More work

Simplifies the code quite a bit
WIP: Renegotiate to enable camera

CMakeLists.txt

@@ -145,6 +145,14 @@ if(ANDROID)
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/android/version.gradle.in ${CMAKE_BINARY_DIR}/version.gradle)
 endif()
 
+include(FindPkgConfig)
+pkg_check_modules(GSTREAMER IMPORTED_TARGET gstreamer-sdp-1.0>1.18 gstreamer-webrtc-1.0>=1.18)
+if (TARGET PkgConfig::GSTREAMER)
+    add_feature_info(voip ON "GStreamer found. Call support is enabled.")
+else()
+    add_feature_info(voip OFF "GStreamer not found. Call support is disabled.")
+endif()
+
 ki18n_install(po)
 
 install(FILES org.kde.neochat.desktop DESTINATION ${KDE_INSTALL_APPDIR})

src/CMakeLists.txt

@@ -65,6 +65,12 @@ ecm_qt_declare_logging_category(neochat
     DEFAULT_SEVERITY Info
 )
 
+ecm_qt_declare_logging_category(neochat
+    HEADER "voip_logging.h"
+    IDENTIFIER "voip"
+    CATEGORY_NAME "org.kde.neochat.voip"
+)
+
 add_executable(neochat-app
     main.cpp
     res.qrc
@@ -111,6 +117,20 @@ endif()
 
 target_include_directories(neochat PRIVATE ${CMAKE_BINARY_DIR})
 target_link_libraries(neochat PUBLIC Qt::Core Qt::Quick Qt::Qml Qt::Gui Qt::Multimedia Qt::Network Qt::QuickControls2 KF${QT_MAJOR_VERSION}::I18n KF${QT_MAJOR_VERSION}::Kirigami2 KF${QT_MAJOR_VERSION}::Notifications KF${QT_MAJOR_VERSION}::ConfigCore KF${QT_MAJOR_VERSION}::ConfigGui KF${QT_MAJOR_VERSION}::CoreAddons KF${QT_MAJOR_VERSION}::SonnetCore  KF${QT_MAJOR_VERSION}::ItemModels Quotient${QUOTIENT_SUFFIX} cmark::cmark ${QTKEYCHAIN_LIBRARIES} QCoro::Core)
+
+if (TARGET PkgConfig::GSTREAMER)
+    target_link_libraries(neochat PUBLIC PkgConfig::GSTREAMER)
+    target_sources(neochat PRIVATE
+        call/callmanager.cpp
+        call/callsession.cpp
+        call/audiosources.cpp
+        call/videosources.cpp
+        call/devicemonitor.cpp
+        models/callparticipantsmodel.cpp
+        call/callparticipant.cpp
+    )
+    target_compile_definitions(neochat PUBLIC GSTREAMER_AVAILABLE)
+endif()
 kconfig_add_kcfg_files(neochat GENERATE_MOC neochatconfig.kcfgc)
 
 if(NEOCHAT_FLATPAK)

src/call/audiosources.cpp

@@ -0,0 +1,99 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#include "audiosources.h"
+
+#include <gst/gst.h>
+
+#include <QDebug>
+#include <QString>
+
+#include "devicemonitor.h"
+
+#include "neochatconfig.h"
+
+int AudioSources::rowCount(const QModelIndex &parent) const
+{
+    Q_UNUSED(parent);
+    return DeviceMonitor::instance().audioSources().size();
+}
+
+QVariant AudioSources::data(const QModelIndex &index, int role) const
+{
+    if (index.row() >= DeviceMonitor::instance().audioSources().size()) {
+        return QVariant(QStringLiteral("DEADBEEF"));
+    }
+    if (role == TitleRole) {
+        return DeviceMonitor::instance().audioSources()[index.row()]->title;
+    }
+    return QVariant();
+}
+
+QHash<int, QByteArray> AudioSources::roleNames() const
+{
+    return {
+        {TitleRole, "title"},
+    };
+}
+
+AudioSources::AudioSources()
+    : QAbstractListModel()
+{
+    connect(&DeviceMonitor::instance(), &DeviceMonitor::audioSourceAdded, this, [this]() {
+        beginResetModel();
+        endResetModel();
+        Q_EMIT currentIndexChanged();
+    });
+    connect(&DeviceMonitor::instance(), &DeviceMonitor::audioSourceRemoved, this, [this]() {
+        beginResetModel();
+        endResetModel();
+        Q_EMIT currentIndexChanged();
+    });
+}
+
+GstDevice *AudioSources::currentDevice() const
+{
+    const auto config = NeoChatConfig::self();
+    const QString name = config->microphone();
+    for (const auto &audioSource : DeviceMonitor::instance().audioSources()) {
+        if (audioSource->title == name) {
+            qDebug() << "WebRTC: microphone:" << name;
+            return audioSource->device;
+        }
+    }
+    return DeviceMonitor::instance().audioSources()[0]->device;
+}
+
+void AudioSources::setCurrentIndex(int index) const
+{
+    if (DeviceMonitor::instance().audioSources().size() == 0) {
+        return;
+    }
+    NeoChatConfig::setMicrophone(DeviceMonitor::instance().audioSources()[index]->title);
+    NeoChatConfig::self()->save();
+}
+
+int AudioSources::currentIndex() const
+{
+    const auto config = NeoChatConfig::self();
+    const QString name = config->microphone();
+    if (name.isEmpty()) {
+        return getDefaultDeviceIndex();
+    }
+    for (auto i = 0; i < DeviceMonitor::instance().audioSources().size(); i++) {
+        if (DeviceMonitor::instance().audioSources()[i]->title == name) {
+            return i;
+        }
+    }
+    return 0;
+}
+
+int AudioSources::getDefaultDeviceIndex() const
+{
+    for (auto i = 0; i < DeviceMonitor::instance().audioSources().size(); i++) {
+        if (DeviceMonitor::instance().audioSources()[i]->isDefault) {
+            return i;
+        }
+    }
+    return 0;
+}

src/call/audiosources.h

@@ -0,0 +1,41 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#pragma once
+
+#include <QtCore/QAbstractListModel>
+
+#include <gst/gst.h>
+
+class AudioSources : public QAbstractListModel
+{
+    Q_OBJECT
+    Q_PROPERTY(int currentIndex READ currentIndex WRITE setCurrentIndex NOTIFY currentIndexChanged)
+
+public:
+    enum Roles {
+        TitleRole = Qt::UserRole + 1,
+    };
+
+    static AudioSources &instance()
+    {
+        static AudioSources _instance;
+        return _instance;
+    }
+
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    QHash<int, QByteArray> roleNames() const override;
+
+    GstDevice *currentDevice() const;
+
+    void setCurrentIndex(int index) const;
+    int currentIndex() const;
+
+Q_SIGNALS:
+    void currentIndexChanged();
+
+private:
+    AudioSources();
+    int getDefaultDeviceIndex() const;
+};

src/call/calldevices.cpp

@@ -0,0 +1,199 @@
+// SPDX-FileCopyrightText: 2021 Nheko Contributors
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-FileCopyrightText: 2021 Carl Schwan <carl@carlschwan.eu>
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "calldevices.h"
+#include "audiodevicesmodel.h"
+#include "neochatconfig.h"
+#include "videodevicesmodel.h"
+#include <QStringView>
+#include <cstring>
+#include <optional>
+
+#include "voiplogging.h"
+
+#ifdef GSTREAMER_AVAILABLE
+extern "C" {
+#include "gst/gst.h"
+}
+#endif
+
+#ifdef GSTREAMER_AVAILABLE
+
+CallDevices::CallDevices()
+    : QObject()
+    , m_audioDevicesModel(new AudioDevicesModel(this))
+    , m_videoDevicesModel(new VideoDevicesModel(this))
+{
+    init();
+}
+
+AudioDevicesModel *CallDevices::audioDevicesModel() const
+{
+    return m_audioDevicesModel;
+}
+
+VideoDevicesModel *CallDevices::videoDevicesModel() const
+{
+    return m_videoDevicesModel;
+}
+
+void CallDevices::addDevice(GstDevice *device)
+{
+    if (!device)
+        return;
+
+    gchar *type = gst_device_get_device_class(device);
+    bool isVideo = !std::strncmp(type, "Video", 5);
+    g_free(type);
+    if (isVideo) {
+        m_videoDevicesModel->addDevice(device);
+        m_videoDevicesModel->setDefaultDevice();
+    } else {
+        m_audioDevicesModel->addDevice(device);
+        m_audioDevicesModel->setDefaultDevice();
+    }
+}
+
+void CallDevices::removeDevice(GstDevice *device, bool changed)
+{
+    if (device) {
+        if (m_audioDevicesModel->removeDevice(device, changed) || m_videoDevicesModel->removeDevice(device, changed))
+            return;
+    }
+}
+
+namespace
+{
+gboolean newBusMessage(GstBus *bus, GstMessage *msg, gpointer user_data)
+{
+    Q_UNUSED(bus)
+    Q_UNUSED(user_data)
+
+    switch (GST_MESSAGE_TYPE(msg)) {
+    case GST_MESSAGE_DEVICE_ADDED: {
+        GstDevice *device;
+        gst_message_parse_device_added(msg, &device);
+        CallDevices::instance().addDevice(device);
+        Q_EMIT CallDevices::instance().devicesChanged();
+        break;
+    }
+    case GST_MESSAGE_DEVICE_REMOVED: {
+        GstDevice *device;
+        gst_message_parse_device_removed(msg, &device);
+        CallDevices::instance().removeDevice(device, false);
+        Q_EMIT CallDevices::instance().devicesChanged();
+        break;
+    }
+    case GST_MESSAGE_DEVICE_CHANGED: {
+        GstDevice *device;
+        GstDevice *oldDevice;
+        gst_message_parse_device_changed(msg, &device, &oldDevice);
+        CallDevices::instance().removeDevice(oldDevice, true);
+        CallDevices::instance().addDevice(device);
+        Q_EMIT CallDevices::instance().devicesChanged();
+        break;
+    }
+    default:
+        break;
+    }
+    return true;
+}
+}
+
+void CallDevices::init()
+{
+    static GstDeviceMonitor *monitor = nullptr;
+    if (!monitor) {
+        monitor = gst_device_monitor_new();
+        Q_ASSERT(monitor);
+        GstCaps *caps = gst_caps_new_empty_simple("audio/x-raw");
+        gst_device_monitor_add_filter(monitor, "Audio/Source", caps);
+        gst_device_monitor_add_filter(monitor, "Audio/Duplex", caps);
+        gst_caps_unref(caps);
+        caps = gst_caps_new_empty_simple("video/x-raw");
+        gst_device_monitor_add_filter(monitor, "Video/Source", caps);
+        gst_device_monitor_add_filter(monitor, "Video/Duplex", caps);
+        gst_caps_unref(caps);
+
+        GstBus *bus = gst_device_monitor_get_bus(monitor);
+        gst_bus_add_watch(bus, newBusMessage, nullptr);
+        gst_object_unref(bus);
+        if (!gst_device_monitor_start(monitor)) {
+            qCCritical(voip) << "Failed to start device monitor";
+            return;
+        } else {
+            qCDebug(voip) << "Device monitor started";
+        }
+    }
+}
+
+bool CallDevices::hasMicrophone() const
+{
+    return m_audioDevicesModel->hasMicrophone();
+}
+
+bool CallDevices::hasCamera() const
+{
+    return m_videoDevicesModel->hasCamera();
+}
+
+QStringList CallDevices::resolutions(const QString &cameraName) const
+{
+    return m_videoDevicesModel->resolutions(cameraName);
+}
+
+QStringList CallDevices::frameRates(const QString &cameraName, const QString &resolution) const
+{
+    if (auto s = m_videoDevicesModel->getVideoSource(cameraName); s) {
+        if (auto it = std::find_if(s->caps.cbegin(),
+                                   s->caps.cend(),
+                                   [&](const auto &c) {
+                                       return c.resolution == resolution;
+                                   });
+            it != s->caps.cend())
+            return it->frameRates;
+    }
+    return {};
+}
+
+GstDevice *CallDevices::audioDevice() const
+{
+    return m_audioDevicesModel->currentDevice();
+}
+
+GstDevice *CallDevices::videoDevice(QPair<int, int> &resolution, QPair<int, int> &frameRate) const
+{
+    return m_videoDevicesModel->currentDevice(resolution, frameRate);
+}
+
+#else
+
+bool CallDevices::hasMicrophone() const
+{
+    return false;
+}
+
+bool CallDevices::hasCamera() const
+{
+    return false;
+}
+
+QStringList CallDevices::names(bool, const QString &) const
+{
+    return {};
+}
+
+QStringList CallDevices::resolutions(const QString &) const
+{
+    return {};
+}
+
+QStringList CallDevices::frameRates(const QString &, const QString &) const
+{
+    return {};
+}
+
+#endif

src/call/calldevices.h

@@ -0,0 +1,64 @@
+// SPDX-FileCopyrightText: 2021 Contributors
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-FileCopyrightText: 2021 Carl Schwan <carl@carlschwan.eu>
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include <QObject>
+
+typedef struct _GstDevice GstDevice;
+
+class CallDevices;
+class AudioDevicesModel;
+class VideoDevicesModel;
+
+class CallDevices : public QObject
+{
+    Q_OBJECT
+
+    Q_PROPERTY(AudioDevicesModel *audioDevices READ audioDevicesModel CONSTANT);
+    Q_PROPERTY(VideoDevicesModel *videoDevices READ videoDevicesModel CONSTANT);
+
+public:
+    static CallDevices &instance()
+    {
+        static CallDevices instance;
+        return instance;
+    }
+    CallDevices(CallDevices const &) = delete;
+    void operator=(CallDevices const &) = delete;
+
+    bool hasMicrophone() const;
+    bool hasCamera() const;
+    QStringList names(bool isVideo, const QString &defaultDevice) const;
+    QStringList resolutions(const QString &cameraName) const;
+    QStringList frameRates(const QString &cameraName, const QString &resolution) const;
+
+    AudioDevicesModel *audioDevicesModel() const;
+    VideoDevicesModel *videoDevicesModel() const;
+
+    void addDevice(GstDevice *device);
+    void removeDevice(GstDevice *device, bool changed);
+
+Q_SIGNALS:
+    void devicesChanged();
+
+private:
+    CallDevices();
+
+    void init();
+    GstDevice *audioDevice() const;
+    GstDevice *videoDevice(QPair<int, int> &resolution, QPair<int, int> &frameRate) const;
+
+    AudioDevicesModel *m_audioDevicesModel;
+    VideoDevicesModel *m_videoDevicesModel;
+
+    friend class CallSession;
+    friend class Audio;
+};

