Merge pull request #1696 from famedly/td/fosdemDemoFork

feat: famedly calls
2024-04-23 17:32:41 +05:30 · 2024-04-23 17:32:41 +05:30 · 32a425a362
parent 8926415485 20a31c1908
commit 32a425a362
38 changed files with 4066 additions and 3109 deletions
--- a/.github/workflows/versions.env
+++ b/.github/workflows/versions.env
@ -1,2 +1,2 @@
-flutter_version=3.19.0
-dart_version=3.3.0
+flutter_version=3.16.9
+dart_version=3.2.6
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -303,7 +303,7 @@ or before logout), excessive linebreaks in markdown messages and a few edge case
 - fix: Check the max server file size after shrinking not before (Krille)
 - fix: casting of a List<dynamic> to List<String> in getEventList and getEventIdList (td)
 - fix: Skip rules with unknown conditions (Nicolas Werner)
- fix: allow passing a WrappedMediaStream to GroupCall.enter() to use as the local user media stream (td)
+- fix: allow passing a WrappedMediaStream to GroupCallSession.enter() to use as the local user media stream (td)

 ## [0.19.0] - 21st April 2023

--- a/lib/encryption/olm_manager.dart
+++ b/lib/encryption/olm_manager.dart
@ -561,6 +561,8 @@ class OlmManager {
        DateTime.now()
            .subtract(Duration(hours: 1))
            .isBefore(_restoredOlmSessionsTime[mapKey]!)) {
+      Logs().w(
+          '[OlmManager] Skipping restore session, one was restored in the past hour');
      return;
    }
    _restoredOlmSessionsTime[mapKey] = DateTime.now();
@ -736,7 +738,7 @@ class OlmManager {

  Future<void> handleToDeviceEvent(ToDeviceEvent event) async {
    if (event.type == EventTypes.Dummy) {
-      // We receive dan encrypted m.dummy. This means that the other end was not able to
+      // We received an encrypted m.dummy. This means that the other end was not able to
      // decrypt our last message. So, we re-send it.
      final encryptedContent = event.encryptedContent;
      if (encryptedContent == null || encryption.olmDatabase == null) {
--- a/lib/matrix.dart
+++ b/lib/matrix.dart
@ -30,13 +30,22 @@ export 'src/database/sqflite_encryption_helper.dart';
 export 'src/event.dart';
 export 'src/presence.dart';
 export 'src/event_status.dart';
-export 'src/voip/call.dart';
-export 'src/voip/group_call.dart';
+export 'src/voip/call_session.dart';
+export 'src/voip/group_call_session.dart';
 export 'src/voip/voip.dart';
-export 'src/voip/voip_content.dart';
-export 'src/voip/conn_tester.dart';
-export 'src/voip/utils.dart';
-export 'src/voip/voip_room_extension.dart';
+export 'src/voip/backend/livekit_backend.dart';
+export 'src/voip/backend/call_backend_model.dart';
+export 'src/voip/backend/mesh_backend.dart';
+export 'src/voip/models/call_events.dart';
+export 'src/voip/models/webrtc_delegate.dart';
+export 'src/voip/models/call_participant.dart';
+export 'src/voip/models/key_provider.dart';
+export 'src/voip/utils/conn_tester.dart';
+export 'src/voip/utils/voip_constants.dart';
+export 'src/voip/utils/rtc_candidate_extension.dart';
+export 'src/voip/utils/famedly_call_extension.dart';
+export 'src/voip/utils/types.dart';
+export 'src/voip/utils/wrapped_media_stream.dart';
 export 'src/room.dart';
 export 'src/timeline.dart';
 export 'src/user.dart';
--- a/lib/matrix_api_lite/model/event_types.dart
+++ b/lib/matrix_api_lite/model/event_types.dart
@ -59,8 +59,6 @@ abstract class EventTypes {
  static const String CallAssertedIdentity = 'm.call.asserted_identity';
  static const String CallAssertedIdentityPrefix =
      'org.matrix.call.asserted_identity';
-  static const String GroupCallPrefix = 'org.matrix.msc3401.call';
-  static const String GroupCallMemberPrefix = 'org.matrix.msc3401.call.member';
  static const String Unknown = 'm.unknown';

  // To device event types
@ -94,6 +92,26 @@ abstract class EventTypes {
  static String secretStorageKey(String keyId) => 'm.secret_storage.key.$keyId';

  // Spaces
-  static const String spaceParent = 'm.space.parent';
-  static const String spaceChild = 'm.space.child';
+  static const String SpaceParent = 'm.space.parent';
+  static const String SpaceChild = 'm.space.child';
+
+  // MatrixRTC
+  static const String GroupCallMember = 'com.famedly.call.member';
+  static const String GroupCallMemberEncryptionKeys =
+      '$GroupCallMember.encryption_keys';
+  static const String GroupCallMemberEncryptionKeysRequest =
+      '$GroupCallMember.encryption_keys_request';
+  static const String GroupCallMemberCandidates = '$GroupCallMember.candidates';
+  static const String GroupCallMemberInvite = '$GroupCallMember.invite';
+  static const String GroupCallMemberAnswer = '$GroupCallMember.answer';
+  static const String GroupCallMemberHangup = '$GroupCallMember.hangup';
+  static const String GroupCallMemberSelectAnswer =
+      '$GroupCallMember.select_answer';
+  static const String GroupCallMemberReject = '$GroupCallMember.reject';
+  static const String GroupCallMemberNegotiate = '$GroupCallMember.negotiate';
+  static const String GroupCallMemberSDPStreamMetadataChanged =
+      '$GroupCallMember.sdp_stream_metadata_changed';
+  static const String GroupCallMemberReplaces = '$GroupCallMember.replaces';
+  static const String GroupCallMemberAssertedIdentity =
+      '$GroupCallMember.asserted_identity';
 }
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@ -219,8 +219,8 @@ class Client extends MatrixApi {
      EventTypes.Encryption,
      EventTypes.RoomCanonicalAlias,
      EventTypes.RoomTombstone,
-      EventTypes.spaceChild,
-      EventTypes.spaceParent,
+      EventTypes.SpaceChild,
+      EventTypes.SpaceParent,
      EventTypes.RoomCreate,
    ]);
    roomPreviewLastEvents.addAll([
@ -231,8 +231,7 @@ class Client extends MatrixApi {
      EventTypes.CallAnswer,
      EventTypes.CallReject,
      EventTypes.CallHangup,
-      EventTypes.GroupCallPrefix,
-      EventTypes.GroupCallMemberPrefix,
+      EventTypes.GroupCallMember,
    ]);

    // register all the default commands
@ -800,8 +799,7 @@ class Client extends MatrixApi {
    if (groupCall) {
      powerLevelContentOverride ??= {};
      powerLevelContentOverride['events'] = <String, dynamic>{
-        EventTypes.GroupCallMemberPrefix: 0,
-        EventTypes.GroupCallPrefix: 0,
+        EventTypes.GroupCallMember: 0,
      };
    }
    final roomId = await createRoom(
@ -1264,6 +1262,10 @@ class Client extends MatrixApi {
  final CachedStreamController<ToDeviceEvent> onToDeviceEvent =
      CachedStreamController();

+  /// Tells you about to-device and room call specific events in sync
+  final CachedStreamController<List<BasicEventWithSender>> onCallEvents =
+      CachedStreamController();
+
  /// Called when the login state e.g. user gets logged out.
  final CachedStreamController<LoginState> onLoginStateChanged =
      CachedStreamController();
@ -1295,41 +1297,6 @@ class Client extends MatrixApi {
  final CachedStreamController<BasicEvent> onAccountData =
      CachedStreamController();

-  /// Will be called on call invites.
-  final CachedStreamController<Event> onCallInvite = CachedStreamController();
-
-  /// Will be called on call hangups.
-  final CachedStreamController<Event> onCallHangup = CachedStreamController();
-
-  /// Will be called on call candidates.
-  final CachedStreamController<Event> onCallCandidates =
-      CachedStreamController();
-
-  /// Will be called on call answers.
-  final CachedStreamController<Event> onCallAnswer = CachedStreamController();
-
-  /// Will be called on call replaces.
-  final CachedStreamController<Event> onCallReplaces = CachedStreamController();
-
-  /// Will be called on select answers.
-  final CachedStreamController<Event> onCallSelectAnswer =
-      CachedStreamController();
-
-  /// Will be called on rejects.
-  final CachedStreamController<Event> onCallReject = CachedStreamController();
-
-  /// Will be called on negotiates.
-  final CachedStreamController<Event> onCallNegotiate =
-      CachedStreamController();
-
-  /// Will be called on Asserted Identity received.
-  final CachedStreamController<Event> onAssertedIdentityReceived =
-      CachedStreamController();
-
-  /// Will be called on SDPStream Metadata changed.
-  final CachedStreamController<Event> onSDPStreamMetadataChangedReceived =
-      CachedStreamController();
-
  /// Will be called when another device is requesting session keys for a room.
  final CachedStreamController<RoomKeyRequest> onRoomKeyRequest =
      CachedStreamController();
@ -1343,9 +1310,6 @@ class Client extends MatrixApi {
  final CachedStreamController<UiaRequest> onUiaRequest =
      CachedStreamController();

-  final CachedStreamController<Event> onGroupCallRequest =
-      CachedStreamController();
-
  final CachedStreamController<Event> onGroupMember = CachedStreamController();

  final CachedStreamController<Event> onRoomState = CachedStreamController();
@ -2069,6 +2033,7 @@ class Client extends MatrixApi {

  Future<void> _handleToDeviceEvents(List<BasicEventWithSender> events) async {
    final Map<String, List<String>> roomsWithNewKeyToSessionId = {};
+    final List<ToDeviceEvent> callToDeviceEvents = [];
    for (final event in events) {
      var toDeviceEvent = ToDeviceEvent.fromJson(event.toJson());
      Logs().v('Got to_device event of type ${toDeviceEvent.type}');
@ -2089,9 +2054,16 @@ class Client extends MatrixApi {
        }
        await encryption?.handleToDeviceEvent(toDeviceEvent);
      }
+      if (toDeviceEvent.type.startsWith(CallConstants.callEventsRegxp)) {
+        callToDeviceEvents.add(toDeviceEvent);
+      }
      onToDeviceEvent.add(toDeviceEvent);
    }

+    if (callToDeviceEvents.isNotEmpty) {
+      onCallEvents.add(callToDeviceEvents);
+    }
+
    // emit updates for all events in the queue
    for (final entry in roomsWithNewKeyToSessionId.entries) {
      final roomId = entry.key;
@ -2257,7 +2229,7 @@ class Client extends MatrixApi {
      {bool store = true}) async {
    // Calling events can be omitted if they are outdated from the same sync. So
    // we collect them first before we handle them.
-    final callEvents = <Event>{};
+    final callEvents = <Event>[];

    for (final event in events) {
      // The client must ignore any new m.room.encryption event to prevent
@ -2308,93 +2280,17 @@ class Client extends MatrixApi {
      if (prevBatch != null &&
          (type == EventUpdateType.timeline ||
              type == EventUpdateType.decryptedTimelineQueue)) {
-        if ((update.content.tryGet<String>('type')?.startsWith('m.call.') ??
-                false) ||
-            (update.content
-                    .tryGet<String>('type')
-                    ?.startsWith('org.matrix.call.') ??
-                false)) {
+        if ((update.content
+                .tryGet<String>('type')
+                ?.startsWith(CallConstants.callEventsRegxp) ??
+            false)) {
          final callEvent = Event.fromJson(update.content, room);
-          final callId = callEvent.content.tryGet<String>('call_id');
          callEvents.add(callEvent);
-
-          // Call Invites should be omitted for a call that is already answered,
-          // has ended, is rejectd or replaced.
-          const callEndedEventTypes = {
-            EventTypes.CallAnswer,
-            EventTypes.CallHangup,
-            EventTypes.CallReject,
-            EventTypes.CallReplaces,
-          };
-          const ommitWhenCallEndedTypes = {
-            EventTypes.CallInvite,
-            EventTypes.CallCandidates,
-            EventTypes.CallNegotiate,
-            EventTypes.CallSDPStreamMetadataChanged,
-            EventTypes.CallSDPStreamMetadataChangedPrefix,
-          };
-
-          if (callEndedEventTypes.contains(callEvent.type)) {
-            callEvents.removeWhere((event) {
-              if (ommitWhenCallEndedTypes.contains(event.type) &&
-                  event.content.tryGet<String>('call_id') == callId) {
-                Logs().v(
-                    'Ommit "${event.type}" event for an already terminated call');
-                return true;
-              }
-              return false;
-            });
-          }
-
-          final age = callEvent.unsigned?.tryGet<int>('age') ??
-              (DateTime.now().millisecondsSinceEpoch -
-                  callEvent.originServerTs.millisecondsSinceEpoch);
-
-          callEvents.removeWhere((element) {
-            if (callEvent.type == EventTypes.CallInvite &&
-                age >
-                    (callEvent.content.tryGet<int>('lifetime') ??
-                        CallTimeouts.callInviteLifetime.inMilliseconds)) {
-              Logs().v(
-                  'Ommiting invite event ${callEvent.eventId} as age was older than lifetime');
-              return true;
-            }
-            return false;
-          });
        }
      }
    }
-
-    callEvents.forEach(_callStreamByCallEvent);
-  }
-
-  void _callStreamByCallEvent(Event event) {
-    if (event.type == EventTypes.CallInvite) {
-      onCallInvite.add(event);
-    } else if (event.type == EventTypes.CallHangup) {
-      onCallHangup.add(event);
-    } else if (event.type == EventTypes.CallAnswer) {
-      onCallAnswer.add(event);
-    } else if (event.type == EventTypes.CallCandidates) {
-      onCallCandidates.add(event);
-    } else if (event.type == EventTypes.CallSelectAnswer) {
-      onCallSelectAnswer.add(event);
-    } else if (event.type == EventTypes.CallReject) {
-      onCallReject.add(event);
-    } else if (event.type == EventTypes.CallNegotiate) {
-      onCallNegotiate.add(event);
-    } else if (event.type == EventTypes.CallReplaces) {
-      onCallReplaces.add(event);
-    } else if (event.type == EventTypes.CallAssertedIdentity ||
-        event.type == EventTypes.CallAssertedIdentityPrefix) {
-      onAssertedIdentityReceived.add(event);
-    } else if (event.type == EventTypes.CallSDPStreamMetadataChanged ||
-        event.type == EventTypes.CallSDPStreamMetadataChangedPrefix) {
-      onSDPStreamMetadataChangedReceived.add(event);
-      // TODO(duan): Only used (org.matrix.msc3401.call) during the current test,
-      // need to add GroupCallPrefix in matrix_api_lite
-    } else if (event.type == EventTypes.GroupCallPrefix) {
-      onGroupCallRequest.add(event);
+    if (callEvents.isNotEmpty) {
+      onCallEvents.add(callEvents);
    }
  }

--- a/lib/src/room.dart
+++ b/lib/src/room.dart
@ -1835,7 +1835,7 @@ class Room {
    return powerForChangingStateEvent(action) <= ownPowerLevel;
  }

-  /// returns the powerlevel required for chaning the `action` defaults to
+  /// returns the powerlevel required for changing the `action` defaults to
  /// state_default if `action` isn't specified in events override.
  /// If there is no state_default in the m.room.power_levels event, the
  /// state_default is 50. If the room contains no m.room.power_levels event,
@ -1850,25 +1850,18 @@ class Room {
        50;
  }

-  bool get canCreateGroupCall =>
-      canChangeStateEvent(EventTypes.GroupCallPrefix) && groupCallsEnabled;
-
-  bool get canJoinGroupCall =>
-      canChangeStateEvent(EventTypes.GroupCallMemberPrefix) &&
-      groupCallsEnabled;
-
-  /// if returned value is not null `org.matrix.msc3401.call.member` is present
+  /// if returned value is not null `EventTypes.GroupCallMember` is present
  /// and group calls can be used
-  bool get groupCallsEnabled {
+  bool get groupCallsEnabledForEveryone {
    final powerLevelMap = getState(EventTypes.RoomPowerLevels)?.content;
    if (powerLevelMap == null) return false;
-    return powerForChangingStateEvent(EventTypes.GroupCallMemberPrefix) <=
-            getDefaultPowerLevel(powerLevelMap) &&
-        powerForChangingStateEvent(EventTypes.GroupCallPrefix) <=
-            getDefaultPowerLevel(powerLevelMap);
+    return powerForChangingStateEvent(EventTypes.GroupCallMember) <=
+        getDefaultPowerLevel(powerLevelMap);
  }

-  /// sets the `org.matrix.msc3401.call.member` power level to users default for
+  bool get canJoinGroupCall => canChangeStateEvent(EventTypes.GroupCallMember);
+
+  /// sets the `EventTypes.GroupCallMember` power level to users default for
  /// group calls, needs permissions to change power levels
  Future<void> enableGroupCalls() async {
    if (!canChangePowerLevel) return;
@ -1878,9 +1871,7 @@ class Room {
      final eventsMap = newPowerLevelMap.tryGetMap<String, Object?>('events') ??
          <String, Object?>{};
      eventsMap.addAll({
-        EventTypes.GroupCallPrefix: getDefaultPowerLevel(currentPowerLevelsMap),
-        EventTypes.GroupCallMemberPrefix:
-            getDefaultPowerLevel(currentPowerLevelsMap)
+        EventTypes.GroupCallMember: getDefaultPowerLevel(currentPowerLevelsMap)
      });
      newPowerLevelMap.addAll({'events': eventsMap});
      await client.setRoomStateWithKey(
@ -2229,14 +2220,14 @@ class Room {
  /// `m.space`.
  bool get isSpace =>
      getState(EventTypes.RoomCreate)?.content.tryGet<String>('type') ==
-      RoomCreationTypes.mSpace; // TODO: Magic string!
+      RoomCreationTypes.mSpace;

  /// The parents of this room. Currently this SDK doesn't yet set the canonical
  /// flag and is not checking if this room is in fact a child of this space.
  /// You should therefore not rely on this and always check the children of
  /// the space.
  List<SpaceParent> get spaceParents =>
-      states[EventTypes.spaceParent]
+      states[EventTypes.SpaceParent]
          ?.values
          .map((state) => SpaceParent.fromState(state))
          .where((child) => child.via.isNotEmpty)
@ -2249,7 +2240,7 @@ class Room {
  /// sorted at the end of the list.
  List<SpaceChild> get spaceChildren => !isSpace
      ? throw Exception('Room is not a space!')
-      : (states[EventTypes.spaceChild]
+      : (states[EventTypes.SpaceChild]
              ?.values
              .map((state) => SpaceChild.fromState(state))
              .where((child) => child.via.isNotEmpty)
@ -2268,12 +2259,12 @@ class Room {
  }) async {
    if (!isSpace) throw Exception('Room is not a space!');
    via ??= [client.userID!.domain!];
-    await client.setRoomStateWithKey(id, EventTypes.spaceChild, roomId, {
+    await client.setRoomStateWithKey(id, EventTypes.SpaceChild, roomId, {
      'via': via,
      if (order != null) 'order': order,
      if (suggested != null) 'suggested': suggested,
    });
-    await client.setRoomStateWithKey(roomId, EventTypes.spaceParent, id, {
+    await client.setRoomStateWithKey(roomId, EventTypes.SpaceParent, id, {
      'via': via,
    });
    return;
--- a/lib/src/utils/matrix_default_localizations.dart
+++ b/lib/src/utils/matrix_default_localizations.dart
@ -235,7 +235,6 @@ class MatrixDefaultLocalizations extends MatrixLocalizations {
  }

  @override
-  // TODO: implement youAcceptedTheInvitation
  String get youAcceptedTheInvitation => 'You accepted the invitation';

  @override
--- a/lib/src/utils/space_child.dart
+++ b/lib/src/utils/space_child.dart
@ -26,7 +26,7 @@ class SpaceChild {
  final bool? suggested;

  SpaceChild.fromState(Event state)
-      : assert(state.type == EventTypes.spaceChild),
+      : assert(state.type == EventTypes.SpaceChild),
        roomId = state.stateKey,
        via = state.content.tryGetList<String>('via') ?? [],
        order = state.content.tryGet<String>('order') ?? '',
@ -39,7 +39,7 @@ class SpaceParent {
  final bool? canonical;

  SpaceParent.fromState(Event state)
-      : assert(state.type == EventTypes.spaceParent),
+      : assert(state.type == EventTypes.SpaceParent),
        roomId = state.stateKey,
        via = state.content.tryGetList<String>('via') ?? [],
        canonical = state.content.tryGet<bool>('canonical');
--- a/lib/src/voip/README.md
+++ b/lib/src/voip/README.md
@ -1,6 +1,14 @@
-# VOIP for Matrix SDK
+# Famedly Calls

-1:1 and group calls
+Supports
+- 1:1 webrtc calls
+- Group calls with:
+  - mesh webrtc calls
+  - just handling state of calls and signallnig for e2ee keys in sfu mode (check `isLivekitCall`)
+
+Places where we diverted from spec afaik:
+- To enable p2p calls between devices of the same user, pass a `invitee_device_id` to the `m.call.invite` method
+- **to-device call events such as in msc3401 MUST `room_id` to map the event to a room**

 ## Overview

@ -8,13 +16,82 @@

 `CallSession` objects are created by calling `inviteToCall` and `onCallInvite`.

