VoIP: remove dependency over WebRtc on SDK

matrix-sdk-android/build.gradle

@@ -178,12 +178,6 @@ dependencies {
     // Phone number https://github.com/google/libphonenumber
     implementation 'com.googlecode.libphonenumber:libphonenumber:8.10.23'
 
-    // Web RTC
-    // org.webrtc:google-webrtc is for development purposes only. See http://webrtc.github.io/webrtc-org/native-code/android/
-    // implementation 'org.webrtc:google-webrtc:1.0.+'
-    // Use the same WebRTC library than the one used by Jitsi library
-    implementation('com.facebook.react:react-native-webrtc:1.84.0-jitsi-5112273@aar')
-
     testImplementation 'junit:junit:4.13'
     testImplementation 'org.robolectric:robolectric:4.3'
     //testImplementation 'org.robolectric:shadows-support-v4:3.0'

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/call/CallState.kt

@@ -16,7 +16,6 @@
 
 package org.matrix.android.sdk.api.session.call
 
-import org.webrtc.PeerConnection
 
 sealed class CallState {
 
@@ -42,7 +41,7 @@ sealed class CallState {
      * Notice that the PeerState failed is not always final, if you switch network, new ice candidtates
      * could be exchanged, and the connection could go back to connected
      * */
-    data class Connected(val iceConnectionState: PeerConnection.PeerConnectionState) : CallState()
+    data class Connected(val iceConnectionState: MxPeerConnectionState) : CallState()
 
     /** Terminated.  Incoming/Outgoing call, the call is terminated */
     object Terminated : CallState()

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/call/MxCall.kt

@@ -16,9 +16,8 @@
 
 package org.matrix.android.sdk.api.session.call
 
+import org.matrix.android.sdk.api.session.room.model.call.CallCandidate
 import org.matrix.android.sdk.api.util.Optional
-import org.webrtc.IceCandidate
-import org.webrtc.SessionDescription
 
 interface MxCallDetail {
     val callId: String
@@ -47,12 +46,12 @@ interface MxCall : MxCallDetail {
      * Pick Up the incoming call
      * It has no effect on outgoing call
      */
-    fun accept(sdp: SessionDescription)
+    fun accept(sdpString: String)
 
     /**
      * SDP negotiation for media pause, hold/resume, ICE restarts and voice/video call up/downgrading
      */
-    fun negotiate(sdp: SessionDescription)
+    fun negotiate(sdpString: String)
 
     /**
      * This has to be sent by the caller's client once it has chosen an answer.
@@ -73,17 +72,17 @@ interface MxCall : MxCallDetail {
      * Start a call
      * Send offer SDP to the other participant.
      */
-    fun offerSdp(sdp: SessionDescription)
+    fun offerSdp(sdpString: String)
 
     /**
      * Send Ice candidate to the other participant.
      */
-    fun sendLocalIceCandidates(candidates: List<IceCandidate>)
+    fun sendLocalIceCandidates(candidates: List<CallCandidate>)
 
     /**
      * Send removed ICE candidates to the other participant.
      */
-    fun sendLocalIceCandidateRemovals(candidates: List<IceCandidate>)
+    fun sendLocalIceCandidateRemovals(candidates: List<CallCandidate>)
 
     fun addListener(listener: StateListener)
     fun removeListener(listener: StateListener)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/call/MxPeerConnectionState.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2020 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.api.session.call;
+
+/**
+ * This is a copy of https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/connectionState
+ * to avoid having the dependency over WebRtc library on sdk.
+ */
+public enum MxPeerConnectionState {
+    NEW,
+    CONNECTING,
+    CONNECTED,
+    DISCONNECTED,
+    FAILED,
+    CLOSED;
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/call/CallCandidate.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2020 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.api.session.room.model.call
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class CallCandidate(
+        /**
+         * Required. The SDP media type this candidate is intended for.
+         */
+        @Json(name = "sdpMid") val sdpMid: String,
+        /**
+         * Required. The index of the SDP 'm' line this candidate is intended for.
+         */
+        @Json(name = "sdpMLineIndex") val sdpMLineIndex: Int,
+        /**
+         * Required. The SDP 'a' line of the candidate.
+         */
+        @Json(name = "candidate") val candidate: String
+)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/call/CallCandidatesContent.kt