src/call/callmanager.cpp

@@ -0,0 +1,617 @@
+// SPDX-FileCopyrightText: 2020-2021 Nheko Authors
+// SPDX-FileCopyrightText: 2021-2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "callmanager.h"
+
+#include "controller.h"
+
+#include <gst/gst.h>
+
+#include "voiplogging.h"
+#include <KLocalizedString>
+#include <QDateTime>
+
+#include <QMediaPlaylist>
+#include <QMimeDatabase>
+#include <qcoro/qcorosignal.h>
+#include <qt_connection_util.h>
+
+#include "neochatconfig.h"
+
+#define CALL_VERSION "1"
+
+CallManager::CallManager()
+{
+    init();
+    connect(&Controller::instance(), &Controller::activeConnectionChanged, this, [this] {
+        updateTurnServers();
+    });
+}
+
+QCoro::Task<void> CallManager::updateTurnServers()
+{
+    if (m_cachedTurnUrisValidUntil > QDateTime::currentDateTime()) {
+        co_return;
+    }
+    Controller::instance().activeConnection()->getTurnServers();
+
+    auto servers = co_await qCoro(Controller::instance().activeConnection(), &Connection::turnServersChanged);
+    m_cachedTurnUrisValidUntil = QDateTime::currentDateTime().addSecs(servers["ttl"].toInt());
+
+    const auto password = servers["password"].toString();
+    const auto username = servers["username"].toString();
+    const auto uris = servers["uris"].toArray();
+
+    m_cachedTurnUris.clear();
+    for (const auto &u : uris) {
+        QString uri = u.toString();
+        auto c = uri.indexOf(':');
+        if (c == -1) {
+            qCWarning(voip) << "Invalid TURN URI:" << uri;
+            continue;
+        }
+        QString scheme = uri.left(c);
+        if (scheme != "turn" && scheme != "turns") {
+            qCWarning(voip) << "Invalid TURN scheme:" << scheme;
+            continue;
+        }
+        m_cachedTurnUris += QStringLiteral("%1://%2:%3@%4").arg(scheme, QUrl::toPercentEncoding(username), QUrl::toPercentEncoding(password), uri.mid(c + 1));
+    }
+}
+
+QString CallManager::callId() const
+{
+    return m_callId;
+}
+
+void CallManager::handleCallEvent(NeoChatRoom *room, const Quotient::RoomEvent *event)
+{
+    if (const auto &inviteEvent = eventCast<const CallInviteEvent>(event)) {
+        handleInvite(room, inviteEvent);
+    } else if (const auto &hangupEvent = eventCast<const CallHangupEvent>(event)) {
+        handleHangup(room, hangupEvent);
+    } else if (const auto &candidatesEvent = eventCast<const CallCandidatesEvent>(event)) {
+        handleCandidates(room, candidatesEvent);
+    } else if (const auto &answerEvent = eventCast<const CallAnswerEvent>(event)) {
+        handleAnswer(room, answerEvent);
+    } else if (const auto &negotiateEvent = eventCast<const CallNegotiateEvent>(event)) {
+        handleNegotiate(room, negotiateEvent);
+    }
+}
+
+void CallManager::checkStartCall()
+{
+    if ((m_incomingCandidates.isEmpty() && !m_incomingSdp.contains("candidates"_ls)) || m_incomingSdp.isEmpty()) {
+        qCDebug(voip) << "Not ready to start this call yet";
+        return;
+    }
+    m_session->acceptAnswer(m_incomingSdp, m_incomingCandidates, m_remoteUser->id());
+    m_incomingCandidates.clear();
+    m_incomingSdp.clear();
+    setGlobalState(ACTIVE);
+}
+
+void CallManager::handleAnswer(NeoChatRoom *room, const Quotient::CallAnswerEvent *event)
+{
+    if (globalState() != OUTGOING) {
+        qCDebug(voip) << "Ignoring answer while in state" << globalState();
+        return;
+    }
+
+    if (event->callId() != m_callId) {
+        qCDebug(voip) << "Ignoring answer for unknown call id" << event->callId() << ". Our call id is" << m_callId;
+        return;
+    }
+
+    if (event->senderId() == room->localUser()->id() && partyId() == event->contentJson()["party_id"].toString()) {
+        qCDebug(voip) << "Ignoring echo for answer";
+        return;
+    }
+
+    if (event->senderId() == room->localUser()->id()) {
+        qCDebug(voip) << "Call was accepted on a different device";
+        // Show the user that call was accepted on a different device
+        // Stop ringing
+        return;
+    }
+
+    // TODO handle that MSC wrt to accepting on other devices
+    m_session->setMetadata(event->contentJson()["org.matrix.msc3077.sdp_stream_metadata"].toObject());
+    m_remotePartyId = event->contentJson()["party_id"].toString();
+    m_incomingSdp = event->sdp();
+    checkStartCall();
+}
+
+void CallManager::handleCandidates(NeoChatRoom *room, const Quotient::CallCandidatesEvent *event)
+{
+    // TODO what if candidates come before invite? this looks wrong
+    if (globalState() == IDLE) {
+        qCDebug(voip) << "Ignoring candidates in state" << globalState();
+        return;
+    }
+
+    if (event->senderId() == room->localUser()->id()) {
+        qCDebug(voip) << "Ignoring candidates sent by ourself";
+        return;
+    }
+
+    if (globalState() == ACTIVE) {
+        QVector<Candidate> candidates;
+        for (const auto &candidate : event->candidates()) {
+            candidates += Candidate{candidate.toObject()["candidate"].toString(),
+                                    candidate.toObject()["sdpMLineIndex"].toInt(),
+                                    candidate.toObject()["sdpMid"].toString()};
+        }
+        m_session->acceptCandidates(candidates);
+        return;
+    }
+
+    qCDebug(voip) << "Storing" << event->candidates().size() << "incoming candidates";
+    for (const auto &candidate : event->candidates()) {
+        m_incomingCandidates +=
+            Candidate{candidate.toObject()["candidate"].toString(), candidate.toObject()["sdpMLineIndex"].toInt(), candidate.toObject()["sdpMid"].toString()};
+    }
+
+    if (globalState() == OUTGOING) {
+        checkStartCall();
+    }
+}
+
+void CallManager::handleInvite(NeoChatRoom *room, const Quotient::CallInviteEvent *event)
+{
+    if (event->senderId() == room->localUser()->id()) {
+        qCDebug(voip) << "Igoring invite sent by ourself";
+        return;
+    }
+    if (globalState() != IDLE) {
+        // TODO handle glare
+        qCDebug(voip) << "Ignoring invite while already in a call";
+        return;
+    }
+
+    if (event->originTimestamp() < QDateTime::currentDateTime().addSecs(-60)) {
+        qCDebug(voip) << "Ignoring outdated invite; sent at:" << event->originTimestamp() << "current:" << QDateTime::currentDateTime();
+        return;
+    }
+
+    setGlobalState(INCOMING);
+
+    m_incomingSdp = event->sdp();
+    setRemoteUser(dynamic_cast<NeoChatUser *>(room->user(event->senderId())));
+    setRoom(room);
+    setCallId(event->callId());
+    setPartyId(generatePartyId());
+    m_remotePartyId = event->contentJson()["party_id"].toString();
+    setLifetime(event->lifetime());
+    Q_EMIT incomingCall(remoteUser(), room, event->lifetime(), callId());
+    ring(event->lifetime());
+}
+
+void CallManager::handleNegotiate(NeoChatRoom *room, const Quotient::CallNegotiateEvent *event)
+{
+    Q_UNUSED(room);
+    if (event->callId() != m_callId) {
+        qCDebug(voip) << "Ignoring negotiate for unknown call id" << event->callId() << ". Our call id is" << m_callId;
+        return;
+    }
+    if (event->partyId() != m_remotePartyId) {
+        qCDebug(voip) << "Ignoring negotiate for unknown party id" << event->partyId() << ". Remote party id is" << m_remotePartyId;
+        return;
+    }
+    if (event->senderId() != m_remoteUser->id()) {
+        qCDebug(voip) << "Ignoring negotiate for unknown user id" << event->senderId() << ". Remote user id is" << m_remoteUser->id();
+        return;
+    }
+    // TODO DUPLICATES FFS
+    m_session->setMetadata(event->contentJson()["org.matrix.msc3077.sdp_stream_metadata"].toObject());
+    m_session->renegotiateOffer(event->sdp(), m_remoteUser->id(), event->contentJson()["description"]["type"] == QStringLiteral("answer"));
+}
+
+void CallManager::ring(int lifetime)
+{
+    // TODO put a better default ringtone in the kcfg
+    // TODO which one? ship one? plasma-mobile-sounds?
+    if (!QFileInfo::exists(NeoChatConfig::ringtone())) {
+        qCWarning(voip) << "Ringtone file doesn't exist. Not audibly ringing";
+        return;
+    }
+    auto ringtone = QUrl::fromLocalFile(NeoChatConfig::ringtone());
+    m_playlist.setPlaybackMode(QMediaPlaylist::Loop);
+    m_playlist.clear();
+    m_ringPlayer.setPlaylist(&m_playlist);
+    m_playlist.addMedia(ringtone);
+    m_ringPlayer.play();
+    QTimer::singleShot(lifetime, this, [this]() {
+        stopRinging();
+        Q_EMIT callEnded();
+    });
+}
+
+void CallManager::stopRinging()
+{
+    m_ringPlayer.stop();
+}
+
+void CallManager::handleHangup(NeoChatRoom *room, const Quotient::CallHangupEvent *event)
+{
+    if (globalState() == IDLE) {
+        qCDebug(voip) << "Ignoring hangup since we're not in a call";
+        return;
+    }
+
+    if (event->senderId() == room->localUser()->id()) {
+        qCDebug(voip) << "Ignoring hangup we sent ourselves";
+        // TODO hangup-to-decline by different device?
+        return;
+    }
+
+    if (event->callId() != m_callId) {
+        qCDebug(voip) << "Hangup not for this call. Event's call id:" << event->callId() << ". Our call id" << m_callId;
+        return;
+    }
+
+    stopRinging();
+    if (m_session) {
+        m_session->end();
+        delete m_session;
+    }
+    setGlobalState(IDLE);
+    Q_EMIT callEnded();
+}
+
+void CallManager::acceptCall()
+{
+    // TODO metadata for this case
+    if (globalState() != INCOMING) {
+        qCWarning(voip) << "Not accepting call while state is" << globalState();
+        return;
+    }
+
+    stopRinging();
+
+    if (!checkPlugins()) {
+        qCCritical(voip) << "Missing plugins; can't accept call";
+    }
+
+    updateTurnServers();
+    // TODO wait until candidates are here
+
+    m_session = CallSession::acceptCall(m_incomingSdp, m_incomingCandidates, m_cachedTurnUris, m_remoteUser->id(), this);
+    m_participants->clear();
+    connect(m_session.data(), &CallSession::stateChanged, this, [this] {
+        Q_EMIT stateChanged();
+        if (state() == CallSession::ICEFAILED) {
+            Q_EMIT callEnded();
+        }
+    }); // TODO refactor away?
+    m_incomingCandidates.clear();
+    connectSingleShot(m_session.data(), &CallSession::answerCreated, this, [this](const QString &_sdp, const QVector<Candidate> &candidates) {
+        const auto &[uuids, sdp] = mangleSdp(_sdp);
+        QVector<std::pair<QString, QString>> msidToPurpose;
+        for (const auto &uuid : uuids) {
+            msidToPurpose += {uuid, "m.usermedia"}; // TODO
+        }
+        auto answer = createAnswer(m_callId, sdp, msidToPurpose);
+        m_room->postJson("m.call.answer", answer);
+        qCWarning(voip) << "Sending Answer";
+        auto c = createCandidates(m_callId, candidates);
+        auto cand = createCandidates(m_callId, candidates);
+        m_room->postJson("m.call.candidates", cand);
+        qCWarning(voip) << "Sending Candidates";
+        setGlobalState(ACTIVE);
+    });
+}
+
+void CallManager::hangupCall()
+{
+    qCDebug(voip) << "Ending call";
+    if (m_session) {
+        m_session->end();
+        delete m_session;
+        m_session = nullptr;
+    }
+    stopRinging();
+    m_room->postJson("m.call.hangup", createHangup(m_callId));
+    setGlobalState(IDLE);
+    Q_EMIT callEnded();
+}
+
+NeoChatUser *CallManager::remoteUser() const
+{
+    return m_remoteUser;
+}
+
+NeoChatRoom *CallManager::room() const
+{
+    return m_room;
+}
+
+CallSession::State CallManager::state() const
+{
+    if (!m_session) {
+        return CallSession::DISCONNECTED;
+    }
+    return m_session->state();
+}
+
+int CallManager::lifetime() const
+{
+    return m_lifetime;
+}
+
+void CallManager::ignoreCall()
+{
+    setLifetime(0);
+    setCallId({});
+    setRoom(nullptr);
+    setRemoteUser(nullptr);
+}
+
+void CallManager::startCall(NeoChatRoom *room)
+{
+    if (m_session) {
+        // Don't start calls if there already is one
+        Q_EMIT Controller::instance().errorOccured(i18n("A call is already started"));
+        return;
+    }
+    if (room->users().size() != 2) {
+        // Don't start calls if the room doesn't have exactly two members
+        Q_EMIT Controller::instance().errorOccured(i18n("Calls are limited to 1:1 rooms"));
+        return;
+    }
+
+    auto missingPlugins = CallSession::missingPlugins();
+    if (!missingPlugins.isEmpty()) {
+        qCCritical(voip) << "Missing GStreamer plugins:" << missingPlugins;
+        Q_EMIT Controller::instance().errorOccured("Missing GStreamer plugins.");
+        return;
+    }
+
+    setLifetime(60000);
+    setRoom(room);
+    setRemoteUser(otherUser(room));
+
+    updateTurnServers();
+
+    setCallId(generateCallId());
+    setPartyId(generatePartyId());
+
+    m_participants->clear();
+    for (const auto &user : m_room->users()) {
+        auto participant = new CallParticipant(m_session);
+        participant->m_user = dynamic_cast<NeoChatUser *>(user);
+        m_participants->addParticipant(participant);
+    }
+
+    m_session = CallSession::startCall(m_cachedTurnUris, this);
+    setGlobalState(OUTGOING);
+    connect(m_session, &CallSession::stateChanged, this, [this] {
+        Q_EMIT stateChanged();
+        if (state() == CallSession::ICEFAILED) {
+            Q_EMIT callEnded();
+        }
+    });
+
+    connectSingleShot(m_session.data(), &CallSession::offerCreated, this, [this](const QString &_sdp, const QVector<Candidate> &candidates) {
+        const auto &[uuids, sdp] = mangleSdp(_sdp);
+        QVector<std::pair<QString, QString>> msidToPurpose;
+        for (const auto &uuid : uuids) {
+            msidToPurpose += {uuid, "m.usermedia"}; // TODO
+        }
+        qCWarning(voip) << "Sending Invite";
+        qCWarning(voip) << "Sending Candidates";
+        auto invite = createInvite(m_callId, sdp, msidToPurpose);
+        auto c = createCandidates(m_callId, candidates);
+        m_room->postJson("m.call.invite", invite);
+        m_room->postJson("m.call.candidates", c);
+    });
+
+    connect(m_session, &CallSession::renegotiate, this, [this](const QString &sdp, const QString &type) {
+        QVector<std::pair<QString, QString>> msidToPurpose;
+        const auto &[uuids, _sdp] = mangleSdp(sdp);
+        for (const auto &uuid : uuids) {
+            msidToPurpose += {uuid, "m.usermedia"}; // TODO
+        }
+        QJsonObject json{
+            {QStringLiteral("lifetime"), 60000},
+            {QStringLiteral("version"), 1},
+            {QStringLiteral("description"), QJsonObject{{QStringLiteral("type"), type}, {QStringLiteral("sdp"), _sdp}}}, // AAAAA
+            {QStringLiteral("party_id"), m_partyId},
+            {QStringLiteral("call_id"), m_callId},
+        };
+        QJsonObject metadata;
+        for (const auto &[stream, purpose] : msidToPurpose) {
+            QJsonObject data = {{"purpose", purpose}};
+            metadata[stream] = data;
+        }
+        json["org.matrix.msc3077.sdp_stream_metadata"] = metadata;
+        m_room->postJson("m.call.negotiate", json);
+    });
+}
+
+QString CallManager::generateCallId() const
+{
+    return QDateTime::currentDateTime().toString("yyyyMMddhhmmsszzz");
+}
+
+QString CallManager::generatePartyId() const
+{
+    return QUuid::createUuid().toString();
+}
+
+void CallManager::setCallId(const QString &callId)
+{
+    m_callId = callId;
+    Q_EMIT callIdChanged();
+}
+
+void CallManager::setPartyId(const QString &partyId)
+{
+    m_partyId = partyId;
+}
+
+void CallManager::setMuted(bool muted)
+{
+    if (!m_session) {
+        return;
+    }
+    m_session->setMuted(muted);
+    Q_EMIT mutedChanged();
+}
+
+bool CallManager::muted() const
+{
+    if (!m_session) {
+        return false;
+    }
+    return m_session->muted();
+}
+
+bool CallManager::init()
+{
+    qRegisterMetaType<Candidate>();
+    qRegisterMetaType<QVector<Candidate>>();
+    GError *error = nullptr;
+    if (!gst_init_check(nullptr, nullptr, &error)) {
+        QString strError;
+        if (error) {
+            strError += error->message;
+            g_error_free(error);
+        }
+        qCCritical(voip) << "Failed to initialize GStreamer:" << strError;
+        return false;
+    }
+
+    gchar *version = gst_version_string();
+    qCDebug(voip) << "GStreamer version" << version;
+    g_free(version);
+
+    // Required to register the qml types
+    auto _sink = gst_element_factory_make("qmlglsink", nullptr);
+    Q_ASSERT(_sink);
+    gst_object_unref(_sink);
+    return true;
+}
+
+void CallManager::setLifetime(int lifetime)
+{
+    m_lifetime = lifetime;
+    Q_EMIT lifetimeChanged();
+}
+
+void CallManager::setRoom(NeoChatRoom *room)
+{
+    m_room = room;
+    Q_EMIT roomChanged();
+}
+
+void CallManager::setRemoteUser(NeoChatUser *user)
+{
+    m_remoteUser = user;
+    Q_EMIT roomChanged();
+}
+
+NeoChatUser *CallManager::otherUser(NeoChatRoom *room)
+{
+    return dynamic_cast<NeoChatUser *>(room->users()[0]->id() == room->localUser()->id() ? room->users()[1] : room->users()[0]);
+}
+
+QJsonObject CallManager::createCandidates(const QString &callId, const QVector<Candidate> &candidates) const
+{
+    QJsonArray candidatesJson;
+    for (const auto &candidate : candidates) {
+        candidatesJson += QJsonObject{{"candidate", candidate.candidate}, {"sdpMid", candidate.sdpMid}, {"sdpMLineIndex", candidate.sdpMLineIndex}};
+    }
+    return QJsonObject{{"call_id", callId}, {"candidates", candidatesJson}, {"version", CALL_VERSION}, {"party_id", "todopartyid"}};
+}
+
+void CallManager::setGlobalState(GlobalState globalState)
+{
+    if (m_globalState == globalState) {
+        return;
+    }
+    m_globalState = globalState;
+    Q_EMIT globalStateChanged();
+}
+
+CallManager::GlobalState CallManager::globalState() const
+{
+    return m_globalState;
+}
+
+CallParticipantsModel *CallManager::callParticipants() const
+{
+    return m_participants;
+}
+
+std::pair<QStringList, QString> CallManager::mangleSdp(const QString &_sdp)
+{
+    QString sdp = _sdp;
+    QRegularExpression regex("msid:user[0-9]+@host-[0-9a-f]+ webrtctransceiver([0-9])");
+    auto iter = regex.globalMatch(sdp);
+    QStringList uuids;
+
+    while (iter.hasNext()) {
+        auto uuid = QUuid::createUuid();
+        auto match = iter.next();
+        uuids += uuid.toString();
+        sdp.replace(match.captured(), QStringLiteral("msid:") + uuid.toString() + QStringLiteral(" foo"));
+    }
+    return {uuids, sdp};
+}
+
+QJsonObject CallManager::createInvite(const QString &callId, const QString &sdp, const QVector<std::pair<QString, QString>> &msidToPurpose) const
+{
+    QJsonObject metadata;
+    for (const auto &[msid, purpose] : msidToPurpose) {
+        metadata[msid] = QJsonObject{{"purpose", purpose}};
+    }
+    return {{"call_id", callId},
+            {"party_id", "todopartyid"},
+            {"lifetime", 60000},
+            {"capabilities", QJsonObject{{"m.call.transferee", false}}},
+            {"offer", QJsonObject{{"sdp", sdp}, {"type", "offer"}}},
+            {"org.matrix.msc3077.sdp_stream_metadata", metadata},
+            {"version", CALL_VERSION}};
+}
+
+QJsonObject CallManager::createHangup(const QString &callId) const
+{
+    return {{"call_id", callId}, {"party_id", "todopartyid"}, {"version", CALL_VERSION}};
+}
+
+QJsonObject CallManager::createAnswer(const QString &callId, const QString &sdp, const QVector<std::pair<QString, QString>> &msidToPurpose) const
+{
+    Q_ASSERT(!callId.isEmpty());
+    QJsonObject metadata;
+    for (const auto &[msid, purpose] : msidToPurpose) {
+        metadata[msid] = QJsonObject{{"purpose", purpose}};
+    }
+    return {{"call_id", callId},
+            {"party_id", "todopartyid"},
+            {"lifetime", "lifetime"},
+            {"capabilities", QJsonObject{{"m.call.transferee", false}}},
+            {"offer", QJsonObject{{"sdp", sdp}, {"type", "offer"}}},
+            {"org.matrix.msc3077.sdp_stream_metadata", metadata},
+            {"version", CALL_VERSION}};
+}
+
+void CallManager::toggleCamera()
+{
+    m_session->toggleCamera();
+}
+QString CallManager::partyId() const
+{
+    return m_partyId;
+}
+
+bool CallManager::checkPlugins() const
+{
+    auto missingPlugins = m_session->missingPlugins();
+    if (!missingPlugins.isEmpty()) {
+        qCCritical(voip) << "Missing GStreamer plugins:" << missingPlugins;
+        Q_EMIT Controller::instance().errorOccured("Missing GStreamer plugins.");
+    }
+    return !missingPlugins.isEmpty();
+}