-`GroupCall` objects are created by calling `createGroupCall`.
+`GroupCallSession` objects are created by calling `fetchOrCreateGroupCall`.
+
+## Group Calls
+
+All communication for group calls happens over to-device events except the `com.famedly.call.member` event.
+
+
+
+Sends the `com.famedly.call.member` event to signal an active membership. The format has to be the following:
+
+### Events -
+
+```json5
+"content": {
+    "memberships": [
+        {
+            "application": "m.call",
+            "backend": {
+                "type": "mesh"
+            },
+            "call_id": "!qoQQTYnzXOHSdEgqQp:im.staging.famedly.de",
+            "device_id": "YVGPEWNLDD",
+            "expires_ts": 1705152401042,
+            "scope": "m.room"
+        }
+    ]
+}
+```
+
+- **application**: could be anything f.ex `m.call`, `m.game` or `m.board`
+- **backend**: see below
+- **call_id**: the call id, currently setting it to the roomId makes the call for the whole room, this is to avoid parallel calls starting up. For user scoped calls in a room you could set this to `AuserId:BuserId`. The sdk does not restrict setting roomId for user scoped calls atm.
+- **device_id**: The sdk supports calling between devices of same users, so this needs to be set to the sender device id.
+- **expires_ts**: ms since epoch when this membership event should be considered expired. Check `lib/src/voip/utils/constants.dart` for current values of how long the inital period is and how often this gets autoupdated.
+- **scope**: room scoped calls are `m.room`, user scoped can be `m.user`
+
+
+
+#### The backend can be either `mesh` or `livekit`
+
+##### Livekit - 
+```json5
+"backend": {
+    "livekit_alias": "!qoQQTYnzXOHSdEgqQp:im.staging.famedly.de",
+    "livekit_service_url": "https://famedly-livekit-server.teedee.dev/jwt",
+    "type": "livekit"
+},
+```
+
+##### Mesh -
+```json5
+"backend": {
+    "type": "mesh"
+},
+```
+
+#### E2EE Events -
+
+When in SFU/Livekit mode, the sdk can handle sending and requesting encryption keys. Currently it uses the following events: 
+
+- sending: `com.famedly.call.encryption_keys`
+- requesting: `com.famedly.call.encryption_keys.request`
+
+As usual remember to send the `party_id`/`sender_session_id` to map your keys to the right userId and deviceId
+
+You need to implement `EncryptionKeyProvider` and set the override the methods to interact with your actual keyProvider. The main one as of now is `onSetEncryptionKey`.
+
+You can request missing keys whenever needed using `groupCall.requestEncrytionKey(remoteParticipants)`.
+

 ## 1:1 calls

 ### 1. Basic call flow

 This flow explains the code flow for a 1v1 call.
+
 This code flow is still used in group call, the only difference is that group call uses `toDevice` message to send `m.call.*` events

 ![1v1 call](images/famedly-1v1-call.drawio.png)
@ -79,11 +156,14 @@ We need to use the matrix roomId to initiate the call, the initial call can be

 After the call is sent, you can use `onCallStateChanged` to listen the call state events. These events are used to change the display of the call UI state, for example, change the control buttons, display `Hangup (cancel)` button before connecting, and display `mute mic, mute cam, hold/unhold, hangup` buttons after connected.

