Wire up FlexFEC in VideoEngine2.

webrtc/media/engine/internalencoderfactory.cc

 /*
  *  Copyright (c) 2016 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.
  */
 
 #include "webrtc/media/engine/internalencoderfactory.h"
 
 #include <utility>
 
 #include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
 #include "webrtc/modules/video_coding/codecs/vp8/include/vp8.h"
 #include "webrtc/modules/video_coding/codecs/vp9/include/vp9.h"
+#include "webrtc/system_wrappers/include/field_trial.h"
 
 namespace cricket {
 
+namespace {
+
+const char kFlexfecFieldTrialName[] = "WebRTC-FlexFEC-03";
+
+bool IsFlexfecFieldTrialEnabled() {
+  return webrtc::field_trial::FindFullName(kFlexfecFieldTrialName) == "Enabled";
+}
+
+}  // namespace
+
 InternalEncoderFactory::InternalEncoderFactory() {
   supported_codecs_.push_back(cricket::VideoCodec(kVp8CodecName));
   if (webrtc::VP9Encoder::IsSupported())
     supported_codecs_.push_back(cricket::VideoCodec(kVp9CodecName));
   if (webrtc::H264Encoder::IsSupported()) {
     cricket::VideoCodec codec(kH264CodecName);
     // TODO(magjed): Move setting these parameters into webrtc::H264Encoder
     // instead.
     // TODO(hta): Set FMTP parameters for all codecs of type H264.
     codec.SetParam(kH264FmtpProfileLevelId,
                    kH264ProfileLevelConstrainedBaseline);
     codec.SetParam(kH264FmtpLevelAsymmetryAllowed, "1");
     codec.SetParam(kH264FmtpPacketizationMode, "1");
     supported_codecs_.push_back(std::move(codec));
   }
 
   supported_codecs_.push_back(cricket::VideoCodec(kRedCodecName));
   supported_codecs_.push_back(cricket::VideoCodec(kUlpfecCodecName));
+
+  if (IsFlexfecFieldTrialEnabled()) {
+    cricket::VideoCodec flexfec_codec(kFlexfecCodecName);
+    // This value is currently arbitrarily set to 10 seconds. (The unit
+    // is microseconds.) This parameter MUST be present in the SDP, but
+    // we never use the actual value anywhere in our code however.
+    // TODO(brandtr): Consider honouring this value in the sender and receiver.
+    flexfec_codec.SetParam(kFlexfecFmtpRepairWindow, "10000000");
+    supported_codecs_.push_back(flexfec_codec);
+  }
 }
 
 InternalEncoderFactory::~InternalEncoderFactory() {}
 
 // WebRtcVideoEncoderFactory implementation.
 webrtc::VideoEncoder* InternalEncoderFactory::CreateVideoEncoder(
     const cricket::VideoCodec& codec) {
   switch (CodecTypeFromName(codec.name)) {
     case webrtc::kVideoCodecH264:
       return webrtc::H264Encoder::Create();
@@ skipping 10 matching lines @@
 InternalEncoderFactory::supported_codecs() const {
   return supported_codecs_;
 }
 
 void InternalEncoderFactory::DestroyVideoEncoder(
     webrtc::VideoEncoder* encoder) {
   delete encoder;
 }
 
 }  // namespace cricket