src/call/callmanager.h

@@ -0,0 +1,159 @@
+// SPDX-FileCopyrightText: 2020-2021 Nheko Authors
+// SPDX-FileCopyrightText: 2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include "neochatroom.h"
+#include "neochatuser.h"
+#include <QAbstractListModel>
+#include <QObject>
+#include <QString>
+#include <events/roomevent.h>
+
+#include "callsession.h"
+
+#include "models/callparticipantsmodel.h"
+#include <events/callevents.h>
+
+#include <QMediaPlayer>
+#include <QMediaPlaylist>
+#include <QTimer>
+#include <qcoro/task.h>
+
+#include <qobjectdefs.h>
+
+class CallSession;
+class QQuickItem;
+
+using namespace Quotient;
+
+class CallManager : public QObject
+{
+    Q_OBJECT
+
+public:
+    enum GlobalState {
+        IDLE,
+        INCOMING,
+        OUTGOING,
+        ACTIVE,
+    };
+    Q_ENUM(GlobalState);
+
+    Q_PROPERTY(GlobalState globalState READ globalState NOTIFY globalStateChanged)
+    Q_PROPERTY(NeoChatUser *remoteUser READ remoteUser NOTIFY remoteUserChanged)
+    Q_PROPERTY(QString callId READ callId NOTIFY callIdChanged)
+    Q_PROPERTY(NeoChatRoom *room READ room NOTIFY roomChanged)
+    Q_PROPERTY(int lifetime READ lifetime NOTIFY lifetimeChanged)
+    Q_PROPERTY(bool muted READ muted WRITE setMuted NOTIFY mutedChanged)
+    Q_PROPERTY(QQuickItem *item MEMBER m_item) // TODO allow for different devices for each session
+    Q_PROPERTY(CallSession::State state READ state NOTIFY stateChanged)
+    Q_PROPERTY(CallParticipantsModel *callParticipants READ callParticipants CONSTANT)
+
+    static CallManager &instance()
+    {
+        static CallManager _instance;
+        return _instance;
+    }
+
+    [[nodiscard]] QString callId() const;
+    [[nodiscard]] QString partyId() const;
+
+    CallSession::State state() const;
+
+    NeoChatUser *remoteUser() const;
+    NeoChatRoom *room() const;
+
+    int lifetime() const;
+
+    bool muted() const;
+    void setMuted(bool muted);
+
+    CallManager::GlobalState globalState() const;
+
+    void handleCallEvent(NeoChatRoom *room, const RoomEvent *event);
+
+    Q_INVOKABLE void startCall(NeoChatRoom *room);
+    Q_INVOKABLE void acceptCall();
+    Q_INVOKABLE void hangupCall();
+    Q_INVOKABLE void ignoreCall();
+
+    Q_INVOKABLE void toggleCamera();
+
+    QCoro::Task<void> updateTurnServers();
+
+    [[nodiscard]] CallParticipantsModel *callParticipants() const;
+
+    QQuickItem *m_item = nullptr;
+
+Q_SIGNALS:
+    void currentCallIdChanged();
+    void incomingCall(NeoChatUser *user, NeoChatRoom *room, int timeout, const QString &callId);
+    void callEnded();
+    void remoteUserChanged();
+    void callIdChanged();
+    void roomChanged();
+    void stateChanged();
+    void lifetimeChanged();
+    void mutedChanged();
+    void globalStateChanged();
+
+private:
+    CallManager();
+    QString m_callId;
+
+    QVector<Candidate> m_incomingCandidates;
+    QString m_incomingSdp;
+
+    [[nodiscard]] bool checkPlugins() const;
+
+    QStringList m_cachedTurnUris;
+    QDateTime m_cachedTurnUrisValidUntil = QDateTime::fromSecsSinceEpoch(0);
+
+    NeoChatUser *m_remoteUser = nullptr;
+    NeoChatRoom *m_room = nullptr;
+    QString m_remotePartyId;
+    QString m_partyId;
+    int m_lifetime = 0;
+
+    GlobalState m_globalState = IDLE;
+
+    void handleInvite(NeoChatRoom *room, const CallInviteEvent *event);
+    void handleHangup(NeoChatRoom *room, const CallHangupEvent *event);
+    void handleCandidates(NeoChatRoom *room, const CallCandidatesEvent *event);
+    void handleAnswer(NeoChatRoom *room, const CallAnswerEvent *event);
+    void handleNegotiate(NeoChatRoom *room, const CallNegotiateEvent *event);
+    void checkStartCall();
+
+    void ring(int lifetime);
+    void stopRinging();
+
+    [[nodiscard]] QString generateCallId() const;
+    [[nodiscard]] QString generatePartyId() const;
+    bool init();
+
+    bool m_initialised = false;
+    QPointer<CallSession> m_session = nullptr;
+
+    void setLifetime(int lifetime);
+    void setRoom(NeoChatRoom *room);
+    void setRemoteUser(NeoChatUser *user);
+    void setCallId(const QString &callId);
+    void setPartyId(const QString &partyId);
+    void setGlobalState(GlobalState state);
+
+    std::pair<QStringList, QString> mangleSdp(const QString &sdp);
+
+    CallParticipantsModel *m_participants = new CallParticipantsModel();
+
+    NeoChatUser *otherUser(NeoChatRoom *room);
+
+    [[nodiscard]] QJsonObject createCandidates(const QString &callId, const QVector<Candidate> &candidates) const;
+    [[nodiscard]] QJsonObject createInvite(const QString &callId, const QString &sdp, const QVector<std::pair<QString, QString>> &msidToPurpose) const;
+    [[nodiscard]] QJsonObject createHangup(const QString &callId) const;
+    [[nodiscard]] QJsonObject createAnswer(const QString &callId, const QString &sdp, const QVector<std::pair<QString, QString>> &msidToPurpose) const;
+
+    QMediaPlayer m_ringPlayer;
+    QMediaPlaylist m_playlist;
+};

src/call/callnegotiateevent.cpp

@@ -0,0 +1,51 @@
+// SPDX-FileCopyrightText: 2022 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#include "callnegotiateevent.h"
+
+using namespace Quotient;
+
+CallNegotiateEvent::CallNegotiateEvent(const QString &callId,
+                                       const QString &partyId,
+                                       int lifetime,
+                                       const QString &sdp,
+                                       bool answer,
+                                       QVector<std::pair<QString, QString>> msidToPurpose)
+    : EventTemplate(callId,
+                    {
+                        {QStringLiteral("lifetime"), lifetime},
+                        {QStringLiteral("version"), 1},
+                        {QStringLiteral("description"),
+                         QJsonObject{{QStringLiteral("type"), answer ? QStringLiteral("answer") : QStringLiteral("offer")}, {QStringLiteral("sdp"), sdp}}},
+                        {QStringLiteral("party_id"), partyId},
+                    })
+{
+    QJsonObject metadata;
+    for (const auto &[stream, purpose] : msidToPurpose) {
+        QJsonObject data = {{"purpose", purpose}};
+        metadata[stream] = purpose;
+    }
+    auto content = editJson();
+    content["org.matrix.msc3077.sdp_stream_metadata"] = metadata;
+    editJson()["content"] = content;
+}
+
+CallNegotiateEvent::CallNegotiateEvent(const QJsonObject &json)
+    : EventTemplate(json)
+{
+}
+
+QString CallNegotiateEvent::partyId() const
+{
+    return contentJson()["party_id"].toString();
+}
+
+QString CallNegotiateEvent::sdp() const
+{
+    return contentJson()["description"]["sdp"].toString();
+}
+
+QJsonObject CallNegotiateEvent::sdpStreamMetadata() const
+{
+    return contentJson()["org.matrix.msc3077.sdp_stream_metadata"].toObject();
+}

src/call/callnegotiateevent.h

@@ -0,0 +1,30 @@
+// SPDX-FileCopyrightText: 2022 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#pragma once
+
+#include <events/callevents.h>
+
+namespace Quotient
+{
+
+class CallNegotiateEvent : public EventTemplate<CallNegotiateEvent, CallEvent>
+{
+public:
+    QUO_EVENT(CallNegotiateEvent, "m.call.negotiate")
+
+    explicit CallNegotiateEvent(const QJsonObject &obj);
+
+    explicit CallNegotiateEvent(const QString &callId,
+                                const QString &partyId,
+                                int lifetime,
+                                const QString &sdp,
+                                bool answer,
+                                QVector<std::pair<QString, QString>> msidToPurpose);
+
+    QString partyId() const;
+    QString sdp() const;
+    // TODO make this a struct instead
+    QJsonObject sdpStreamMetadata() const;
+};
+}

src/call/callparticipant.cpp

@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: 2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "callparticipant.h"
+
+NeoChatUser *CallParticipant::user() const
+{
+    return m_user;
+}
+
+bool CallParticipant::hasCamera() const
+{
+    return m_hasCamera;
+}
+
+CallParticipant::CallParticipant(QObject *parent)
+    : QObject(parent)
+{
+}
+
+void CallParticipant::initCamera(QQuickItem *item)
+{
+    QTimer::singleShot(500, this, [=] {
+        Q_EMIT initialized(item);
+    });
+}

src/call/callparticipant.h

@@ -0,0 +1,36 @@
+// SPDX-FileCopyrightText: 2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <QObject>
+#include <QTimer>
+
+#include "neochatuser.h"
+
+class QQuickItem;
+
+class CallParticipant : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(NeoChatUser *user READ user CONSTANT)
+    Q_PROPERTY(bool hasCamera READ hasCamera NOTIFY hasCameraChanged)
+
+public:
+    NeoChatUser *m_user = nullptr;
+    bool m_hasCamera = false;
+
+    Q_INVOKABLE void initCamera(QQuickItem *item);
+
+    [[nodiscard]] NeoChatUser *user() const;
+
+    [[nodiscard]] bool hasCamera() const;
+
+    explicit CallParticipant(QObject *parent = nullptr);
+
+Q_SIGNALS:
+    void initialized(QQuickItem *item);
+    void heightChanged();
+    void widthChanged();
+    void hasCameraChanged();
+};

