Add a webrtc{en,de}coderfactory implementation for VideoToolbox

webrtc/sdk/objc/Framework/Classes/RTCPeerConnectionFactory.mm

 /*
  *  Copyright 2015 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.
  */
 
 #import "RTCPeerConnectionFactory+Private.h"
 
 #import "NSString+StdString.h"
 #import "RTCAVFoundationVideoSource+Private.h"
 #import "RTCAudioSource+Private.h"
 #import "RTCAudioTrack+Private.h"
 #import "RTCMediaConstraints+Private.h"
 #import "RTCMediaStream+Private.h"
 #import "RTCPeerConnection+Private.h"
 #import "RTCVideoSource+Private.h"
 #import "RTCVideoTrack+Private.h"
 #import "WebRTC/RTCLogging.h"
 
+#include "videotoolboxvideocodecfactory.h"
+
 @implementation RTCPeerConnectionFactory {
   std::unique_ptr<rtc::Thread> _networkThread;
   std::unique_ptr<rtc::Thread> _workerThread;
   std::unique_ptr<rtc::Thread> _signalingThread;
   BOOL _hasStartedAecDump;
 }
 
 @synthesize nativeFactory = _nativeFactory;
 
 - (instancetype)init {
   if ((self = [super init])) {
     _networkThread = rtc::Thread::CreateWithSocketServer();
     BOOL result = _networkThread->Start();
     NSAssert(result, @"Failed to start network thread.");
 
     _workerThread = rtc::Thread::Create();
     result = _workerThread->Start();
     NSAssert(result, @"Failed to start worker thread.");
 
     _signalingThread = rtc::Thread::Create();
     result = _signalingThread->Start();
     NSAssert(result, @"Failed to start signaling thread.");
 
+    const auto encoder_factory = new webrtc::VideoToolboxVideoEncoderFactory();

[magjed_webrtc, 2016/11/01 14:00:20]

nit: Maybe this would be slightly more clear:

std::unique_ptr<cricket::WebRtcVideoEncoderFactory> encoder_factory(
    new webrtc::VideoToolboxVideoEncoderFactory());
...
encoder_factory.release()

but I don't feel strongly about it.

[kthelgason, 2016/11/01 15:14:30]

I think that's a lot of typing to no specific purpose, but I understand what you
mean. I added a comment clarifying the transfer of ownership, but I can do this
as well if you want.

+    const auto decoder_factory = new webrtc::VideoToolboxVideoDecoderFactory();
+
     _nativeFactory = webrtc::CreatePeerConnectionFactory(
         _networkThread.get(), _workerThread.get(), _signalingThread.get(),
-        nullptr, nullptr, nullptr);
+        nullptr, encoder_factory, decoder_factory);
     NSAssert(_nativeFactory, @"Failed to initialize PeerConnectionFactory!");
   }
   return self;
 }
 
 - (RTCAudioSource *)audioSourceWithConstraints:(nullable RTCMediaConstraints *)constraints {
   std::unique_ptr<webrtc::MediaConstraints> nativeConstraints;
   if (constraints) {
     nativeConstraints = constraints.nativeConstraints;
   }
@@ skipping 61 matching lines @@
   _hasStartedAecDump = _nativeFactory->StartAecDump(fd, maxSizeInBytes);
   return _hasStartedAecDump;
 }
 
 - (void)stopAecDump {
   _nativeFactory->StopAecDump();
   _hasStartedAecDump = NO;
 }
 
 @end