+You cannot call a whole room, please specify the userId you intend to call in `inviteToCall`
+
+
 ```dart
 final voip = VoIP(client, MyVoipApp());

 /// Create a new call
-final newCall = await voip.inviteToCall(roomId, CallType.kVideo);
+final newCall = await voip.inviteToCall(roomId, CallType.kVideo, userId);

 newCall.onCallStateChanged.stream.listen((state) {
  /// handle call state change event，
--- a/lib/src/voip/backend/call_backend_model.dart
+++ b/lib/src/voip/backend/call_backend_model.dart
@ -0,0 +1,112 @@
+import 'dart:async';
+
+import 'package:matrix/matrix.dart';
+import 'package:matrix/src/voip/models/call_membership.dart';
+
+abstract class CallBackend {
+  String type;
+
+  CallBackend({
+    required this.type,
+  });
+
+  factory CallBackend.fromJson(Map<String, Object?> json) {
+    final String type = json['type'] as String;
+    if (type == 'mesh') {
+      return MeshBackend(
+        type: type,
+      );
+    } else if (type == 'livekit') {
+      return LiveKitBackend(
+        livekitAlias: json['livekit_alias'] as String,
+        livekitServiceUrl: json['livekit_service_url'] as String,
+        type: type,
+      );
+    } else {
+      throw ArgumentError('Invalid type: $type');
+    }
+  }
+
+  Map<String, Object?> toJson();
+
+  bool get e2eeEnabled;
+
+  CallParticipant? get activeSpeaker;
+
+  WrappedMediaStream? get localUserMediaStream;
+
+  WrappedMediaStream? get localScreenshareStream;
+
+  List<WrappedMediaStream> get userMediaStreams;
+
+  List<WrappedMediaStream> get screenShareStreams;
+
+  bool get isLocalVideoMuted;
+
+  bool get isMicrophoneMuted;
+
+  Future<WrappedMediaStream?> initLocalStream(
+    GroupCallSession groupCall, {
+    WrappedMediaStream? stream,
+  });
+
+  Future<void> updateMediaDeviceForCalls();
+
+  Future<void> setupP2PCallsWithExistingMembers(GroupCallSession groupCall);
+
+  Future<void> setupP2PCallWithNewMember(
+    GroupCallSession groupCall,
+    CallParticipant rp,
+    CallMembership mem,
+  );
+
+  Future<void> dispose(GroupCallSession groupCall);
+
+  Future<void> onNewParticipant(
+    GroupCallSession groupCall,
+    List<CallParticipant> anyJoined,
+  );
+
+  Future<void> onLeftParticipant(
+    GroupCallSession groupCall,
+    List<CallParticipant> anyLeft,
+  );
+
+  Future<void> requestEncrytionKey(
+    GroupCallSession groupCall,
+    List<CallParticipant> remoteParticipants,
+  );
+
+  Future<void> onCallEncryption(
+    GroupCallSession groupCall,
+    String userId,
+    String deviceId,
+    Map<String, dynamic> content,
+  );
+
+  Future<void> onCallEncryptionKeyRequest(
+    GroupCallSession groupCall,
+    String userId,
+    String deviceId,
+    Map<String, dynamic> content,
+  );
+
+  Future<void> setDeviceMuted(
+    GroupCallSession groupCall,
+    bool muted,
+    MediaInputKind kind,
+  );
+
+  Future<void> setScreensharingEnabled(
+    GroupCallSession groupCall,
+    bool enabled,
+    String desktopCapturerSourceId,
+  );
+
+  List<Map<String, String>>? getCurrentFeeds();
+
+  @override
+  bool operator ==(Object other);
+  @override
+  int get hashCode;
+}
--- a/lib/src/voip/backend/livekit_backend.dart
+++ b/lib/src/voip/backend/livekit_backend.dart
@ -0,0 +1,506 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'package:matrix/matrix.dart';
+import 'package:matrix/src/utils/crypto/crypto.dart';
+import 'package:matrix/src/voip/models/call_membership.dart';
+
+class LiveKitBackend extends CallBackend {
+  final String livekitServiceUrl;
+  final String livekitAlias;
+
+  @override
+  final bool e2eeEnabled;
+
+  LiveKitBackend({
+    required this.livekitServiceUrl,
+    required this.livekitAlias,
+    super.type = 'livekit',
+    this.e2eeEnabled = true,
+  });
+
+  Timer? _memberLeaveEncKeyRotateDebounceTimer;
+
+  /// participant:keyIndex:keyBin
+  final Map<CallParticipant, Map<int, Uint8List>> _encryptionKeysMap = {};
+
+  final List<Future> _setNewKeyTimeouts = [];
+
+  int _indexCounter = 0;
+
+  /// used to send the key again incase someone `onCallEncryptionKeyRequest` but don't just send
+  /// the last one because you also cycle back in your window which means you
+  /// could potentially end up sharing a past key
+  int get latestLocalKeyIndex => _latestLocalKeyIndex;
+  int _latestLocalKeyIndex = 0;
+
+  /// the key currently being used by the local cryptor, can possibly not be the latest
+  /// key, check `latestLocalKeyIndex` for latest key
+  int get currentLocalKeyIndex => _currentLocalKeyIndex;
+  int _currentLocalKeyIndex = 0;
+
+  Map<int, Uint8List>? _getKeysForParticipant(CallParticipant participant) {
+    return _encryptionKeysMap[participant];
+  }
+
+  /// always chooses the next possible index, we cycle after 16 because
+  /// no real adv with infinite list
+  int _getNewEncryptionKeyIndex() {
+    final newIndex = _indexCounter % 16;
+    _indexCounter++;
+    return newIndex;
+  }
+
+  /// makes a new e2ee key for local user and sets it with a delay if specified
+  /// used on first join and when someone leaves
+  ///
+  /// also does the sending for you
+  Future<void> _makeNewSenderKey(
+      GroupCallSession groupCall, bool delayBeforeUsingKeyOurself) async {
+    final key = secureRandomBytes(32);
+    final keyIndex = _getNewEncryptionKeyIndex();
+    Logs().i('[VOIP E2EE] Generated new key $key at index $keyIndex');
+
+    await _setEncryptionKey(
+      groupCall,
+      groupCall.localParticipant!,
+      keyIndex,
+      key,
+      delayBeforeUsingKeyOurself: delayBeforeUsingKeyOurself,
+      send: true,
+    );
+  }
+
+  /// also does the sending for you
+  Future<void> _ratchetLocalParticipantKey(
+    GroupCallSession groupCall,
+    List<CallParticipant> sendTo,
+  ) async {
+    final keyProvider = groupCall.voip.delegate.keyProvider;
+
+    if (keyProvider == null) {
+      throw Exception('[VOIP] _ratchetKey called but KeyProvider was null');
+    }
+
+    final myKeys = _encryptionKeysMap[groupCall.localParticipant];
+
+    if (myKeys == null || myKeys.isEmpty) {
+      await _makeNewSenderKey(groupCall, false);
+      return;
+    }
+
+    Uint8List? ratchetedKey;
+
+    while (ratchetedKey == null || ratchetedKey.isEmpty) {
+      Logs().i('[VOIP E2EE] Ignoring empty ratcheted key');
+      ratchetedKey = await keyProvider.onRatchetKey(
+        groupCall.localParticipant!,
+        latestLocalKeyIndex,
+      );
+    }
+
+    Logs().i(
+        '[VOIP E2EE] Ratched latest key to $ratchetedKey at idx $latestLocalKeyIndex');
+
+    await _setEncryptionKey(
+      groupCall,
+      groupCall.localParticipant!,
+      latestLocalKeyIndex,
+      ratchetedKey,
+      delayBeforeUsingKeyOurself: false,
+      send: true,
+      sendTo: sendTo,
+    );
+  }
+
+  /// sets incoming keys and also sends the key if it was for the local user
+  /// if sendTo is null, its sent to all _participants, see `_sendEncryptionKeysEvent`
+  Future<void> _setEncryptionKey(
+    GroupCallSession groupCall,
+    CallParticipant participant,
+    int encryptionKeyIndex,
+    Uint8List encryptionKeyBin, {
+    bool delayBeforeUsingKeyOurself = false,
+    bool send = false,
+    List<CallParticipant>? sendTo,
+  }) async {
+    final encryptionKeys =
+        _encryptionKeysMap[participant] ?? <int, Uint8List>{};
+
+    encryptionKeys[encryptionKeyIndex] = encryptionKeyBin;
+    _encryptionKeysMap[participant] = encryptionKeys;
+    if (participant.isLocal) {
+      _latestLocalKeyIndex = encryptionKeyIndex;
+    }
+
+    if (send) {
+      await _sendEncryptionKeysEvent(
+        groupCall,
+        encryptionKeyIndex,
+        sendTo: sendTo,
+      );
+    }
+
+    if (delayBeforeUsingKeyOurself) {
+      // now wait for the key to propogate and then set it, hopefully users can
+      // stil decrypt everything
+      final useKeyTimeout = Future.delayed(CallTimeouts.useKeyDelay, () async {
+        Logs().i(
+            '[VOIP E2EE] setting key changed event for ${participant.id} idx $encryptionKeyIndex key $encryptionKeyBin');
+        await groupCall.voip.delegate.keyProvider?.onSetEncryptionKey(
+            participant, encryptionKeyBin, encryptionKeyIndex);
+        if (participant.isLocal) {
+          _currentLocalKeyIndex = encryptionKeyIndex;
+        }
+      });
+      _setNewKeyTimeouts.add(useKeyTimeout);
+    } else {
+      Logs().i(
+          '[VOIP E2EE] setting key changed event for ${participant.id} idx $encryptionKeyIndex key $encryptionKeyBin');
+      await groupCall.voip.delegate.keyProvider?.onSetEncryptionKey(
+          participant, encryptionKeyBin, encryptionKeyIndex);
+      if (participant.isLocal) {
+        _currentLocalKeyIndex = encryptionKeyIndex;
+      }
+    }
+  }
+
+  /// sends the enc key to the devices using todevice, passing a list of
+  /// sendTo only sends events to them
+  /// setting keyIndex to null will send the latestKey
+  Future<void> _sendEncryptionKeysEvent(
+    GroupCallSession groupCall,
+    int keyIndex, {
+    List<CallParticipant>? sendTo,
+  }) async {
+    Logs().i('Sending encryption keys event');
+
+    final myKeys = _getKeysForParticipant(groupCall.localParticipant!);
+    final myLatestKey = myKeys?[keyIndex];
+
+    final sendKeysTo =
+        sendTo ?? groupCall.participants.where((p) => !p.isLocal);
+
+    if (myKeys == null || myLatestKey == null) {
+      Logs().w(
+          '[VOIP E2EE] _sendEncryptionKeysEvent Tried to send encryption keys event but no keys found!');
+      await _makeNewSenderKey(groupCall, false);
+      await _sendEncryptionKeysEvent(
+        groupCall,
+        keyIndex,
+        sendTo: sendTo,
+      );
+      return;
+    }
+
+    try {
+      final keyContent = EncryptionKeysEventContent(
+        [EncryptionKeyEntry(keyIndex, base64Encode(myLatestKey))],
+        groupCall.groupCallId,
+      );
+      final Map<String, Object> data = {
+        ...keyContent.toJson(),
+        // used to find group call in groupCalls when ToDeviceEvent happens,
+        // plays nicely with backwards compatibility for mesh calls
+        'conf_id': groupCall.groupCallId,
+        'device_id': groupCall.client.deviceID!,
+        'room_id': groupCall.room.id,
+      };
+      await _sendToDeviceEvent(
+        groupCall,
+        sendTo ?? sendKeysTo.toList(),
+        data,
+        EventTypes.GroupCallMemberEncryptionKeys,
+      );
+    } catch (e, s) {
+      Logs().e('[VOIP] Failed to send e2ee keys, retrying', e, s);
+      await _sendEncryptionKeysEvent(
+        groupCall,
+        keyIndex,
+        sendTo: sendTo,
+      );
+    }
+  }
+
+  Future<void> _sendToDeviceEvent(
+    GroupCallSession groupCall,
+    List<CallParticipant> remoteParticipants,
+    Map<String, Object> data,
+    String eventType,
+  ) async {
+    Logs().v(
+        '[VOIP] _sendToDeviceEvent: sending ${data.toString()} to ${remoteParticipants.map((e) => e.id)} ');
+    final txid =
+        VoIP.customTxid ?? groupCall.client.generateUniqueTransactionId();
+    final mustEncrypt =
+        groupCall.room.encrypted && groupCall.client.encryptionEnabled;
+
+    // could just combine the two but do not want to rewrite the enc thingy
+    // wrappers here again.
+    final List<DeviceKeys> mustEncryptkeysToSendTo = [];
+    final Map<String, Map<String, Map<String, Object>>> unencryptedDataToSend =
+        {};
+
+    for (final participant in remoteParticipants) {
+      if (participant.deviceId == null) continue;
+      if (mustEncrypt) {
+        await groupCall.client.userDeviceKeysLoading;
+        final deviceKey = groupCall.client.userDeviceKeys[participant.userId]
+            ?.deviceKeys[participant.deviceId];
+        if (deviceKey != null) {
+          mustEncryptkeysToSendTo.add(deviceKey);
+        }
+      } else {
+        unencryptedDataToSend.addAll({
+          participant.userId: {participant.deviceId!: data}
+        });
+      }
+    }
+
+    // prepped data, now we send
+    if (mustEncrypt) {
+      await groupCall.client.sendToDeviceEncrypted(
+        mustEncryptkeysToSendTo,
+        eventType,
+        data,
+      );
+    } else {
+      await groupCall.client.sendToDevice(
+        eventType,
+        txid,
+        unencryptedDataToSend,
+      );
+    }
+  }
+
+  @override
+  Map<String, Object?> toJson() {
+    return {
+      'type': type,
+      'livekit_service_url': livekitServiceUrl,
+      'livekit_alias': livekitAlias,
+    };
+  }
+
+  @override
+  Future<void> requestEncrytionKey(
+    GroupCallSession groupCall,
+    List<CallParticipant> remoteParticipants,
+  ) async {
+    final Map<String, Object> data = {
+      'conf_id': groupCall.groupCallId,
+      'device_id': groupCall.client.deviceID!,
+      'room_id': groupCall.room.id,
+    };
+
+    await _sendToDeviceEvent(
+      groupCall,
+      remoteParticipants,
+      data,
+      EventTypes.GroupCallMemberEncryptionKeysRequest,
+    );
+  }
+
+  @override
+  Future<void> onCallEncryption(
+    GroupCallSession groupCall,
+    String userId,
+    String deviceId,
+    Map<String, dynamic> content,
+  ) async {
+    if (!e2eeEnabled) {
+      Logs().w('[VOIP] got sframe key but we do not support e2ee');
+      return;
+    }
+    final keyContent = EncryptionKeysEventContent.fromJson(content);
+
+    final callId = keyContent.callId;
+
+    if (keyContent.keys.isEmpty) {
+      Logs().w(
+          '[VOIP E2EE] Received m.call.encryption_keys where keys is empty: callId=$callId');
+      return;
+    } else {
+      Logs().i(
+          '[VOIP E2EE]: onCallEncryption, got keys from $userId:$deviceId ${keyContent.toJson()}');
+    }
+
+    for (final key in keyContent.keys) {
+      final encryptionKey = key.key;
+      final encryptionKeyIndex = key.index;
+      await _setEncryptionKey(
+        groupCall,
+        CallParticipant(groupCall.voip, userId: userId, deviceId: deviceId),
+        encryptionKeyIndex,
+        // base64Decode here because we receive base64Encoded version
+        base64Decode(encryptionKey),
+        delayBeforeUsingKeyOurself: false,
+        send: false,
+      );
+    }
+  }
+
+  @override
+  Future<void> onCallEncryptionKeyRequest(
+    GroupCallSession groupCall,
+    String userId,
+    String deviceId,
+    Map<String, dynamic> content,
+  ) async {
+    if (!e2eeEnabled) {
+      Logs().w('[VOIP] got sframe key request but we do not support e2ee');
+      return;
+    }
+    final mems = groupCall.room.getCallMembershipsForUser(userId);
+    if (mems
+        .where(
+          (mem) =>
+              mem.callId == groupCall.groupCallId &&
+              mem.userId == userId &&
+              mem.deviceId == deviceId &&
+              !mem.isExpired &&
+              // sanity checks
+              mem.backend.type == groupCall.backend.type &&
+              mem.roomId == groupCall.room.id &&
+              mem.application == groupCall.application,
+        )
+        .isNotEmpty) {
+      Logs().d(
+          '[VOIP] onCallEncryptionKeyRequest: request checks out, sending key on index: $latestLocalKeyIndex to $userId:$deviceId');
+      await _sendEncryptionKeysEvent(
+        groupCall,
+        _latestLocalKeyIndex,
+        sendTo: [
+          CallParticipant(
+            groupCall.voip,
+            userId: userId,
+            deviceId: deviceId,
+          )
+        ],
+      );
+    }
+  }
+
+  @override
+  Future<void> onNewParticipant(
+    GroupCallSession groupCall,
+    List<CallParticipant> anyJoined,
+  ) async {
+    if (!e2eeEnabled) return;
+    if (groupCall.voip.enableSFUE2EEKeyRatcheting) {
+      await _ratchetLocalParticipantKey(groupCall, anyJoined);
+    } else {
+      await _makeNewSenderKey(groupCall, true);
+    }
+  }
+
+  @override
+  Future<void> onLeftParticipant(
+    GroupCallSession groupCall,
+    List<CallParticipant> anyLeft,
+  ) async {
+    _encryptionKeysMap.removeWhere((key, value) => anyLeft.contains(key));
+
+    // debounce it because people leave at the same time
+    if (_memberLeaveEncKeyRotateDebounceTimer != null) {
+      _memberLeaveEncKeyRotateDebounceTimer!.cancel();
+    }
+    _memberLeaveEncKeyRotateDebounceTimer =
+        Timer(CallTimeouts.makeKeyDelay, () async {
+      await _makeNewSenderKey(groupCall, true);
+    });
+  }
+
+  @override
+  Future<void> dispose(GroupCallSession groupCall) async {
+    // only remove our own, to save requesting if we join again, yes the other side
+    // will send it anyway but welp
+    _encryptionKeysMap.remove(groupCall.localParticipant!);
+    _currentLocalKeyIndex = 0;
+    _latestLocalKeyIndex = 0;
+    _memberLeaveEncKeyRotateDebounceTimer?.cancel();
+  }
+
+  @override
+  List<Map<String, String>>? getCurrentFeeds() {
+    return null;
+  }
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is LiveKitBackend &&
+          type == other.type &&
+          livekitServiceUrl == other.livekitServiceUrl &&
+          livekitAlias == other.livekitAlias;
+
+  @override
+  int get hashCode =>
+      type.hashCode ^ livekitServiceUrl.hashCode ^ livekitAlias.hashCode;
+
+  /// get everything else from your livekit sdk in your client
+  @override
+  Future<WrappedMediaStream?> initLocalStream(GroupCallSession groupCall,
+      {WrappedMediaStream? stream}) async {
+    return null;
+  }
+
+  @override
+  CallParticipant? get activeSpeaker => null;
+
+  /// these are unimplemented on purpose so that you know you have
+  /// used the wrong method
+  @override
+  bool get isLocalVideoMuted =>
+      throw UnimplementedError('Use livekit sdk for this');
+
+  @override
+  bool get isMicrophoneMuted =>
+      throw UnimplementedError('Use livekit sdk for this');
+
+  @override
+  WrappedMediaStream? get localScreenshareStream =>
+      throw UnimplementedError('Use livekit sdk for this');
+
+  @override
+  WrappedMediaStream? get localUserMediaStream =>
+      throw UnimplementedError('Use livekit sdk for this');
+
+  @override
+  List<WrappedMediaStream> get screenShareStreams =>
+      throw UnimplementedError('Use livekit sdk for this');
+
+  @override
+  List<WrappedMediaStream> get userMediaStreams =>
+      throw UnimplementedError('Use livekit sdk for this');
+
+  @override
+  Future<void> setDeviceMuted(
+      GroupCallSession groupCall, bool muted, MediaInputKind kind) async {
+    return;
+  }
+
+  @override
+  Future<void> setScreensharingEnabled(GroupCallSession groupCall, bool enabled,
+      String desktopCapturerSourceId) async {
+    return;
+  }
+
+  @override
+  Future<void> setupP2PCallWithNewMember(GroupCallSession groupCall,
+      CallParticipant rp, CallMembership mem) async {
+    return;
+  }
+
+  @override
+  Future<void> setupP2PCallsWithExistingMembers(
+      GroupCallSession groupCall) async {
+    return;
+  }
+
+  @override
+  Future<void> updateMediaDeviceForCalls() async {
+    return;
+  }
+}
--- a/lib/src/voip/backend/mesh_backend.dart
+++ b/lib/src/voip/backend/mesh_backend.dart
@ -0,0 +1,877 @@
+import 'dart:async';
+
+import 'package:collection/collection.dart';
+import 'package:webrtc_interface/webrtc_interface.dart';
+
+import 'package:matrix/matrix.dart';
+import 'package:matrix/src/utils/cached_stream_controller.dart';
+import 'package:matrix/src/voip/models/call_membership.dart';
+import 'package:matrix/src/voip/models/call_options.dart';
+import 'package:matrix/src/voip/utils/stream_helper.dart';
+import 'package:matrix/src/voip/utils/user_media_constraints.dart';
+
+class MeshBackend extends CallBackend {
+  MeshBackend({
+    super.type = 'mesh',
+  });
+
+  final List<CallSession> _callSessions = [];
+
+  /// participant:volume
+  final Map<CallParticipant, double> _audioLevelsMap = {};
+
+  StreamSubscription<CallSession>? _callSubscription;
+
+  Timer? _activeSpeakerLoopTimeout;
+
+  final CachedStreamController<WrappedMediaStream> onStreamAdd =
+      CachedStreamController();
+
+  final CachedStreamController<WrappedMediaStream> onStreamRemoved =
+      CachedStreamController();
+
+  final CachedStreamController<GroupCallSession> onGroupCallFeedsChanged =
+      CachedStreamController();
+
+  @override
+  Map<String, Object?> toJson() {
+    return {
+      'type': type,
+    };
+  }
+
+  CallParticipant? _activeSpeaker;
+  WrappedMediaStream? _localUserMediaStream;
+  WrappedMediaStream? _localScreenshareStream;
+  final List<WrappedMediaStream> _userMediaStreams = [];
+  final List<WrappedMediaStream> _screenshareStreams = [];
+
+  List<WrappedMediaStream> _getLocalStreams() {
+    final feeds = <WrappedMediaStream>[];
+
+    if (localUserMediaStream != null) {
+      feeds.add(localUserMediaStream!);
+    }
+
+    if (localScreenshareStream != null) {
+      feeds.add(localScreenshareStream!);
+    }
+
+    return feeds;
+  }
+
+  Future<MediaStream> _getUserMedia(
+      GroupCallSession groupCall, CallType type) async {
+    final mediaConstraints = {
+      'audio': UserMediaConstraints.micMediaConstraints,
+      'video': type == CallType.kVideo
+          ? UserMediaConstraints.camMediaConstraints
+          : false,
+    };
+
+    try {
+      return await groupCall.voip.delegate.mediaDevices
+          .getUserMedia(mediaConstraints);
+    } catch (e) {
+      groupCall.setState(GroupCallState.localCallFeedUninitialized);
+      rethrow;
+    }
+  }
+
+  Future<MediaStream> _getDisplayMedia(GroupCallSession groupCall) async {