src/call/callsession.cpp

@@ -0,0 +1,916 @@
+// SPDX-FileCopyrightText: 2021 Nheko Contributors
+// SPDX-FileCopyrightText: 2021 Carl Schwan <carl@carlschwan.eu>
+// SPDX-FileCopyrightText: 2021-2022 Tobias Fella <fella@posteo.de>
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "calldevices.h"
+
+#include <QDebug>
+#include <QThread>
+
+#include <gst/gst.h>
+
+#define GST_USE_UNSTABLE_API
+#include <gst/webrtc/webrtc.h>
+#undef GST_USE_UNSTABLE_API
+
+#include "voiplogging.h"
+
+#include "audiosources.h"
+#include "videosources.h"
+
+#include <qcoro/qcorosignal.h>
+
+#define private public
+#include "callsession.h"
+#undef private
+#include "callmanager.h"
+#include <qt_connection_util.h>
+
+#define STUN_SERVER "stun://turn.matrix.org:3478" // TODO make STUN server configurable
+
+#define INSTANCE                                                                                                                                               \
+    Q_ASSERT(user_data);                                                                                                                                       \
+    auto instance = static_cast<CallSession *>(user_data);
+
+GstElement *createElement(const char *type, GstElement *pipe, const char *name = nullptr)
+{
+    auto element = gst_element_factory_make(type, name);
+    Q_ASSERT_X(element, __FUNCTION__, QStringLiteral("Failed to create element %1 %2").arg(type, name).toLatin1());
+    if (pipe) {
+        gst_bin_add_many(GST_BIN(pipe), element, nullptr);
+    }
+    return element;
+}
+
+GstElement *binGetByName(GstElement *bin, const char *name)
+{
+    auto element = gst_bin_get_by_name(GST_BIN(bin), name);
+    Q_ASSERT_X(element, __FUNCTION__, QStringLiteral("Failed to get element by name: %1").arg(name).toLatin1());
+    return element;
+}
+
+struct KeyFrameRequestData {
+    GstElement *pipe = nullptr;
+    GstElement *decodeBin = nullptr;
+    gint packetsLost = 0;
+    guint timerId = 0;
+    QString statsField;
+} keyFrameRequestData;
+
+std::pair<int, int> getResolution(GstPad *pad)
+{
+    std::pair<int, int> ret;
+    auto caps = gst_pad_get_current_caps(pad);
+    auto structure = gst_caps_get_structure(caps, 0);
+    gst_structure_get_int(structure, "width", &ret.first);
+    gst_structure_get_int(structure, "height", &ret.second);
+    gst_caps_unref(caps);
+    return ret;
+}
+
+std::pair<int, int> getResolution(GstElement *pipe, const gchar *elementName, const gchar *padName)
+{
+    auto element = binGetByName(pipe, elementName);
+    auto pad = gst_element_get_static_pad(element, padName);
+    auto ret = getResolution(pad);
+    gst_object_unref(pad);
+    gst_object_unref(element);
+    return ret;
+}
+
+void setLocalDescription(GstPromise *promise, gpointer user_data)
+{
+    INSTANCE
+    qCDebug(voip) << "Setting local description";
+    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);
+    auto webrtcbin = binGetByName(instance->m_pipe, "webrtcbin");
+    Q_ASSERT(gstsdp);
+    g_signal_emit_by_name(webrtcbin, "set-local-description", gstsdp, nullptr);
+    gchar *sdp = gst_sdp_message_as_text(gstsdp->sdp);
+    if (!instance->m_localSdp.isEmpty()) {
+        // This is a renegotiation
+        qWarning() << "emitting renegotiate";
+        Q_EMIT instance->renegotiate(QString(sdp), isAnswer ? QStringLiteral("answer") : QStringLiteral("offer"));
+    }
+    instance->m_localSdp = QString(sdp);
+    g_free(sdp);
+    gst_webrtc_session_description_free(gstsdp);
+    qCDebug(voip) << "Local description set:" << isAnswer;
+}
+
+bool contains(std::string_view str1, std::string_view str2)
+{
+    return std::search(str1.cbegin(),
+                       str1.cend(),
+                       str2.cbegin(),
+                       str2.cend(),
+                       [](unsigned char c1, unsigned char c2) {
+                           return std::tolower(c1) == std::tolower(c2);
+                       })
+        != str1.cend();
+}
+
+void createOffer(GstElement *webrtc, CallSession *session)
+{
+    // TODO ?!?
+    if (!session->m_localSdp.isEmpty()) {
+        return;
+    }
+    qCWarning(voip) << "Creating Offer";
+    auto promise = gst_promise_new_with_change_func(setLocalDescription, session, nullptr);
+    g_signal_emit_by_name(webrtc, "create-offer", nullptr, promise);
+}
+
+void createAnswer(GstPromise *promise, gpointer user_data)
+{
+    INSTANCE
+    qCDebug(voip) << "Creating Answer";
+    gst_promise_unref(promise);
+    promise = gst_promise_new_with_change_func(setLocalDescription, instance, nullptr);
+    auto webrtcbin = binGetByName(instance->m_pipe, "webrtcbin");
+    g_signal_emit_by_name(webrtcbin, "create-answer", nullptr, promise);
+}
+
+bool getMediaAttributes(const GstSDPMessage *sdp, const char *mediaType, const char *encoding, int &payloadType, bool &receiveOnly, bool &sendOnly)
+{
+    payloadType = -1;
+    receiveOnly = false;
+    sendOnly = false;
+    for (guint mlineIndex = 0; mlineIndex < gst_sdp_message_medias_len(sdp); mlineIndex++) {
+        const GstSDPMedia *media = gst_sdp_message_get_media(sdp, mlineIndex);
+        if (!strcmp(gst_sdp_media_get_media(media), mediaType)) {
+            receiveOnly = gst_sdp_media_get_attribute_val(media, "recvonly") != nullptr;
+            sendOnly = gst_sdp_media_get_attribute_val(media, "sendonly") != nullptr;
+            const gchar *rtpval = nullptr;
+            for (guint n = 0; n == 0 || rtpval; n++) {
+                rtpval = gst_sdp_media_get_attribute_val_n(media, "rtpmap", n);
+                if (rtpval && contains(rtpval, encoding)) {
+                    payloadType = QString::fromLatin1(rtpval).toInt();
+                    break;
+                }
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
+GstWebRTCSessionDescription *parseSDP(const QString &sdp, GstWebRTCSDPType type)
+{
+    GstSDPMessage *message;
+    gst_sdp_message_new(&message);
+    if (gst_sdp_message_parse_buffer((guint8 *)sdp.toLatin1().data(), sdp.size(), message) == GST_SDP_OK) {
+        return gst_webrtc_session_description_new(type, message);
+    } else {
+        qCCritical(voip) << "Failed to parse remote SDP";
+        gst_sdp_message_free(message);
+        return nullptr;
+    }
+}
+
+void addLocalICECandidate(GstElement *webrtc, guint mlineIndex, const gchar *candidate, gpointer user_data)
+{
+    Q_UNUSED(webrtc);
+    INSTANCE
+    // qCWarning(voip) << "Adding local ICE Candidates";
+    instance->m_localCandidates += Candidate{candidate, static_cast<int>(mlineIndex), QString()};
+}
+
+void iceConnectionStateChanged(GstElement *webrtc, GParamSpec *pspec, gpointer user_data)
+{
+    Q_UNUSED(pspec);
+    INSTANCE
+    GstWebRTCICEConnectionState newState;
+    g_object_get(webrtc, "ice-connection-state", &newState, nullptr);
+    switch (newState) {
+    case GST_WEBRTC_ICE_CONNECTION_STATE_NEW:
+    case GST_WEBRTC_ICE_CONNECTION_STATE_CHECKING:
+        instance->setState(CallSession::CONNECTING);
+        break;
+    case GST_WEBRTC_ICE_CONNECTION_STATE_FAILED:
+        instance->setState(CallSession::ICEFAILED);
+        break;
+    case GST_WEBRTC_ICE_CONNECTION_STATE_CONNECTED:
+        instance->setState(CallSession::CONNECTED);
+    case GST_WEBRTC_ICE_CONNECTION_STATE_COMPLETED:
+    case GST_WEBRTC_ICE_CONNECTION_STATE_DISCONNECTED:
+    case GST_WEBRTC_ICE_CONNECTION_STATE_CLOSED:
+    default:
+        break;
+    }
+}
+
+GstElement *newAudioSinkChain(GstElement *pipe)
+{
+    qCWarning(voip) << "New Audio Sink Chain";
+    GstElement *queue = createElement("queue", pipe);
+    GstElement *convert = createElement("audioconvert", pipe);
+    GstElement *resample = createElement("audioresample", pipe);
+    GstElement *sink = createElement("autoaudiosink", pipe);
+    gst_element_link_many(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);
+    return queue;
+}
+
+void sendKeyFrameRequest()
+{
+    auto sinkpad = gst_element_get_static_pad(keyFrameRequestData.decodeBin, "sink");
+    if (!gst_pad_push_event(sinkpad, gst_event_new_custom(GST_EVENT_CUSTOM_UPSTREAM, gst_structure_new_empty("GstForceKeyUnit")))) {
+        qCWarning(voip) << "Keyframe request failed";
+    }
+    gst_object_unref(sinkpad);
+}
+
+void onGetStats(GstPromise *promise, gpointer)
+{
+    auto reply = gst_promise_get_reply(promise);
+    GstStructure *rtpStats;
+    if (!gst_structure_get(reply, keyFrameRequestData.statsField.toLatin1().data(), GST_TYPE_STRUCTURE, &rtpStats, nullptr)) {
+        gst_promise_unref(promise);
+        return;
+    }
+    auto packetsLost = 0;
+    gst_structure_get_int(rtpStats, "packets-lost", &packetsLost);
+    gst_structure_free(rtpStats);
+    gst_promise_unref(promise);
+    if (packetsLost > keyFrameRequestData.packetsLost) {
+        qCWarning(voip) << "inbound video lost packet count:" << packetsLost;
+        keyFrameRequestData.packetsLost = packetsLost;
+        sendKeyFrameRequest();
+    }
+}
+
+// TODO port to QTimer?
+gboolean testPacketLoss(gpointer)
+{
+    if (!keyFrameRequestData.pipe) {
+        return false;
+    }
+
+    auto webrtc = binGetByName(keyFrameRequestData.pipe, "webrtcbin");
+    auto promise = gst_promise_new_with_change_func(onGetStats, nullptr, nullptr);
+    g_signal_emit_by_name(webrtc, "get-stats", nullptr, promise);
+    gst_object_unref(webrtc);
+    return true;
+}
+
+GstElement *newVideoSinkChain(GstElement *pipe, QQuickItem *quickItem)
+{
+    Q_ASSERT(pipe);
+    Q_ASSERT(quickItem);
+    qCWarning(voip) << "Creating Video Sink Chain";
+    auto queue = createElement("queue", pipe);
+    auto compositor = createElement("compositor", pipe);
+    auto glupload = createElement("glupload", pipe);
+    auto glcolorconvert = createElement("glcolorconvert", pipe);
+    auto qmlglsink = createElement("qmlglsink", nullptr);
+    auto glsinkbin = createElement("glsinkbin", pipe);
+    g_object_set(qmlglsink, "widget", quickItem, nullptr);
+    g_object_set(glsinkbin, "sink", qmlglsink, nullptr);
+    gst_element_link_many(queue, compositor, glupload, glcolorconvert, glsinkbin, nullptr);
+    gst_element_sync_state_with_parent(queue);
+    gst_element_sync_state_with_parent(compositor);
+    gst_element_sync_state_with_parent(glupload);
+    gst_element_sync_state_with_parent(glcolorconvert);
+    gst_element_sync_state_with_parent(glsinkbin);
+    return queue;
+}
+
+static GstPadProbeReturn pad_cb(GstPad *pad, GstPadProbeInfo *info, gpointer user_data)
+{
+    Q_UNUSED(pad);
+    // auto stream = static_cast<VideoStream *>(user_data);
+    auto event = GST_PAD_PROBE_INFO_EVENT(info);
+    if (GST_EVENT_CAPS == GST_EVENT_TYPE(event)) {
+        GstCaps *caps = gst_caps_new_any();
+        int width, height;
+        gst_event_parse_caps(event, &caps);
+        auto structure = gst_caps_get_structure(caps, 0);
+        gst_structure_get_int(structure, "width", &width);
+        gst_structure_get_int(structure, "height", &height);
+        // stream->setWidth(width);
+        // stream->setHeight(height);
+        // TODO needed?
+    }
+    return GST_PAD_PROBE_OK;
+}
+
+void linkNewPad(GstElement *decodeBin, GstPad *newpad, gpointer user_data)
+{
+    INSTANCE
+    qCWarning(voip) << "Linking New Pad";
+    auto sinkpad = gst_element_get_static_pad(decodeBin, "sink");
+    auto sinkcaps = gst_pad_get_current_caps(sinkpad);
+    auto structure = gst_caps_get_structure(sinkcaps, 0);
+
+    gchar *mediaType = nullptr;
+    guint ssrc = 0;
+    gst_structure_get(structure, "media", G_TYPE_STRING, &mediaType, "ssrc", G_TYPE_UINT, &ssrc, nullptr);
+    gst_caps_unref(sinkcaps);
+    gst_object_unref(sinkpad);
+
+    GstElement *queue = nullptr;
+    if (!strcmp(mediaType, "audio")) {
+        qCWarning(voip) << "Receiving audio stream";
+        queue = newAudioSinkChain(instance->m_pipe);
+    } else if (!strcmp(mediaType, "video")) {
+        qCWarning(voip) << "Receiving video stream";
+        auto fake = createElement("fakesink", instance->m_pipe);
+        auto selector = createElement("output-selector", instance->m_pipe);
+        auto selectorSink = gst_element_get_static_pad(selector, "sink");
+        auto selectorSrc1 = gst_element_request_pad_simple(selector, "src_%u");
+        gst_pad_link(newpad, selectorSink);
+        auto fakepad = gst_element_get_static_pad(fake, "sink");
+        gst_pad_link(selectorSrc1, fakepad);
+        g_object_set(selector, "active-pad", selectorSrc1, nullptr);
+
+        auto msid = instance->ssrcToMsid[ssrc];
+
+        // gst_pad_add_probe(newpad, GST_PAD_PROBE_TYPE_EVENT_BOTH, pad_cb, stream, nullptr);
+        auto manager = dynamic_cast<CallManager *>(instance->parent());
+        auto participants = manager->callParticipants();
+        auto user = dynamic_cast<NeoChatUser *>(manager->room()->user(instance->msidToUserId[msid]));
+        participants->setHasCamera(user, true);
+
+        auto participant = participants->callParticipantForUser(user);
+
+        // gst_pad_add_probe(newpad, GST_PAD_PROBE_TYPE_EVENT_BOTH, pad_cb, nullptr, nullptr);
+        connectSingleShot(participant, &CallParticipant::initialized, instance, [=](QQuickItem *item) {
+            gst_pad_unlink(newpad, fakepad);
+            auto queue = newVideoSinkChain(instance->m_pipe, item);
+            auto queuepad = gst_element_get_static_pad(queue, "sink");
+            Q_ASSERT(queuepad);
+            auto selectorSrc = gst_element_request_pad_simple(selector, "src_%u");
+            auto ok = GST_PAD_LINK_SUCCESSFUL(gst_pad_link(selectorSrc, queuepad));
+            Q_ASSERT(ok);
+            g_object_set(selector, "active-pad", selectorSrc, nullptr);
+            instance->setState(CallSession::CONNECTED);
+            keyFrameRequestData.pipe = instance->m_pipe;
+            keyFrameRequestData.decodeBin = decodeBin;
+            keyFrameRequestData.timerId = g_timeout_add_seconds(3, testPacketLoss, nullptr);
+            keyFrameRequestData.statsField = QStringLiteral("rtp-inbound-stream-stats_") + QString::number(ssrc);
+            gst_object_unref(queuepad);
+            g_free(mediaType);
+        });
+        return;
+    } else {
+        g_free(mediaType);
+        qCWarning(voip) << "Unknown pad type:" << GST_PAD_NAME(newpad);
+        return;
+    }
+    auto queuepad = gst_element_get_static_pad(queue, "sink");
+    Q_ASSERT(queuepad);
+    auto ok = GST_PAD_LINK_SUCCESSFUL(gst_pad_link(newpad, queuepad));
+    Q_ASSERT(ok);
+    gst_object_unref(queuepad);
+    g_free(mediaType);
+}
+
+void setWaitForKeyFrame(GstBin *decodeBin, GstElement *element, gpointer)
+{
+    Q_UNUSED(decodeBin);
+    if (!strcmp(gst_plugin_feature_get_name(GST_PLUGIN_FEATURE(gst_element_get_factory(element))), "rtpvp8depay")) {
+        g_object_set(element, "wait-for-keyframe", TRUE, nullptr);
+    }
+}
+
+void addDecodeBin(GstElement *webrtc, GstPad *newpad, gpointer user_data)
+{
+    Q_UNUSED(webrtc);
+    if (GST_PAD_DIRECTION(newpad) != GST_PAD_SRC) {
+        return;
+    }
+
+    INSTANCE
+
+    auto decodeBin = createElement("decodebin", instance->m_pipe);
+    // Investigate hardware, see nheko source
+    g_object_set(decodeBin, "force-sw-decoders", TRUE, nullptr);
+    g_signal_connect(decodeBin, "pad-added", G_CALLBACK(linkNewPad), instance);
+    g_signal_connect(decodeBin, "element-added", G_CALLBACK(setWaitForKeyFrame), nullptr);
+    gst_element_sync_state_with_parent(decodeBin);
+    auto sinkpad = gst_element_get_static_pad(decodeBin, "sink");
+    if (GST_PAD_LINK_FAILED(gst_pad_link(newpad, sinkpad))) {
+        // TODO: Error handling
+        qCWarning(voip) << "Unable to link decodebin";
+    }
+    gst_object_unref(sinkpad);
+}
+
+void iceGatheringStateChanged(GstElement *webrtc, GParamSpec *pspec, gpointer user_data)
+{
+    Q_UNUSED(pspec);
+    INSTANCE
+
+    GstWebRTCICEGatheringState newState;
+    g_object_get(webrtc, "ice-gathering-state", &newState, nullptr);
+    if (newState == GST_WEBRTC_ICE_GATHERING_STATE_COMPLETE) {
+        qCWarning(voip) << "GstWebRTCICEGatheringState -> Complete";
+        if (instance->m_isOffering) {
+            Q_EMIT instance->offerCreated(instance->m_localSdp, instance->m_localCandidates);
+            instance->setState(CallSession::OFFERSENT);
+        } else {
+            Q_EMIT instance->answerCreated(instance->m_localSdp, instance->m_localCandidates);
+            instance->setState(CallSession::ANSWERSENT);
+        }
+    }
+}
+
+gboolean newBusMessage(GstBus *bus, GstMessage *msg, gpointer user_data)
+{
+    Q_UNUSED(bus);
+    INSTANCE
+
+    switch (GST_MESSAGE_TYPE(msg)) {
+    case GST_MESSAGE_EOS:
+        qCWarning(voip) << "End of stream";
+        // TODO: Error handling
+        instance->end();
+        break;
+    case GST_MESSAGE_ERROR:
+        GError *error;
