (!plugin) {
+      strError += needed[i];
+      initialised_ = false;
+      continue;
+    }
+    gst_object_unref(plugin);
+  }
+
+  if (!initialised_) {
+    nhlog::ui()->error(strError);
+    if (errorMessage)
+      *errorMessage = strError;
+  }
+  return initialised_;
+}
+
+bool
+WebRTCSession::createOffer()
+{
+  gisoffer = true;
+  glocalsdp.clear();
+  gcandidates.clear();
+  return startPipeline(111); // a dynamic opus payload type
+}
+
+bool
+WebRTCSession::acceptOffer(const std::string& sdp)
+{
+  nhlog::ui()->debug("Received offer:\n{}", sdp);
+  gisoffer = false;
+  glocalsdp.clear();
+  gcandidates.clear();
+
+  // eg a=rtpmap:111 opus/48000/2
+  int opusPayloadType = 0;
+  if (auto e = sdp.find("opus"); e == std::string::npos) {
+    nhlog::ui()->error("WebRTC: remote offer - opus media attribute missing");
+    return false;
+  }
+  else {
+    if (auto s = sdp.rfind(':', e); s == std::string::npos) {
+      nhlog::ui()->error("WebRTC: remote offer - unable to determine opus payload type");
+      return false;
+    }
+    else {
+      ++s;
+      try {
+        opusPayloadType = std::stoi(std::string(sdp, s, e - s));
+      }
+      catch(...) {
+        nhlog::ui()->error("WebRTC: remote offer - unable to determine opus payload type");
+        return false;
+      }
+    }
+  }
+
+  GstWebRTCSessionDescription *offer = parseSDP(sdp, GST_WEBRTC_SDP_TYPE_OFFER);
+  if (!offer)
+    return false;
+
+  if (!startPipeline(opusPayloadType))
+    return false;
+
+  // set-remote-description first, then create-answer
+  GstPromise *promise = gst_promise_new_with_change_func(createAnswer, webrtc_, nullptr);
+  g_signal_emit_by_name(webrtc_, "set-remote-description", offer, promise);
+  gst_webrtc_session_description_free(offer);
+  return true;
+}
+
+bool
+WebRTCSession::startPipeline(int opusPayloadType)
+{
+  if (isActive())
+    return false;
+
+  if (!createPipeline(opusPayloadType))
+    return false;
+
+  webrtc_ = gst_bin_get_by_name(GST_BIN(pipe_), "webrtcbin");
+
+  if (!stunServer_.empty()) {
+    nhlog::ui()->info("WebRTC: Setting stun server: {}", stunServer_);
+    g_object_set(webrtc_, "stun-server", stunServer_.c_str(), nullptr);
+  }
+  addTurnServers();
+
+  // generate the offer when the pipeline goes to PLAYING
+  if (gisoffer)
+    g_signal_connect(webrtc_, "on-negotiation-needed", G_CALLBACK(generateOffer), nullptr);
+
+  // on-ice-candidate is emitted when a local ICE candidate has been gathered
+  g_signal_connect(webrtc_, "on-ice-candidate", G_CALLBACK(addLocalICECandidate), nullptr);
+
+  // incoming streams trigger pad-added
+  gst_element_set_state(pipe_, GST_STATE_READY);
+  g_signal_connect(webrtc_, "pad-added", G_CALLBACK(addDecodeBin), pipe_);
+
+  // webrtcbin lifetime is the same as that of the pipeline
+  gst_object_unref(webrtc_);
+
+  // start the pipeline
+  GstStateChangeReturn ret = gst_element_set_state(pipe_, GST_STATE_PLAYING);
+  if (ret == GST_STATE_CHANGE_FAILURE) {
+    nhlog::ui()->error("WebRTC: unable to start pipeline");
+    gst_object_unref(pipe_);
+    pipe_ = nullptr;
+    webrtc_ = nullptr;
+    return false;
+  }
+
+  GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(pipe_));
+  gst_bus_add_watch(bus, newBusMessage, this);
+  gst_object_unref(bus);
+  emit pipelineChanged(true);
+  return true;
+}
+
+#define RTP_CAPS_OPUS "application/x-rtp,media=audio,encoding-name=OPUS,payload="
+
+bool
+WebRTCSession::createPipeline(int opusPayloadType)
+{
+  std::string pipeline("webrtcbin bundle-policy=max-bundle name=webrtcbin "
+      "autoaudiosrc ! volume name=srclevel ! audioconvert ! audioresample ! queue ! opusenc ! rtpopuspay ! "
+      "queue ! " RTP_CAPS_OPUS  + std::to_string(opusPayloadType) + " ! webrtcbin.");
+
+  webrtc_ = nullptr;
+  GError *error = nullptr;
+  pipe_ = gst_parse_launch(pipeline.c_str(), &error);
+  if (error) {
+    nhlog::ui()->error("WebRTC: Failed to parse pipeline: {}", error->message);
+    g_error_free(error);
+    if (pipe_) {
+      gst_object_unref(pipe_);
+      pipe_ = nullptr;
+    }
+    return false;
+  }
+  return true;
+}
+
+bool
+WebRTCSession::acceptAnswer(const std::string &sdp)
+{
+  nhlog::ui()->debug("WebRTC: Received sdp:\n{}", sdp);
+  if (!isActive())
+    return false;
+
+  GstWebRTCSessionDescription *answer = parseSDP(sdp, GST_WEBRTC_SDP_TYPE_ANSWER);
+  if (!answer)
+    return false;
+
+  g_signal_emit_by_name(webrtc_, "set-remote-description", answer, nullptr);
+  gst_webrtc_session_description_free(answer);
+  return true;
+}
+
+void
+WebRTCSession::acceptICECandidates(const std::vector<mtx::events::msg::CallCandidates::Candidate>& candidates)
+{
+  if (isActive()) {
+    for (const auto& c : candidates)
+      g_signal_emit_by_name(webrtc_, "add-ice-candidate", c.sdpMLineIndex, c.candidate.c_str());
+  }
+}
+
+bool
+WebRTCSession::toggleMuteAudioSrc(bool &isMuted)
+{
+  if (!isActive())
+    return false;
+
+  GstElement *srclevel = gst_bin_get_by_name(GST_BIN(pipe_), "srclevel");
+  if (!srclevel)
+    return false;
+
+  gboolean muted;
+  g_object_get(srclevel, "mute", &muted, nullptr);
+  g_object_set(srclevel, "mute", !muted, nullptr);
+  gst_object_unref(srclevel);
+  isMuted = !muted;
+  return true;
+}
+
+void
+WebRTCSession::end()
+{
+  if (pipe_) {
+    gst_element_set_state(pipe_, GST_STATE_NULL);
+    gst_object_unref(pipe_);
+    pipe_ = nullptr;
+  }
+  webrtc_ = nullptr;
+  emit pipelineChanged(false);
+}
+
+void
+WebRTCSession::addTurnServers()
+{
+  if (!webrtc_)
+    return;
+
+  for (const auto &uri : turnServers_) {
+    gboolean res;
+    g_signal_emit_by_name(webrtc_, "add-turn-server", uri.c_str(), (gpointer)(&res));
+    if (res)
+      nhlog::ui()->info("WebRTC: Set TURN server: {}", uri);