+    final mediaConstraints = {
+      'audio': false,
+      'video': true,
+    };
+    try {
+      return await groupCall.voip.delegate.mediaDevices
+          .getDisplayMedia(mediaConstraints);
+    } catch (e, s) {
+      Logs().e('[VOIP] _getDisplayMedia failed because,', e, s);
+      rethrow;
+    }
+  }
+
+  CallSession? _getCallForParticipant(
+      GroupCallSession groupCall, CallParticipant participant) {
+    return _callSessions.singleWhereOrNull((call) =>
+        call.groupCallId == groupCall.groupCallId &&
+        CallParticipant(
+              groupCall.voip,
+              userId: call.remoteUserId!,
+              deviceId: call.remoteDeviceId,
+            ) ==
+            participant);
+  }
+
+  Future<void> _addCall(GroupCallSession groupCall, CallSession call) async {
+    _callSessions.add(call);
+    await _initCall(groupCall, call);
+    groupCall.onGroupCallEvent.add(GroupCallStateChange.callsChanged);
+  }
+
+  /// init a peer call from group calls.
+  Future<void> _initCall(GroupCallSession groupCall, CallSession call) async {
+    if (call.remoteUserId == null) {
+      throw Exception(
+          'Cannot init call without proper invitee user and device Id');
+    }
+
+    call.onCallStateChanged.stream.listen(((event) async {
+      await _onCallStateChanged(call, event);
+    }));
+
+    call.onCallReplaced.stream.listen((CallSession newCall) async {
+      await _replaceCall(groupCall, call, newCall);
+    });
+
+    call.onCallStreamsChanged.stream.listen((call) async {
+      await call.tryRemoveStopedStreams();
+      await _onStreamsChanged(groupCall, call);
+    });
+
+    call.onCallHangupNotifierForGroupCalls.stream.listen((event) async {
+      await _onCallHangup(groupCall, call);
+    });
+
+    call.onStreamAdd.stream.listen((stream) {
+      if (!stream.isLocal()) {
+        onStreamAdd.add(stream);
+      }
+    });
+
+    call.onStreamRemoved.stream.listen((stream) {
+      if (!stream.isLocal()) {
+        onStreamRemoved.add(stream);
+      }
+    });
+  }
+
+  Future<void> _replaceCall(
+    GroupCallSession groupCall,
+    CallSession existingCall,
+    CallSession replacementCall,
+  ) async {
+    final existingCallIndex = _callSessions
+        .indexWhere((element) => element.callId == existingCall.callId);
+
+    if (existingCallIndex == -1) {
+      throw Exception('Couldn\'t find call to replace');
+    }
+
+    _callSessions.removeAt(existingCallIndex);
+    _callSessions.add(replacementCall);
+
+    await _disposeCall(groupCall, existingCall, CallErrorCode.replaced);
+    await _initCall(groupCall, replacementCall);
+
+    groupCall.onGroupCallEvent.add(GroupCallStateChange.callsChanged);
+  }
+
+  /// Removes a peer call from group calls.
+  Future<void> _removeCall(GroupCallSession groupCall, CallSession call,
+      CallErrorCode hangupReason) async {
+    await _disposeCall(groupCall, call, hangupReason);
+
+    _callSessions.removeWhere((element) => call.callId == element.callId);
+
+    groupCall.onGroupCallEvent.add(GroupCallStateChange.callsChanged);
+  }
+
+  Future<void> _disposeCall(GroupCallSession groupCall, CallSession call,
+      CallErrorCode hangupReason) async {
+    if (call.remoteUserId == null) {
+      throw Exception(
+          'Cannot init call without proper invitee user and device Id');
+    }
+
+    if (call.hangupReason == CallErrorCode.replaced) {
+      return;
+    }
+
+    if (call.state != CallState.kEnded) {
+      // no need to emit individual handleCallEnded on group calls
+      // also prevents a loop of hangup and onCallHangupNotifierForGroupCalls
+      await call.hangup(reason: hangupReason, shouldEmit: false);
+    }
+
+    final usermediaStream = _getUserMediaStreamByParticipantId(
+      CallParticipant(
+        groupCall.voip,
+        userId: call.remoteUserId!,
+        deviceId: call.remoteDeviceId,
+      ).id,
+    );
+
+    if (usermediaStream != null) {
+      await _removeUserMediaStream(groupCall, usermediaStream);
+    }
+
+    final screenshareStream = _getScreenshareStreamByParticipantId(
+      CallParticipant(
+        groupCall.voip,
+        userId: call.remoteUserId!,
+        deviceId: call.remoteDeviceId,
+      ).id,
+    );
+
+    if (screenshareStream != null) {
+      await _removeScreenshareStream(groupCall, screenshareStream);
+    }
+  }
+
+  Future<void> _onStreamsChanged(
+      GroupCallSession groupCall, CallSession call) async {
+    if (call.remoteUserId == null) {
+      throw Exception(
+          'Cannot init call without proper invitee user and device Id');
+    }
+
+    final currentUserMediaStream = _getUserMediaStreamByParticipantId(
+      CallParticipant(
+        groupCall.voip,
+        userId: call.remoteUserId!,
+        deviceId: call.remoteDeviceId,
+      ).id,
+    );
+
+    final remoteUsermediaStream = call.remoteUserMediaStream;
+    final remoteStreamChanged = remoteUsermediaStream != currentUserMediaStream;
+
+    if (remoteStreamChanged) {
+      if (currentUserMediaStream == null && remoteUsermediaStream != null) {
+        await _addUserMediaStream(groupCall, remoteUsermediaStream);
+      } else if (currentUserMediaStream != null &&
+          remoteUsermediaStream != null) {
+        await _replaceUserMediaStream(
+            groupCall, currentUserMediaStream, remoteUsermediaStream);
+      } else if (currentUserMediaStream != null &&
+          remoteUsermediaStream == null) {
+        await _removeUserMediaStream(groupCall, currentUserMediaStream);
+      }
+    }
+
+    final currentScreenshareStream =
+        _getScreenshareStreamByParticipantId(CallParticipant(
+      groupCall.voip,
+      userId: call.remoteUserId!,
+      deviceId: call.remoteDeviceId,
+    ).id);
+    final remoteScreensharingStream = call.remoteScreenSharingStream;
+    final remoteScreenshareStreamChanged =
+        remoteScreensharingStream != currentScreenshareStream;
+
+    if (remoteScreenshareStreamChanged) {
+      if (currentScreenshareStream == null &&
+          remoteScreensharingStream != null) {
+        _addScreenshareStream(groupCall, remoteScreensharingStream);
+      } else if (currentScreenshareStream != null &&
+          remoteScreensharingStream != null) {
+        await _replaceScreenshareStream(
+            groupCall, currentScreenshareStream, remoteScreensharingStream);
+      } else if (currentScreenshareStream != null &&
+          remoteScreensharingStream == null) {
+        await _removeScreenshareStream(groupCall, currentScreenshareStream);
+      }
+    }
+
+    onGroupCallFeedsChanged.add(groupCall);
+  }
+
+  WrappedMediaStream? _getUserMediaStreamByParticipantId(String participantId) {
+    final stream = _userMediaStreams
+        .where((stream) => stream.participant.id == participantId);
+    if (stream.isNotEmpty) {
+      return stream.first;
+    }
+    return null;
+  }
+
+  void _onActiveSpeakerLoop(GroupCallSession groupCall) async {
+    CallParticipant? nextActiveSpeaker;
+    // idc about screen sharing atm.
+    final userMediaStreamsCopyList =
+        List<WrappedMediaStream>.from(_userMediaStreams);
+    for (final stream in userMediaStreamsCopyList) {
+      if (stream.participant.isLocal && stream.pc == null) {
+        continue;
+      }
+
+      final List<StatsReport> statsReport = await stream.pc!.getStats();
+      statsReport
+          .removeWhere((element) => !element.values.containsKey('audioLevel'));
+
+      // https://www.w3.org/TR/webrtc-stats/#summary
+      final otherPartyAudioLevel = statsReport
+          .singleWhereOrNull((element) =>
+              element.type == 'inbound-rtp' &&
+              element.values['kind'] == 'audio')
+          ?.values['audioLevel'];
+      if (otherPartyAudioLevel != null) {
+        _audioLevelsMap[stream.participant] = otherPartyAudioLevel;
+      }
+
+      // https://www.w3.org/TR/webrtc-stats/#dom-rtcstatstype-media-source
+      // firefox does not seem to have this though. Works on chrome and android
+      final ownAudioLevel = statsReport
+          .singleWhereOrNull((element) =>
+              element.type == 'media-source' &&
+              element.values['kind'] == 'audio')
+          ?.values['audioLevel'];
+      if (groupCall.localParticipant != null &&
+          ownAudioLevel != null &&
+          _audioLevelsMap[groupCall.localParticipant] != ownAudioLevel) {
+        _audioLevelsMap[groupCall.localParticipant!] = ownAudioLevel;
+      }
+    }
+
+    double maxAudioLevel = double.negativeInfinity;
+    // TODO: we probably want a threshold here?
+    _audioLevelsMap.forEach((key, value) {
+      if (value > maxAudioLevel) {
+        nextActiveSpeaker = key;
+        maxAudioLevel = value;
+      }
+    });
+
+    if (nextActiveSpeaker != null && _activeSpeaker != nextActiveSpeaker) {
+      _activeSpeaker = nextActiveSpeaker;
+      groupCall.onGroupCallEvent.add(GroupCallStateChange.activeSpeakerChanged);
+    }
+    _activeSpeakerLoopTimeout?.cancel();
+    _activeSpeakerLoopTimeout = Timer(
+      CallConstants.activeSpeakerInterval,
+      () => _onActiveSpeakerLoop(groupCall),
+    );
+  }
+
+  WrappedMediaStream? _getScreenshareStreamByParticipantId(
+      String participantId) {
+    final stream = _screenshareStreams
+        .where((stream) => stream.participant.id == participantId);
+    if (stream.isNotEmpty) {
+      return stream.first;
+    }
+    return null;
+  }
+
+  void _addScreenshareStream(
+      GroupCallSession groupCall, WrappedMediaStream stream) {
+    _screenshareStreams.add(stream);
+    onStreamAdd.add(stream);
+    groupCall.onGroupCallEvent
+        .add(GroupCallStateChange.screenshareStreamsChanged);
+  }
+
+  Future<void> _replaceScreenshareStream(
+    GroupCallSession groupCall,
+    WrappedMediaStream existingStream,
+    WrappedMediaStream replacementStream,
+  ) async {
+    final streamIndex = _screenshareStreams.indexWhere(
+        (stream) => stream.participant.id == existingStream.participant.id);
+
+    if (streamIndex == -1) {
+      throw Exception('Couldn\'t find screenshare stream to replace');
+    }
+
+    _screenshareStreams.replaceRange(streamIndex, 1, [replacementStream]);
+
+    await existingStream.dispose();
+    groupCall.onGroupCallEvent
+        .add(GroupCallStateChange.screenshareStreamsChanged);
+  }
+
+  Future<void> _removeScreenshareStream(
+    GroupCallSession groupCall,
+    WrappedMediaStream stream,
+  ) async {
+    final streamIndex = _screenshareStreams
+        .indexWhere((stream) => stream.participant.id == stream.participant.id);
+
+    if (streamIndex == -1) {
+      throw Exception('Couldn\'t find screenshare stream to remove');
+    }
+
+    _screenshareStreams.removeWhere(
+        (element) => element.participant.id == stream.participant.id);
+
+    onStreamRemoved.add(stream);
+
+    if (stream.isLocal()) {
+      await stopMediaStream(stream.stream);
+    }
+
+    groupCall.onGroupCallEvent
+        .add(GroupCallStateChange.screenshareStreamsChanged);
+  }
+
+  Future<void> _onCallStateChanged(CallSession call, CallState state) async {
+    final audioMuted = localUserMediaStream?.isAudioMuted() ?? true;
+    if (call.localUserMediaStream != null &&
+        call.isMicrophoneMuted != audioMuted) {
+      await call.setMicrophoneMuted(audioMuted);
+    }
+
+    final videoMuted = localUserMediaStream?.isVideoMuted() ?? true;
+
+    if (call.localUserMediaStream != null &&
+        call.isLocalVideoMuted != videoMuted) {
+      await call.setLocalVideoMuted(videoMuted);
+    }
+  }
+
+  Future<void> _onCallHangup(
+    GroupCallSession groupCall,
+    CallSession call,
+  ) async {
+    if (call.hangupReason == CallErrorCode.replaced) {
+      return;
+    }
+    await _onStreamsChanged(groupCall, call);
+    await _removeCall(groupCall, call, call.hangupReason!);
+  }
+
+  Future<void> _addUserMediaStream(
+    GroupCallSession groupCall,
+    WrappedMediaStream stream,
+  ) async {
+    _userMediaStreams.add(stream);
+    onStreamAdd.add(stream);
+    groupCall.onGroupCallEvent
+        .add(GroupCallStateChange.userMediaStreamsChanged);
+  }
+
+  Future<void> _replaceUserMediaStream(
+    GroupCallSession groupCall,
+    WrappedMediaStream existingStream,
+    WrappedMediaStream replacementStream,
+  ) async {
+    final streamIndex = _userMediaStreams.indexWhere(
+        (stream) => stream.participant.id == existingStream.participant.id);
+
+    if (streamIndex == -1) {
+      throw Exception('Couldn\'t find user media stream to replace');
+    }
+
+    _userMediaStreams.replaceRange(streamIndex, 1, [replacementStream]);
+
+    await existingStream.dispose();
+    groupCall.onGroupCallEvent
+        .add(GroupCallStateChange.userMediaStreamsChanged);
+  }
+
+  Future<void> _removeUserMediaStream(
+    GroupCallSession groupCall,
+    WrappedMediaStream stream,
+  ) async {
+    final streamIndex = _userMediaStreams.indexWhere(
+        (element) => element.participant.id == stream.participant.id);
+
+    if (streamIndex == -1) {
+      throw Exception('Couldn\'t find user media stream to remove');
+    }
+
+    _userMediaStreams.removeWhere(
+        (element) => element.participant.id == stream.participant.id);
+    _audioLevelsMap.remove(stream.participant);
+    onStreamRemoved.add(stream);
+
+    if (stream.isLocal()) {
+      await stopMediaStream(stream.stream);
+    }
+
+    groupCall.onGroupCallEvent
+        .add(GroupCallStateChange.userMediaStreamsChanged);
+
+    if (_activeSpeaker == stream.participant && _userMediaStreams.isNotEmpty) {
+      _activeSpeaker = _userMediaStreams[0].participant;
+      groupCall.onGroupCallEvent.add(GroupCallStateChange.activeSpeakerChanged);
+    }
+  }
+
+  @override
+  bool get e2eeEnabled => false;
+
+  @override
+  CallParticipant? get activeSpeaker => _activeSpeaker;
+
+  @override
+  WrappedMediaStream? get localUserMediaStream => _localUserMediaStream;
+
+  @override
+  WrappedMediaStream? get localScreenshareStream => _localScreenshareStream;
+
+  @override
+  List<WrappedMediaStream> get userMediaStreams =>
+      List.unmodifiable(_userMediaStreams);
+
+  @override
+  List<WrappedMediaStream> get screenShareStreams =>
+      List.unmodifiable(_screenshareStreams);
+
+  @override
+  Future<void> updateMediaDeviceForCalls() async {
+    for (final call in _callSessions) {
+      await call.updateMediaDeviceForCall();
+    }
+  }
+
+  /// Initializes the local user media stream.
+  /// The media stream must be prepared before the group call enters.
+  /// if you allow the user to configure their camera and such ahead of time,
+  /// you can pass that `stream` on to this function.
+  /// This allows you to configure the camera before joining the call without
+  ///  having to reopen the stream and possibly losing settings.
+  @override
+  Future<WrappedMediaStream?> initLocalStream(GroupCallSession groupCall,
+      {WrappedMediaStream? stream}) async {
+    if (groupCall.state != GroupCallState.localCallFeedUninitialized) {
+      throw Exception(
+          'Cannot initialize local call feed in the ${groupCall.state} state.');
+    }
+
+    groupCall.setState(GroupCallState.initializingLocalCallFeed);
+
+    WrappedMediaStream localWrappedMediaStream;
+
+    if (stream == null) {
+      MediaStream stream;
+
+      try {
+        stream = await _getUserMedia(groupCall, CallType.kVideo);
+      } catch (error) {
+        groupCall.setState(GroupCallState.localCallFeedUninitialized);
+        rethrow;
+      }
+
+      localWrappedMediaStream = WrappedMediaStream(
+        stream: stream,
+        participant: groupCall.localParticipant!,
+        room: groupCall.room,
+        client: groupCall.client,
+        purpose: SDPStreamMetadataPurpose.Usermedia,
+        audioMuted: stream.getAudioTracks().isEmpty,
+        videoMuted: stream.getVideoTracks().isEmpty,
+        isGroupCall: true,
+        voip: groupCall.voip,
+      );
+    } else {
+      localWrappedMediaStream = stream;
+    }
+
+    _localUserMediaStream = localWrappedMediaStream;
+    await _addUserMediaStream(groupCall, localWrappedMediaStream);
+
+    groupCall.setState(GroupCallState.localCallFeedInitialized);
+
+    _activeSpeaker = null;
+
+    return localWrappedMediaStream;
+  }
+
+  @override
+  Future<void> setDeviceMuted(
+      GroupCallSession groupCall, bool muted, MediaInputKind kind) async {
+    if (!await hasMediaDevice(groupCall.voip.delegate, kind)) {
+      return;
+    }
+
+    if (localUserMediaStream != null) {
+      switch (kind) {
+        case MediaInputKind.audioinput:
+          localUserMediaStream!.setAudioMuted(muted);
+          setTracksEnabled(
+              localUserMediaStream!.stream!.getAudioTracks(), !muted);
+          for (final call in _callSessions) {
+            await call.setMicrophoneMuted(muted);
+          }
+          break;
+        case MediaInputKind.videoinput:
+          localUserMediaStream!.setVideoMuted(muted);
+          setTracksEnabled(
+              localUserMediaStream!.stream!.getVideoTracks(), !muted);
+          for (final call in _callSessions) {
+            await call.setLocalVideoMuted(muted);
+          }
+          break;
+        default:
+      }
+    }
+
+    groupCall.onGroupCallEvent.add(GroupCallStateChange.localMuteStateChanged);
+    return;
+  }
+
+  Future<void> _onIncomingCall(
+      GroupCallSession groupCall, CallSession newCall) async {
+    // The incoming calls may be for another room, which we will ignore.
+    if (newCall.room.id != groupCall.room.id) {
+      return;
+    }
+
+    if (newCall.state != CallState.kRinging) {
+      Logs().w('Incoming call no longer in ringing state. Ignoring.');
+      return;
+    }
+
+    if (newCall.groupCallId == null ||
+        newCall.groupCallId != groupCall.groupCallId) {
+      Logs().v(
+          'Incoming call with groupCallId ${newCall.groupCallId} ignored because it doesn\'t match the current group call');
+      await newCall.reject();
+      return;
+    }
+
+    final existingCall = _getCallForParticipant(
+      groupCall,
+      CallParticipant(
+        groupCall.voip,
+        userId: newCall.remoteUserId!,
+        deviceId: newCall.remoteDeviceId,
+      ),
+    );
+
+    if (existingCall != null && existingCall.callId == newCall.callId) {
+      return;
+    }
+
+    Logs().v(
+        'GroupCallSession: incoming call from: ${newCall.remoteUserId}${newCall.remoteDeviceId}${newCall.remotePartyId}');
+
+    // Check if the user calling has an existing call and use this call instead.
+    if (existingCall != null) {
+      await _replaceCall(groupCall, existingCall, newCall);
+    } else {
+      await _addCall(groupCall, newCall);
+    }
+
+    await newCall.answerWithStreams(_getLocalStreams());
+  }
+
+  @override
+  Future<void> setScreensharingEnabled(
+    GroupCallSession groupCall,
+    bool enabled,
+    String desktopCapturerSourceId,
+  ) async {
+    if (enabled == (localScreenshareStream != null)) {
+      return;
+    }
+
+    if (enabled) {
+      try {
+        Logs().v('Asking for screensharing permissions...');
+        final stream = await _getDisplayMedia(groupCall);
+        for (final track in stream.getTracks()) {
+          // screen sharing should only have 1 video track anyway, so this only
+          // fires once
+          track.onEnded = () async {
+            await setScreensharingEnabled(groupCall, false, '');
+          };
+        }
+        Logs().v(
+            'Screensharing permissions granted. Setting screensharing enabled on all calls');
+        _localScreenshareStream = WrappedMediaStream(
+          stream: stream,
+          participant: groupCall.localParticipant!,
+          room: groupCall.room,
+          client: groupCall.client,
+          purpose: SDPStreamMetadataPurpose.Screenshare,
+          audioMuted: stream.getAudioTracks().isEmpty,
+          videoMuted: stream.getVideoTracks().isEmpty,
+          isGroupCall: true,
+          voip: groupCall.voip,
+        );
+
+        _addScreenshareStream(groupCall, localScreenshareStream!);
+
+        groupCall.onGroupCallEvent
+            .add(GroupCallStateChange.localScreenshareStateChanged);
+        for (final call in _callSessions) {
+          await call.addLocalStream(
+              await localScreenshareStream!.stream!.clone(),
+              localScreenshareStream!.purpose);
+        }
+
+        await groupCall.sendMemberStateEvent();
+
+        return;
+      } catch (e, s) {
+        Logs().e('[VOIP] Enabling screensharing error', e, s);
+        groupCall.onGroupCallEvent.add(GroupCallStateChange.error);
+        return;
+      }
+    } else {
+      for (final call in _callSessions) {
+        await call.removeLocalStream(call.localScreenSharingStream!);
+      }
+      await stopMediaStream(localScreenshareStream?.stream);
+      await _removeScreenshareStream(groupCall, localScreenshareStream!);
+      _localScreenshareStream = null;
+
+      await groupCall.sendMemberStateEvent();
+
+      groupCall.onGroupCallEvent
+          .add(GroupCallStateChange.localMuteStateChanged);
+      return;
+    }
+  }
+
+  @override
+  Future<void> dispose(GroupCallSession groupCall) async {
+    if (localUserMediaStream != null) {