+        gchar *debug;
+        gst_message_parse_error(msg, &error, &debug);
+        qCWarning(voip) << "Error from element:" << GST_OBJECT_NAME(msg->src) << error->message;
+        // TODO: Error handling
+        g_clear_error(&error);
+        g_free(debug);
+        instance->end();
+        break;
+    default:
+        break;
+    }
+    return TRUE;
+}
+
+CallSession::CallSession(QObject *parent)
+    : QObject(parent)
+{
+}
+
+void CallSession::acceptAnswer(const QString &sdp, const QVector<Candidate> &candidates, const QString &userId)
+{
+    qCDebug(voip) << "Accepting Answer";
+    if (m_state != CallSession::OFFERSENT) {
+        return;
+    }
+
+    GstWebRTCSessionDescription *answer = parseSDP(sdp, GST_WEBRTC_SDP_TYPE_ANSWER);
+    if (!answer) {
+        end();
+        return;
+    }
+
+    acceptCandidates(candidates);
+
+    setRemoteDescription(answer, userId);
+}
+
+void CallSession::setRemoteDescription(GstWebRTCSessionDescription *remote, const QString &userId, GstPromise *promise)
+{
+    GstElement *webrtcbin = binGetByName(m_pipe, "webrtcbin");
+    auto sdp = remote->sdp;
+    for (guint i = 0; i < gst_sdp_message_medias_len(sdp); i++) {
+        auto media = gst_sdp_message_get_media(sdp, i);
+        QList<uint32_t> ssrcs;
+        QString msid;
+        for (guint j = 0; j < gst_sdp_media_attributes_len(media); j++) {
+            auto attribute = gst_sdp_media_get_attribute(media, j);
+            if (!strcmp(attribute->key, "ssrc")) {
+                ssrcs += QString(attribute->value).split(" ")[0].toUInt();
+            }
+            if (!strcmp(attribute->key, "msid")) {
+                msid = QString(attribute->value).split(" ")[0];
+            }
+        }
+        for (const auto &ssrc : ssrcs) {
+            ssrcToMsid[ssrc] = msid;
+        }
+        msidToUserId[msid] = userId;
+    }
+    g_signal_emit_by_name(webrtcbin, "set-remote-description", remote, promise);
+}
+
+void CallSession::renegotiateOffer(const QString &_offer, const QString &userId, bool answer)
+{
+    GstWebRTCSessionDescription *sdp = parseSDP(_offer, answer ? GST_WEBRTC_SDP_TYPE_ANSWER : GST_WEBRTC_SDP_TYPE_OFFER);
+    if (!sdp) {
+        Q_ASSERT(false);
+    }
+    GstElement *webrtcbin = binGetByName(m_pipe, "webrtcbin");
+
+    setRemoteDescription(sdp, userId);
+    qWarning() << "answer:" << answer;
+    if (!answer) {
+        GstPromise *promise = gst_promise_new_with_change_func(setLocalDescription, this, nullptr);
+        g_signal_emit_by_name(webrtcbin, "create-answer", nullptr, promise);
+    }
+}
+
+void CallSession::acceptOffer(const QString &sdp, const QVector<Candidate> remoteCandidates, const QString &userId)
+{
+    Q_ASSERT(!sdp.isEmpty());
+    Q_ASSERT(!remoteCandidates.isEmpty());
+    qCDebug(voip) << "Accepting offer";
+    if (m_state != CallSession::DISCONNECTED) {
+        return;
+    }
+    m_isOffering = false;
+
+    GstWebRTCSessionDescription *offer = parseSDP(sdp, GST_WEBRTC_SDP_TYPE_OFFER);
+    if (!offer) {
+        qCCritical(voip) << "Not an offer";
+        return;
+    }
+
+    int opusPayloadType;
+    bool receiveOnly;
+    bool sendOnly;
+    if (getMediaAttributes(offer->sdp, "audio", "opus", opusPayloadType, receiveOnly, sendOnly)) {
+        if (opusPayloadType == -1) {
+            qCCritical(voip) << "No OPUS in offer";
+            gst_webrtc_session_description_free(offer);
+            return;
+        }
+    } else {
+        qCCritical(voip) << "No audio in offer";
+        gst_webrtc_session_description_free(offer);
+        return;
+    }
+    startPipeline();
+
+    QThread::msleep(1000); // ?
+
+    acceptCandidates(remoteCandidates);
+
+    auto promise = gst_promise_new_with_change_func(createAnswer, this, nullptr);
+    setRemoteDescription(offer, userId, promise);
+    gst_webrtc_session_description_free(offer);
+}
+
+void CallSession::createCall()
+{
+    qCDebug(voip) << "Creating call";
+    m_isOffering = true;
+    startPipeline();
+}
+
+void CallSession::startPipeline()
+{
+    qCDebug(voip) << "Starting Pipeline";
+    if (m_state != CallSession::DISCONNECTED) {
+        return;
+    }
+    m_state = CallSession::INITIATING;
+    Q_EMIT stateChanged();
+
+    createPipeline();
+
+    auto webrtcbin = binGetByName(m_pipe, "webrtcbin");
+    Q_ASSERT(webrtcbin);
+    if (false /*TODO: CHECK USE STUN*/) {
+        qCDebug(voip) << "Setting STUN server:" << STUN_SERVER;
+        g_object_set(webrtcbin, "stun-server", STUN_SERVER, nullptr);
+    }
+
+    for (const auto &uri : m_turnServers) {
+        qCDebug(voip) << "Setting turn server:" << uri;
+        gboolean udata;
+        g_signal_emit_by_name(webrtcbin, "add-turn-server", uri.toLatin1().data(), (gpointer)(&udata));
+    }
+
+    if (m_turnServers.empty()) {
+        qCWarning(voip) << "No TURN servers provided";
+    }
+
+    if (m_isOffering) {
+        g_signal_connect(webrtcbin, "on-negotiation-needed", G_CALLBACK(::createOffer), this);
+    }
+
+    g_signal_connect(webrtcbin, "on-ice-candidate", G_CALLBACK(addLocalICECandidate), this);
+    g_signal_connect(webrtcbin, "notify::ice-connection-state", G_CALLBACK(iceConnectionStateChanged), this);
+
+    gst_element_set_state(m_pipe, GST_STATE_READY);
+    g_signal_connect(webrtcbin, "pad-added", G_CALLBACK(addDecodeBin), this);
+
+    g_signal_connect(webrtcbin, "notify::ice-gathering-state", G_CALLBACK(iceGatheringStateChanged), this);
+    gst_object_unref(webrtcbin);
+
+    GstStateChangeReturn ret = gst_element_set_state(m_pipe, GST_STATE_PLAYING);
+    if (ret == GST_STATE_CHANGE_FAILURE) {
+        // TODO: Error handling
+        qCCritical(voip) << "Unable to start pipeline";
+        end();
+        return;
+    }
+
+    GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(m_pipe));
+    m_busWatchId = gst_bus_add_watch(bus, newBusMessage, this);
+    gst_object_unref(bus);
+
+    m_state = CallSession::INITIATED;
+    Q_EMIT stateChanged();
+}
+
+void CallSession::end()
+{
+    qCDebug(voip) << "Ending Call";
+    if (m_pipe) {
+        gst_element_set_state(m_pipe, GST_STATE_NULL);
+        gst_object_unref(m_pipe);
+        m_pipe = nullptr;
+        keyFrameRequestData.pipe = nullptr;
+        if (m_busWatchId) {
+            g_source_remove(m_busWatchId);
+            m_busWatchId = 0;
+        }
+    }
+    if (m_state != CallSession::DISCONNECTED) {
+        m_state = CallSession::DISCONNECTED;
+        Q_EMIT stateChanged();
+    }
+}
+
+void CallSession::createPipeline()
+{
+    qCWarning(voip) << "Creating Pipeline";
+    auto device = AudioSources::instance().currentDevice();
+    if (!device) {
+        return;
+    }
+    m_pipe = gst_pipeline_new(nullptr);
+    auto source = gst_device_create_element(device, nullptr);
+    auto volume = createElement("volume", m_pipe, "srclevel");
+    auto convert = createElement("audioconvert", m_pipe);
+    auto resample = createElement("audioresample", m_pipe);
+    auto queue1 = createElement("queue", m_pipe);
+    auto opusenc = createElement("opusenc", m_pipe);
+    auto rtp = createElement("rtpopuspay", m_pipe);
+    auto queue2 = createElement("queue", m_pipe);
+    auto capsfilter = createElement("capsfilter", m_pipe);
+
+    auto rtpcaps = gst_caps_new_simple("application/x-rtp",
+                                       "media",
+                                       G_TYPE_STRING,
+                                       "audio",
+                                       "encoding-name",
+                                       G_TYPE_STRING,
+                                       "OPUS",
+                                       "payload",
+                                       G_TYPE_INT,
+                                       OPUS_PAYLOAD_TYPE,
+                                       nullptr);
+    Q_ASSERT(rtpcaps);
+    g_object_set(capsfilter, "caps", rtpcaps, nullptr);
+    gst_caps_unref(rtpcaps);
+
+    auto webrtcbin = createElement("webrtcbin", m_pipe, "webrtcbin");
+    g_object_set(webrtcbin, "bundle-policy", GST_WEBRTC_BUNDLE_POLICY_MAX_BUNDLE, nullptr);
+
+    gst_bin_add_many(GST_BIN(m_pipe), source, nullptr);
+
+    if (!gst_element_link_many(source, volume, convert, resample, queue1, opusenc, rtp, queue2, capsfilter, webrtcbin, nullptr)) {
+        qCCritical(voip) << "Failed to link pipeline";
+        // TODO propagate errors up and end call
+        return;
+    }
+}
+
+void CallSession::toggleCamera()
+{
+    // TODO do this only once
+    static bool inited = false;
+    if (!inited) {
+        addVideoPipeline();
+        inited = true;
+    }
+}
+
+bool CallSession::addVideoPipeline()
+{
+    qCDebug(voip) << "Adding Video Pipeline";
+    auto videoconvert = createElement("videoconvertscale", m_pipe);
+    auto tee = createElement("tee", m_pipe);
+    auto device = VideoSources::instance().currentDevice();
+    auto deviceCaps = device->caps[VideoSources::instance().capsIndex()];
+    int width = deviceCaps.width;
+    int height = deviceCaps.height;
+    int framerate = deviceCaps.framerates.back();
+    if (!device) {
+        return false;
+    }
+    auto camera = gst_device_create_element(device->device, nullptr);
+    gst_bin_add_many(GST_BIN(m_pipe), camera, nullptr);
+
+    auto caps =
+        gst_caps_new_simple("video/x-raw", "width", G_TYPE_INT, width, "height", G_TYPE_INT, height, "framerate", GST_TYPE_FRACTION, framerate, 1, nullptr);
+    auto camerafilter = createElement("capsfilter", m_pipe);
+    g_object_set(camerafilter, "caps", caps, nullptr);
+    gst_caps_unref(caps);
+
+    gst_element_link(camera, videoconvert);
+
+    if (!gst_element_link_many(videoconvert, camerafilter, nullptr)) {
+        qCWarning(voip) << "Failed to link camera elements";
+        // TODO: Error handling
+        return false;
+    }
+    if (!gst_element_link(camerafilter, tee)) {
+        qCWarning(voip) << "Failed to link camerafilter -> tee";
+        // TODO: Error handling
+        return false;
+    }
+
+    auto queue = createElement("queue", m_pipe);
+    g_object_set(queue, "leaky", true, nullptr);
+    auto vp8enc = createElement("vp8enc", m_pipe);
+    g_object_set(vp8enc, "deadline", 1, nullptr);
+    g_object_set(vp8enc, "error-resilient", 1, nullptr);
+    auto rtpvp8pay = createElement("rtpvp8pay", m_pipe);
+    auto rtpqueue = createElement("queue", m_pipe);
+    auto rtpcapsfilter = createElement("capsfilter", m_pipe);
+    auto rtpcaps = gst_caps_new_simple("application/x-rtp",
+                                       "media",
+                                       G_TYPE_STRING,
+                                       "video",
+                                       "encoding-name",
+                                       G_TYPE_STRING,
+                                       "VP8",
+                                       "payload",
+                                       G_TYPE_INT,
+                                       VP8_PAYLOAD_TYPE,
+                                       nullptr);
+    g_object_set(rtpcapsfilter, "caps", rtpcaps, nullptr);
+    gst_caps_unref(rtpcaps);
+
+    auto webrtcbin = binGetByName(m_pipe, "webrtcbin");
+    if (!gst_element_link_many(tee, queue, vp8enc, rtpvp8pay, rtpqueue, rtpcapsfilter, webrtcbin, nullptr)) {
+        qCCritical(voip) << "Failed to link rtp video elements";
+        gst_object_unref(webrtcbin);
+        return false;
+    }
+    auto promise = gst_promise_new_with_change_func(setLocalDescription, this, nullptr);
+    g_signal_emit_by_name(webrtcbin, "create-offer", nullptr, promise);
+
+    gst_object_unref(webrtcbin);
+
+    auto newpad = gst_element_request_pad_simple(tee, "src_%u");
+    Q_ASSERT(newpad);
+
+    auto fake = createElement("fakesink", m_pipe);
+    auto selector = createElement("output-selector", m_pipe);
+    auto selectorSink = gst_element_get_static_pad(selector, "sink");
+    auto selectorSrc1 = gst_element_request_pad_simple(selector, "src_%u");
+    gst_pad_link(newpad, selectorSink);
+    auto fakepad = gst_element_get_static_pad(fake, "sink");
+    gst_pad_link(selectorSrc1, fakepad);
+    g_object_set(selector, "active-pad", selectorSrc1, nullptr);
+
+    // gst_pad_add_probe(newpad, GST_PAD_PROBE_TYPE_EVENT_BOTH, pad_cb, stream, nullptr);
+    auto manager = dynamic_cast<CallManager *>(parent());
+    auto participants = manager->callParticipants();
+    auto user = dynamic_cast<NeoChatUser *>(manager->room()->localUser());
+    participants->setHasCamera(user, true);
+
+    connectSingleShot(participants->callParticipantForUser(user), &CallParticipant::initialized, this, [=](QQuickItem *item) {
+        gst_pad_unlink(newpad, fakepad);
+        Q_ASSERT(item);
+
+        auto queue = newVideoSinkChain(m_pipe, item);
+        Q_ASSERT(queue);
+        auto queuepad = gst_element_get_static_pad(queue, "sink");
+        Q_ASSERT(queuepad);
+        auto selectorSrc = gst_element_request_pad_simple(selector, "src_%u");
+        Q_ASSERT(selectorSrc);
+        auto ok = GST_PAD_LINK_SUCCESSFUL(gst_pad_link(selectorSrc, queuepad));
+        Q_ASSERT(ok);
+        g_object_set(selector, "active-pad", selectorSrc, nullptr);
+        gst_object_unref(queuepad);
+        gst_element_set_state(m_pipe, GST_STATE_READY); // TODO experimental
+        gst_element_set_state(m_pipe, GST_STATE_PLAYING); // TODO experimental
+        GST_DEBUG_BIN_TO_DOT_FILE(GST_BIN(m_pipe), GST_DEBUG_GRAPH_SHOW_ALL, "foo");
+    });
+    return true;
+}
+
+void CallSession::setTurnServers(QStringList servers)
+{
+    qCDebug(voip) << "Setting Turn Servers";
+    qWarning() << "TURN SERVERS" << servers;
+    m_turnServers = servers;
+}
+
+void CallSession::acceptCandidates(const QVector<Candidate> &candidates)
+{
+    qCDebug(voip) << "Accepting ICE Candidates";
+    auto webrtcbin = binGetByName(m_pipe, "webrtcbin");
+    for (const auto &c : candidates) {
+        qCDebug(voip) << "Remote candidate:" << c.candidate << c.sdpMLineIndex;
+        g_signal_emit_by_name(webrtcbin, "add-ice-candidate", c.sdpMLineIndex, c.candidate.toLatin1().data());
+    }
+}
+
+QStringList CallSession::missingPlugins()
+{
+    GstRegistry *registry = gst_registry_get();
+    static const QVector<QString> videoPlugins = {
+        QLatin1String("compositor"),
+        QLatin1String("opengl"),
+        QLatin1String("qmlgl"),
+        QLatin1String("rtp"),
+        QLatin1String("videoconvertscale"),
+        QLatin1String("vpx"),
+    };
+    static const QVector<QString> audioPlugins = {
+        QStringLiteral("audioconvert"),
+        QStringLiteral("audioresample"),
+        QStringLiteral("autodetect"),
+        QStringLiteral("dtls"),
+        QStringLiteral("nice"),
+        QStringLiteral("opus"),
+        QStringLiteral("playback"),
+        QStringLiteral("rtpmanager"),
+        QStringLiteral("srtp"),
+        QStringLiteral("volume"),
+        QStringLiteral("webrtc"),
+    };
+    QStringList missingPlugins;
+    for (const auto &pluginName : videoPlugins + audioPlugins) {
+        auto plugin = gst_registry_find_plugin(registry, pluginName.toLatin1().data());
+        if (!plugin) {
+            missingPlugins << pluginName;
+        }
+        gst_object_unref(plugin);
+    }
+    return missingPlugins;
+}
+
+void CallSession::setMuted(bool muted)
+{
+    const auto srclevel = binGetByName(m_pipe, "srclevel");
+    g_object_set(srclevel, "mute", muted, nullptr);
+    gst_object_unref(srclevel);
+    Q_EMIT mutedChanged();
+}
+
+bool CallSession::muted() const
+{
+    if (m_state < CallSession::CONNECTING) {
+        return false;
+    }
+    if (!m_pipe) {
+        return false;
+    }
+    const auto srclevel = binGetByName(m_pipe, "srclevel");
+    bool muted;
+    if (!srclevel) {
+        return false;
+    }
+    g_object_get(srclevel, "mute", &muted, nullptr);
+    // gst_object_unref(srclevel); //TODO why does this crash?
+    return muted;
+}
+
+CallSession *
+CallSession::acceptCall(const QString &sdp, const QVector<Candidate> &candidates, const QStringList &turnUris, const QString &userId, QObject *parent)
+{
+    auto instance = new CallSession(parent);
+    instance->setTurnServers(turnUris);
+    instance->acceptOffer(sdp, candidates, userId);
+    return instance;
+}
+
+CallSession *CallSession::startCall(const QStringList &turnUris, QObject *parent)
+{
+    auto instance = new CallSession(parent);
+
+    instance->setTurnServers(turnUris);
+    instance->createCall();
+    return instance;
+}
+
+CallSession::State CallSession::state() const
+{
+    return m_state;
+}
+
+void CallSession::setState(CallSession::State state)
+{
+    qCWarning(voip) << "Setting state" << state;
+    m_state = state;
+    Q_EMIT stateChanged();
+}
+
+void CallSession::setMetadata(QJsonObject metadata)
+{
+    m_metadata = metadata;
+}