+    else
+      nhlog::ui()->error("WebRTC: Failed to set TURN server: {}", uri);
+  }
+}
+
+namespace {
+
+gboolean
+newBusMessage(GstBus *bus G_GNUC_UNUSED, GstMessage *msg, gpointer user_data)
+{
+  WebRTCSession *session = (WebRTCSession*)user_data;
+  switch (GST_MESSAGE_TYPE(msg)) {
+    case GST_MESSAGE_EOS:
+      session->end();
+      break;
+    case GST_MESSAGE_ERROR:
+      GError *error;
+      gchar *debug;
+      gst_message_parse_error(msg, &error, &debug);
+      nhlog::ui()->error("WebRTC: Error from element {}: {}", GST_OBJECT_NAME(msg->src), error->message);
+      g_clear_error(&error);
+      g_free(debug);
+      session->end();
+      break;
+    default:
+      break;
+  }
+  return TRUE;
+}
+
+GstWebRTCSessionDescription*
+parseSDP(const std::string &sdp, GstWebRTCSDPType type)
+{
+  GstSDPMessage *msg;
+  gst_sdp_message_new(&msg);
+  if (gst_sdp_message_parse_buffer((guint8*)sdp.c_str(), sdp.size(), msg) == GST_SDP_OK) {
+    return gst_webrtc_session_description_new(type, msg);
+  }
+  else {
+    nhlog::ui()->error("WebRTC: Failed to parse remote session description");
+    gst_object_unref(msg);
+    return nullptr;
+  }
+}
+
+void
+generateOffer(GstElement *webrtc)
+{
+  // create-offer first, then set-local-description
+  GstPromise *promise = gst_promise_new_with_change_func(setLocalDescription, webrtc, nullptr);
+  g_signal_emit_by_name(webrtc, "create-offer", nullptr, promise);
+}
+
+void
+setLocalDescription(GstPromise *promise, gpointer webrtc)
+{
+  const GstStructure *reply = gst_promise_get_reply(promise);
+  gboolean isAnswer = gst_structure_id_has_field(reply, g_quark_from_string("answer"));
+  GstWebRTCSessionDescription *gstsdp = nullptr;
+  gst_structure_get(reply, isAnswer ? "answer" : "offer", GST_TYPE_WEBRTC_SESSION_DESCRIPTION, &gstsdp, nullptr);
+  gst_promise_unref(promise);
+  g_signal_emit_by_name(webrtc, "set-local-description", gstsdp, nullptr);
+
+  gchar *sdp = gst_sdp_message_as_text(gstsdp->sdp);
+  glocalsdp = std::string(sdp);
+  g_free(sdp);
+  gst_webrtc_session_description_free(gstsdp);
+
+  nhlog::ui()->debug("WebRTC: Local description set ({}):\n{}", isAnswer ? "answer" : "offer", glocalsdp);
+}
+
+void
+addLocalICECandidate(GstElement *webrtc G_GNUC_UNUSED, guint mlineIndex, gchar *candidate, gpointer G_GNUC_UNUSED)
+{
+  gcandidates.push_back({"audio", (uint16_t)mlineIndex, candidate});
+
+  // GStreamer v1.16: webrtcbin's notify::ice-gathering-state triggers GST_WEBRTC_ICE_GATHERING_STATE_COMPLETE too early
+  // fixed in v1.18
+  // use a 100ms timeout in the meantime
+  static guint timerid = 0;
+  if (timerid)
+    g_source_remove(timerid);
+
+  timerid = g_timeout_add(100, onICEGatheringCompletion, &timerid);
+}
+
+gboolean
+onICEGatheringCompletion(gpointer timerid)
+{
+  *(guint*)(timerid) = 0;
+  if (gisoffer)
+    emit WebRTCSession::instance().offerCreated(glocalsdp, gcandidates);
+  else
+    emit WebRTCSession::instance().answerCreated(glocalsdp, gcandidates);
+
+  return FALSE;
+}
+
+void
+createAnswer(GstPromise *promise, gpointer webrtc)
+{
+  // create-answer first, then set-local-description
+  gst_promise_unref(promise);
+  promise = gst_promise_new_with_change_func(setLocalDescription, webrtc, nullptr);
+  g_signal_emit_by_name(webrtc, "create-answer", nullptr, promise);
+}
+
+void
+addDecodeBin(GstElement *webrtc G_GNUC_UNUSED, GstPad *newpad, GstElement *pipe)
+{
+  if (GST_PAD_DIRECTION(newpad) != GST_PAD_SRC)
+    return;
+
+  GstElement *decodebin = gst_element_factory_make("decodebin", nullptr);
+  g_signal_connect(decodebin, "pad-added", G_CALLBACK(linkNewPad), pipe);
+  gst_bin_add(GST_BIN(pipe), decodebin);
+  gst_element_sync_state_with_parent(decodebin);
+  GstPad *sinkpad = gst_element_get_static_pad(decodebin, "sink");
+  if (GST_PAD_LINK_FAILED(gst_pad_link(newpad, sinkpad)))
+    nhlog::ui()->error("WebRTC: Unable to link new pad");
+  gst_object_unref(sinkpad);
+}
+
+void
+linkNewPad(GstElement *decodebin G_GNUC_UNUSED, GstPad *newpad, GstElement *pipe)
+{
+  GstCaps *caps = gst_pad_get_current_caps(newpad);
+  if (!caps)
+    return;
+
+  const gchar *name = gst_structure_get_name(gst_caps_get_structure(caps, 0));
+  gst_caps_unref(caps);
+
+  GstPad *queuepad = nullptr;
+  GstElement *queue = gst_element_factory_make("queue", nullptr);
+
+  if (g_str_has_prefix(name, "audio")) {
+    GstElement *convert = gst_element_factory_make("audioconvert", nullptr);
+    GstElement *resample = gst_element_factory_make("audioresample", nullptr);
+    GstElement *sink = gst_element_factory_make("autoaudiosink", nullptr);
+    gst_bin_add_many(GST_BIN(pipe), queue, convert, resample, sink, nullptr);
+    gst_element_sync_state_with_parent(queue);
+    gst_element_sync_state_with_parent(convert);
+    gst_element_sync_state_with_parent(resample);
+    gst_element_sync_state_with_parent(sink);
+    gst_element_link_many(queue, convert, resample, sink, nullptr);
+    queuepad = gst_element_get_static_pad(queue, "sink");
+  }
+  else if (g_str_has_prefix(name, "video")) {
+    GstElement *convert = gst_element_factory_make("videoconvert", nullptr);
+    GstElement *sink = gst_element_factory_make("autovideosink", nullptr);
+    gst_bin_add_many(GST_BIN(pipe), queue, convert, sink, nullptr);
+    gst_element_sync_state_with_parent(queue);
+    gst_element_sync_state_with_parent(convert);
+    gst_element_sync_state_with_parent(sink);
+    gst_element_link_many(queue, convert, sink, nullptr);
+    queuepad = gst_element_get_static_pad(queue, "sink");
+  }
+
+  if (queuepad) {
+    if (GST_PAD_LINK_FAILED(gst_pad_link(newpad, queuepad)))
+      nhlog::ui()->error("WebRTC: Unable to link new pad");
+    gst_object_unref(queuepad);
+  }
+}
+
+}