+      await _removeUserMediaStream(groupCall, localUserMediaStream!);
+      _localUserMediaStream = null;
+    }
+
+    if (localScreenshareStream != null) {
+      await stopMediaStream(localScreenshareStream!.stream);
+      await _removeScreenshareStream(groupCall, localScreenshareStream!);
+      _localScreenshareStream = null;
+    }
+
+    // removeCall removes it from `_callSessions` later.
+    final callsCopy = _callSessions.toList();
+
+    for (final call in callsCopy) {
+      await _removeCall(groupCall, call, CallErrorCode.userHangup);
+    }
+
+    _activeSpeaker = null;
+    _activeSpeakerLoopTimeout?.cancel();
+    await _callSubscription?.cancel();
+  }
+
+  @override
+  bool get isLocalVideoMuted {
+    if (localUserMediaStream != null) {
+      return localUserMediaStream!.isVideoMuted();
+    }
+
+    return true;
+  }
+
+  @override
+  bool get isMicrophoneMuted {
+    if (localUserMediaStream != null) {
+      return localUserMediaStream!.isAudioMuted();
+    }
+
+    return true;
+  }
+
+  @override
+  Future<void> setupP2PCallsWithExistingMembers(
+      GroupCallSession groupCall) async {
+    for (final call in _callSessions) {
+      await _onIncomingCall(groupCall, call);
+    }
+
+    _callSubscription = groupCall.voip.onIncomingCall.stream.listen(
+      (newCall) => _onIncomingCall(groupCall, newCall),
+    );
+
+    _onActiveSpeakerLoop(groupCall);
+  }
+
+  @override
+  Future<void> setupP2PCallWithNewMember(
+    GroupCallSession groupCall,
+    CallParticipant rp,
+    CallMembership mem,
+  ) async {
+    final existingCall = _getCallForParticipant(groupCall, rp);
+    if (existingCall != null) {
+      if (existingCall.remoteSessionId != mem.membershipId) {
+        await existingCall.hangup(reason: CallErrorCode.unknownError);
+      } else {
+        Logs().e(
+            '[VOIP] onMemberStateChanged Not updating _participants list, already have a ongoing call with ${rp.id}');
+        return;
+      }
+    }
+
+    // Only initiate a call with a participant who has a id that is lexicographically
+    // less than your own. Otherwise, that user will call you.
+    if (groupCall.localParticipant!.id.compareTo(rp.id) > 0) {
+      Logs().i('[VOIP] Waiting for ${rp.id} to send call invite.');
+      return;
+    }
+
+    final opts = CallOptions(
+      callId: genCallID(),
+      room: groupCall.room,
+      voip: groupCall.voip,
+      dir: CallDirection.kOutgoing,
+      localPartyId: groupCall.voip.currentSessionId,
+      groupCallId: groupCall.groupCallId,
+      type: CallType.kVideo,
+      iceServers: await groupCall.voip.getIceServers(),
+    );
+    final newCall = groupCall.voip.createNewCall(opts);
+
+    /// both invitee userId and deviceId are set here because there can be
+    /// multiple devices from same user in a call, so we specifiy who the
+    /// invite is for
+    ///
+    /// MOVE TO CREATENEWCALL?
+    newCall.remoteUserId = mem.userId;
+    newCall.remoteDeviceId = mem.deviceId;
+    // party id set to when answered
+    newCall.remoteSessionId = mem.membershipId;
+
+    await newCall.placeCallWithStreams(_getLocalStreams(),
+        requestScreenSharing: mem.feeds?.any((element) =>
+                element['purpose'] == SDPStreamMetadataPurpose.Screenshare) ??
+            false);
+
+    await _addCall(groupCall, newCall);
+  }
+
+  @override
+  List<Map<String, String>>? getCurrentFeeds() {
+    return _getLocalStreams()
+        .map((feed) => ({
+              'purpose': feed.purpose,
+            }))
+        .toList();
+  }
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) || other is MeshBackend && type == other.type;
+  @override
+  int get hashCode => type.hashCode;
+
+  /// get everything is livekit specific mesh calls shouldn't be affected by these
+  @override
+  Future<void> onCallEncryption(GroupCallSession groupCall, String userId,
+      String deviceId, Map<String, dynamic> content) async {
+    return;
+  }
+
+  @override
+  Future<void> onCallEncryptionKeyRequest(GroupCallSession groupCall,
+      String userId, String deviceId, Map<String, dynamic> content) async {
+    return;
+  }
+
+  @override
+  Future<void> onLeftParticipant(
+      GroupCallSession groupCall, List<CallParticipant> anyLeft) async {
+    return;
+  }
+
+  @override
+  Future<void> onNewParticipant(
+      GroupCallSession groupCall, List<CallParticipant> anyJoined) async {
+    return;
+  }
+
+  @override
+  Future<void> requestEncrytionKey(GroupCallSession groupCall,
+      List<CallParticipant> remoteParticipants) async {
+    return;
+  }
+}
--- a/lib/src/voip/call_session.dart
+++ b/lib/src/voip/call_session.dart
--- a/lib/src/voip/group_call.dart
+++ b/lib/src/voip/group_call.dart
--- a/lib/src/voip/group_call_session.dart
+++ b/lib/src/voip/group_call_session.dart
@ -0,0 +1,272 @@
+/*
+ *   Famedly Matrix SDK
+ *   Copyright (C) 2021 Famedly GmbH
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General License as
+ *   published by the Free Software Foundation, either version 3 of the
+ *   License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import 'dart:async';
+import 'dart:core';
+
+import 'package:matrix/matrix.dart';
+import 'package:matrix/src/utils/cached_stream_controller.dart';
+import 'package:matrix/src/voip/models/call_membership.dart';
+import 'package:matrix/src/voip/models/voip_id.dart';
+import 'package:matrix/src/voip/utils/stream_helper.dart';
+
+/// Holds methods for managing a group call. This class is also responsible for
+/// holding and managing the individual `CallSession`s in a group call.
+class GroupCallSession {
+  // Config
+  final Client client;
+  final VoIP voip;
+  final Room room;
+
+  /// is a list of backend to allow passing multiple backend in the future
+  /// we use the first backend everywhere as of now
+  final CallBackend backend;
+
+  /// something like normal calls or thirdroom
+  final String? application;
+
+  /// either room scoped or user scoped calls
+  final String? scope;
+
+  GroupCallState state = GroupCallState.localCallFeedUninitialized;
+
+  CallParticipant? get localParticipant => voip.localParticipant;
+
+  List<CallParticipant> get participants => List.unmodifiable(_participants);
+  final List<CallParticipant> _participants = [];
+
+  String groupCallId;
+
+  final CachedStreamController<GroupCallState> onGroupCallState =
+      CachedStreamController();
+
+  final CachedStreamController<GroupCallStateChange> onGroupCallEvent =
+      CachedStreamController();
+
+  Timer? _resendMemberStateEventTimer;
+
+  factory GroupCallSession.withAutoGenId(
+    Room room,
+    VoIP voip,
+    CallBackend backend,
+    String? application,
+    String? scope,
+    String? groupCallId,
+  ) {
+    return GroupCallSession(
+      client: room.client,
+      room: room,
+      voip: voip,
+      backend: backend,
+      application: application ?? 'm.call',
+      scope: scope ?? 'm.room',
+      groupCallId: groupCallId ?? genCallID(),
+    );
+  }
+
+  GroupCallSession({
+    required this.client,
+    required this.room,
+    required this.voip,
+    required this.backend,
+    required this.groupCallId,
+    required this.application,
+    required this.scope,
+  });
+
+  String get avatarName =>
+      _getUser().calcDisplayname(mxidLocalPartFallback: false);
+
+  String? get displayName => _getUser().displayName;
+
+  User _getUser() {
+    return room.unsafeGetUserFromMemoryOrFallback(client.userID!);
+  }
+
+  void setState(GroupCallState newState) {
+    state = newState;
+    onGroupCallState.add(newState);
+    onGroupCallEvent.add(GroupCallStateChange.groupCallStateChanged);
+  }
+
+  bool hasLocalParticipant() {
+    return _participants.contains(localParticipant);
+  }
+
+  /// enter the group call.
+  Future<void> enter({WrappedMediaStream? stream}) async {
+    if (!(state == GroupCallState.localCallFeedUninitialized ||
+        state == GroupCallState.localCallFeedInitialized)) {
+      throw Exception('Cannot enter call in the $state state');
+    }
+
+    if (state == GroupCallState.localCallFeedUninitialized) {
+      await backend.initLocalStream(this, stream: stream);
+    }
+
+    await sendMemberStateEvent();
+
+    setState(GroupCallState.entered);
+
+    Logs().v('Entered group call $groupCallId');
+
+    // Set up _participants for the members currently in the call.
+    // Other members will be picked up by the RoomState.members event.
+    await onMemberStateChanged();
+
+    await backend.setupP2PCallsWithExistingMembers(this);
+
+    voip.currentGroupCID = VoipId(roomId: room.id, callId: groupCallId);
+
+    await voip.delegate.handleNewGroupCall(this);
+  }
+
+  Future<void> leave() async {
+    await removeMemberStateEvent();
+    await backend.dispose(this);
+    setState(GroupCallState.localCallFeedUninitialized);
+    voip.currentGroupCID = null;
+    _participants.clear();
+    voip.groupCalls.remove(VoipId(roomId: room.id, callId: groupCallId));
+    await voip.delegate.handleGroupCallEnded(this);
+    _resendMemberStateEventTimer?.cancel();
+    setState(GroupCallState.ended);
+  }
+
+  Future<void> sendMemberStateEvent() async {
+    await room.updateFamedlyCallMemberStateEvent(
+      CallMembership(
+        userId: client.userID!,
+        roomId: room.id,
+        callId: groupCallId,
+        application: application,
+        scope: scope,
+        backend: backend,
+        deviceId: client.deviceID!,
+        expiresTs: DateTime.now()
+            .add(CallTimeouts.expireTsBumpDuration)
+            .millisecondsSinceEpoch,
+        membershipId: voip.currentSessionId,
+        feeds: backend.getCurrentFeeds(),
+      ),
+    );
+
+    if (_resendMemberStateEventTimer != null) {
+      _resendMemberStateEventTimer!.cancel();
+    }
+    _resendMemberStateEventTimer = Timer.periodic(
+        CallTimeouts.updateExpireTsTimerDuration, ((timer) async {
+      Logs().d('sendMemberStateEvent updating member event with timer');
+      if (state != GroupCallState.ended ||
+          state != GroupCallState.localCallFeedUninitialized) {
+        await sendMemberStateEvent();
+      } else {
+        Logs().d(
+            '[VOIP] deteceted groupCall in state $state, removing state event');
+        await removeMemberStateEvent();
+      }
+    }));
+  }
+
+  Future<void> removeMemberStateEvent() {
+    if (_resendMemberStateEventTimer != null) {
+      Logs().d('resend member event timer cancelled');
+      _resendMemberStateEventTimer!.cancel();
+      _resendMemberStateEventTimer = null;
+    }
+    return room.removeFamedlyCallMemberEvent(
+      groupCallId,
+      client.deviceID!,
+      application: application,
+      scope: scope,
+    );
+  }
+
+  /// compltetely rebuilds the local _participants list
+  Future<void> onMemberStateChanged() async {
+    if (state != GroupCallState.entered) {
+      Logs().d(
+          '[VOIP] early return onMemberStateChanged, group call state is not Entered. Actual state: ${state.toString()} ');
+      return;
+    }
+
+    // The member events may be received for another room, which we will ignore.
+    final mems =
+        room.getCallMembershipsFromRoom().values.expand((element) => element);
+    final memsForCurrentGroupCall = mems.where((element) {
+      return element.callId == groupCallId &&
+          !element.isExpired &&
+          element.application == application &&
+          element.scope == scope &&
+          element.roomId == room.id; // sanity checks
+    }).toList();
+
+    final ignoredMems =
+        mems.where((element) => !memsForCurrentGroupCall.contains(element));
+
+    for (final mem in ignoredMems) {
+      Logs().w(
+          '[VOIP] Ignored ${mem.userId}\'s mem event ${mem.toJson()} while updating _participants list for callId: $groupCallId, expiry status: ${mem.isExpired}');
+    }
+
+    final List<CallParticipant> newP = [];
+
+    for (final mem in memsForCurrentGroupCall) {
+      final rp = CallParticipant(
+        voip,
+        userId: mem.userId,
+        deviceId: mem.deviceId,
+      );
+
+      newP.add(rp);
+
+      if (rp.isLocal) continue;
+
+      if (state != GroupCallState.entered) {
+        Logs().w(
+            '[VOIP] onMemberStateChanged groupCall state is currently $state, skipping member update');
+        continue;
+      }
+
+      await backend.setupP2PCallWithNewMember(this, rp, mem);
+    }
+    final newPcopy = List<CallParticipant>.from(newP);
+    final oldPcopy = List<CallParticipant>.from(_participants);
+    final anyJoined = newPcopy.where((element) => !oldPcopy.contains(element));
+    final anyLeft = oldPcopy.where((element) => !newPcopy.contains(element));
+
+    if (anyJoined.isNotEmpty || anyLeft.isNotEmpty) {
+      if (anyJoined.isNotEmpty) {
+        Logs().d('anyJoined: ${anyJoined.map((e) => e.id).toString()}');
+        _participants.addAll(anyJoined);
+        await backend.onNewParticipant(this, anyJoined.toList());
+      }
+      if (anyLeft.isNotEmpty) {
+        Logs().d('anyLeft: ${anyLeft.map((e) => e.id).toString()}');
+        for (final leftp in anyLeft) {
+          _participants.remove(leftp);
+        }
+        await backend.onLeftParticipant(this, anyLeft.toList());
+      }
+
+      onGroupCallEvent.add(GroupCallStateChange.participantsChanged);
+      Logs().d(
+          '[VOIP] onMemberStateChanged current list: ${_participants.map((e) => e.id).toString()}');
+    }
+  }
+}
--- a/lib/src/voip/models/call_events.dart
+++ b/lib/src/voip/models/call_events.dart
@ -60,12 +60,12 @@ class CallReplaces {
        target_user: CallReplacesTarget.fromJson(json['target_user']),
      );

-  Map<String, dynamic> toJson() => {
-        if (replacement_id != null) 'replacement_id': replacement_id,
+  Map<String, Object> toJson() => {
+        if (replacement_id != null) 'replacement_id': replacement_id!,
        if (target_user != null) 'target_user': target_user!.toJson(),
-        if (create_call != null) 'create_call': create_call,
-        if (await_call != null) 'await_call': await_call,
-        if (target_room != null) 'target_room': target_room,
+        if (create_call != null) 'create_call': create_call!,
+        if (await_call != null) 'await_call': await_call!,
+        if (target_room != null) 'target_room': target_room!,
      };
 }

--- a/lib/src/voip/models/call_membership.dart
+++ b/lib/src/voip/models/call_membership.dart
@ -0,0 +1,124 @@
+import 'package:matrix/matrix.dart';
+
+class FamedlyCallMemberEvent {
+  final List<CallMembership> memberships;
+
+  FamedlyCallMemberEvent({required this.memberships});
+
+  Map<String, dynamic> toJson() {
+    return {'memberships': memberships.map((e) => e.toJson()).toList()};
+  }
+
+  factory FamedlyCallMemberEvent.fromJson(Event event) {
+    final List<CallMembership> callMemberships = [];
+    final memberships = event.content.tryGetList('memberships');
+    if (memberships != null && memberships.isNotEmpty) {
+      for (final mem in memberships) {
+        if (isValidMemEvent(mem)) {
+          final callMem =
+              CallMembership.fromJson(mem, event.senderId, event.room.id);
+          if (callMem != null) callMemberships.add(callMem);
+        }
+      }
+    }
+    return FamedlyCallMemberEvent(memberships: callMemberships);
+  }
+}
+
+class CallMembership {
+  final String userId;
+  final String callId;
+  final String? application;
+  final String? scope;
+  final CallBackend backend;
+  final String deviceId;
+  final int expiresTs;
+  final String membershipId;
+  final List? feeds;
+
+  final String roomId;
+
+  CallMembership({
+    required this.userId,
+    required this.callId,
+    required this.backend,
+    required this.deviceId,
+    required this.expiresTs,
+    required this.roomId,
+    required this.membershipId,
+    this.application = 'm.call',
+    this.scope = 'm.room',
+    this.feeds,
+  });
+
+  Map<String, dynamic> toJson() {
+    return {
+      'call_id': callId,
+      'application': application,
+      'scope': scope,
+      'foci_active': [backend.toJson()],
+      'device_id': deviceId,
+      'expires_ts': expiresTs,
+      'expires': 7200000, // element compatibiltiy remove asap
+      'membershipID': membershipId, // sessionId
+      if (feeds != null) 'feeds': feeds,
+    };
+  }
+
+  static CallMembership? fromJson(Map json, String userId, String roomId) {
+    try {
+      return CallMembership(
+        userId: userId,
+        roomId: roomId,
+        callId: json['call_id'],
+        application: json['application'],
+        scope: json['scope'],
+        backend: (json['foci_active'] as List)
+            .map((e) => CallBackend.fromJson(e))
+            .first,
+        deviceId: json['device_id'],
+        expiresTs: json['expires_ts'],
+        membershipId:
+            json['membershipID'] ?? 'someone_forgot_to_set_the_membershipID',
+        feeds: json['feeds'],
+      );
+    } catch (e, s) {
+      Logs().e('[VOIP] call membership parsing failed. $json', e, s);
+      return null;
+    }
+  }
+
+  @override
+  bool operator ==(other) =>
+      identical(this, other) ||
+      other is CallMembership &&
+          runtimeType == other.runtimeType &&
+          userId == other.userId &&
+          roomId == other.roomId &&
+          callId == other.callId &&
+          application == other.application &&
+          scope == other.scope &&
+          backend.type == other.backend.type &&
+          deviceId == other.deviceId &&
+          membershipId == other.membershipId;
+
+  @override
+  int get hashCode =>
+      userId.hashCode ^
+      roomId.hashCode ^
+      callId.hashCode ^
+      application.hashCode ^
+      scope.hashCode ^
+      backend.type.hashCode ^
+      deviceId.hashCode ^
+      membershipId.hashCode;
+
+  // with a buffer of 1 minute just incase we were slow to process a
+  // call event, if the device is actually dead it should
+  // get removed pretty soon
+  bool get isExpired =>
+      expiresTs <
+      DateTime.now()
+          .subtract(CallTimeouts.expireTsBumpDuration)
+          .millisecondsSinceEpoch;
+}
--- a/lib/src/voip/models/call_options.dart
+++ b/lib/src/voip/models/call_options.dart
@ -0,0 +1,26 @@
+import 'package:matrix/matrix.dart';
+
+/// Initialization parameters of the call session.
+class CallOptions {
+  final String callId;
+  final CallType type;
+  final CallDirection dir;
+
+  /// client.deviceID
+  final String localPartyId;
+  final VoIP voip;
+  final Room room;
+  final List<Map<String, dynamic>> iceServers;
+  final String? groupCallId;
+
+  CallOptions({
+    required this.callId,
+    required this.type,
+    required this.dir,
+    required this.localPartyId,
+    required this.voip,
+    required this.room,
+    required this.iceServers,
+    this.groupCallId,
+  });
+}
--- a/lib/src/voip/models/call_participant.dart
+++ b/lib/src/voip/models/call_participant.dart
@ -0,0 +1,39 @@
+import 'package:matrix/matrix.dart';
+
+class CallParticipant {
+  final VoIP voip;
+  final String userId;
+  final String? deviceId;
+
+  CallParticipant(
+    this.voip, {
+    required this.userId,
+    this.deviceId,
+  });
+
+  bool get isLocal =>
+      userId == voip.client.userID && deviceId == voip.client.deviceID;
+
+  String get id {
+    String pid = userId;
+    if (deviceId != null) {
+      pid += ':$deviceId';
+    }
+    return pid;
+  }
+
+  @override
+  String toString() {
+    return id;
+  }
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is CallParticipant &&
+          userId == other.userId &&
+          deviceId == other.deviceId;
+
+  @override
+  int get hashCode => userId.hashCode ^ deviceId.hashCode;
+}
--- a/lib/src/voip/models/key_provider.dart
+++ b/lib/src/voip/models/key_provider.dart
@ -0,0 +1,55 @@
+import 'dart:typed_data';
+
+import 'package:matrix/matrix.dart';
+
+enum E2EEKeyMode {
+  kNone,
+  kSharedKey,
+  kPerParticipant,
+}
+
+abstract class EncryptionKeyProvider {
+  Future<void> onSetEncryptionKey(
+      CallParticipant participant, Uint8List key, int index);
+
+  Future<Uint8List> onRatchetKey(CallParticipant participant, int index);
+
+  Future<Uint8List> onExportKey(CallParticipant participant, int index);
+}
+
+class EncryptionKeyEntry {
+  final int index;
+  final String key;
+  EncryptionKeyEntry(this.index, this.key);
+
+  factory EncryptionKeyEntry.fromJson(Map<String, dynamic> json) =>
+      EncryptionKeyEntry(
+        json['index'] as int,
+        json['key'] as String,
+      );
+
+  Map<String, dynamic> toJson() => {
+        'index': index,
+        'key': key,
+      };
+}
+
+class EncryptionKeysEventContent {
+  // Get the participant info from todevice message params
+  final List<EncryptionKeyEntry> keys;
+  final String callId;
+  EncryptionKeysEventContent(this.keys, this.callId);
+
+  factory EncryptionKeysEventContent.fromJson(Map<String, dynamic> json) =>
+      EncryptionKeysEventContent(
+          (json['keys'] as List<dynamic>)
+              .map(
+                  (e) => EncryptionKeyEntry.fromJson(e as Map<String, dynamic>))
+              .toList(),
+          json['call_id'] as String);
+
+  Map<String, dynamic> toJson() => {
+        'keys': keys.map((e) => e.toJson()).toList(),
+        'call_id': callId,
+      };
+}
--- a/lib/src/voip/models/voip_id.dart
+++ b/lib/src/voip/models/voip_id.dart