src/call/callsession.h

@@ -0,0 +1,113 @@
+// SPDX-FileCopyrightText: 2021 Nheko Contributors
+// SPDX-FileCopyrightText: 2021 Carl Schwan <carl@carlschwan.eu>
+// SPDX-FileCopyrightText: 2021-2022 Tobias Fella <fella@posteo.de>
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <QJsonObject>
+#include <QMetaType>
+#include <QObject>
+#include <QQuickItem>
+#include <QString>
+#include <variant>
+#define GST_USE_UNSTABLE_API
+#include <gst/webrtc/webrtc.h>
+
+#include <gst/gst.h>
+
+#define OPUS_PAYLOAD_TYPE 111
+#define VP8_PAYLOAD_TYPE 96
+
+class CallDevices;
+class VideoStream;
+
+struct Candidate {
+    QString candidate;
+    int sdpMLineIndex;
+    QString sdpMid;
+};
+
+Q_DECLARE_METATYPE(Candidate)
+Q_DECLARE_METATYPE(QVector<Candidate>)
+
+class CallSession : public QObject
+{
+    Q_OBJECT
+
+public:
+    enum State {
+        DISCONNECTED,
+        ICEFAILED,
+        INITIATING,
+        INITIATED,
+        OFFERSENT,
+        ANSWERSENT,
+        CONNECTING,
+        CONNECTED,
+    };
+    Q_ENUM(State);
+
+    Q_PROPERTY(CallSession::State state READ state NOTIFY stateChanged)
+    Q_PROPERTY(bool muted READ muted WRITE setMuted NOTIFY mutedChanged)
+
+    // For outgoing calls
+    static CallSession *startCall(const QStringList &turnUris, QObject *parent = nullptr);
+    void acceptAnswer(const QString &sdp, const QVector<Candidate> &candidates, const QString &parent);
+
+    // For incoming calls
+    static CallSession *
+    acceptCall(const QString &sdp, const QVector<Candidate> &candidates, const QStringList &turnUris, const QString &userId, QObject *parent = nullptr);
+
+    void end();
+
+    void renegotiateOffer(const QString &offer, const QString &userId, bool answer);
+    void setTurnServers(QStringList servers);
+
+    static QStringList missingPlugins();
+
+    CallSession::State state() const;
+
+    void toggleCamera();
+    bool muted() const;
+    void setMuted(bool muted);
+    void setMetadata(QJsonObject metadata);
+    void acceptCandidates(const QVector<Candidate> &candidates);
+
+    QMap<QString, QString> msidToUserId;
+Q_SIGNALS:
+    void stateChanged();
+    void offerCreated(const QString &sdp, const QVector<Candidate> &candidates);
+
+    void answerCreated(const QString &sdp, const QVector<Candidate> &candidates);
+
+    void mutedChanged();
+    void newVideoStream(VideoStream *stream);
+
+    void renegotiate(QString sdp, const QString &type);
+
+private:
+    CallSession(QObject *parent = nullptr);
+    void acceptOffer(const QString &sdp, const QVector<Candidate> remoteCandidates, const QString &userId);
+    void createCall();
+
+    void setRemoteDescription(GstWebRTCSessionDescription *remote, const QString &userId, GstPromise *promise = nullptr);
+    void startPipeline();
+    void createPipeline();
+    bool addVideoPipeline();
+
+    void setState(CallSession::State state);
+    GstPad *m_activePad;
+    GstElement *m_inputSelector;
+    CallSession::State m_state = CallSession::DISCONNECTED;
+    unsigned int m_busWatchId = 0;
+    QStringList m_turnServers;
+    QVector<Candidate> m_localCandidates;
+    QString m_localSdp;
+    GstElement *m_pipe = nullptr;
+    bool m_isOffering = false;
+    QMap<int, QString> ssrcToMsid;
+    QJsonObject m_metadata;
+    GstPad *m_inactivePad;
+};

src/call/devicemonitor.cpp

@@ -0,0 +1,165 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#include "devicemonitor.h"
+#include "voiplogging.h"
+#include <QTimer>
+
+QDebug operator<<(QDebug dbg, const GstStructure *props)
+{
+    QDebugStateSaver saver(dbg);
+    auto asStr = gst_structure_to_string(props);
+    dbg << asStr;
+    g_free(asStr);
+    return dbg;
+}
+
+static gboolean deviceCallback(GstBus *bus, GstMessage *message, gpointer user_data)
+{
+    Q_UNUSED(bus);
+    auto monitor = static_cast<DeviceMonitor *>(user_data);
+    return monitor->callback(message);
+}
+
+DeviceMonitor::DeviceMonitor()
+    : QObject()
+{
+    QTimer::singleShot(0, this, &DeviceMonitor::init);
+}
+
+void DeviceMonitor::init()
+{
+    if (m_monitor) {
+        return;
+    }
+    m_monitor = gst_device_monitor_new();
+    GstCaps *caps = gst_caps_new_empty_simple("audio/x-raw");
+    gst_device_monitor_add_filter(m_monitor, "Audio/Source", caps);
+
+    gst_caps_unref(caps);
+    caps = gst_caps_new_empty_simple("video/x-raw");
+    gst_device_monitor_add_filter(m_monitor, "Video/Source", caps);
+    gst_caps_unref(caps);
+
+    GstBus *bus = gst_device_monitor_get_bus(m_monitor);
+    gst_bus_add_watch(bus, deviceCallback, this);
+    gst_object_unref(bus);
+
+    if (!gst_device_monitor_start(m_monitor)) {
+        qWarning() << "Failed to start device monitor";
+    }
+}
+
+QVector<AudioSource *> DeviceMonitor::audioSources() const
+{
+    return m_audioSources;
+}
+
+QVector<VideoSource *> DeviceMonitor::videoSources() const
+{
+    return m_videoSources;
+}
+
+void DeviceMonitor::handleVideoSource(GstDevice *device)
+{
+    auto source = new VideoSource();
+    auto title = gst_device_get_display_name(device);
+    source->title = QString(title);
+    g_free(title);
+    source->device = device;
+
+    auto caps = gst_device_get_caps(device);
+    auto size = gst_caps_get_size(caps);
+    for (size_t i = 0; i < size; i++) {
+        VideoCap videoCap;
+        GstStructure *cap = gst_caps_get_structure(caps, i);
+        const gchar *name = gst_structure_get_name(cap);
+        if (strcmp(name, "video/x-raw")) {
+            // TODO g_free(name);
+            continue;
+        }
+        // TODO g_free(name);
+        gst_structure_get(cap, "width", G_TYPE_INT, &videoCap.width, "height", G_TYPE_INT, &videoCap.height, nullptr);
+        const auto framerate = gst_structure_get_value(cap, "framerate");
+        if (GST_VALUE_HOLDS_FRACTION(framerate)) {
+            auto numerator = gst_value_get_fraction_numerator(framerate);
+            auto denominator = gst_value_get_fraction_denominator(framerate);
+            videoCap.framerates += (float)numerator / denominator;
+        }
+        // unref cap?
+        source->caps += videoCap;
+    }
+    m_videoSources += source;
+    Q_EMIT videoSourceAdded();
+}
+
+void DeviceMonitor::handleAudioSource(GstDevice *device)
+{
+    auto source = new AudioSource();
+    auto title = gst_device_get_display_name(device);
+    source->title = QString(title);
+    g_free(title);
+
+    GstStructure *props = gst_device_get_properties(device);
+    gboolean isDefault = false;
+    if (gst_structure_has_field(props, "is-default")) {
+        gst_structure_get_boolean(props, "is-default", &isDefault);
+    }
+    gst_structure_free(props);
+    source->isDefault = isDefault;
+
+    source->device = device;
+    m_audioSources += source;
+    Q_EMIT audioSourceAdded();
+}
+
+bool DeviceMonitor::callback(GstMessage *message)
+{
+    GstDevice *device;
+    switch (GST_MESSAGE_TYPE(message)) {
+    case GST_MESSAGE_DEVICE_ADDED: {
+        gst_message_parse_device_added(message, &device);
+        auto name = gst_device_get_display_name(device);
+        auto props = gst_device_get_properties(device);
+        qCDebug(voip) << name << props;
+        gst_structure_free(props);
+        if (gst_device_has_classes(device, "Video/Source")) {
+            handleVideoSource(device);
+        } else if (gst_device_has_classes(device, "Audio/Source")) {
+            handleAudioSource(device);
+        }
+        g_free(name);
+        gst_object_unref(device);
+        break;
+    }
+    case GST_MESSAGE_DEVICE_REMOVED: {
+        gst_message_parse_device_removed(message, &device);
+        auto name = gst_device_get_display_name(device);
+        auto props = gst_device_get_properties(device);
+        qCDebug(voip) << name << props;
+        if (gst_device_has_classes(device, "Video/Source")) {
+            m_videoSources.erase(std::remove_if(m_videoSources.begin(),
+                                                m_videoSources.end(),
+                                                [name](auto d) {
+                                                    return d->title == QString(name);
+                                                }),
+                                 m_videoSources.end());
+            Q_EMIT videoSourceRemoved();
+        } else if (gst_device_has_classes(device, "Audio/Source")) {
+            m_audioSources.erase(std::remove_if(m_audioSources.begin(),
+                                                m_audioSources.end(),
+                                                [name](auto d) {
+                                                    return d->title == QString(name);
+                                                }),
+                                 m_audioSources.end());
+            Q_EMIT audioSourceRemoved();
+        }
+        g_free(name);
+        gst_object_unref(device);
+        break;
+    }
+    default:
+        break;
+    }
+    return G_SOURCE_CONTINUE;
+}

src/call/devicemonitor.h

@@ -0,0 +1,59 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#pragma once
+
+#include <QtCore/QDebug>
+#include <QtCore/QObject>
+#include <QtCore/QVector>
+
+#include <gst/gst.h>
+
+struct AudioSource {
+    QString title;
+    GstDevice *device;
+    bool isDefault;
+};
+struct VideoCap {
+    int width;
+    int height;
+    QVector<float> framerates;
+};
+
+struct VideoSource {
+    QString title;
+    GstDevice *device;
+    QVector<VideoCap> caps;
+};
+
+class DeviceMonitor : public QObject
+{
+    Q_OBJECT
+
+public:
+    static DeviceMonitor &instance()
+    {
+        static DeviceMonitor _instance;
+        return _instance;
+    }
+
+    QVector<AudioSource *> audioSources() const;
+    QVector<VideoSource *> videoSources() const;
+    bool callback(GstMessage *message);
+    void init();
+
+Q_SIGNALS:
+    void videoSourceAdded();
+    void audioSourceAdded();
+
+    void videoSourceRemoved();
+    void audioSourceRemoved();
+
+private:
+    DeviceMonitor();
+    GstDeviceMonitor *m_monitor = nullptr;
+    QVector<AudioSource *> m_audioSources;
+    QVector<VideoSource *> m_videoSources;
+    void handleVideoSource(GstDevice *device);
+    void handleAudioSource(GstDevice *device);
+};

src/call/videosources.cpp

@@ -0,0 +1,142 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#include "videosources.h"
+
+#include <gst/gst.h>
+
+// #include "pipelinemanager.h"
+#include <QDebug>
+#include <QString>
+
+#include "devicemonitor.h"
+#include "neochatconfig.h"
+
+int VideoSources::rowCount(const QModelIndex &parent) const
+{
+    Q_UNUSED(parent);
+    return DeviceMonitor::instance().videoSources().size();
+}
+
+QVariant VideoSources::data(const QModelIndex &index, int role) const
+{
+    if (index.row() >= DeviceMonitor::instance().videoSources().size()) {
+        return QVariant(QStringLiteral("DEADBEEF"));
+    }
+    if (role == TitleRole) {
+        return DeviceMonitor::instance().videoSources()[index.row()]->title;
+    }
+    return QVariant();
+}
+
+QHash<int, QByteArray> VideoSources::roleNames() const
+{
+    return {
+        {TitleRole, "title"},
+    };
+}
+
+VideoSources::VideoSources()
+    : QAbstractListModel()
+{
+    connect(&DeviceMonitor::instance(), &DeviceMonitor::videoSourceAdded, this, [this]() {
+        beginResetModel();
+        endResetModel();
+        Q_EMIT currentIndexChanged();
+    });
+    connect(&DeviceMonitor::instance(), &DeviceMonitor::videoSourceRemoved, this, [this]() {
+        beginResetModel();
+        endResetModel();
+        Q_EMIT currentIndexChanged();
+    });
+}
+
+void VideoSources::foo(int index)
+{
+    auto device = DeviceMonitor::instance().videoSources()[index]->device;
+
+    auto bin = gst_bin_new(nullptr);
+
+    GstElement *videoconvert = gst_element_factory_make("videoconvert", nullptr);
+    // GstElement *videorate = gst_element_factory_make("videorate", nullptr);
+
+    GstElement *filter = gst_element_factory_make("capsfilter", nullptr);
+    GstCaps *caps = gst_caps_new_simple("video/x-raw", "width", G_TYPE_INT, 1920, "height", G_TYPE_INT, 1080, "framerate", GST_TYPE_FRACTION, 5, 1, nullptr);
+    g_object_set(filter, "caps", caps, nullptr);
+    gst_caps_unref(caps);
+    GstElement *deviceElement = gst_device_create_element(device, nullptr);
+
+    gst_bin_add_many(GST_BIN(bin), deviceElement, videoconvert, filter, nullptr);
+    gst_element_link_many(deviceElement, videoconvert, filter, nullptr);
+
+    // GstPad *pad = gst_element_get_static_pad(filter, "src");
+    GstPad *pad = gst_element_get_static_pad(filter, "src");
+    auto ghostpad = gst_ghost_pad_new("src", pad);
+    gst_element_add_pad(bin, ghostpad);
+    gst_object_unref(pad);
+    // PipelineManager::instance().add(bin);
+}
+
+const VideoSource *VideoSources::currentDevice() const
+{
+    const auto config = NeoChatConfig::self();
+    const QString name = config->camera();
+    for (const auto &videoSource : DeviceMonitor::instance().videoSources()) {
+        if (videoSource->title == name) {
+            qDebug() << "WebRTC: camera:" << name;
+            return videoSource;
+        }
+    }
+    if (DeviceMonitor::instance().videoSources().length() == 0) {
+        return nullptr;
+    }
+    return DeviceMonitor::instance().videoSources()[0];
+}
+
+void VideoSources::setCurrentIndex(int index)
+{
+    if (DeviceMonitor::instance().videoSources().size() == 0) {
+        return;
+    }
+    NeoChatConfig::setCamera(DeviceMonitor::instance().videoSources()[index]->title);
+    NeoChatConfig::self()->save();
+
+    setCapsIndex(0);
+}
+
+int VideoSources::currentIndex() const
+{
+    const auto config = NeoChatConfig::self();
+    const QString name = config->camera();
+    for (auto i = 0; i < DeviceMonitor::instance().videoSources().size(); i++) {
+        if (DeviceMonitor::instance().videoSources()[i]->title == name) {
+            return i;
+        }
+    }
+    return 0;
+}
+
+QStringList VideoSources::caps(int index) const
+{
+    if (index >= DeviceMonitor::instance().videoSources().size()) {
+        return QStringList();
+    }
+    const auto &caps = DeviceMonitor::instance().videoSources()[index]->caps;
+    QStringList strings;
+    for (const auto &cap : caps) {
+        strings += QStringLiteral("%1x%2, %3 FPS").arg(cap.width).arg(cap.height).arg(cap.framerates.back());
+    }
+    return strings;
+}
+
+void VideoSources::setCapsIndex(int index)
+{
+    NeoChatConfig::self()->setCameraCaps(index);
+    NeoChatConfig::self()->save();
+    Q_EMIT capsIndexChanged();
+}
+
+int VideoSources::capsIndex() const
+{
+    return NeoChatConfig::self()->cameraCaps();
+}