src/WebRTCSession.h

@@ -0,0 +1,58 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include <QObject>
+
+#include "mtx/events/voip.hpp"
+
+typedef struct _GstElement GstElement;
+
+class WebRTCSession : public QObject
+{
+        Q_OBJECT
+
+public:
+        static WebRTCSession& instance()
+        {
+          static WebRTCSession instance;
+          return instance;
+        }
+
+        bool init(std::string *errorMessage = nullptr);
+
+        bool createOffer();
+        bool acceptOffer(const std::string &sdp);
+        bool acceptAnswer(const std::string &sdp);
+        void acceptICECandidates(const std::vector<mtx::events::msg::CallCandidates::Candidate>&);
+
+        bool isActive() { return pipe_ != nullptr; }
+        bool toggleMuteAudioSrc(bool &isMuted);
+        void end();
+
+        void setStunServer(const std::string &stunServer) {stunServer_ = stunServer;}
+        void setTurnServers(const std::vector<std::string> &uris) {turnServers_ = uris;}
+
+signals:
+        void offerCreated(const std::string &sdp, const std::vector<mtx::events::msg::CallCandidates::Candidate>&);
+        void answerCreated(const std::string &sdp, const std::vector<mtx::events::msg::CallCandidates::Candidate>&);
+        void pipelineChanged(bool started);
+
+private:
+        WebRTCSession() : QObject() {}
+
+        bool initialised_ = false;
+        GstElement *pipe_ = nullptr;
+        GstElement *webrtc_ = nullptr;
+        std::string stunServer_;
+        std::vector<std::string> turnServers_;
+
+        bool startPipeline(int opusPayloadType);
+        bool createPipeline(int opusPayloadType);
+        void addTurnServers();
+
+public:
+        WebRTCSession(WebRTCSession const&) = delete;
+        void operator=(WebRTCSession const&) = delete;
+};

