Add set degradation preference method

Author: mekya

.gitignore

@@ -4,3 +4,4 @@ Podfile.lock
 Release-iphoneos.xcarchive
 Release-iphonesimulator.xcarchive
 Release*
+Package.resolved

WebRTCiOSSDK/api/AntMediaClient.swift

@@ -116,11 +116,15 @@ open class AntMediaClient: NSObject, AntMediaClientProtocol {
 
     private var cameraSourceFPS: Int = 30;
 
+    /**
+    Degradation preference when publishing streams. By default its values is maintainResolution because when resolution changes HLS playback does not play in safari
+    */
+    private var degradationPreference: RTCDegradationPreference = RTCDegradationPreference.maintainResolution;
+    
     var pingTimer: Timer?
 
     var disableTrackId:String?
 
-    
     var reconnectIfRequiresScheduled: Bool = false;
 
     struct HandshakeMessage:Codable {
@@ -533,6 +537,7 @@ open class AntMediaClient: NSObject, AntMediaClientProtocol {
             self.webRTCClientMap[id] = WebRTCClient.init(remoteVideoView: remoteView, localVideoView: localView, delegate: self, mode: mode != .unspecified ? mode : self.mode , cameraPosition: self.cameraPosition, targetWidth: self.targetWidth, targetHeight: self.targetHeight, videoEnabled: self.videoEnable, enableDataChannel: self.enableDataChannel, useExternalCameraSource: self.useExternalCameraSource, externalAudio: self.externalAudioEnabled, externalVideoCapture: self.externalVideoCapture, cameraSourceFPS: self.cameraSourceFPS, streamId:id);
 
             self.webRTCClientMap[id]?.setToken(token)
+            self.webRTCClientMap[id]?.setDegradationPreference(degradationPreference: self.degradationPreference);
 
             AntMediaClient.rtcAudioSession.add(self);
         }
@@ -1180,6 +1185,19 @@ open class AntMediaClient: NSObject, AntMediaClientProtocol {
         }
     }
 
+    public func setDegradationPreference(_ degradationPreference: RTCDegradationPreference) 
+    {
+       self.degradationPreference = degradationPreference;
+       let rtc = self.webRTCClientMap[self.getPublisherStreamId()]
+
+       guard let params = rtc?.videoSender?.parameters else {
+           return
+       }
+
+       params.degradationPreference = (degradationPreference.rawValue) as NSNumber
+       rtc?.videoSender?.parameters = params
+    }
+    
     public func disconnect() {
         for (streamId, webrtcClient) in self.webRTCClientMap {
             webrtcClient.disconnect()

WebRTCiOSSDK/api/AntMediaClientProtocol.swift

@@ -345,6 +345,11 @@ public protocol AntMediaClientProtocol {
      */
     func join(streamId:String)
 
+    /**
+    Set the degradation prefernece in publishing streams. It can be called before the stream starts or while it's streaming.
+     */
+    func setDegradationPreference(_ degradationPreference: RTCDegradationPreference);
+    
     /**
       Disconnects  websocket connection
      */

WebRTCiOSSDK/api/webrtc/WebRTCClient.swift

@@ -60,6 +60,8 @@ class WebRTCClient: NSObject {
      State of the connection
      */
     var iceConnectionState:RTCIceConnectionState = .new;
+    
+    private var degradationPreference:RTCDegradationPreference = .maintainResolution;
 
     public init(remoteVideoView: RTCVideoRenderer?, localVideoView: RTCVideoRenderer?, delegate: WebRTCClientDelegate, externalAudio:Bool) {
         super.init()
@@ -405,10 +407,9 @@ class WebRTCClient: NSObject {
             let videoTrack = WebRTCClient.factory.videoTrack(with: videoSource, trackId: "video0")
             return videoTrack
         }
-        
-       
     }
 
+    
     private func addLocalMediaStream() -> Bool {
 
 
@@ -418,6 +419,15 @@ class WebRTCClient: NSObject {
             self.localVideoTrack = createVideoTrack();
 
             self.videoSender = self.peerConnection?.add(self.localVideoTrack,  streamIds: [LOCAL_MEDIA_STREAM_ID])
+            
+            if let params = videoSender?.parameters 
+            {
+                params.degradationPreference = (self.degradationPreference.rawValue) as NSNumber
+                videoSender?.parameters = params
+            }
+            else {
+                AntMediaClient.printf("DegradationPreference cannot be set");
+            }
         }
 
         let audioSource = WebRTCClient.factory.audioSource(with: Config.createTestConstraints())
@@ -432,6 +442,10 @@ class WebRTCClient: NSObject {
         return true
     }
 
+    public func setDegradationPreference(degradationPreference:RTCDegradationPreference) {
+        self.degradationPreference = degradationPreference
+    }
+    
     public func switchCamera() {
 
         let cameraVideoCapturer = self.videoCapturer as? RTCCameraVideoCapturer;