@@ -36,26 +36,9 @@ data class CallCandidatesContent(
         /**
          * Required. Array of objects describing the candidates.
          */
-        @Json(name = "candidates") val candidates: List<Candidate> = emptyList(),
+        @Json(name = "candidates") val candidates: List<CallCandidate> = emptyList(),
         /**
          * Required. The version of the VoIP specification this messages adheres to. This specification is version 0.
          */
         @Json(name = "version") override val version: String? = "0"
-): CallSignallingContent  {
+): CallSignallingContent
-
-    @JsonClass(generateAdapter = true)
-    data class Candidate(
-            /**
-             * Required. The SDP media type this candidate is intended for.
-             */
-            @Json(name = "sdpMid") val sdpMid: String,
-            /**
-             * Required. The index of the SDP 'm' line this candidate is intended for.
-             */
-            @Json(name = "sdpMLineIndex") val sdpMLineIndex: Int,
-            /**
-             * Required. The SDP 'a' line of the candidate.
-             */
-            @Json(name = "candidate") val candidate: String
-    )
-}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/model/call/SdpType.kt

@@ -18,7 +18,6 @@ package org.matrix.android.sdk.api.session.room.model.call
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
-import org.webrtc.SessionDescription
 
 @JsonClass(generateAdapter = false)
 enum class SdpType {
@@ -28,19 +27,3 @@ enum class SdpType {
     @Json(name = "answer")
     ANSWER;
 }
-
-fun SdpType.asWebRTC(): SessionDescription.Type {
-    return if (this == SdpType.OFFER) {
-        SessionDescription.Type.OFFER
-    } else {
-        SessionDescription.Type.ANSWER
-    }
-}
-
-fun SessionDescription.Type.toSdpType(): SdpType {
-    return if (this == SessionDescription.Type.OFFER) {
-        SdpType.OFFER
-    } else {
-        SdpType.ANSWER
-    }
-}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/call/model/MxCallImpl.kt

@@ -25,19 +25,18 @@ import org.matrix.android.sdk.api.session.events.model.LocalEcho
 import org.matrix.android.sdk.api.session.events.model.UnsignedData
 import org.matrix.android.sdk.api.session.events.model.toContent
 import org.matrix.android.sdk.api.session.room.model.call.CallAnswerContent
+import org.matrix.android.sdk.api.session.room.model.call.CallCandidate
 import org.matrix.android.sdk.api.session.room.model.call.CallCandidatesContent
 import org.matrix.android.sdk.api.session.room.model.call.CallHangupContent
 import org.matrix.android.sdk.api.session.room.model.call.CallInviteContent
 import org.matrix.android.sdk.api.session.room.model.call.CallNegotiateContent
 import org.matrix.android.sdk.api.session.room.model.call.CallRejectContent
 import org.matrix.android.sdk.api.session.room.model.call.CallSelectAnswerContent
-import org.matrix.android.sdk.api.session.room.model.call.toSdpType
+import org.matrix.android.sdk.api.session.room.model.call.SdpType
 import org.matrix.android.sdk.api.util.Optional
 import org.matrix.android.sdk.internal.session.call.DefaultCallSignalingService
 import org.matrix.android.sdk.internal.session.room.send.queue.EventSenderProcessor
 import org.matrix.android.sdk.internal.session.room.send.LocalEchoEventFactory
-import org.webrtc.IceCandidate
-import org.webrtc.SessionDescription
 import timber.log.Timber
 
 internal class MxCallImpl(
@@ -90,7 +89,7 @@ internal class MxCallImpl(
         }
     }
 