@ -0,0 +1,24 @@
+class VoipId {
+  final String roomId;
+  final String callId;
+
+  String get id => '$roomId:$callId';
+
+  factory VoipId.fromId(String id) {
+    final int lastIndex = id.lastIndexOf(':');
+    return VoipId(
+      roomId: id.substring(0, lastIndex),
+      callId: id.substring(lastIndex + 1),
+    );
+  }
+
+  VoipId({required this.roomId, required this.callId});
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is VoipId && roomId == other.roomId && callId == other.callId;
+
+  @override
+  int get hashCode => roomId.hashCode ^ callId.hashCode;
+}
--- a/lib/src/voip/models/webrtc_delegate.dart
+++ b/lib/src/voip/models/webrtc_delegate.dart
@ -0,0 +1,25 @@
+import 'package:webrtc_interface/webrtc_interface.dart';
+
+import 'package:matrix/matrix.dart';
+
+/// Delegate WebRTC basic functionality.
+abstract class WebRTCDelegate {
+  MediaDevices get mediaDevices;
+  Future<RTCPeerConnection> createPeerConnection(
+      Map<String, dynamic> configuration,
+      [Map<String, dynamic> constraints = const {}]);
+  Future<void> playRingtone();
+  Future<void> stopRingtone();
+  Future<void> handleNewCall(CallSession session);
+  Future<void> handleCallEnded(CallSession session);
+  Future<void> handleMissedCall(CallSession session);
+  Future<void> handleNewGroupCall(GroupCallSession groupCall);
+  Future<void> handleGroupCallEnded(GroupCallSession groupCall);
+  bool get isWeb;
+
+  /// This should be set to false if any calls in the client are in kConnected
+  /// state. If another room tries to call you during a connected call this fires
+  /// a handleMissedCall
+  bool get canHandleNewCall;
+  EncryptionKeyProvider? get keyProvider;
+}
--- a/lib/src/voip/utils.dart
+++ b/lib/src/voip/utils.dart
@ -1,47 +0,0 @@
-import 'dart:async';
-
-import 'package:random_string/random_string.dart';
-import 'package:webrtc_interface/webrtc_interface.dart';
-
-import 'package:matrix/matrix.dart';
-
-Future<void> stopMediaStream(MediaStream? stream) async {
-  if (stream != null) {
-    for (final track in stream.getTracks()) {
-      try {
-        await track.stop();
-      } catch (e, s) {
-        Logs().e('[VOIP] stopping track ${track.id} failed', e, s);
-      }
-    }
-    try {
-      await stream.dispose();
-    } catch (e, s) {
-      Logs().e('[VOIP] disposing stream ${stream.id} failed', e, s);
-    }
-  }
-}
-
-void setTracksEnabled(List<MediaStreamTrack> tracks, bool enabled) {
-  for (final element in tracks) {
-    element.enabled = enabled;
-  }
-}
-
-Future<bool> hasAudioDevice() async {
-  //TODO(duan): implement this, check if there is any audio device
-  return true;
-}
-
-Future<bool> hasVideoDevice() async {
-  //TODO(duan): implement this, check if there is any video device
-  return true;
-}
-
-String roomAliasFromRoomName(String roomName) {
-  return roomName.trim().replaceAll('-', '').toLowerCase();
-}
-
-String genCallID() {
-  return '${DateTime.now().millisecondsSinceEpoch}${randomAlphaNumeric(16)}';
-}
--- a/lib/src/voip/utils/conn_tester.dart
+++ b/lib/src/voip/utils/conn_tester.dart
@ -12,7 +12,7 @@ class ConnectionTester {
  TurnServerCredentials? _turnServerCredentials;

  Future<bool> verifyTurnServer() async {
-    final iceServers = await getIceSevers();
+    final iceServers = await getIceServers();
    final configuration = <String, dynamic>{
      'iceServers': iceServers,
      'sdpSemantics': 'unified-plan',
@ -95,7 +95,7 @@ class ConnectionTester {
    return iterations;
  }

-  Future<List<Map<String, dynamic>>> getIceSevers() async {
+  Future<List<Map<String, dynamic>>> getIceServers() async {
    if (_turnServerCredentials == null) {
      try {
        _turnServerCredentials = await client.getTurnServer();
--- a/lib/src/voip/utils/famedly_call_extension.dart
+++ b/lib/src/voip/utils/famedly_call_extension.dart
@ -0,0 +1,167 @@
+import 'package:collection/collection.dart';
+
+import 'package:matrix/matrix.dart';
+import 'package:matrix/src/voip/models/call_membership.dart';
+
+extension FamedlyCallMemberEventsExtension on Room {
+  /// a map of every users famedly call event, holds the memberships list
+  /// returns sorted according to originTs (oldest to newest)
+  Map<String, FamedlyCallMemberEvent> getFamedlyCallEvents() {
+    final Map<String, FamedlyCallMemberEvent> mappedEvents = {};
+    final famedlyCallMemberStates =
+        states.tryGetMap<String, Event>(EventTypes.GroupCallMember);
+
+    if (famedlyCallMemberStates == null) return {};
+    final sortedEvents = famedlyCallMemberStates.values
+        .sorted((a, b) => a.originServerTs.compareTo(b.originServerTs));
+
+    for (final element in sortedEvents) {
+      mappedEvents
+          .addAll({element.senderId: FamedlyCallMemberEvent.fromJson(element)});
+    }
+    return mappedEvents;
+  }
+
+  /// extracts memberships list form a famedly call event and maps it to a userid
+  /// returns sorted (oldest to newest)
+  Map<String, List<CallMembership>> getCallMembershipsFromRoom() {
+    final parsedMemberEvents = getFamedlyCallEvents();
+    final Map<String, List<CallMembership>> memberships = {};
+    for (final element in parsedMemberEvents.entries) {
+      memberships.addAll({element.key: element.value.memberships});
+    }
+    return memberships;
+  }
+
+  /// returns a list of memberships in the room for `user`
+  List<CallMembership> getCallMembershipsForUser(String userId) {
+    final parsedMemberEvents = getCallMembershipsFromRoom();
+    final mem = parsedMemberEvents.tryGet<List<CallMembership>>(userId);
+    return mem ?? [];
+  }
+
+  /// returns the user count (not sessions, yet) for the group call with id: `groupCallId`.
+  /// returns 0 if group call not found
+  int groupCallParticipantCount(String groupCallId) {
+    int participantCount = 0;
+    // userid:membership
+    final memberships = getCallMembershipsFromRoom();
+
+    memberships.forEach((key, value) {
+      for (final membership in value) {
+        if (membership.callId == groupCallId && !membership.isExpired) {
+          participantCount++;
+        }
+      }
+    });
+
+    return participantCount;
+  }
+
+  bool get hasActiveGroupCall {
+    if (activeGroupCallIds.isNotEmpty) {
+      return true;
+    }
+    return false;
+  }
+
+  /// list of active group call ids
+  List<String> get activeGroupCallIds {
+    final Set<String> ids = {};
+    final memberships = getCallMembershipsFromRoom();
+
+    memberships.forEach((key, value) {
+      for (final mem in value) {
+        if (!mem.isExpired) ids.add(mem.callId);
+      }
+    });
+    return ids.toList();
+  }
+
+  /// passing no `CallMembership` removes it from the state event.
+  Future<void> updateFamedlyCallMemberStateEvent(
+      CallMembership callMembership) async {
+    final ownMemberships = getCallMembershipsForUser(client.userID!);
+
+    // do not bother removing other deviceId expired events because we have no
+    // ownership over them
+    ownMemberships
+        .removeWhere((element) => client.deviceID! == element.deviceId);
+
+    ownMemberships.removeWhere((e) => e == callMembership);
+
+    ownMemberships.add(callMembership);
+
+    final newContent = {
+      'memberships': List.from(ownMemberships.map((e) => e.toJson()))
+    };
+
+    await setFamedlyCallMemberEvent(newContent);
+  }
+
+  Future<void> removeFamedlyCallMemberEvent(
+    String groupCallId,
+    String deviceId, {
+    String? application = 'm.call',
+    String? scope = 'm.room',
+  }) async {
+    final ownMemberships = getCallMembershipsForUser(client.userID!);
+
+    ownMemberships.removeWhere((mem) =>
+        mem.callId == groupCallId &&
+        mem.deviceId == deviceId &&
+        mem.application == application &&
+        mem.scope == scope);
+
+    final newContent = {
+      'memberships': List.from(ownMemberships.map((e) => e.toJson()))
+    };
+    await setFamedlyCallMemberEvent(newContent);
+  }
+
+  Future<void> setFamedlyCallMemberEvent(Map<String, List> newContent) async {
+    if (groupCallsEnabledForEveryone) {
+      await client.setRoomStateWithKey(
+        id,
+        EventTypes.GroupCallMember,
+        client.userID!,
+        newContent,
+      );
+    } else {
+      Logs().w(
+          '[VOIP] cannot send ${EventTypes.GroupCallMember} events in room: $id, fix your PLs');
+    }
+  }
+
+  /// returns a list of memberships from a famedly call matrix event
+  List<CallMembership> getCallMembershipsFromEvent(MatrixEvent event) {
+    if (event.roomId != id) return [];
+    return getCallMembershipsFromEventContent(
+        event.content, event.senderId, event.roomId!);
+  }
+
+  /// returns a list of memberships from a famedly call matrix event
+  List<CallMembership> getCallMembershipsFromEventContent(
+      Map<String, Object?> content, String senderId, String roomId) {
+    final mems = content.tryGetList<Map>('memberships');
+    final callMems = <CallMembership>[];
+    for (final m in mems ?? []) {
+      final mem = CallMembership.fromJson(m, senderId, roomId);
+      if (mem != null) callMems.add(mem);
+    }
+    return callMems;
+  }
+}
+
+bool isValidMemEvent(Map<String, Object?> event) {
+  if (event['call_id'] is String &&
+      event['device_id'] is String &&
+      event['expires_ts'] is num &&
+      event['foci_active'] is List) {
+    return true;
+  } else {
+    Logs()
+        .w('[VOIP] FamedlyCallMemberEvent ignoring unclean membership $event');
+    return false;
+  }
+}
--- a/lib/src/voip/utils/rtc_candidate_extension.dart
+++ b/lib/src/voip/utils/rtc_candidate_extension.dart
@ -0,0 +1,9 @@
+import 'package:webrtc_interface/webrtc_interface.dart';
+
+extension RTCIceCandidateExt on RTCIceCandidate {
+  bool get isValid =>
+      sdpMLineIndex != null &&
+      sdpMid != null &&
+      candidate != null &&
+      candidate!.isNotEmpty;
+}
--- a/lib/src/voip/utils/stream_helper.dart
+++ b/lib/src/voip/utils/stream_helper.dart
@ -0,0 +1,65 @@
+import 'package:collection/collection.dart';
+import 'package:random_string/random_string.dart';
+import 'package:webrtc_interface/webrtc_interface.dart';
+
+import 'package:matrix/matrix.dart';
+
+Future<void> stopMediaStream(MediaStream? stream) async {
+  if (stream != null) {
+    for (final track in stream.getTracks()) {
+      try {
+        await track.stop();
+      } catch (e, s) {
+        Logs().e('[VOIP] stopping track ${track.id} failed', e, s);
+      }
+    }
+    try {
+      await stream.dispose();
+    } catch (e, s) {
+      Logs().e('[VOIP] disposing stream ${stream.id} failed', e, s);
+    }
+  }
+}
+
+void setTracksEnabled(List<MediaStreamTrack> tracks, bool enabled) {
+  for (final element in tracks) {
+    element.enabled = enabled;
+  }
+}
+
+Future<bool> hasMediaDevice(
+    WebRTCDelegate delegate, MediaInputKind mediaInputKind) async {
+  final devices = await delegate.mediaDevices.enumerateDevices();
+  return devices
+      .where((device) => device.kind == mediaInputKind.name)
+      .isNotEmpty;
+}
+
+Future<void> updateMediaDevice(
+  WebRTCDelegate delegate,
+  MediaKind kind,
+  List<RTCRtpSender> userRtpSenders, [
+  MediaStreamTrack? track,
+]) async {
+  final sender = userRtpSenders
+      .firstWhereOrNull((element) => element.track!.kind == kind.name);
+  await sender?.track?.stop();
+  if (track != null) {
+    await sender?.replaceTrack(track);
+  } else {
+    final stream = await delegate.mediaDevices.getUserMedia({kind.name: true});
+    MediaStreamTrack? track;
+    if (kind == MediaKind.audio) {
+      track = stream.getAudioTracks().firstOrNull;
+    } else if (kind == MediaKind.video) {
+      track = stream.getVideoTracks().firstOrNull;
+    }
+    if (track != null) {
+      await sender?.replaceTrack(track);
+    }
+  }
+}
+
+String genCallID() {
+  return '${DateTime.now().millisecondsSinceEpoch}${randomAlphaNumeric(16)}';
+}
--- a/lib/src/voip/utils/types.dart
+++ b/lib/src/voip/utils/types.dart
@ -0,0 +1,187 @@
+// ignore_for_file: constant_identifier_names
+
+enum EncryptionKeyTypes { remote, local }
+
+// Call state
+enum CallState {
+  /// The call is inilalized but not yet started
+  kFledgling,
+
+  /// The first time an invite is sent, the local has createdOffer
+  kInviteSent,
+
+  /// getUserMedia or getDisplayMedia has been called,
+  /// but MediaStream has not yet been returned
+  kWaitLocalMedia,
+
+  /// The local has createdOffer
+  kCreateOffer,
+
+  /// Received a remote offer message and created a local Answer
+  kCreateAnswer,
+
+  /// Answer sdp is set, but ice is not connected
+  kConnecting,
+
+  /// WebRTC media stream is connected
+  kConnected,
+
+  /// The call was received, but no processing has been done yet.
+  kRinging,
+
+  /// Ending a call
+  kEnding,
+
+  /// End of call
+  kEnded,
+}
+
+enum CallErrorCode {
+  /// The user chose to end the call
+  userHangup('user_hangup'),
+
+  /// An error code when the local client failed to create an offer.
+  localOfferFailed('local_offer_failed'),
+
+  /// An error code when there is no local mic/camera to use. This may be because
+  /// the hardware isn't plugged in, or the user has explicitly denied access.
+  userMediaFailed('user_media_failed'),
+
+  /// Error code used when a call event failed to send
+  /// because unknown devices were present in the room
+  unknownDevice('unknown_device'),
+
+  /// An answer could not be created
+  createAnswer('create_answer'),
+
+  /// The session description from the other side could not be set
+
+  setRemoteDescription('set_remote_description'),
+
+  /// The session description from this side could not be set
+  setLocalDescription('set_local_description'),
+
+  /// A different device answered the call
+  answeredElsewhere('answered_elsewhere'),
+
+  /// No media connection could be established to the other party
+  iceFailed('ice_failed'),
+
+  /// The invite timed out whilst waiting for an answer
+  inviteTimeout('invite_timeout'),
+
+  /// The call was replaced by another call
+  replaced('replaced'),
+
+  /// Signalling for the call could not be sent (other than the initial invite)
+  iceTimeout('ice_timeout'),
+
+  /// The remote party is busy
+  userBusy('user_busy'),
+
+  /// We transferred the call off to somewhere else
+  transferred('transferred'),
+
+  /// Some other failure occurred that meant the client was unable to continue
+  /// the call rather than the user choosing to end it.
+  unknownError('unknown_error');
+
+  final String reason;
+
+  const CallErrorCode(this.reason);
+}
+
+class CallError extends Error {
+  final CallErrorCode code;
+  final String msg;
+  final dynamic err;
+  CallError(this.code, this.msg, this.err);
+
+  @override
+  String toString() {
+    return '[$code] $msg, err: ${err.toString()}';
+  }
+}
+
+enum CallStateChange {
+  /// The call was hangup by the local|remote user.
+  kHangup,
+
+  /// The call state has changed
+  kState,
+
+  /// The call got some error.
+  kError,
+
+  /// Call transfer
+  kReplaced,
+
+  /// The value of isLocalOnHold() has changed
+  kLocalHoldUnhold,
+
+  /// The value of isRemoteOnHold() has changed
+  kRemoteHoldUnhold,
+
+  /// Feeds have changed
+  kFeedsChanged,
+
+  /// For sip calls. support in the future.
+  kAssertedIdentityChanged,
+}
+
+enum CallType { kVoice, kVideo }
+
+enum CallDirection { kIncoming, kOutgoing }
+
+enum CallParty { kLocal, kRemote }
+
+enum MediaInputKind { videoinput, audioinput }
+
+enum MediaKind { video, audio }
+
+enum GroupCallErrorCode {
+  /// An error code when there is no local mic/camera to use. This may be because
+  /// the hardware isn't plugged in, or the user has explicitly denied access.
+  userMediaFailed('user_media_failed'),
+
+  /// Some other failure occurred that meant the client was unable to continue
+  /// the call rather than the user choosing to end it.
+  unknownError('unknownError');
+
+  final String reason;
+
+  const GroupCallErrorCode(this.reason);
+}
+
+class GroupCallError extends Error {
+  final GroupCallErrorCode code;
+  final String msg;
+  final dynamic err;
+  GroupCallError(this.code, this.msg, this.err);
+
+  @override
+  String toString() {
+    return 'Group Call Error: [$code] $msg, err: ${err.toString()}';
+  }
+}
+
+enum GroupCallStateChange {
+  groupCallStateChanged,
+  activeSpeakerChanged,
+  callsChanged,
+  userMediaStreamsChanged,
+  screenshareStreamsChanged,
+  localScreenshareStateChanged,
+  localMuteStateChanged,
+  participantsChanged,
+  error
+}
+
+enum GroupCallState {
+  localCallFeedUninitialized,
+  initializingLocalCallFeed,
+  localCallFeedInitialized,
+  entering,
+  entered,
+  ended
+}
--- a/lib/src/voip/utils/voip_constants.dart
+++ b/lib/src/voip/utils/voip_constants.dart
@ -0,0 +1,62 @@
+import 'package:matrix/matrix.dart';
+
+/// https://github.com/matrix-org/matrix-doc/pull/2746
+/// version 1
+const String voipProtoVersion = '1';
+
+class CallTimeouts {
+  /// The default life time for call events, in millisecond.
+  static const defaultCallEventLifetime = Duration(seconds: 10);
+
+  /// The length of time a call can be ringing for.
+  static const callInviteLifetime = Duration(seconds: 60);
+
+  /// The delay for ice gathering.
+  static const iceGatheringDelay = Duration(milliseconds: 200);
+
+  /// Delay before createOffer.
+  static const delayBeforeOffer = Duration(milliseconds: 100);
+
+  /// How often to update the expiresTs
+  static const updateExpireTsTimerDuration = Duration(minutes: 2);
+
+  /// the expiresTs bump
+  static const expireTsBumpDuration = Duration(minutes: 6);
+
+  /// Update the active speaker value
+  static const activeSpeakerInterval = Duration(seconds: 5);
+
+  // source: element call?
+  /// A delay after a member leaves before we create and publish a new key, because people
+  /// tend to leave calls at the same time
+  static const makeKeyDelay = Duration(seconds: 2);
+
+  /// The delay between creating and sending a new key and starting to encrypt with it. This gives others
+  /// a chance to receive the new key to minimise the chance they don't get media they can't decrypt.
+  /// The total time between a member leaving and the call switching to new keys is therefore
+  /// makeKeyDelay + useKeyDelay
+  static const useKeyDelay = Duration(seconds: 4);
+}
+
+class CallConstants {
+  static final callEventsRegxp = RegExp(
+      r'm.call.|org.matrix.call.|org.matrix.msc3401.call.|com.famedly.call.');
+
+  static const callEndedEventTypes = {
+    EventTypes.CallAnswer,
+    EventTypes.CallHangup,
+    EventTypes.CallReject,
+    EventTypes.CallReplaces,
+  };
+  static const omitWhenCallEndedTypes = {
+    EventTypes.CallInvite,
+    EventTypes.CallCandidates,
+    EventTypes.CallNegotiate,
+    EventTypes.CallSDPStreamMetadataChanged,
+    EventTypes.CallSDPStreamMetadataChangedPrefix,
+  };
+
+  static const updateExpireTsTimerDuration = Duration(seconds: 15);
+  static const expireTsBumpDuration = Duration(seconds: 45);
+  static const activeSpeakerInterval = Duration(seconds: 5);
+}
--- a/lib/src/voip/utils/wrapped_media_stream.dart
+++ b/lib/src/voip/utils/wrapped_media_stream.dart
@ -0,0 +1,100 @@
+import 'package:webrtc_interface/webrtc_interface.dart';
+
+import 'package:matrix/matrix.dart';
+import 'package:matrix/src/utils/cached_stream_controller.dart';
+import 'package:matrix/src/voip/utils/stream_helper.dart';
+
+/// Wrapped MediaStream, used to adapt Widget to display
+class WrappedMediaStream {
+  MediaStream? stream;
+  final CallParticipant participant;
+  final Room room;
+  final VoIP voip;
+
+  /// Current stream type, usermedia or screen-sharing
+  String purpose;
+  bool audioMuted;
+  bool videoMuted;
+  final Client client;
+  final bool isGroupCall;
+  final RTCPeerConnection? pc;
+
+  /// for debug
+  String get title =>
+      '${client.userID!}:${client.deviceID!} $displayName:$purpose:a[$audioMuted]:v[$videoMuted]';
+  bool stopped = false;
+
+  final CachedStreamController<WrappedMediaStream> onMuteStateChanged =
+      CachedStreamController();
+
+  final CachedStreamController<MediaStream> onStreamChanged =
+      CachedStreamController();
+
+  WrappedMediaStream({
+    this.stream,
+    this.pc,
+    required this.room,
+    required this.participant,
+    required this.purpose,
+    required this.client,
+    required this.audioMuted,
+    required this.videoMuted,
+    required this.isGroupCall,
+    required this.voip,
+  });
+
+  String get id => '${stream?.id}: $title';
+
+  Future<void> dispose() async {
+    // AOT it
+    const isWeb = bool.fromEnvironment('dart.library.js_util');
+
+    // libwebrtc does not provide a way to clone MediaStreams. So stopping the
+    // local stream here would break calls with all other participants if anyone
+    // leaves. The local stream is manually disposed when user leaves. On web
+    // streams are actually cloned.
+    if (!isGroupCall || isWeb) {
+      await stopMediaStream(stream);
+    }
+
+    stream = null;
+  }
+
+  Uri? get avatarUrl => getUser().avatarUrl;
+
+  String get avatarName =>
+      getUser().calcDisplayname(mxidLocalPartFallback: false);
+
+  String? get displayName => getUser().displayName;
+
+  User getUser() {
+    return room.unsafeGetUserFromMemoryOrFallback(participant.userId);
+  }
+
+  bool isLocal() {
+    return participant == voip.localParticipant;