src/dialogs/AcceptCall.cpp

@@ -0,0 +1,53 @@
+#include <QLabel>
+#include <QPushButton>
+#include <QVBoxLayout>
+
+#include "Config.h"
+#include "dialogs/AcceptCall.h"
+
+namespace dialogs {
+
+AcceptCall::AcceptCall(const QString &caller, const QString &displayName, QWidget *parent)
+  : QWidget(parent)
+{
+        setAutoFillBackground(true);
+        setWindowFlags(Qt::Tool | Qt::WindowStaysOnTopHint);
+        setWindowModality(Qt::WindowModal);
+        setAttribute(Qt::WA_DeleteOnClose, true);
+
+        auto layout = new QVBoxLayout(this);
+        layout->setSpacing(conf::modals::WIDGET_SPACING);
+        layout->setMargin(conf::modals::WIDGET_MARGIN);
+
+        auto buttonLayout = new QHBoxLayout();
+        buttonLayout->setSpacing(15);
+        buttonLayout->setMargin(0);
+
+        acceptBtn_ = new QPushButton(tr("Accept"), this);
+        acceptBtn_->setDefault(true);
+        rejectBtn_ = new QPushButton(tr("Reject"), this);
+
+        buttonLayout->addStretch(1);
+        buttonLayout->addWidget(acceptBtn_);
+        buttonLayout->addWidget(rejectBtn_);
+
+        QLabel *label;
+        if (!displayName.isEmpty() && displayName != caller)
+                label = new QLabel("Accept call from " + displayName + " (" + caller + ")?", this);
+        else
+                label = new QLabel("Accept call from " + caller + "?", this);
+
+        layout->addWidget(label);
+        layout->addLayout(buttonLayout);
+
+        connect(acceptBtn_, &QPushButton::clicked, this, [this]() {
+                emit accept();
+                emit close();
+        });
+        connect(rejectBtn_, &QPushButton::clicked, this, [this]() {
+                emit reject();
+                emit close();
+        });
+}
+
+}

src/dialogs/AcceptCall.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <QString>
+#include <QWidget>
+
+class QPushButton;
+
+namespace dialogs {
+
+class AcceptCall : public QWidget
+{
+        Q_OBJECT
+
+public:
+        AcceptCall(const QString &caller, const QString &displayName, QWidget *parent = nullptr);
+
+signals:
+        void accept();
+        void reject();
+
+private:
+        QPushButton *acceptBtn_;
+        QPushButton *rejectBtn_;
+};
+
+}

src/dialogs/PlaceCall.cpp

@@ -0,0 +1,60 @@
+#include <QLabel>
+#include <QPushButton>
+#include <QString>
+#include <QVBoxLayout>
+
+#include "Config.h"
+#include "dialogs/PlaceCall.h"
+
+namespace dialogs {
+
+PlaceCall::PlaceCall(const QString &callee, const QString &displayName, QWidget *parent)
+  : QWidget(parent)
+{
+        setAutoFillBackground(true);
+        setWindowFlags(Qt::Tool | Qt::WindowStaysOnTopHint);
+        setWindowModality(Qt::WindowModal);
+        setAttribute(Qt::WA_DeleteOnClose, true);
+
+        auto layout = new QVBoxLayout(this);
+        layout->setSpacing(conf::modals::WIDGET_SPACING);
+        layout->setMargin(conf::modals::WIDGET_MARGIN);
+
+        auto buttonLayout = new QHBoxLayout();
+        buttonLayout->setSpacing(15);
+        buttonLayout->setMargin(0);
+
+        voiceBtn_ = new QPushButton(tr("Voice Call"), this);
+        voiceBtn_->setDefault(true);
+        videoBtn_  = new QPushButton(tr("Video Call"), this);
+        cancelBtn_ = new QPushButton(tr("Cancel"), this);
+
+        buttonLayout->addStretch(1);
+        buttonLayout->addWidget(voiceBtn_);
+        buttonLayout->addWidget(videoBtn_);
+        buttonLayout->addWidget(cancelBtn_);
+
+        QLabel *label;
+        if (!displayName.isEmpty() && displayName != callee)
+                label = new QLabel("Place a call to " + displayName + " (" + callee + ")?", this);
+        else
+                label = new QLabel("Place a call to " + callee + "?", this);
+
+        layout->addWidget(label);
+        layout->addLayout(buttonLayout);
+
+        connect(voiceBtn_, &QPushButton::clicked, this, [this]() {
+                emit voice();
+                emit close();
+        });
+        connect(videoBtn_, &QPushButton::clicked, this, [this]() {
+                emit video();
+                emit close();
+        });
+        connect(cancelBtn_, &QPushButton::clicked, this, [this]() {
+                emit cancel();
+                emit close();
+        });
+}
+
+}

src/dialogs/PlaceCall.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <QWidget>
+
+class QPushButton;
+class QString;
+
+namespace dialogs {
+
+class PlaceCall : public QWidget
+{
+        Q_OBJECT
+
+public:
+        PlaceCall(const QString &callee, const QString &displayName, QWidget *parent = nullptr);
+
+signals:
+        void voice();
+        void video();
+        void cancel();
+
+private:
+        QPushButton *voiceBtn_;
+        QPushButton *videoBtn_;
+        QPushButton *cancelBtn_;
+};
+
+}

