Add video codec setting to AppRTCMobile on iOS.

webrtc/examples/objc/AppRTCMobile/ARDAppClient.m

 /*
  *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 81 matching lines @@
 - (void)timerDidFire:(NSTimer *)timer {
   _timerHandler();
 }
 
 @end
 
 @implementation ARDAppClient {
   RTCFileLogger *_fileLogger;
   ARDTimerProxy *_statsTimer;
   RTCMediaConstraints *_cameraConstraints;
+  NSString *_videoCodec;

[kthelgason, 2017/03/09 13:39:43]

Maybe make this a property and @synthesize it. Then you get the setter for free.

[sakal, 2017/03/10 10:25:27]

Done.

   NSNumber *_maxBitrate;
 }
 
 @synthesize shouldGetStats = _shouldGetStats;
 @synthesize state = _state;
 @synthesize delegate = _delegate;
 @synthesize roomServerClient = _roomServerClient;
 @synthesize channel = _channel;
 @synthesize loopbackChannel = _loopbackChannel;
 @synthesize turnClient = _turnClient;
@@ skipping 201 matching lines @@
   if (kARDAppClientEnableTracing) {
     RTCStopInternalCapture();
   }
 #endif
 }
 
 - (void)setCameraConstraints:(RTCMediaConstraints *)mediaConstraints {
   _cameraConstraints = mediaConstraints;
 }
 
+- (void)setVideoCodec:(NSString *)videoCodec {
+  _videoCodec = videoCodec;
+}
+
 - (void)setMaxBitrate:(NSNumber *)maxBitrate {
   _maxBitrate = maxBitrate;
 }
 
 #pragma mark - ARDSignalingChannelDelegate
 
 - (void)channel:(id<ARDSignalingChannel>)channel
     didReceiveMessage:(ARDSignalingMessage *)message {
   switch (message.type) {
     case kARDSignalingMessageTypeOffer:
@@ skipping 112 matching lines @@
       NSDictionary *userInfo = @{
         NSLocalizedDescriptionKey: @"Failed to create session description.",
       };
       NSError *sdpError =
           [[NSError alloc] initWithDomain:kARDAppClientErrorDomain
                                      code:kARDAppClientErrorCreateSDP
                                  userInfo:userInfo];
       [_delegate appClient:self didError:sdpError];
       return;
     }
-    // Prefer H264 if available.
-    RTCSessionDescription *sdpPreferringH264 =
+    // Prefer codec from settings if available.
+    RTCSessionDescription *sdpPreferringCodec =
         [ARDSDPUtils descriptionForDescription:sdp
-                           preferredVideoCodec:@"H264"];
+                           preferredVideoCodec:_videoCodec];
     __weak ARDAppClient *weakSelf = self;
-    [_peerConnection setLocalDescription:sdpPreferringH264
+    [_peerConnection setLocalDescription:sdpPreferringCodec
                        completionHandler:^(NSError *error) {
       ARDAppClient *strongSelf = weakSelf;
       [strongSelf peerConnection:strongSelf.peerConnection
           didSetSessionDescriptionWithError:error];
     }];
     ARDSessionDescriptionMessage *message =
         [[ARDSessionDescriptionMessage alloc]
-            initWithDescription:sdpPreferringH264];
+            initWithDescription:sdpPreferringCodec];
     [self sendSignalingMessage:message];
     [self setMaxBitrateForPeerConnectionVideoSender];
   });
 }
 
 - (void)peerConnection:(RTCPeerConnection *)peerConnection
     didSetSessionDescriptionWithError:(NSError *)error {
   dispatch_async(dispatch_get_main_queue(), ^{
     if (error) {
       RTCLogError(@"Failed to set session description. Error: %@", error);
@@ skipping 120 matching lines @@
 // Processes the given signaling message based on its type.
 - (void)processSignalingMessage:(ARDSignalingMessage *)message {
   NSParameterAssert(_peerConnection ||
       message.type == kARDSignalingMessageTypeBye);
   switch (message.type) {
     case kARDSignalingMessageTypeOffer:
     case kARDSignalingMessageTypeAnswer: {
       ARDSessionDescriptionMessage *sdpMessage =
           (ARDSessionDescriptionMessage *)message;
       RTCSessionDescription *description = sdpMessage.sessionDescription;
-      // Prefer H264 if available.
-      RTCSessionDescription *sdpPreferringH264 =
+      // Prefer codec set in settings if available.
+      RTCSessionDescription *sdpPreferringCodec =
           [ARDSDPUtils descriptionForDescription:description
-                             preferredVideoCodec:@"H264"];
+                             preferredVideoCodec:_videoCodec];
       __weak ARDAppClient *weakSelf = self;
-      [_peerConnection setRemoteDescription:sdpPreferringH264
+      [_peerConnection setRemoteDescription:sdpPreferringCodec
                           completionHandler:^(NSError *error) {
         ARDAppClient *strongSelf = weakSelf;
         [strongSelf peerConnection:strongSelf.peerConnection
             didSetSessionDescriptionWithError:error];
       }];
       break;
     }
     case kARDSignalingMessageTypeCandidate: {
       ARDICECandidateMessage *candidateMessage =
           (ARDICECandidateMessage *)message;
@@ skipping 229 matching lines @@
                                          code:kARDAppClientErrorInvalidRoom
                                      userInfo:@{
         NSLocalizedDescriptionKey: @"Invalid room.",
       }];
       break;
   }
   return error;
 }
 
 @end