+  }
+
+  bool isAudioMuted() {
+    return (stream != null && stream!.getAudioTracks().isEmpty) || audioMuted;
+  }
+
+  bool isVideoMuted() {
+    return (stream != null && stream!.getVideoTracks().isEmpty) || videoMuted;
+  }
+
+  void setNewStream(MediaStream newStream) {
+    stream = newStream;
+    onStreamChanged.add(stream!);
+  }
+
+  void setAudioMuted(bool muted) {
+    audioMuted = muted;
+    onMuteStateChanged.add(this);
+  }
+
+  void setVideoMuted(bool muted) {
+    videoMuted = muted;
+    onMuteStateChanged.add(this);
+  }
+}
--- a/lib/src/voip/voip.dart
+++ b/lib/src/voip/voip.dart
--- a/lib/src/voip/voip_room_extension.dart
+++ b/lib/src/voip/voip_room_extension.dart
@ -1,101 +0,0 @@
-import 'package:collection/collection.dart';
-
-import 'package:matrix/matrix.dart';
-
-extension GroupCallUtils on Room {
-  /// returns the user count (not sessions, yet) for the group call with id: `groupCallId`.
-  /// returns 0 if group call not found
-  int? groupCallParticipantCount(String groupCallId) {
-    int participantCount = 0;
-    final groupCallMemberStates =
-        states.tryGetMap<String, Event>(EventTypes.GroupCallMemberPrefix);
-    if (groupCallMemberStates != null) {
-      groupCallMemberStates.forEach((userId, memberStateEvent) {
-        if (!callMemberStateForIdIsExpired(memberStateEvent, groupCallId)) {
-          participantCount++;
-        }
-      });
-    }
-    return participantCount;
-  }
-
-  bool get hasActiveGroupCall {
-    if (activeGroupCallEvents.isNotEmpty) {
-      return true;
-    }
-    return false;
-  }
-
-  /// list of active group calls
-  List<Event> get activeGroupCallEvents {
-    final groupCallStates =
-        states.tryGetMap<String, Event>(EventTypes.GroupCallPrefix);
-    if (groupCallStates != null) {
-      groupCallStates.values
-          .toList()
-          .sort((a, b) => a.originServerTs.compareTo(b.originServerTs));
-      return groupCallStates.values
-          .where((element) =>
-              !element.content.containsKey('m.terminated') &&
-              callMemberStateIsExpired(element))
-          .toList();
-    }
-    return [];
-  }
-
-  static const staleCallCheckerDuration = Duration(seconds: 30);
-
-  /// checks if a member event has any existing non-expired callId
-  bool callMemberStateIsExpired(MatrixEvent event) {
-    final callMemberState = IGroupCallRoomMemberState.fromJson(event);
-    final calls = callMemberState.calls;
-    return calls
-        .where((call) => call.devices.any((d) =>
-            (d.expires_ts ?? 0) +
-                staleCallCheckerDuration
-                    .inMilliseconds > // buffer for sync glare
-            DateTime.now().millisecondsSinceEpoch))
-        .isEmpty;
-  }
-
-  /// checks if the member event has `groupCallId` unexpired, if not it checks if
-  /// the whole event is expired or not
-  bool callMemberStateForIdIsExpired(
-      MatrixEvent groupCallMemberStateEvent, String groupCallId) {
-    final callMemberState =
-        IGroupCallRoomMemberState.fromJson(groupCallMemberStateEvent);
-    final calls = callMemberState.calls;
-    if (calls.isNotEmpty) {
-      final call =
-          calls.singleWhereOrNull((call) => call.call_id == groupCallId);
-      if (call != null) {
-        return call.devices.where((device) => device.expires_ts != null).every(
-            (device) =>
-                (device.expires_ts ?? 0) +
-                    staleCallCheckerDuration
-                        .inMilliseconds < // buffer for sync glare
-                DateTime.now().millisecondsSinceEpoch);
-      } else {
-        Logs().d(
-            '[VOIP] Did not find $groupCallId in member events, probably sync glare');
-        return false;
-      }
-    } else {
-      // Last 30 seconds to get yourself together.
-      // This saves us from accidentally killing calls which were just created and
-      // whose state event we haven't recieved yet in sync.
-      // (option 2 was local echo member state events, but reverting them if anything
-      // fails sounds pain)
-      final expiredfr = groupCallMemberStateEvent.originServerTs
-              .add(staleCallCheckerDuration)
-              .millisecondsSinceEpoch <
-          DateTime.now().millisecondsSinceEpoch;
-
-      if (!expiredfr) {
-        Logs().d(
-            '[VOIP] Last 30 seconds for state event from ${groupCallMemberStateEvent.senderId}');
-      }
-      return expiredfr;
-    }
-  }
-}
--- a/pubspec.yaml
+++ b/pubspec.yaml
@ -32,7 +32,7 @@ dependencies:
  sqflite_common: ^2.4.5
  sqlite3: ^2.1.0
  typed_data: ^1.3.2
-  webrtc_interface: ^1.0.13
+  webrtc_interface: ^1.2.0

 dev_dependencies:
  build_runner: ^2.4.8
@ -43,7 +43,4 @@ dev_dependencies:
  lints: ^3.0.0
  sqflite_common_ffi: 2.3.2+1 # v2.3.3 doesn't support dart v3.2.x
  test: ^1.15.7
-  #flutter_test: {sdk: flutter}
-#dependency_overrides:
-#  matrix_api_lite:
-#    path: ../matrix_api_lite
+
--- a/test/calls_test.dart
+++ b/test/calls_test.dart
@ -2,6 +2,9 @@ import 'package:test/test.dart';
 import 'package:webrtc_interface/webrtc_interface.dart';

 import 'package:matrix/matrix.dart';
+import 'package:matrix/src/voip/models/call_membership.dart';
+import 'package:matrix/src/voip/models/call_options.dart';
+import 'package:matrix/src/voip/models/voip_id.dart';
 import 'fake_client.dart';
 import 'webrtc_stub.dart';

@ -13,25 +16,35 @@ void main() {
    Logs().level = Level.info;
    setUp(() async {
      matrix = await getClient();
+
      voip = VoIP(matrix, MockWebRTCDelegate());
      VoIP.customTxid = '1234';
      final id = '!calls:example.com';
-
      room = matrix.getRoomById(id)!;
    });

    test('Test call methods', () async {
-      final call = CallSession(CallOptions()..room = room);
-      await call.sendInviteToCall(room, '1234', 1234, '4567', '7890', 'sdp',
+      final call = CallSession(
+        CallOptions(
+          callId: '1234',
+          type: CallType.kVoice,
+          dir: CallDirection.kOutgoing,
+          localPartyId: '4567',
+          voip: voip,
+          room: room,
+          iceServers: [],
+        ),
+      );
+      await call.sendInviteToCall(room, '1234', 1234, '4567', 'sdp',
          txid: '1234');
      await call.sendAnswerCall(room, '1234', 'sdp', '4567', txid: '1234');
      await call.sendCallCandidates(room, '1234', '4567', [], txid: '1234');
      await call.sendSelectCallAnswer(room, '1234', '4567', '6789',
          txid: '1234');
-      await call.sendCallReject(room, '1234', '4567', 'busy', txid: '1234');
+      await call.sendCallReject(room, '1234', '4567', txid: '1234');
      await call.sendCallNegotiate(room, '1234', 1234, '4567', 'sdp',
          txid: '1234');
-      await call.sendHangupCall(room, '1234', '4567', 'user_hangup',
+      await call.sendHangupCall(room, '1234', '4567', 'userHangup',
          txid: '1234');
      await call.sendAssertedIdentity(
          room,
@ -152,12 +165,14 @@ void main() {
              )
            ]))
          })));
-      while (voip.currentCID != 'originTsValidCall') {
+      while (voip.currentCID !=
+          VoipId(roomId: room.id, callId: 'originTsValidCall')) {
        // call invite looks valid, call should be created now :D
        await Future.delayed(Duration(milliseconds: 50));
        Logs().d('Waiting for currentCID to update');
      }
-      expect(voip.currentCID, 'originTsValidCall');
+      expect(voip.currentCID,
+          VoipId(roomId: room.id, callId: 'originTsValidCall'));
      final call = voip.calls[voip.currentCID]!;
      expect(call.state, CallState.kRinging);
      await call.answer(txid: '1234');
@ -219,7 +234,7 @@ void main() {

      expect(call.state, CallState.kConnected);

-      await call.hangup();
+      await call.hangup(reason: CallErrorCode.userHangup);
      expect(call.state, CallState.kEnded);
      expect(voip.currentCID, null);
    });
@ -277,12 +292,14 @@ void main() {
              )
            ]))
          })));
-      while (voip.currentCID != 'answer_elseWhere') {
+      while (voip.currentCID !=
+          VoipId(roomId: room.id, callId: 'answer_elseWhere')) {
        // call invite looks valid, call should be created now :D
        await Future.delayed(Duration(milliseconds: 50));
        Logs().d('Waiting for currentCID to update');
      }
-      expect(voip.currentCID, 'answer_elseWhere');
+      expect(
+          voip.currentCID, VoipId(roomId: room.id, callId: 'answer_elseWhere'));
      final call = voip.calls[voip.currentCID]!;
      expect(call.state, CallState.kRinging);

@ -368,12 +385,13 @@ void main() {
              )
            ]))
          })));
-      while (voip.currentCID != 'reject_call') {
+      while (
+          voip.currentCID != VoipId(roomId: room.id, callId: 'reject_call')) {
        // call invite looks valid, call should be created now :D
        await Future.delayed(Duration(milliseconds: 50));
        Logs().d('Waiting for currentCID to update');
      }
-      expect(voip.currentCID, 'reject_call');
+      expect(voip.currentCID, VoipId(roomId: room.id, callId: 'reject_call'));
      final call = voip.calls[voip.currentCID]!;
      expect(call.state, CallState.kRinging);

@ -386,7 +404,11 @@ void main() {

    test('Glare after invite was sent', () async {
      expect(voip.currentCID, null);
-      final firstCall = await voip.inviteToCall(room.id, CallType.kVoice);
+      final firstCall = await voip.inviteToCall(
+        room,
+        CallType.kVoice,
+        userId: '@alice:testing.com',
+      );
      await firstCall.pc!.onRenegotiationNeeded!.call();
      expect(firstCall.state, CallState.kInviteSent);
      // KABOOM YOU JUST GLARED
@ -412,12 +434,17 @@ void main() {
            ]))
          })));
      await Future.delayed(Duration(seconds: 3));
-      expect(voip.currentCID, firstCall.callId);
-      await firstCall.hangup();
+      expect(
+          voip.currentCID, VoipId(roomId: room.id, callId: firstCall.callId));
+      await firstCall.hangup(reason: CallErrorCode.userBusy);
    });
    test('Glare before invite was sent', () async {
      expect(voip.currentCID, null);
-      final firstCall = await voip.inviteToCall(room.id, CallType.kVoice);
+      final firstCall = await voip.inviteToCall(
+        room,
+        CallType.kVoice,
+        userId: '@alice:testing.com',
+      );
      expect(firstCall.state, CallState.kCreateOffer);
      // KABOOM YOU JUST GLARED, but this tiem you were still preparing your call
      // so just cancel that instead
@ -443,7 +470,306 @@ void main() {
            ]))
          })));
      await Future.delayed(Duration(seconds: 3));
-      expect(voip.currentCID, 'zzzz_glare_2nd_call');
+      expect(voip.currentCID,
+          VoipId(roomId: room.id, callId: 'zzzz_glare_2nd_call'));
+    });
+
+    test('getFamedlyCallEvents sort order', () {
+      room.setState(
+        Event(
+          content: {
+            'memberships': [
+              CallMembership(
+                userId: '@test1:example.com',
+                callId: '1111',
+                backend: MeshBackend(),
+                deviceId: '1111',
+                expiresTs: DateTime.now()
+                    .add(Duration(hours: 12))
+                    .millisecondsSinceEpoch,
+                roomId: room.id,
+                membershipId: voip.currentSessionId,
+              ).toJson(),
+            ]
+          },
+          type: EventTypes.GroupCallMember,
+          eventId: 'asdfasdf',
+          senderId: '@test1:example.com',
+          originServerTs: DateTime.now().add(Duration(hours: 12)),
+          room: room,
+          stateKey: '@test1:example.com',
+        ),
+      );
+      room.setState(
+        Event(
+          content: {
+            'memberships': [
+              CallMembership(
+                userId: '@test2:example.com',
+                callId: '1111',
+                backend: MeshBackend(),
+                deviceId: '1111',
+                expiresTs: DateTime.now().millisecondsSinceEpoch,
+                roomId: room.id,
+                membershipId: voip.currentSessionId,
+              ).toJson(),
+            ]
+          },
+          type: EventTypes.GroupCallMember,
+          eventId: 'asdfasdf',
+          senderId: '@test2:example.com',
+          originServerTs: DateTime.now(),
+          room: room,
+          stateKey: '@test2:example.com',
+        ),
+      );
+      room.setState(
+        Event(
+          content: {
+            'memberships': [
+              CallMembership(
+                userId: '@test2.0:example.com',
+                callId: '1111',
+                backend: MeshBackend(),
+                deviceId: '1111',
+                expiresTs: DateTime.now().millisecondsSinceEpoch,
+                roomId: room.id,
+                membershipId: voip.currentSessionId,
+              ).toJson(),
+            ]
+          },
+          type: EventTypes.GroupCallMember,
+          eventId: 'asdfasdf',
+          senderId: '@test2.0:example.com',
+          originServerTs: DateTime.now(),
+          room: room,
+          stateKey: '@test2.0:example.com',
+        ),
+      );
+      room.setState(
+        Event(
+          content: {
+            'memberships': [
+              CallMembership(
+                userId: '@test3:example.com',
+                callId: '1111',
+                backend: MeshBackend(),
+                deviceId: '1111',
+                expiresTs: DateTime.now()
+                    .subtract(Duration(hours: 1))
+                    .millisecondsSinceEpoch,
+                roomId: room.id,
+                membershipId: voip.currentSessionId,
+              ).toJson(),
+            ]
+          },
+          type: EventTypes.GroupCallMember,
+          eventId: 'asdfasdf',
+          senderId: '@test3:example.com',
+          originServerTs: DateTime.now().subtract(Duration(hours: 1)),
+          room: room,
+          stateKey: '@test3:example.com',
+        ),
+      );
+      expect(room.getFamedlyCallEvents().entries.elementAt(0).key,
+          '@test3:example.com');
+      expect(room.getFamedlyCallEvents().entries.elementAt(1).key,
+          '@test2:example.com');
+      expect(room.getFamedlyCallEvents().entries.elementAt(2).key,
+          '@test2.0:example.com');
+      expect(room.getFamedlyCallEvents().entries.elementAt(3).key,
+          '@test1:example.com');
+      expect(room.getCallMembershipsFromRoom().entries.elementAt(0).key,
+          '@test3:example.com');
+      expect(room.getCallMembershipsFromRoom().entries.elementAt(1).key,
+          '@test2:example.com');
+      expect(room.getCallMembershipsFromRoom().entries.elementAt(2).key,
+          '@test2.0:example.com');
+      expect(room.getCallMembershipsFromRoom().entries.elementAt(3).key,
+          '@test1:example.com');
+    });
+
+    test('Enabling group calls', () async {
+      // users default is 0 and so group calls not enabled
+      room.setState(
+        Event(
+          senderId: '@test:example.com',
+          type: 'm.room.power_levels',
+          room: room,
+          eventId: '123a',
+          content: {
+            'events': {EventTypes.GroupCallMember: 100},
+            'state_default': 50,
+            'users_default': 0
+          },
+          originServerTs: DateTime.now(),
+          stateKey: '',
+        ),
+      );
+      expect(room.canJoinGroupCall, false);
+      expect(room.groupCallsEnabledForEveryone, false);
+
+      room.setState(
+        Event(
+          senderId: '@test:example.com',
+          type: 'm.room.power_levels',
+          room: room,
+          eventId: '123a',
+          content: {
+            'events': {EventTypes.GroupCallMember: 27},
+            'state_default': 50,
+            'users_default': 49
+          },
+          originServerTs: DateTime.now(),
+          stateKey: '',
+        ),
+      );
+      expect(room.canJoinGroupCall, true);
+      expect(room.groupCallsEnabledForEveryone, true);
+
+      // state_default 50 and user_default 0, use enableGroupCall
+      room.setState(
+        Event(
+            senderId: '@test:example.com',
+            type: 'm.room.power_levels',
+            room: room,
+            eventId: '123',
+            content: {
+              'state_default': 50,
+              'users': {'@test:fakeServer.notExisting': 100},
+              'users_default': 0
+            },
+            originServerTs: DateTime.now(),
+            stateKey: ''),
+      );
+      expect(room.canJoinGroupCall, true); // because admin
+      expect(room.groupCallsEnabledForEveryone, false);
+      await room.enableGroupCalls();
+      expect(room.canJoinGroupCall, true);
+      expect(room.groupCallsEnabledForEveryone, true);
+
+      // state_default 50 and user_default unspecified, use enableGroupCall
+      room.setState(
+        Event(
+          senderId: '@test:example.com',
+          type: 'm.room.power_levels',
+          room: room,
+          eventId: '123',
+          content: {
+            'state_default': 50,
+            'users': {'@test:fakeServer.notExisting': 100},
+          },
+          originServerTs: DateTime.now(),
+          stateKey: '',
+        ),
+      );
+
+      expect(room.canJoinGroupCall, true); // because admin
+      expect(room.groupCallsEnabledForEveryone, false);
+      await room.enableGroupCalls();
+      expect(room.canJoinGroupCall, true);
+      expect(room.groupCallsEnabledForEveryone, true);
+
+      // state_default is 0 so users should be able to send state events
+      room.setState(
+        Event(
+          senderId: '@test:example.com',
+          type: 'm.room.power_levels',
+          room: room,
+          eventId: '123',
+          content: {
+            'state_default': 0,
+            'users': {'@test:fakeServer.notExisting': 100},
+          },
+          originServerTs: DateTime.now(),
+          stateKey: '',
+        ),
+      );
+      expect(room.canJoinGroupCall, true);
+      expect(room.groupCallsEnabledForEveryone, true);
+    });
+
+    test('group call participants count', () {
+      room.setState(
+        Event(
+            senderId: '@test1:example.com',
+            type: EventTypes.GroupCallMember,
+            room: room,
+            eventId: '1234177',
+            content: {
+              'memberships': [
+                CallMembership(
+                  userId: '@test1:example.com',
+                  callId: 'participants_count',
+                  backend: MeshBackend(),
+                  deviceId: '1111',
+                  expiresTs: DateTime.now()
+                      .subtract(Duration(hours: 1))
+                      .millisecondsSinceEpoch,
+                  roomId: room.id,
+                  membershipId: voip.currentSessionId,
+                ).toJson(),
+              ]
+            },
+            originServerTs: DateTime.now(),
+            stateKey: '@test1:example.com'),
+      );
+
+      expect(room.groupCallParticipantCount('participants_count'), 0);
+      expect(room.hasActiveGroupCall, false);
+
+      room.setState(
+        Event(
+            senderId: '@test2:example.com',
+            type: EventTypes.GroupCallMember,
+            room: room,
+            eventId: '1234177',
+            content: {
+              'memberships': [
+                CallMembership(
+                  userId: '@test2:example.com',
+                  callId: 'participants_count',
+                  backend: MeshBackend(),
+                  deviceId: '1111',
+                  expiresTs: DateTime.now()
+                      .add(Duration(hours: 1))
+                      .millisecondsSinceEpoch,
+                  roomId: room.id,
+                  membershipId: voip.currentSessionId,
+                ).toJson(),
+              ]
+            },
+            originServerTs: DateTime.now(),
+            stateKey: '@test2:example.com'),
+      );
+      expect(room.groupCallParticipantCount('participants_count'), 1);
+      expect(room.hasActiveGroupCall, true);
+
+      room.setState(
+        Event(
+            senderId: '@test3:example.com',
+            type: EventTypes.GroupCallMember,
+            room: room,
+            eventId: '1231234124123',
+            content: {
+              'memberships': [
+                CallMembership(
+                  userId: '@test3:example.com',
+                  callId: 'participants_count',
+                  backend: MeshBackend(),
+                  deviceId: '1111',
+                  expiresTs: DateTime.now().millisecondsSinceEpoch,
+                  roomId: room.id,
+                  membershipId: voip.currentSessionId,
+                ).toJson(),
+              ]
+            },
+            originServerTs: DateTime.now(),
+            stateKey: '@test3:example.com'),
+      );
+
+      expect(room.groupCallParticipantCount('participants_count'), 2);
+      expect(room.hasActiveGroupCall, true);
    });
  });
 }
--- a/test/fake_matrix_api.dart
+++ b/test/fake_matrix_api.dart
@ -2581,6 +2581,10 @@ class FakeMatrixApi extends BaseClient {
          (var reqI) => {
                'event_id': '42',
              },
+      '/client/v3/rooms/!calls%3Aexample.com/state/m.room.power_levels':
+          (var reqI) => {