src/call/videosources.h

@@ -0,0 +1,51 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#pragma once
+
+#include <QtCore/QAbstractListModel>
+
+#include <gst/gst.h>
+
+#include "devicemonitor.h"
+
+class VideoSources : public QAbstractListModel
+{
+    Q_OBJECT
+    Q_PROPERTY(int currentIndex READ currentIndex WRITE setCurrentIndex NOTIFY currentIndexChanged)
+    Q_PROPERTY(int capsIndex READ capsIndex WRITE setCapsIndex NOTIFY capsIndexChanged)
+public:
+    enum Roles {
+        TitleRole = Qt::UserRole + 1,
+        DeviceRole,
+    };
+
+    static VideoSources &instance()
+    {
+        static VideoSources _instance;
+        return _instance;
+    }
+
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    QHash<int, QByteArray> roleNames() const override;
+
+    Q_INVOKABLE void foo(int index);
+
+    const VideoSource *currentDevice() const;
+
+    void setCurrentIndex(int index);
+    int currentIndex() const;
+
+    void setCapsIndex(int index);
+    int capsIndex() const;
+
+    Q_INVOKABLE QStringList caps(int index) const;
+
+Q_SIGNALS:
+    void currentIndexChanged();
+    void capsIndexChanged();
+
+private:
+    VideoSources();
+};

src/controller.cpp

@@ -736,3 +736,12 @@ QVariantList Controller::getSupportedRoomVersions(Quotient::Connection *connecti
 
     return supportedRoomVersions;
 }
+
+bool Controller::callsSupported() const
+{
+#ifdef GSTREAMER_AVAILABLE
+    return true;
+#else
+    return false;
+#endif
+}

src/controller.h

@@ -100,6 +100,7 @@ class Controller : public QObject
      * This is the only way to gate NeoChat features in flatpaks in QML.
      */
     Q_PROPERTY(bool isFlatpak READ isFlatpak CONSTANT)
+    Q_PROPERTY(bool callsSupported READ callsSupported CONSTANT)
 
 public:
     /**
@@ -197,6 +198,7 @@ public:
     int quotientMinorVersion() const;
 
     bool isFlatpak() const;
+    bool callsSupported() const;
 
     /**
      * @brief Return a string for the input timestamp.

src/main.cpp

@@ -86,6 +86,8 @@
 #ifdef QUOTIENT_07
 #include <keyverificationsession.h>
 #endif
+#include <room.h>
+
 #ifdef HAVE_COLORSCHEME
 #include "colorschemer.h"
 #endif
@@ -93,6 +95,14 @@
 #include "models/statemodel.h"
 #include "neochatuser.h"
 
+#ifdef GSTREAMER_AVAILABLE
+#include "call/audiosources.h"
+#include "call/callmanager.h"
+#include "call/callparticipant.h"
+#include "call/videosources.h"
+#include "models/callparticipantsmodel.h"
+#endif
+
 #ifdef HAVE_RUNNER
 #include "runner.h"
 #include <QDBusConnection>
@@ -183,6 +193,22 @@ int main(int argc, char *argv[])
 #endif
                        QStringLiteral("https://github.com/quotient-im/libquotient"),
                        KAboutLicense::LGPL_V2_1);
+#ifdef GSTREAMER_AVAILABLE
+    guint major, minor, micro, nano;
+    gst_version(&major, &minor, &micro, &nano);
+    about.addComponent(QStringLiteral("GStreamer"),
+                       i18nc("Description of GStreamer", "Open Source Multimedia Framework"),
+                       i18nc("<version number> (built against <possibly different version number>)",
+                             "%1.%2.%3.%4 (built against %5.%6.%7.%8)",
+                             major,
+                             minor,
+                             micro,
+                             nano,
+                             GST_VERSION_MAJOR,
+                             GST_VERSION_MINOR,
+                             GST_VERSION_MICRO,
+                             GST_VERSION_NANO));
+#endif
 
     KAboutData::setApplicationData(about);
     QGuiApplication::setWindowIcon(QIcon::fromTheme(QStringLiteral("org.kde.neochat")));
@@ -263,6 +289,10 @@ int main(int argc, char *argv[])
     qmlRegisterUncreatableType<NeoChatUser>("org.kde.neochat", 1, 0, "NeoChatUser", {});
     qmlRegisterUncreatableType<NeoChatRoom>("org.kde.neochat", 1, 0, "NeoChatRoom", {});
 
+#ifdef GSTREAMER_AVAILABLE
+    qmlRegisterUncreatableType<CallParticipantsModel>("org.kde.neochat", 1, 0, "CallParticipantsModel", "Get through CallManager");
+    qmlRegisterUncreatableType<CallParticipant>("org.kde.neochat", 1, 0, "CallParticipant", "Get through model");
+#endif
     qRegisterMetaType<User *>("User*");
     qRegisterMetaType<User *>("const User*");
     qRegisterMetaType<User *>("const Quotient::User*");
@@ -279,6 +309,13 @@ int main(int argc, char *argv[])
     qmlRegisterUncreatableType<KeyVerificationSession>("org.kde.neochat", 1, 0, "KeyVerificationSession", {});
     qRegisterMetaType<QVector<EmojiEntry>>("QVector<EmojiEntry>");
 #endif
+#endif
+
+#ifdef GSTREAMER_AVAILABLE
+    qmlRegisterSingletonInstance("org.kde.neochat", 1, 0, "AudioSources", &AudioSources::instance());
+    qmlRegisterSingletonInstance("org.kde.neochat", 1, 0, "VideoSources", &VideoSources::instance());
+    qmlRegisterSingletonInstance("org.kde.neochat", 1, 0, "CallManager", &CallManager::instance());
+    qmlRegisterUncreatableType<CallSession>("org.kde.neochat", 1, 0, "CallSession", "ENUM");
 #endif
     qmlRegisterSingletonType("org.kde.neochat", 1, 0, "About", [](QQmlEngine *engine, QJSEngine *) -> QJSValue {
         return engine->toScriptValue(KAboutData::applicationData());

src/models/callparticipantsmodel.cpp

@@ -0,0 +1,58 @@
+// SPDX-FileCopyrightText: 2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "callparticipantsmodel.h"
+
+QVariant CallParticipantsModel::data(const QModelIndex &index, int role) const
+{
+    if (role == ObjectRole) {
+        return QVariant::fromValue(m_callParticipants[index.row()]);
+    }
+    return {};
+}
+
+int CallParticipantsModel::rowCount(const QModelIndex &parent) const
+{
+    Q_UNUSED(parent);
+    return m_callParticipants.size();
+}
+
+void CallParticipantsModel::clear()
+{
+    beginRemoveRows(QModelIndex(), 0, m_callParticipants.size() - 1);
+    m_callParticipants.clear();
+    endRemoveRows();
+}
+
+CallParticipant *CallParticipantsModel::callParticipantForUser(NeoChatUser *user)
+{
+    for (const auto &callParticipant : m_callParticipants) {
+        if (callParticipant->m_user == user) {
+            return callParticipant;
+        }
+    }
+    return nullptr;
+}
+
+QHash<int, QByteArray> CallParticipantsModel::roleNames() const
+{
+    return {
+        {WidthRole, "width"},
+        {HeightRole, "height"},
+        {PadRole, "pad"},
+        {ObjectRole, "object"},
+    };
+}
+
+void CallParticipantsModel::addParticipant(CallParticipant *callParticipant)
+{
+    beginInsertRows(QModelIndex(), m_callParticipants.size(), m_callParticipants.size());
+    m_callParticipants += callParticipant;
+    endInsertRows();
+}
+
+void CallParticipantsModel::setHasCamera(NeoChatUser *user, bool hasCamera)
+{
+    callParticipantForUser(user)->m_hasCamera = hasCamera;
+    Q_EMIT callParticipantForUser(user)->hasCameraChanged();
+}

src/models/callparticipantsmodel.h

@@ -0,0 +1,38 @@
+// SPDX-FileCopyrightText: 2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <QAbstractListModel>
+#include <QVector>
+
+#include "call/callparticipant.h"
+#include "neochatuser.h"
+
+class CallParticipantsModel : public QAbstractListModel
+{
+    Q_OBJECT
+
+public:
+    enum Roles {
+        WidthRole,
+        HeightRole,
+        PadRole,
+        ObjectRole,
+    };
+    Q_ENUM(Roles);
+
+    [[nodiscard]] QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    [[nodiscard]] int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    [[nodiscard]] QHash<int, QByteArray> roleNames() const override;
+    ;
+
+    void addParticipant(CallParticipant *callParticipant);
+    CallParticipant *callParticipantForUser(NeoChatUser *user);
+
+    void setHasCamera(NeoChatUser *user, bool hasCamera);
+    void clear();
+
+private:
+    QVector<CallParticipant *> m_callParticipants;
+};

src/models/messageeventmodel.cpp

@@ -521,6 +521,9 @@ QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
 
             return DelegateType::Message;
         }
+        if (evt.matrixType() == "m.call.invite") {
+            return DelegateType::CallInvite;
+        }
         if (is<const StickerEvent>(evt)) {
             return DelegateType::Sticker;
         }

src/models/messageeventmodel.h

@@ -53,6 +53,7 @@ public:
         ReadMarker, /**< The local user read marker. */
         Poll, /**< The initial event for a poll. */
         Location, /**< A location event. */
+        CallInvite, /**< An invitation to a call. */
         Other, /**< Anything that cannot be classified as another type. */
     };
     Q_ENUM(DelegateType);

src/models/roomlistmodel.cpp

@@ -234,12 +234,23 @@ void RoomListModel::handleNotifications()
                 } else {
                     avatar_image = room->avatar(128);
                 }
-                NotificationsManager::instance().postNotification(dynamic_cast<NeoChatRoom *>(room),
-                                                                  sender->displayname(room),
-                                                                  notification["event"].toObject()["content"].toObject()["body"].toString(),
-                                                                  avatar_image,
-                                                                  notification["event"].toObject()["event_id"].toString(),
-                                                                  true);
+                if (notification["event"]["type"].toString() == QStringLiteral("m.call.invite")) {
+#ifdef GSTREAMER_AVAILABLE
+                    NotificationsManager::instance().postCallInviteNotification(
+                        dynamic_cast<NeoChatRoom *>(room),
+                        room->displayName(),
+                        sender->displayname(room),
+                        avatar_image,
+                        notification["event"]["content"]["offer"]["sdp"].toString().contains(QStringLiteral("video")));
+#endif
+                } else {
+                    NotificationsManager::instance().postNotification(dynamic_cast<NeoChatRoom *>(room),
+                                                                      sender->displayname(room),
+                                                                      notification["event"].toObject()["content"].toObject()["body"].toString(),
+                                                                      avatar_image,
+                                                                      notification["event"].toObject()["event_id"].toString(),
+                                                                      true);
+                }
             }
         }
     });

src/neochataccountregistry.cpp

@@ -54,12 +54,12 @@ QVariant AccountRegistry::data(const QModelIndex &index, int role) const
     const auto account = m_accounts[index.row()];
 
     switch (role) {
-        case ConnectionRole:
-            return QVariant::fromValue(account);
-        case UserIdRole:
-            return QVariant::fromValue(account->userId());
-        default:
-            return {};
+    case ConnectionRole:
+        return QVariant::fromValue(account);
+    case UserIdRole:
+        return QVariant::fromValue(account->userId());
+    default:
+        return {};
     }
 
     return {};

src/neochatconfig.kcfg

@@ -147,5 +147,23 @@
       <default></default>
     </entry>
   </group>
+  <group name="Voip">
+    <entry name="Microphone" type="string">
+      <label>Name of the microphone</label>
+    </entry>
+    <entry name="Camera" type="string">
+      <label>Name of the camera</label>
+    </entry>
+    <entry name="CameraCaps" type="int">
+      <label>Index of the camera caps</label>
+    </entry>
+    <entry name="ScreenShareFrameRate" type="int">
+      <label>Frame rate of the screenshare</label>
+    </entry>
+    <entry name="Ringtone" type="String">
+      <label>Ringtone</label>
+      <default>/usr/share/sounds/plasma-mobile/stereo/ringtones/Spatial.oga</default>
+    </entry>
+  </group>
 </kcfg>
 

src/neochatroom.cpp

@@ -42,6 +42,9 @@
 #endif
 #include <qt_connection_util.h>
 
+#ifdef GSTREAMER_AVAILABLE
+#include "call/callmanager.h"
+#endif
 #include "controller.h"
 #include "events/joinrulesevent.h"
 #include "neochatconfig.h"
@@ -122,6 +125,13 @@ NeoChatRoom::NeoChatRoom(Connection *connection, QString roomId, JoinState joinS
         Q_EMIT canEncryptRoomChanged();
     });
     connect(connection, &Connection::capabilitiesLoaded, this, &NeoChatRoom::maxRoomVersionChanged);
+
+#ifdef GSTREAMER_AVAILABLE
+    connect(this, &Room::callEvent, this, [=](Room *room, const RoomEvent *event) {
+        CallManager::instance().handleCallEvent(static_cast<NeoChatRoom *>(room), event);
+    });
+#endif
+
     connect(this, &Room::changed, this, [this]() {
         Q_EMIT defaultUrlPreviewStateChanged();
     });
@@ -1677,7 +1687,6 @@ void NeoChatRoom::setPushNotificationState(PushNotificationState::State state)
 
     m_currentPushNotificationState = state;
     Q_EMIT pushNotificationStateChanged(m_currentPushNotificationState);
-
 }
 
 void NeoChatRoom::updatePushNotificationState(QString type)

src/notificationsmanager.cpp

@@ -22,6 +22,9 @@
 #include <csapi/pushrules.h>
 #include <jobs/basejob.h>
 #include <user.h>
+#ifdef GSTREAMER_AVAILABLE
+#include "call/callmanager.h"
+#endif
 
 #include "controller.h"
 #include "neochatconfig.h"
@@ -606,3 +609,35 @@ QVector<QVariant> NotificationsManager::toActions(PushNotificationAction::Action
 
     return actions;
 }
+
+#ifdef GSTREAMER_AVAILABLE
+void NotificationsManager::postCallInviteNotification(NeoChatRoom *room, const QString &roomName, const QString &sender, const QImage &icon, bool video)
+{
+    QPixmap img;
+    img.convertFromImage(icon);
+    KNotification *notification = new KNotification("message");
+
+    if (sender == roomName) {
+        notification->setTitle(sender);
+    } else {
+        notification->setTitle(i18n("%1 (%2)", sender, roomName));
+    }
+
+    notification->setText(video ? i18n("%1 is inviting you to a video call", sender) : i18n("%1 is inviting you to a voice call", sender));
+    notification->setPixmap(img);
+    notification->setDefaultAction(i18n("Open NeoChat in this room"));
+    connect(notification, &KNotification::defaultActivated, this, [=]() {
+        RoomManager::instance().enterRoom(room);
+        WindowController::instance().showAndRaiseWindow(notification->xdgActivationToken());
+    });
+    notification->setActions({i18n("Accept"), i18n("Decline")});
+    connect(notification, &KNotification::action1Activated, this, [=]() {
+        CallManager::instance().acceptCall();
+    });
+    connect(notification, &KNotification::action2Activated, this, [=]() {
+        CallManager::instance().hangupCall();
+    });
+    notification->sendEvent();
+    m_notifications.insert(room->id(), notification);
+}
+#endif

src/notificationsmanager.h

@@ -156,6 +156,7 @@ public:
      * @brief Display a native notification for an invite.
      */
     void postInviteNotification(NeoChatRoom *room, const QString &title, const QString &sender, const QImage &icon);
+    void postCallInviteNotification(NeoChatRoom *room, const QString &roomName, const QString &sender, const QImage &icon, bool video);
 