src/timeline/TimelineModel.cpp

@@ -121,6 +121,21 @@ struct RoomEventType
         {
                 return qml_mtx_events::EventType::Redacted;
         }
+        qml_mtx_events::EventType operator()(
+          const mtx::events::Event<mtx::events::msg::CallInvite> &)
+        {
+                return qml_mtx_events::EventType::CallInvite;
+        }
+        qml_mtx_events::EventType operator()(
+          const mtx::events::Event<mtx::events::msg::CallAnswer> &)
+        {
+                return qml_mtx_events::EventType::CallAnswer;
+        }
+        qml_mtx_events::EventType operator()(
+          const mtx::events::Event<mtx::events::msg::CallHangUp> &)
+        {
+                return qml_mtx_events::EventType::CallHangUp;
+        }
         // ::EventType::Type operator()(const Event<mtx::events::msg::Location> &e) { return
         // ::EventType::LocationMessage; }
 };
@@ -538,7 +553,7 @@ TimelineModel::addEvents(const mtx::responses::Timeline &timeline)
         if (timeline.events.empty())
                 return;
 
-        std::vector<QString> ids = internalAddEvents(timeline.events);
+        std::vector<QString> ids = internalAddEvents(timeline.events, true);
 
         if (!ids.empty()) {
                 beginInsertRows(QModelIndex(), 0, static_cast<int>(ids.size() - 1));
@@ -572,6 +587,23 @@ isMessage(const mtx::events::EncryptedEvent<T> &)
         return true;
 }
 
+auto
+isMessage(const mtx::events::RoomEvent<mtx::events::msg::CallInvite> &)
+{
+        return true;
+}
+
+auto
+isMessage(const mtx::events::RoomEvent<mtx::events::msg::CallAnswer> &)
+{
+        return true;
+}
+auto
+isMessage(const mtx::events::RoomEvent<mtx::events::msg::CallHangUp> &)
+{
+        return true;
+}
+
 // Workaround. We also want to see a room at the top, if we just joined it
 auto
 isYourJoin(const mtx::events::StateEvent<mtx::events::state::Member> &e)
@@ -623,7 +655,8 @@ TimelineModel::updateLastMessage()
 
 std::vector<QString>
 TimelineModel::internalAddEvents(
-  const std::vector<mtx::events::collections::TimelineEvents> &timeline)
+  const std::vector<mtx::events::collections::TimelineEvents> &timeline,
+  bool emitCallEvents)
 {
         std::vector<QString> ids;
         for (auto e : timeline) {
@@ -717,6 +750,46 @@ TimelineModel::internalAddEvents(
 
                         if (encInfo)
                                 emit newEncryptedImage(encInfo.value());
+
+                        if (emitCallEvents) {
+                                // event room_id is not set, apparently due to spec bug
+                                if (auto callInvite = std::get_if<
+                                      mtx::events::RoomEvent<mtx::events::msg::CallInvite>>(&e_)) {
+                                        callInvite->room_id = room_id_.toStdString();
+                                        emit newCallEvent(e_);
+                                } else if (std::holds_alternative<mtx::events::RoomEvent<
+                                             mtx::events::msg::CallCandidates>>(e_) ||
+                                           std::holds_alternative<
+                                             mtx::events::RoomEvent<mtx::events::msg::CallAnswer>>( e_) ||
+                                           std::holds_alternative<
+                                             mtx::events::RoomEvent<mtx::events::msg::CallHangUp>>( e_)) {
+                                        emit newCallEvent(e_);
+                                }
+                        }
+                }
+
+                if (std::holds_alternative<
+                      mtx::events::RoomEvent<mtx::events::msg::CallCandidates>>(e)) {
+                        // don't display CallCandidate events to user
+                        events.insert(id, e);
+                        if (emitCallEvents)
+                                emit newCallEvent(e);
+                        continue;
+                }
+
+                if (emitCallEvents) {
+                        // event room_id is not set, apparently due to spec bug
+                        if (auto callInvite =
+                              std::get_if<mtx::events::RoomEvent<mtx::events::msg::CallInvite>>(
+                                &e)) {
+                                callInvite->room_id = room_id_.toStdString();
+                                emit newCallEvent(e);
+                        } else if (std::holds_alternative<
+                                     mtx::events::RoomEvent<mtx::events::msg::CallAnswer>>(e) ||
+                                   std::holds_alternative<
+                                     mtx::events::RoomEvent<mtx::events::msg::CallHangUp>>(e)) {
+                                emit newCallEvent(e);
+                        }
                 }
 
                 this->events.insert(id, e);
@@ -774,7 +847,7 @@ TimelineModel::readEvent(const std::string &id)
 void
 TimelineModel::addBackwardsEvents(const mtx::responses::Messages &msgs)
 {
-        std::vector<QString> ids = internalAddEvents(msgs.chunk);
+        std::vector<QString> ids = internalAddEvents(msgs.chunk, false);
 
         if (!ids.empty()) {
                 beginInsertRows(QModelIndex(),
@@ -1064,14 +1137,17 @@ TimelineModel::markEventsAsRead(const std::vector<QString> &event_ids)
 }
 
 void
-TimelineModel::sendEncryptedMessage(const std::string &txn_id, nlohmann::json content)
+TimelineModel::sendEncryptedMessageEvent(const std::string &txn_id,
+                                         nlohmann::json content,
+                                         mtx::events::EventType eventType)
 {
         const auto room_id = room_id_.toStdString();
 
         using namespace mtx::events;
         using namespace mtx::identifiers;
 