+                'event_id': '42',
+              },
      '/client/v3/directory/list/room/!localpart%3Aexample.com': (var req) =>
          {},
      '/client/v3/room_keys/version/5': (var req) => {},
@ -2600,11 +2604,7 @@ class FakeMatrixApi extends BaseClient {
          },
      '/client/unstable/org.matrix.msc3814.v1/dehydrated_device': (var _) => {
            'device_id': 'DEHYDDEV',
-          },
-      '/client/v3/rooms/${Uri.encodeComponent("!localpart:server.abc")}/state/${Uri.encodeComponent("org.matrix.msc3401.call")}/${Uri.encodeComponent("1675856324414gzczMtfzTk0DKgEw")}':
-          (var req) => {
-                'event_id': 'groupCall',
-              },
+          }
    },
    'DELETE': {
      '/unknown/token': (var req) => {'errcode': 'M_UNKNOWN_TOKEN'},
--- a/test/room_test.dart
+++ b/test/room_test.dart
@ -647,179 +647,10 @@ void main() {
      expect(room.canChangeStateEvent('m.room.power_levels'), false);
      expect(room.canChangeStateEvent('m.room.member'), false);
      expect(room.canSendEvent('m.room.message'), true);
-      final resp = await room.setPower('@test:fakeServer.notExisting', 90);
+      final resp = await room.setPower('@test:fakeServer.notExisting', 0);
      expect(resp, '42');
    });

-    test('Enabling group calls', () async {
-      expect(room.groupCallsEnabled, false);
-
-      // users default is 0 and so group calls not enabled
-      room.setState(
-        Event(
-          senderId: '@test:example.com',
-          type: 'm.room.power_levels',
-          room: room,
-          eventId: '123a',
-          content: {
-            'events': {EventTypes.GroupCallMemberPrefix: 100},
-            'state_default': 50,
-            'users_default': 0
-          },
-          originServerTs: DateTime.now(),
-          stateKey: '',
-        ),
-      );
-      expect(room.groupCallsEnabled, false);
-
-      // one of the group call permissions is unspecified in events override
-      room.setState(
-        Event(
-          senderId: '@test:example.com',
-          type: 'm.room.power_levels',
-          room: room,
-          eventId: '123a',
-          content: {
-            'events': {EventTypes.GroupCallMemberPrefix: 27},
-            'state_default': 50,
-            'users_default': 49
-          },
-          originServerTs: DateTime.now(),
-          stateKey: '',
-        ),
-      );
-      expect(room.groupCallsEnabled, false);
-
-      // only override one of the group calls permission, other one still less
-      // than users_default and state_default
-      room.setState(
-        Event(
-          senderId: '@test:example.com',
-          type: 'm.room.power_levels',
-          room: room,
-          eventId: '123a',
-          content: {
-            'events': {
-              EventTypes.GroupCallMemberPrefix: 27,
-              EventTypes.GroupCallPrefix: 0
-            },
-            'state_default': 50,
-            'users_default': 2
-          },
-          originServerTs: DateTime.now(),
-          stateKey: '',
-        ),
-      );
-      expect(room.groupCallsEnabled, false);
-      expect(room.canJoinGroupCall, false);
-      expect(room.canCreateGroupCall, false);
-
-      // state_default 50 and user_default 26, but override evnents present
-      room.setState(
-        Event(
-          senderId: '@test:example.com',
-          type: 'm.room.power_levels',
-          room: room,
-          eventId: '123a',
-          content: {
-            'events': {
-              EventTypes.GroupCallMemberPrefix: 25,
-              EventTypes.GroupCallPrefix: 25
-            },
-            'state_default': 50,
-            'users_default': 26
-          },
-          originServerTs: DateTime.now(),
-          stateKey: '',
-        ),
-      );
-      expect(room.groupCallsEnabled, true);
-      expect(room.canJoinGroupCall, true);
-      expect(room.canCreateGroupCall, true);
-
-      // state_default 50 and user_default 0, use enableGroupCall
-      room.setState(
-        Event(
-            senderId: '@test:example.com',
-            type: 'm.room.power_levels',
-            room: room,
-            eventId: '123',
-            content: {
-              'state_default': 50,
-              'users': {'@test:fakeServer.notExisting': 100},
-              'users_default': 0
-            },
-            originServerTs: DateTime.now(),
-            stateKey: ''),
-      );
-      expect(room.groupCallsEnabled, false);
-      expect(room.canJoinGroupCall, false);
-      expect(room.canCreateGroupCall, false);
-      await room.enableGroupCalls();
-      expect(room.groupCallsEnabled, true);
-
-      // state_default 50 and user_default unspecified, use enableGroupCall
-      room.setState(
-        Event(
-          senderId: '@test:example.com',
-          type: 'm.room.power_levels',
-          room: room,
-          eventId: '123',
-          content: {
-            'state_default': 50,
-            'users': {'@test:fakeServer.notExisting': 100},
-          },
-          originServerTs: DateTime.now(),
-          stateKey: '',
-        ),
-      );
-      await room.enableGroupCalls();
-      expect(room.groupCallsEnabled, true);
-      expect(room.canJoinGroupCall, true);
-      expect(room.canCreateGroupCall, true);
-
-      // state_default is 0 so users should be able to send state events
-      room.setState(
-        Event(
-          senderId: '@test:example.com',
-          type: 'm.room.power_levels',
-          room: room,
-          eventId: '123',
-          content: {
-            'state_default': 0,
-            'users': {'@test:fakeServer.notExisting': 100},
-          },
-          originServerTs: DateTime.now(),
-          stateKey: '',
-        ),
-      );
-      expect(room.groupCallsEnabled, true);
-      expect(room.canJoinGroupCall, true);
-      expect(room.canCreateGroupCall, true);
-      room.setState(
-        Event(
-          senderId: '@test:example.com',
-          type: 'm.room.power_levels',
-          room: room,
-          eventId: '123abc',
-          content: {
-            'ban': 50,
-            'events': {'m.room.name': 0, 'm.room.power_levels': 100},
-            'events_default': 0,
-            'invite': 50,
-            'kick': 50,
-            'notifications': {'room': 20},
-            'redact': 50,
-            'state_default': 50,
-            'users': {},
-            'users_default': 0
-          },
-          originServerTs: DateTime.now(),
-          stateKey: '',
-        ),
-      );
-    });
-
    test('invite', () async {
      await room.invite('Testname');
    });
@ -1375,7 +1206,7 @@ void main() {
      expect(room.isSpace, true);

      expect(room.spaceParents.isEmpty, true);
-      room.states[EventTypes.spaceParent] = {
+      room.states[EventTypes.SpaceParent] = {
        '!1234:example.invalid': Event.fromJson(
          {
            'content': {
@ -1385,7 +1216,7 @@ void main() {
            'origin_server_ts': 1432735824653,
            'room_id': '!jEsUZKDJdhlrceRyVU:example.org',
            'sender': '@example:example.org',
-            'type': EventTypes.spaceParent,
+            'type': EventTypes.SpaceParent,
            'unsigned': {'age': 1234},
            'state_key': '!1234:example.invalid',
          },
@ -1395,7 +1226,7 @@ void main() {
      expect(room.spaceParents.length, 1);

      expect(room.spaceChildren.isEmpty, true);
-      room.states[EventTypes.spaceChild] = {
+      room.states[EventTypes.SpaceChild] = {
        '!b:example.invalid': Event.fromJson(
          {
            'content': {
@ -1406,7 +1237,7 @@ void main() {
            'origin_server_ts': 1432735824653,
            'room_id': '!jEsUZKDJdhlrceRyVU:example.org',
            'sender': '@example:example.org',
-            'type': EventTypes.spaceChild,
+            'type': EventTypes.SpaceChild,
            'unsigned': {'age': 1234},
            'state_key': '!b:example.invalid',
          },
@ -1422,7 +1253,7 @@ void main() {
            'origin_server_ts': 1432735824653,
            'room_id': '!jEsUZKDJdhlrceRyVU:example.org',
            'sender': '@example:example.org',
-            'type': EventTypes.spaceChild,
+            'type': EventTypes.SpaceChild,
            'unsigned': {'age': 1234},
            'state_key': '!c:example.invalid',
          },
@ -1437,7 +1268,7 @@ void main() {
            'origin_server_ts': 1432735824653,
            'room_id': '!jEsUZKDJdhlrceRyVU:example.org',
            'sender': '@example:example.org',
-            'type': EventTypes.spaceChild,
+            'type': EventTypes.SpaceChild,
            'unsigned': {'age': 1234},
            'state_key': '!noorder:example.invalid',
          },
@ -1453,7 +1284,7 @@ void main() {
            'origin_server_ts': 1432735824653,
            'room_id': '!jEsUZKDJdhlrceRyVU:example.org',
            'sender': '@example:example.org',
-            'type': EventTypes.spaceChild,
+            'type': EventTypes.SpaceChild,
            'unsigned': {'age': 1234},
            'state_key': '!a:example.invalid',
          },
@ -1485,7 +1316,6 @@ void main() {
    test('inviteLink', () async {
      // ensure we don't rerequest members
      room.summary.mJoinedMemberCount = 4;
-
      var matrixToLink = await room.matrixToInviteLink();
      expect(matrixToLink.toString(),
          'https://matrix.to/#/%23testalias%3Aexample.com');
@ -1504,181 +1334,6 @@ void main() {
          'https://matrix.to/#/!localpart%3Aserver.abc?via=example.com&via=test.abc&via=example.org');
    });

-    test('callMemberStateIsExpired', () {
-      expect(
-          room.callMemberStateForIdIsExpired(
-              Event(
-                  senderId: '@test:example.com',
-                  type: EventTypes.GroupCallMemberPrefix,
-                  room: room,
-                  eventId: '1231234124',
-                  content: {
-                    'm.calls': [
-                      {
-                        'm.call_id': '1674811248673789288k7d60n5976',
-                        'm.devices': [
-                          {
-                            'device_id': 'ZEEGCGPTGI',
-                            'session_id': 'cbAtVZdLBnJq',
-                            'm.expires_ts': 1674813039415,
-                            'feeds': [
-                              {'purpose': 'm.usermedia'}
-                            ]
-                          }
-                        ]
-                      },
-                    ],
-                  },
-                  originServerTs: DateTime.now(),
-                  stateKey: ''),
-              '1674811248673789288k7d60n5976'),
-          true);
-      expect(
-          room.callMemberStateForIdIsExpired(
-              Event(
-                  senderId: '@test:example.com',
-                  type: EventTypes.GroupCallMemberPrefix,
-                  room: room,
-                  eventId: '1231234124',
-                  content: {
-                    'm.calls': [
-                      {
-                        'm.call_id': '1674811256006mfqnmsAbzqxjYtWZ',
-                        'm.devices': [
-                          {
-                            'device_id': 'ZEEGCGPTGI',
-                            'session_id': 'fhovqxwcasdfr',
-                            'expires_ts': DateTime.now()
-                                .add(Duration(minutes: 1))
-                                .millisecondsSinceEpoch,
-                            'feeds': [
-                              {'purpose': 'm.usermedia'}
-                            ]
-                          }
-                        ]
-                      }
-                    ],
-                  },
-                  originServerTs: DateTime.now(),
-                  stateKey: ''),
-              '1674811256006mfqnmsAbzqxjYtWZ'),
-          false);
-    });
-
-    test('group call participants count', () {
-      room.setState(
-        Event(
-            senderId: '@test:example.com',
-            type: EventTypes.GroupCallMemberPrefix,
-            room: room,
-            eventId: '1234177',
-            content: {
-              'm.calls': [
-                {
-                  'm.call_id': '1674811256006mfqnmsAbzqxjYtWZ',
-                  'm.devices': [
-                    {
-                      'device_id': 'ZEEGCGPTGI',
-                      'session_id': 'fhovqxwcasdfr',
-                      'expires_ts': DateTime.now()
-                          .add(Duration(minutes: 1))
-                          .millisecondsSinceEpoch,
-                      'feeds': [
-                        {'purpose': 'm.usermedia'}
-                      ]
-                    },
-                  ]
-                }
-              ],
-            },
-            originServerTs: DateTime.now(),
-            stateKey: '@test:example.com'),
-      );
-      room.setState(
-        Event(
-            senderId: '@test0:example.com',
-            type: EventTypes.GroupCallMemberPrefix,
-            room: room,
-            eventId: '1234177',
-            content: {
-              'm.calls': [
-                {
-                  'm.call_id': '1674811256006mfqnmsAbzqxjYtWZ',
-                  'm.devices': [
-                    {
-                      'device_id': 'ZEEGCGPTGI',
-                      'session_id': 'fhovqxwcasdfr',
-                      'expires_ts': DateTime.now()
-                          .add(Duration(minutes: 2))
-                          .millisecondsSinceEpoch,
-                      'feeds': [
-                        {'purpose': 'm.usermedia'}
-                      ]
-                    },
-                  ]
-                }
-              ],
-            },
-            originServerTs: DateTime.now(),
-            stateKey: '@test0:example.com'),
-      );
-      room.setState(
-        Event(
-            senderId: '@test2:example.com',
-            type: EventTypes.GroupCallMemberPrefix,
-            room: room,
-            eventId: '1231234124123',
-            content: {
-              'm.calls': [
-                {
-                  'm.call_id': '1674811256006mfqnmsAbzqxjYtWZ',
-                  'm.devices': [
-                    {
-                      'device_id': 'ZEEGCGPTGI',
-                      'session_id': 'fhovqxwcasdfr',
-                      'feeds': [
-                        {'purpose': 'm.usermedia'}
-                      ]
-                    },
-                  ]
-                }
-              ],
-            },
-            originServerTs: DateTime.now(),
-            stateKey: '@test2:example.com'),
-      );
-      room.setState(
-        Event(
-            senderId: '@test3:example.com',
-            type: EventTypes.GroupCallMemberPrefix,
-            room: room,
-            eventId: '123123412445',
-            content: {
-              'm.calls': [
-                {
-                  'm.call_id': '1674811256006mfqnmsAbzqxjYtWZ',
-                  'm.devices': [
-                    {
-                      'device_id': 'ZEEGCGPTGI',
-                      'session_id': 'fhovqxwcasdfr',
-                      'expires_ts': DateTime.now()
-                          .subtract(Duration(minutes: 1))
-                          .millisecondsSinceEpoch,
-                      'feeds': [
-                        {'purpose': 'm.usermedia'}
-                      ]
-                    },
-                  ]
-                }
-              ],
-            },
-            originServerTs: DateTime.now(),
-            stateKey: '@test3:example.com'),
-      );
-      expect(
-          room.groupCallParticipantCount('1674811256006mfqnmsAbzqxjYtWZ'), 2);
-    });
-
    test('EventTooLarge on exceeding max PDU size', () async {
      try {
        await room.sendTextEvent('''
--- a/test/webrtc_stub.dart
+++ b/test/webrtc_stub.dart
@ -6,7 +6,6 @@ import 'package:matrix/matrix.dart';

 class MockWebRTCDelegate implements WebRTCDelegate {
  @override
-  // TODO: implement canHandleNewCall
  bool get canHandleNewCall => true;

  @override
@ -16,18 +15,13 @@ class MockWebRTCDelegate implements WebRTCDelegate {
  ]) async =>
      MockRTCPeerConnection();

-  @override
-  VideoRenderer createRenderer() {
-    return MockVideoRenderer();
-  }
-
  @override
  Future<void> handleCallEnded(CallSession session) async {
    Logs().i('handleCallEnded called in MockWebRTCDelegate');
  }

  @override
-  Future<void> handleGroupCallEnded(GroupCall groupCall) async {
+  Future<void> handleGroupCallEnded(GroupCallSession groupCall) async {
    Logs().i('handleGroupCallEnded called in MockWebRTCDelegate');
  }

@ -42,7 +36,7 @@ class MockWebRTCDelegate implements WebRTCDelegate {
  }

  @override
-  Future<void> handleNewGroupCall(GroupCall groupCall) async {
+  Future<void> handleNewGroupCall(GroupCallSession groupCall) async {
    Logs().i('handleNewGroupCall called in MockWebRTCDelegate');
  }

@ -61,6 +55,27 @@ class MockWebRTCDelegate implements WebRTCDelegate {
  Future<void> stopRingtone() async {
    Logs().i('stopRingtone called in MockWebRTCDelegate');
  }
+
+  @override
+  EncryptionKeyProvider? get keyProvider => MockEncryptionKeyProvider();
+}
+
+class MockEncryptionKeyProvider implements EncryptionKeyProvider {
+  @override
+  Future<void> onSetEncryptionKey(
+      CallParticipant participant, Uint8List key, int index) async {
+    Logs().i('Mock onSetEncryptionKey called for ${participant.id} ');
+  }
+
+  @override
+  Future<Uint8List> onExportKey(CallParticipant participant, int index) {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<Uint8List> onRatchetKey(CallParticipant participant, int index) {
+    throw UnimplementedError();
+  }
 }

 class MockMediaDevices implements MediaDevices {
@ -69,25 +84,21 @@ class MockMediaDevices implements MediaDevices {

  @override
  Future<List<MediaDeviceInfo>> enumerateDevices() {
-    // TODO: implement enumerateDevices
    throw UnimplementedError();
  }

  @override
  Future<MediaStream> getDisplayMedia(Map<String, dynamic> mediaConstraints) {
-    // TODO: implement getDisplayMedia
    throw UnimplementedError();
  }

  @override
  Future<List> getSources() {
-    // TODO: implement getSources
    throw UnimplementedError();
  }

  @override
  MediaTrackSupportedConstraints getSupportedConstraints() {
-    // TODO: implement getSupportedConstraints
    throw UnimplementedError();
  }

@ -99,7 +110,6 @@ class MockMediaDevices implements MediaDevices {

  @override
  Future<MediaDeviceInfo> selectAudioOutput([AudioOutputOptions? options]) {
-    // TODO: implement selectAudioOutput
    throw UnimplementedError();
  }
 }
@ -347,15 +357,12 @@ class MockRTCPeerConnection implements RTCPeerConnection {
  }

  @override
-  // TODO: implement receivers
  Future<List<RTCRtpReceiver>> get receivers => throw UnimplementedError();

  @override
-  // TODO: implement senders
  Future<List<RTCRtpSender>> get senders => throw UnimplementedError();

  @override
-  // TODO: implement transceivers
  Future<List<RTCRtpTransceiver>> get transceivers =>
      throw UnimplementedError();
 }
@ -415,65 +422,53 @@ class MockRTCRtpTransceiver implements RTCRtpTransceiver {
  }

  @override
-  // TODO: implement stoped
  bool get stoped => throw UnimplementedError();
 }

 class MockRTCRtpSender implements RTCRtpSender {
  @override
  Future<void> dispose() {
-    // TODO: implement dispose
    throw UnimplementedError();
  }

  @override
-  // TODO: implement dtmfSender
  RTCDTMFSender get dtmfSender => throw UnimplementedError();

  @override
  Future<List<StatsReport>> getStats() {
-    // TODO: implement getStats
    throw UnimplementedError();
  }

  @override
-  // TODO: implement ownsTrack
  bool get ownsTrack => throw UnimplementedError();

  @override
-  // TODO: implement parameters
  RTCRtpParameters get parameters => throw UnimplementedError();

  @override
  Future<void> replaceTrack(MediaStreamTrack? track) {
-    // TODO: implement replaceTrack
    throw UnimplementedError();
  }

  @override
-  // TODO: implement senderId
  String get senderId => throw UnimplementedError();

  @override
  Future<bool> setParameters(RTCRtpParameters parameters) {
-    // TODO: implement setParameters
    throw UnimplementedError();
  }

  @override
  Future<void> setStreams(List<MediaStream> streams) {
-    // TODO: implement setStreams
    throw UnimplementedError();
  }

  @override
  Future<void> setTrack(MediaStreamTrack? track, {bool takeOwnership = true}) {
-    // TODO: implement setTrack
    throw UnimplementedError();
  }

  @override
-  // TODO: implement track
  MediaStreamTrack? get track => throw UnimplementedError();
  // Mock implementation for RTCRtpSender
 }
@ -485,20 +480,16 @@ class MockRTCRtpReceiver implements RTCRtpReceiver {

  @override
  Future<List<StatsReport>> getStats() {
-    // TODO: implement getStats
    throw UnimplementedError();
  }

  @override
-  // TODO: implement parameters
  RTCRtpParameters get parameters => throw UnimplementedError();

  @override
-  // TODO: implement receiverId
  String get receiverId => throw UnimplementedError();

  @override
-  // TODO: implement track
  MediaStreamTrack? get track => throw UnimplementedError();
  // Mock implementation for RTCRtpReceiver
 }