-    override fun offerSdp(sdp: SessionDescription) {
+    override fun offerSdp(sdpString: String) {
         if (!isOutgoing) return
         Timber.v("## VOIP offerSdp $callId")
         state = CallState.Dialing
@@ -98,29 +97,23 @@ internal class MxCallImpl(
                 callId = callId,
                 partyId = ourPartyId,
                 lifetime = DefaultCallSignalingService.CALL_TIMEOUT_MS,
-                offer = CallInviteContent.Offer(sdp = sdp.description)
+                offer = CallInviteContent.Offer(sdp = sdpString)
         )
                 .let { createEventAndLocalEcho(type = EventType.CALL_INVITE, roomId = roomId, content = it.toContent()) }
                 .also { eventSenderProcessor.postEvent(it) }
     }
 
-    override fun sendLocalIceCandidates(candidates: List<IceCandidate>) {
+    override fun sendLocalIceCandidates(candidates: List<CallCandidate>) {
         CallCandidatesContent(
                 callId = callId,
                 partyId = ourPartyId,
-                candidates = candidates.map {
+                candidates = candidates
-                    CallCandidatesContent.Candidate(
-                            sdpMid = it.sdpMid,
-                            sdpMLineIndex = it.sdpMLineIndex,
-                            candidate = it.sdp
-                    )
-                }
         )
                 .let { createEventAndLocalEcho(type = EventType.CALL_CANDIDATES, roomId = roomId, content = it.toContent()) }
                 .also { eventSenderProcessor.postEvent(it) }
     }
 
-    override fun sendLocalIceCandidateRemovals(candidates: List<IceCandidate>) {
+    override fun sendLocalIceCandidateRemovals(candidates: List<CallCandidate>) {
         // For now we don't support this flow
     }
 
@@ -153,26 +146,26 @@ internal class MxCallImpl(
         state = CallState.Terminated
     }
 
-    override fun accept(sdp: SessionDescription) {
+    override fun accept(sdpString: String) {
         Timber.v("## VOIP accept $callId")
         if (isOutgoing) return
         state = CallState.Answering
         CallAnswerContent(
                 callId = callId,
                 partyId = ourPartyId,
-                answer = CallAnswerContent.Answer(sdp = sdp.description)
+                answer = CallAnswerContent.Answer(sdp = sdpString)
         )
                 .let { createEventAndLocalEcho(type = EventType.CALL_ANSWER, roomId = roomId, content = it.toContent()) }
                 .also { eventSenderProcessor.postEvent(it) }
     }
 
-    override fun negotiate(sdp: SessionDescription) {
+    override fun negotiate(sdpString: String) {
         Timber.v("## VOIP negotiate $callId")
         CallNegotiateContent(
                 callId = callId,
                 partyId = ourPartyId,
                 lifetime = DefaultCallSignalingService.CALL_TIMEOUT_MS,
-                description = CallNegotiateContent.Description(sdp = sdp.description, type = sdp.type.toSdpType())
+                description = CallNegotiateContent.Description(sdp = sdpString, type = SdpType.OFFER)
         )
                 .let { createEventAndLocalEcho(type = EventType.CALL_NEGOTIATE, roomId = roomId, content = it.toContent()) }
                 .also { eventSenderProcessor.postEvent(it) }

vector/src/main/java/im/vector/app/core/ui/views/ActiveCallViewHolder.kt

@@ -22,7 +22,7 @@ import androidx.core.view.isVisible
 import im.vector.app.core.utils.DebouncedClickListener
 import im.vector.app.features.call.WebRtcPeerConnectionManager
 import org.matrix.android.sdk.api.session.call.CallState
-import org.matrix.android.sdk.api.session.call.EglUtils
+import im.vector.app.features.call.utils.EglUtils
 import org.matrix.android.sdk.api.session.call.MxCall
 import org.webrtc.RendererCommon
 import org.webrtc.SurfaceViewRenderer