-        json doc = {{"type", "m.room.message"}, {"content", content}, {"room_id", room_id}};
+        json doc = {
+          {"type", mtx::events::to_string(eventType)}, {"content", content}, {"room_id", room_id}};
 
         try {
                 // Check if we have already an outbound megolm session then we can use.
@@ -1375,75 +1451,91 @@ struct SendMessageVisitor
           , model_(model)
         {}
 
-        // Do-nothing operator for all unhandled events
+        template<typename T, mtx::events::EventType Event>
-        template<typename T>
+        void sendRoomEvent(const mtx::events::RoomEvent<T> &msg)
-        void operator()(const mtx::events::Event<T> &)
-        {}
-        // Operator for m.room.message events that contain a msgtype in their content
-        template<typename T,
-                 std::enable_if_t<std::is_same<decltype(T::msgtype), std::string>::value, int> = 0>
-        void operator()(const mtx::events::RoomEvent<T> &msg)
-
         {
                 if (cache::isRoomEncrypted(model_->room_id_.toStdString())) {
                         auto encInfo = mtx::accessors::file(msg);
                         if (encInfo)
                                 emit model_->newEncryptedImage(encInfo.value());
 
-                        model_->sendEncryptedMessage(txn_id_qstr_.toStdString(),
+                        model_->sendEncryptedMessageEvent(
-                                                     nlohmann::json(msg.content));
+                          txn_id_qstr_.toStdString(), nlohmann::json(msg.content), Event);
                 } else {
-                        QString txn_id_qstr  = txn_id_qstr_;
+                        sendUnencryptedRoomEvent<T, Event>(msg);
-                        TimelineModel *model = model_;
-                        http::client()->send_room_message<T, mtx::events::EventType::RoomMessage>(
-                          model->room_id_.toStdString(),
-                          txn_id_qstr.toStdString(),
-                          msg.content,
-                          [txn_id_qstr, model](const mtx::responses::EventId &res,
-                                               mtx::http::RequestErr err) {
-                                  if (err) {
-                                          const int status_code =
-                                            static_cast<int>(err->status_code);
-                                          nhlog::net()->warn("[{}] failed to send message: {} {}",
-                                                             txn_id_qstr.toStdString(),
-                                                             err->matrix_error.error,
-                                                             status_code);
-                                          emit model->messageFailed(txn_id_qstr);
-                                  }
-                                  emit model->messageSent(
-                                    txn_id_qstr, QString::fromStdString(res.event_id.to_string()));
-                          });
                 }
         }
 
+        template<typename T, mtx::events::EventType Event>
+        void sendUnencryptedRoomEvent(const mtx::events::RoomEvent<T> &msg)
+        {
+                QString txn_id_qstr  = txn_id_qstr_;
+                TimelineModel *model = model_;
+                http::client()->send_room_message<T, Event>(
+                  model->room_id_.toStdString(),
+                  txn_id_qstr.toStdString(),
+                  msg.content,
+                  [txn_id_qstr, model](const mtx::responses::EventId &res,
+                                       mtx::http::RequestErr err) {
+                          if (err) {
+                                  const int status_code = static_cast<int>(err->status_code);
+                                  nhlog::net()->warn("[{}] failed to send message: {} {}",
+                                                     txn_id_qstr.toStdString(),
+                                                     err->matrix_error.error,
+                                                     status_code);
+                                  emit model->messageFailed(txn_id_qstr);
+                          }
+                          emit model->messageSent(txn_id_qstr,
+                                                  QString::fromStdString(res.event_id.to_string()));
+                  });
+        }
+
+        // Do-nothing operator for all unhandled events
+        template<typename T>
+        void operator()(const mtx::events::Event<T> &)
+        {}
+
+        // Operator for m.room.message events that contain a msgtype in their content
+        template<typename T,
+                 std::enable_if_t<std::is_same<decltype(T::msgtype), std::string>::value, int> = 0>
+        void operator()(const mtx::events::RoomEvent<T> &msg)
+        {
+                sendRoomEvent<T, mtx::events::EventType::RoomMessage>(msg);
+        }
+
         // Special operator for reactions, which are a type of m.room.message, but need to be
         // handled distinctly for their differences from normal room messages.  Specifically,
         // reactions need to have the relation outside of ciphertext, or synapse / the homeserver
         // cannot handle it correctly.  See the MSC for more details:
         // https://github.com/matrix-org/matrix-doc/blob/matthew/msc1849/proposals/1849-aggregations.md#end-to-end-encryption
         void operator()(const mtx::events::RoomEvent<mtx::events::msg::Reaction> &msg)
-
         {
-                QString txn_id_qstr  = txn_id_qstr_;
+                sendUnencryptedRoomEvent<mtx::events::msg::Reaction,
-                TimelineModel *model = model_;
+                                         mtx::events::EventType::Reaction>(msg);
-                http::client()
+        }
-                  ->send_room_message<mtx::events::msg::Reaction, mtx::events::EventType::Reaction>(
+
-                    model->room_id_.toStdString(),
+        void operator()(const mtx::events::RoomEvent<mtx::events::msg::CallInvite> &event)
-                    txn_id_qstr.toStdString(),
+        {
-                    msg.content,
+                sendRoomEvent<mtx::events::msg::CallInvite, mtx::events::EventType::CallInvite>(
-                    [txn_id_qstr, model](const mtx::responses::EventId &res,
+                  event);
-                                         mtx::http::RequestErr err) {
+        }
-                            if (err) {
+
-                                    const int status_code = static_cast<int>(err->status_code);
+        void operator()(const mtx::events::RoomEvent<mtx::events::msg::CallCandidates> &event)
-                                    nhlog::net()->warn("[{}] failed to send message: {} {}",
+        {
-                                                       txn_id_qstr.toStdString(),
+                sendRoomEvent<mtx::events::msg::CallCandidates,
-                                                       err->matrix_error.error,
+                              mtx::events::EventType::CallCandidates>(event);
-                                                       status_code);
+        }
-                                    emit model->messageFailed(txn_id_qstr);
+
-                            }
+        void operator()(const mtx::events::RoomEvent<mtx::events::msg::CallAnswer> &event)
-                            emit model->messageSent(
+        {
-                              txn_id_qstr, QString::fromStdString(res.event_id.to_string()));
+                sendRoomEvent<mtx::events::msg::CallAnswer, mtx::events::EventType::CallAnswer>(
-                    });
+                  event);
+        }
+
+        void operator()(const mtx::events::RoomEvent<mtx::events::msg::CallHangUp> &event)
+        {
+                sendRoomEvent<mtx::events::msg::CallHangUp, mtx::events::EventType::CallHangUp>(
+                  event);
         }
 