     /**
      * @brief Clear an existing invite notification for the given room.

src/qml/Component/Call/CallPageButton.qml

@@ -0,0 +1,86 @@
+// SPDX-FileCopyrightText: 2022 Carson Black <uhhadd@gmail.com>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+import QtQuick 2.0
+import QtQuick.Controls 2.7 as QQC2
+import QtQuick.Layouts 1.1
+import org.kde.kirigami 2.13 as Kirigami
+
+QQC2.AbstractButton {
+    id: control
+
+    property int temprament: CallPageButton.Neutral
+    property bool shimmering: false
+
+    enum Temprament {
+        Neutral,
+        Constructive,
+        Destructive
+    }
+
+    padding: Kirigami.Units.largeSpacing
+    contentItem: ColumnLayout {
+        QQC2.Control {
+            padding: Kirigami.Units.gridUnit
+
+            Kirigami.Theme.colorSet: Kirigami.Theme.Button
+            Layout.alignment: Qt.AlignHCenter
+
+            contentItem: Kirigami.Icon {
+                implicitHeight: Kirigami.Units.iconSizes.medium
+                implicitWidth: Kirigami.Units.iconSizes.medium
+                source: control.icon.name
+            }
+            background: Rectangle {
+                Kirigami.Theme.colorSet: Kirigami.Theme.Button
+
+                ShimmerGradient {
+                    id: shimmerGradient
+                    color: {
+                        switch (control.temprament) {
+                        case CallPageButton.Neutral:
+                            return Kirigami.Theme.textColor
+                        case CallPageButton.Constructive:
+                            return Kirigami.Theme.positiveTextColor
+                        case CallPageButton.Destructive:
+                            return Kirigami.Theme.negativeTextColor
+                        }
+                    }
+                }
+
+                color: {
+                    if (control.checked) {
+                        return Kirigami.Theme.focusColor
+                    }
+
+                    switch (control.temprament) {
+                    case CallPageButton.Neutral:
+                        return Kirigami.Theme.backgroundColor
+                    case CallPageButton.Constructive:
+                        return Kirigami.Theme.positiveBackgroundColor
+                    case CallPageButton.Destructive:
+                        return Kirigami.Theme.negativeBackgroundColor
+                    }
+                }
+                border.color: Kirigami.Theme.focusColor
+                border.width: control.visualFocus ? 2 : 0
+                radius: height/2
+
+                Rectangle {
+                    visible: control.shimmering
+                    anchors.fill: parent
+                    radius: height/2
+
+                    gradient: control.shimmering ? shimmerGradient : null
+                }
+            }
+        }
+        QQC2.Label {
+            text: control.text
+            font: Kirigami.Theme.smallFont
+
+            horizontalAlignment: Qt.AlignHCenter
+            Layout.fillWidth: true
+        }
+    }
+}

src/qml/Component/Call/VideoStreamDelegate.qml

@@ -0,0 +1,67 @@
+// SPDX-FileCopyrightText: 2022 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+import QtQuick 2.15
+import QtQuick.Controls 2.15 as QQC2
+import QtQuick.Layouts 1.15
+
+import org.kde.kirigami 2.15 as Kirigami
+import org.freedesktop.gstreamer.GLVideoItem 1.0
+
+import org.kde.neochat 1.0
+
+Rectangle {
+    id: videoStreamDelegate
+
+    implicitWidth: height / 9 * 16
+    implicitHeight: 300
+    color: "black"
+    radius: 10
+
+    QQC2.Label {
+        anchors.top: parent.top
+        anchors.horizontalCenter: parent.horizontalCenter
+        color: "white"
+        text: model.object.user.id
+    }
+
+    RowLayout {
+        anchors.fill: parent
+        Loader {
+            active: model.object.hasCamera
+            Layout.maximumWidth: parent.width
+            Layout.maximumHeight: parent.height
+            Layout.preferredHeight: parent.height
+            Layout.preferredWidth: parent.width
+            Layout.alignment: Qt.AlignHCenter | Qt.AlignVCenter
+            onActiveChanged: {
+                if (active) {
+                    model.object.initCamera(camera)
+                }
+            }
+            Component.onCompleted: if (active) model.object.initCamera(camera)
+            GstGLVideoItem {
+                id: camera
+                width: parent.width
+                height: parent.height
+            }
+        }
+        Loader {
+            active: false
+            Layout.maximumWidth: parent.width
+            Layout.maximumHeight: parent.height
+            Layout.preferredHeight: parent.height
+            Layout.preferredWidth: parent.width
+            Layout.alignment: Qt.AlignHCenter | Qt.AlignVCenter
+            GstGLVideoItem {
+                id: screenCast
+                width: parent.width
+                height: parent.height
+
+                Component.onCompleted: {
+                    model.object.initCamera(this)
+                }
+            }
+        }
+    }
+}

src/qml/Component/Timeline/CallInviteDelegate.qml

@@ -0,0 +1,24 @@
+// SPDX-FileCopyrightText: 2022 Carson Black <uhhadd@gmail.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+import QtQuick 2.15
+import QtQuick.Controls 2.15 as QQC2
+import QtQuick.Layouts 1.15
+
+import org.kde.kirigami 2.15 as Kirigami
+import org.kde.neochat 1.0
+
+TimelineContainer {
+    id: root
+
+    width: ListView.view.width
+
+    innerObject: QQC2.Control {
+        Layout.leftMargin: Config.showAvatarInTimeline ? Kirigami.Units.largeSpacing : 0
+        padding: Kirigami.Units.gridUnit*2
+
+        contentItem: QQC2.Label {
+            text: root.author.isLocalUser ? i18n("Outgoing Call") : i18n("Incoming Call")
+        }
+    }
+}

src/qml/Component/Timeline/EventDelegate.qml

@@ -18,6 +18,11 @@ DelegateChooser {
         delegate: StateDelegate {}
     }
 
+    DelegateChoice {
+        roleValue: MessageEventModel.CallInvite
+        delegate: CallInviteDelegate {}
+    }
+
     DelegateChoice {
         roleValue: MessageEventModel.Emote
         delegate: MessageDelegate {}

src/qml/Page/CallPage.qml

@@ -0,0 +1,138 @@
+/* SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+import QtQuick 2.12
+import QtQuick.Controls 2.12 as QQC2
+import QtQuick.Layouts 1.12
+
+import org.kde.kirigami 2.14 as Kirigami
+
+import QtGraphicalEffects 1.15
+
+import org.kde.neochat 1.0
+
+Kirigami.Page {
+    id: page
+
+    title: CallManager.hasInvite ? i18n("Incoming Call")
+            : CallManager.isInviting ? i18n("Calling")
+            : CallManager.state == CallSession.Initiating ? i18n("Configuring Call")
+            : i18n("Call")
+
+    ColumnLayout {
+        id: column
+        anchors.fill: parent
+
+        RowLayout {
+            id: streams
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+            Repeater {
+                id: videos
+                model: CallManager.callParticipants
+                delegate: VideoStreamDelegate {
+                    Layout.fillHeight: true
+                    Layout.fillWidth: true
+                    Layout.alignment: Qt.AlignHCenter
+                }
+            }
+        }
+
+
+        Kirigami.Avatar {
+            visible: videos.count === 0
+            Layout.preferredWidth: Kirigami.Units.iconSizes.huge
+            Layout.preferredHeight: Kirigami.Units.iconSizes.huge
+            Layout.alignment: Qt.AlignHCenter
+
+            name: CallManager.room.displayName
+            source: "image://mxc/" + CallManager.room.avatarMediaId
+        }
+
+        //QQC2.Label {
+            //text: CallManager.remoteUser.displayName
+
+            //horizontalAlignment: Text.AlignHCenter
+            //Layout.fillWidth: true
+        //}
+
+        //QQC2.Label {
+            //text: CallManager.room.displayName
+
+            //horizontalAlignment: Text.AlignHCenter
+            //Layout.fillWidth: true
+        //}
+
+        RowLayout {
+            Layout.alignment: Qt.AlignHCenter
+
+            id: buttonRow
+            spacing: Kirigami.Units.gridUnit
+
+            CallPageButton {
+                text: i18n("Accept")
+                icon.name: "call-start"
+                shimmering: true
+                temprament: CallPageButton.Constructive
+                visible: CallManager.globalState === CallManager.INCOMING
+
+                onClicked: {
+                    visible = false; //TODO declarify
+                    CallManager.acceptCall()
+                }
+            }
+            CallPageButton {
+                text: checked ? i18n("Disable Camera") : i18n("Enable Camera")
+                icon.name: checked ? "camera-on" : "camera-off"
+                checkable: true
+                onToggled: CallManager.toggleCamera()
+            }
+            CallPageButton {
+                text: checked ? i18n("Unmute Speaker") : i18n("Mute Speaker")
+                icon.name: checked ? "audio-volume-muted" : "audio-speakers-symbolic"
+                checkable: true
+            }
+            CallPageButton {
+                text: checked ? i18n("Unmute Microphone") : i18n("Mute Microphone")
+                icon.name: checked ? "microphone-sensitivity-muted" : "microphone-sensitivity-high"
+                checkable: true
+                checked: CallManager.muted
+
+                onToggled: CallManager.muted = !CallManager.muted
+            }
+            CallPageButton {
+                text: i18n("Configure Devices")
+                icon.name: "settings-configure"
+                onClicked: callConfigurationSheet.open()
+            }
+            CallPageButton {
+                id: denyButton
+                visible: CallManager.globalState === CallManager.INCOMING
+                text: i18n("Deny")
+                icon.name: "call-stop"
+                shimmering: true
+                temprament: CallPageButton.Destructive
+
+                onClicked: CallManager.hangupCall()
+            }
+            CallPageButton {
+                visible: !denyButton.visible
+                text: CallManager.isInviting ? i18n("Cancel") : i18n("Hang Up")
+                icon.name: "call-stop"
+                shimmering: CallManager.isInviting
+                temprament: CallPageButton.Destructive
+
+                onClicked: CallManager.hangupCall()
+            }
+        }
+    }
+
+    Connections {
+        target: CallManager
+        function onCallEnded() {
+            page.closeDialog()
+        }
+    }
+}

src/qml/Page/RoomPage.qml

@@ -52,6 +52,16 @@ Kirigami.Page {
         }
     }
 
+    actions.main: Kirigami.Action {
+        text: i18n("Call")
+        icon.name: "call-start"
+        visible: Controller.callsSupported && root.currentRoom.joinedCount === 2
+        onTriggered: {
+            CallManager.startCall(root.currentRoom, true)
+        }
+    }
+
+
     Loader {
         id: timelineViewLoader
         anchors.fill: parent

src/qml/Settings/CallConfigurationPage.qml

@@ -0,0 +1,78 @@
+// SPDX-FileCopyrightText: 2023 Tobias Fella <tobias.fella@kde.org>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+import QtQuick 2.15
+import QtQuick.Controls 2.15 as QQC2
+import QtQuick.Layouts 1.15
+
+import org.kde.kirigami 2.15 as Kirigami
+import org.kde.kirigamiaddons.labs.mobileform 0.1 as MobileForm
+
+import org.kde.neochat 1.0
+
+Kirigami.ScrollablePage {
+    title: i18nc("@title:window", "Calls")
+
+    leftPadding: 0
+    rightPadding: 0
+    ColumnLayout {
+        MobileForm.FormCard {
+            Layout.topMargin: Kirigami.Units.largeSpacing
+            Layout.fillWidth: true
+            contentItem: ColumnLayout {
+                spacing: 0
+                MobileForm.FormCardHeader {
+                    title: i18n("Incoming Calls")
+                }
+                MobileForm.FormCheckDelegate {
+                    text: i18n("Ring")
+                    checked: Config.ring // TODO
+                    enabled: !Config.isRingImmutable //TODO
+                    onToggled: {
+                        Config.ring = checked
+                        Config.sync()
+                    }
+                }
+                MobileForm.FormTextFieldDelegate {
+                    label: i18n("Ringtone")
+                    text: Config.ringtone
+                    enabled: true //TODO
+                    onEditingFinished: {
+                        // TODO
+                    }
+                }
+                //TODO file chooser
+            }
+        }
+
+        MobileForm.FormCard {
+            Layout.topMargin: Kirigami.Units.largeSpacing
+            Layout.fillWidth: true
+            contentItem: ColumnLayout {
+                spacing: 0
+                MobileForm.FormCardHeader {
+                    title: i18n("Default Devices")
+                }
+
+                MobileForm.FormComboBoxDelegate {
+                    text: i18n("Microphone")
+                    description: i18n("This microphone will be used by default during calls. You can also switch the microphone during calls.")
+                    model: AudioSources
+                    enabled: true //TODO
+                    onCurrentIndexChanged: {
+                        // TODO
+                    }
+                }
+                MobileForm.FormComboBoxDelegate {
+                    text: i18n("Camera")
+                    description: i18n("This camera will be used by default during calls. You can also switch the camera during calls.")
+                    model: VideoSources
+                    enabled: true // TODO
+                    onCurrentIndexChanged: {
+                        // TODO
+                    }
+                }
+            }
+        }
+    }
+}

src/qml/Settings/SettingsPage.qml

@@ -58,6 +58,12 @@ Kirigami.CategorizedSettings {
             icon.name: "computer"
             page: Qt.resolvedUrl("DevicesPage.qml")
         },
+        Kirigami.SettingAction {
+            actionName: "calls"
+            text: i18n("Calls")
+            iconName: "call-start"
+            page: Qt.resolvedUrl("CallConfigurationPage.qml")
+        },
         Kirigami.SettingAction {
             actionName: "aboutNeochat"
             text: i18n("About NeoChat")

src/qml/main.qml

@@ -43,6 +43,18 @@ Kirigami.ApplicationWindow {
         source: Qt.resolvedUrl("qrc:/GlobalMenu.qml")
     }
 
+    Connections {
+        target: Controller.callsSupported ? CallManager : undefined
+
+        function onGlobalStateChanged() {
+            if (CallManager.globalState === CallManager.OUTGOING || CallManager.globalState === CallManager.INCOMING) {
+                pageStack.pushDialogLayer("qrc:/CallPage.qml", {}, {
+                    title: i18n("Call")
+                })
+            }
+        }
+    }
+
     // This timer allows to batch update the window size change to reduce
     // the io load and also work around the fact that x/y/width/height are
     // changed when loading the page and overwrite the saved geometry from

src/res.qrc

@@ -105,6 +105,7 @@
         <file alias="GlobalNotificationsPage.qml">qml/Settings/GlobalNotificationsPage.qml</file>
         <file alias="NotificationRuleItem.qml">qml/Settings/NotificationRuleItem.qml</file>
         <file alias="AppearanceSettingsPage.qml">qml/Settings/AppearanceSettingsPage.qml</file>
+        <file alias="CallConfigurationPage.qml">qml/Settings/CallConfigurationPage.qml</file>
         <file alias="AccountsPage.qml">qml/Settings/AccountsPage.qml</file>
         <file alias="AccountEditorPage.qml">qml/Settings/AccountEditorPage.qml</file>
         <file alias="DevicesPage.qml">qml/Settings/DevicesPage.qml</file>
@@ -127,5 +128,9 @@
         <file alias="AvatarTabButton.qml">qml/Component/AvatarTabButton.qml</file>
         <file alias="SpaceDrawer.qml">qml/Page/RoomList/SpaceDrawer.qml</file>
         <file alias="OsmLocationPlugin.qml">qml/Component/Timeline/OsmLocationPlugin.qml</file>
+        <file alias="CallPageButton.qml">qml/Component/Call/CallPageButton.qml</file>
+        <file alias="VideoStreamDelegate.qml">qml/Component/Call/VideoStreamDelegate.qml</file>
+        <file alias="CallPage.qml">qml/Page/CallPage.qml</file>
+        <file alias="CallInviteDelegate.qml">qml/Component/Timeline/CallInviteDelegate.qml</file>
     </qresource>
 </RCC>