vector/src/main/java/im/vector/app/features/call/CallControlsView.kt

@@ -29,6 +29,7 @@ import butterknife.OnClick
 import im.vector.app.R
 import kotlinx.android.synthetic.main.view_call_controls.view.*
 import org.matrix.android.sdk.api.session.call.CallState
+import org.matrix.android.sdk.api.session.call.MxPeerConnectionState
 import org.webrtc.PeerConnection
 
 class CallControlsView @JvmOverloads constructor(
@@ -129,7 +130,7 @@ class CallControlsView @JvmOverloads constructor(
                 connectedControls.isVisible = false
             }
             is CallState.Connected    -> {
-                if (callState.iceConnectionState == PeerConnection.PeerConnectionState.CONNECTED) {
+                if (callState.iceConnectionState == MxPeerConnectionState.CONNECTED) {
                     ringingControls.isVisible = false
                     connectedControls.isVisible = true
                     iv_video_toggle.isVisible = state.isVideoCall

vector/src/main/java/im/vector/app/features/call/VectorCallActivity.kt

@@ -52,8 +52,9 @@ import io.reactivex.android.schedulers.AndroidSchedulers
 import kotlinx.android.parcel.Parcelize
 import kotlinx.android.synthetic.main.activity_call.*
 import org.matrix.android.sdk.api.session.call.CallState
-import org.matrix.android.sdk.api.session.call.EglUtils
+import im.vector.app.features.call.utils.EglUtils
 import org.matrix.android.sdk.api.session.call.MxCallDetail
+import org.matrix.android.sdk.api.session.call.MxPeerConnectionState
 import org.matrix.android.sdk.api.session.call.TurnServerResponse
 import org.webrtc.EglBase
 import org.webrtc.PeerConnection
@@ -255,7 +256,7 @@ class VectorCallActivity : VectorBaseActivity(), CallControlsView.InteractionLis
                 configureCallInfo(state)
             }
             is CallState.Connected    -> {
-                if (callState.iceConnectionState == PeerConnection.PeerConnectionState.CONNECTED) {
+                if (callState.iceConnectionState == MxPeerConnectionState.CONNECTED) {
                     if (callArgs.isVideoCall) {
                         callVideoGroup.isVisible = true
                         callInfoGroup.isVisible = false

vector/src/main/java/im/vector/app/features/call/VectorCallViewModel.kt

@@ -30,6 +30,7 @@ import org.matrix.android.sdk.api.MatrixCallback
 import org.matrix.android.sdk.api.session.Session
 import org.matrix.android.sdk.api.session.call.CallState
 import org.matrix.android.sdk.api.session.call.MxCall
+import org.matrix.android.sdk.api.session.call.MxPeerConnectionState
 import org.matrix.android.sdk.api.session.call.TurnServerResponse
 import org.matrix.android.sdk.api.util.MatrixItem
 import org.matrix.android.sdk.api.util.toMatrixItem
@@ -53,7 +54,7 @@ class VectorCallViewModel @AssistedInject constructor(
     private val callStateListener = object : MxCall.StateListener {
         override fun onStateUpdate(call: MxCall) {
             val callState = call.state
-            if (callState is CallState.Connected && callState.iceConnectionState == PeerConnection.PeerConnectionState.CONNECTED) {
+            if (callState is CallState.Connected && callState.iceConnectionState == MxPeerConnectionState.CONNECTED) {
                 hasBeenConnectedOnce = true
                 connectionTimeoutTimer?.cancel()
                 connectionTimeoutTimer = null