         QString txn_id_qstr_;
@@ -1467,14 +1559,13 @@ TimelineModel::addPendingMessage(mtx::events::collections::TimelineEvents event)
 {
         std::visit(
           [](auto &msg) {
-                  msg.type             = mtx::events::EventType::RoomMessage;
                   msg.event_id         = http::client()->generate_txn_id();
                   msg.sender           = http::client()->user_id().to_string();
                   msg.origin_server_ts = QDateTime::currentMSecsSinceEpoch();
           },
           event);
 
-        internalAddEvents({event});
+        internalAddEvents({event}, false);
 
         QString txn_id_qstr = QString::fromStdString(mtx::accessors::event_id(event));
         pending.push_back(txn_id_qstr);

src/timeline/TimelineModel.h

@@ -36,6 +36,12 @@ enum EventType
         Aliases,
         /// m.room.avatar
         Avatar,
+        /// m.call.invite
+        CallInvite,
+        /// m.call.answer
+        CallAnswer,
+        /// m.call.hangup
+        CallHangUp,
         /// m.room.canonical_alias
         CanonicalAlias,
         /// m.room.create
@@ -200,7 +206,7 @@ public:
         void updateLastMessage();
         void addEvents(const mtx::responses::Timeline &events);
         template<class T>
-        void sendMessage(const T &msg);
+        void sendMessageEvent(const T &content, mtx::events::EventType eventType);
         RelatedInfo relatedInfo(QString id);
 
 public slots:
@@ -255,13 +261,17 @@ signals:
         void typingUsersChanged(std::vector<QString> users);
         void replyChanged(QString reply);
         void paginationInProgressChanged(const bool);
+        void newCallEvent(const mtx::events::collections::TimelineEvents &event);
 
 private:
         DecryptionResult decryptEvent(
           const mtx::events::EncryptedEvent<mtx::events::msg::Encrypted> &e) const;
         std::vector<QString> internalAddEvents(
-          const std::vector<mtx::events::collections::TimelineEvents> &timeline);
+          const std::vector<mtx::events::collections::TimelineEvents> &timeline,
-        void sendEncryptedMessage(const std::string &txn_id, nlohmann::json content);
+          bool emitCallEvents);
+        void sendEncryptedMessageEvent(const std::string &txn_id,
+                                       nlohmann::json content,
+                                       mtx::events::EventType);
         void handleClaimedKeys(std::shared_ptr<StateKeeper> keeper,
                                const std::map<std::string, std::string> &room_key,
                                const std::map<std::string, DevicePublicKeys> &pks,
@@ -296,9 +306,10 @@ private:
 
 template<class T>
 void
-TimelineModel::sendMessage(const T &msg)
+TimelineModel::sendMessageEvent(const T &content, mtx::events::EventType eventType)
 {
         mtx::events::RoomEvent<T> msgCopy = {};
-        msgCopy.content                   = msg;
+        msgCopy.content                   = content;
+        msgCopy.type                      = eventType;
         emit newMessageToSend(msgCopy);
 }

src/timeline/TimelineViewManager.cpp

@@ -3,8 +3,10 @@
 #include <QMetaType>
 #include <QPalette>
 #include <QQmlContext>
+#include <QString>
 
 #include "BlurhashProvider.h"
+#include "CallManager.h"
 #include "ChatPage.h"
 #include "ColorImageProvider.h"
 #include "DelegateChooser.h"
@@ -71,10 +73,13 @@ TimelineViewManager::userStatus(QString id) const
         return QString::fromStdString(cache::statusMessage(id.toStdString()));
 }
 
-TimelineViewManager::TimelineViewManager(QSharedPointer<UserSettings> userSettings, QWidget *parent)
+TimelineViewManager::TimelineViewManager(QSharedPointer<UserSettings> userSettings,
+                                         CallManager *callManager,
+                                         QWidget *parent)
   : imgProvider(new MxcImageProvider())
   , colorImgProvider(new ColorImageProvider())
   , blurhashProvider(new BlurhashProvider())
+  , callManager_(callManager)
   , settings(userSettings)
 {
         qmlRegisterUncreatableMetaObject(qml_mtx_events::staticMetaObject,
@@ -139,7 +144,17 @@ TimelineViewManager::sync(const mtx::responses::Rooms &rooms)
                 // addRoom will only add the room, if it doesn't exist
                 addRoom(QString::fromStdString(room_id));
                 const auto &room_model = models.value(QString::fromStdString(room_id));
+                if (!isInitialSync_)
+                        connect(room_model.data(),
+                                &TimelineModel::newCallEvent,
+                                callManager_,
+                                &CallManager::syncEvent);
                 room_model->addEvents(room.timeline);
+                if (!isInitialSync_)
+                        disconnect(room_model.data(),
+                                   &TimelineModel::newCallEvent,
+                                   callManager_,
+                                   &CallManager::syncEvent);
 
                 if (ChatPage::instance()->userSettings()->typingNotifications()) {
                         std::vector<QString> typing;
@@ -285,7 +300,7 @@ TimelineViewManager::queueTextMessage(const QString &msg)
                 timeline_->resetReply();
         }
 