vector/src/main/java/im/vector/app/features/call/WebRtcPeerConnectionManager.kt

@@ -46,8 +46,11 @@ import org.matrix.android.sdk.api.extensions.tryOrNull
 import org.matrix.android.sdk.api.session.Session
 import org.matrix.android.sdk.api.session.call.CallListener
 import org.matrix.android.sdk.api.session.call.CallState
-import org.matrix.android.sdk.api.session.call.EglUtils
+import im.vector.app.features.call.utils.EglUtils
+import im.vector.app.features.call.utils.asWebRTC
+import im.vector.app.features.call.utils.mapToCallCandidate
 import org.matrix.android.sdk.api.session.call.MxCall
+import org.matrix.android.sdk.api.session.call.MxPeerConnectionState
 import org.matrix.android.sdk.api.session.call.TurnServerResponse
 import org.matrix.android.sdk.api.session.room.model.call.CallAnswerContent
 import org.matrix.android.sdk.api.session.room.model.call.CallCandidatesContent
@@ -57,7 +60,6 @@ import org.matrix.android.sdk.api.session.room.model.call.CallNegotiateContent
 import org.matrix.android.sdk.api.session.room.model.call.CallRejectContent
 import org.matrix.android.sdk.api.session.room.model.call.CallSelectAnswerContent
 import org.matrix.android.sdk.api.session.room.model.call.SdpType
-import org.matrix.android.sdk.api.session.room.model.call.asWebRTC
 import org.matrix.android.sdk.internal.util.awaitCallback
 import org.webrtc.AudioSource
 import org.webrtc.AudioTrack
@@ -150,7 +152,7 @@ class WebRtcPeerConnectionManager @Inject constructor(
                     if (it.isNotEmpty()) {
                         Timber.v("## Sending local ice candidates to call")
                         // it.forEach { peerConnection?.addIceCandidate(it) }
-                        mxCall.sendLocalIceCandidates(it)
+                        mxCall.sendLocalIceCandidates(it.mapToCallCandidate())
                     }
                 }
 
@@ -329,9 +331,9 @@ class WebRtcPeerConnectionManager @Inject constructor(
             }
             if (call.state == CallState.CreateOffer) {
                 // send offer to peer
-                call.offerSdp(sessionDescription)
+                call.offerSdp(sessionDescription.description)
             } else {
-                call.negotiate(sessionDescription)
+                call.negotiate(sessionDescription.description)
             }
         } catch (failure: Throwable) {
             // Need to handle error properly.
@@ -455,7 +457,7 @@ class WebRtcPeerConnectionManager @Inject constructor(
 