-        timeline_->sendMessage(text);
+        timeline_->sendMessageEvent(text, mtx::events::EventType::RoomMessage);
 }
 
 void
@@ -307,7 +322,7 @@ TimelineViewManager::queueEmoteMessage(const QString &msg)
         }
 
         if (timeline_)
-                timeline_->sendMessage(emote);
+                timeline_->sendMessageEvent(emote, mtx::events::EventType::RoomMessage);
 }
 
 void
@@ -337,7 +352,7 @@ TimelineViewManager::queueReactionMessage(const QString &roomId,
         reaction.relates_to.key      = reactionKey.toStdString();
 
         auto model = models.value(roomId);
-        model->sendMessage(reaction);
+        model->sendMessageEvent(reaction, mtx::events::EventType::RoomMessage);
 }
 
 void
@@ -366,7 +381,7 @@ TimelineViewManager::queueImageMessage(const QString &roomid,
                 model->resetReply();
         }
 
-        model->sendMessage(image);
+        model->sendMessageEvent(image, mtx::events::EventType::RoomMessage);
 }
 
 void
@@ -391,7 +406,7 @@ TimelineViewManager::queueFileMessage(
                 model->resetReply();
         }
 
-        model->sendMessage(file);
+        model->sendMessageEvent(file, mtx::events::EventType::RoomMessage);
 }
 
 void
@@ -415,7 +430,7 @@ TimelineViewManager::queueAudioMessage(const QString &roomid,
                 model->resetReply();
         }
 
-        model->sendMessage(audio);
+        model->sendMessageEvent(audio, mtx::events::EventType::RoomMessage);
 }
 
 void
@@ -439,5 +454,34 @@ TimelineViewManager::queueVideoMessage(const QString &roomid,
                 model->resetReply();
         }
 
-        model->sendMessage(video);
+        model->sendMessageEvent(video, mtx::events::EventType::RoomMessage);
+}
+
+void
+TimelineViewManager::queueCallMessage(const QString &roomid,
+                                      const mtx::events::msg::CallInvite &callInvite)
+{
+        models.value(roomid)->sendMessageEvent(callInvite, mtx::events::EventType::CallInvite);
+}
+
+void
+TimelineViewManager::queueCallMessage(const QString &roomid,
+                                      const mtx::events::msg::CallCandidates &callCandidates)
+{
+        models.value(roomid)->sendMessageEvent(callCandidates,
+                                               mtx::events::EventType::CallCandidates);
+}
+
+void
+TimelineViewManager::queueCallMessage(const QString &roomid,
+                                      const mtx::events::msg::CallAnswer &callAnswer)
+{
+        models.value(roomid)->sendMessageEvent(callAnswer, mtx::events::EventType::CallAnswer);
+}
+
+void
+TimelineViewManager::queueCallMessage(const QString &roomid,
+                                      const mtx::events::msg::CallHangUp &callHangUp)
+{
+        models.value(roomid)->sendMessageEvent(callHangUp, mtx::events::EventType::CallHangUp);
 }

src/timeline/TimelineViewManager.h

@@ -18,6 +18,7 @@
 
 class MxcImageProvider;
 class BlurhashProvider;
+class CallManager;
 class ColorImageProvider;
 class UserSettings;
 
@@ -31,7 +32,9 @@ class TimelineViewManager : public QObject
           bool isInitialSync MEMBER isInitialSync_ READ isInitialSync NOTIFY initialSyncChanged)
 
 public:
-        TimelineViewManager(QSharedPointer<UserSettings> userSettings, QWidget *parent = nullptr);
+        TimelineViewManager(QSharedPointer<UserSettings> userSettings,
+                            CallManager *callManager,
+                            QWidget *parent = nullptr);
         QWidget *getWidget() const { return container; }
 
         void sync(const mtx::responses::Rooms &rooms);
@@ -96,6 +99,11 @@ public slots:
                                const QString &url,
                                const QString &mime,
                                uint64_t dsize);
+        void queueCallMessage(const QString &roomid, const mtx::events::msg::CallInvite &);
+        void queueCallMessage(const QString &roomid, const mtx::events::msg::CallCandidates &);
+        void queueCallMessage(const QString &roomid, const mtx::events::msg::CallAnswer &);
+        void queueCallMessage(const QString &roomid, const mtx::events::msg::CallHangUp &);
+
         void updateEncryptedDescriptions();
 
 private:
@@ -111,7 +119,8 @@ private:
         BlurhashProvider *blurhashProvider;
 
         QHash<QString, QSharedPointer<TimelineModel>> models;
-        TimelineModel *timeline_ = nullptr;
+        TimelineModel *timeline_  = nullptr;
+        CallManager *callManager_ = nullptr;
 
         bool isInitialSync_ = true;