         // create a answer, set local description and send via signaling
         createAnswer(callContext)?.also {
-            callContext.mxCall.accept(it)
+            callContext.mxCall.accept(it.description)
         }
         Timber.v("## VOIP remoteCandidateSource ${callContext.remoteCandidateSource}")
         callContext.remoteIceCandidateDisposable = callContext.remoteCandidateSource?.subscribe({
@@ -969,7 +971,7 @@ class WebRtcPeerConnectionManager @Inject constructor(
                 peerConnection.awaitSetRemoteDescription(sdp)
                 if (type == SdpType.OFFER) {
                     createAnswer(call)?.also {
-                        call.mxCall.negotiate(it)
+                        call.mxCall.negotiate(sdpText)
                     }
                 }
             } catch (failure: Throwable) {
@@ -1053,7 +1055,7 @@ class WebRtcPeerConnectionManager @Inject constructor(
                  * or is closed (state "closed"); in addition, at least one transport is either "connected" or "completed"
                  */
                 PeerConnection.PeerConnectionState.CONNECTED -> {
-                    callContext.mxCall.state = CallState.Connected(newState)
+                    callContext.mxCall.state = CallState.Connected(MxPeerConnectionState.CONNECTED)
                     callAudioManager.onCallConnected(callContext.mxCall)
                 }
                 /**
@@ -1062,7 +1064,7 @@ class WebRtcPeerConnectionManager @Inject constructor(
                 PeerConnection.PeerConnectionState.FAILED -> {
                     // This can be temporary, e.g when other ice not yet received...
                     // callContext.mxCall.state = CallState.ERROR
-                    callContext.mxCall.state = CallState.Connected(newState)
+                    callContext.mxCall.state = CallState.Connected(MxPeerConnectionState.FAILED)
                 }
                 /**
                  * At least one of the connection's ICE transports (RTCIceTransports or RTCDtlsTransports) are in the "new" state,
@@ -1070,26 +1072,27 @@ class WebRtcPeerConnectionManager @Inject constructor(
                  * or all of the connection's transports are in the "closed" state.
                  */
                 PeerConnection.PeerConnectionState.NEW,
-
                     /**
                      * One or more of the ICE transports are currently in the process of establishing a connection;
                      * that is, their RTCIceConnectionState is either "checking" or "connected", and no transports are in the "failed" state
                      */
                 PeerConnection.PeerConnectionState.CONNECTING -> {
-                    callContext.mxCall.state = CallState.Connected(PeerConnection.PeerConnectionState.CONNECTING)
+                    callContext.mxCall.state = CallState.Connected(MxPeerConnectionState.CONNECTING)
                 }
                 /**
                  * The RTCPeerConnection is closed.
                  * This value was in the RTCSignalingState enum (and therefore found by reading the value of the signalingState)
                  * property until the May 13, 2016 draft of the specification.
                  */
-                PeerConnection.PeerConnectionState.CLOSED,
+                PeerConnection.PeerConnectionState.CLOSED -> {
+                    callContext.mxCall.state = CallState.Connected(MxPeerConnectionState.CLOSED)
+                }
                 /**
                  * At least one of the ICE transports for the connection is in the "disconnected" state and none of
                  * the other transports are in the state "failed", "connecting", or "checking".
                  */
                 PeerConnection.PeerConnectionState.DISCONNECTED -> {
-                    callContext.mxCall.state = CallState.Connected(newState)
+                    callContext.mxCall.state = CallState.Connected(MxPeerConnectionState.DISCONNECTED)
                 }
                 null -> {
                 }

vector/src/main/java/im/vector/app/features/call/utils/EglUtils.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 The Matrix.org Foundation C.I.C.
+ * Copyright (c) 2020 New Vector Ltd
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.matrix.android.sdk.api.session.call
+package im.vector.app.features.call.utils
 
 import org.webrtc.EglBase
 import timber.log.Timber

vector/src/main/java/im/vector/app/features/call/utils/PeerConnectionExt.kt

@@ -17,6 +17,7 @@
 package im.vector.app.features.call.utils
 
 import im.vector.app.features.call.SdpObserverAdapter
+import org.matrix.android.sdk.api.session.call.MxPeerConnectionState
 import org.webrtc.MediaConstraints
 import org.webrtc.PeerConnection
 import org.webrtc.SessionDescription
@@ -79,4 +80,3 @@ suspend fun PeerConnection.awaitSetRemoteDescription(sessionDescription: Session
         }
     }, sessionDescription)
 }
-

vector/src/main/java/im/vector/app/features/call/utils/WebRtcMapping.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2020 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package im.vector.app.features.call.utils
+
+import org.matrix.android.sdk.api.session.room.model.call.CallCandidate
+import org.matrix.android.sdk.api.session.room.model.call.SdpType
+import org.webrtc.IceCandidate
+import org.webrtc.SessionDescription
+
+fun List<IceCandidate>.mapToCallCandidate() = map {
+    CallCandidate(
+            sdpMid = it.sdpMid,
+            sdpMLineIndex = it.sdpMLineIndex,
+            candidate = it.sdp
+    )
+}
+
+fun SdpType.asWebRTC(): SessionDescription.Type {
+    return if (this == SdpType.OFFER) {
+        SessionDescription.Type.OFFER
+    } else {
+        SessionDescription.Type.ANSWER
+    }
+}
+
+