Jitter delay now depend on protection mode (FEC/NACK).

webrtc/modules/video_coding/video_receiver.cc

 /*
  *  Copyright (c) 2013 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 157 matching lines @@
   switch (videoProtection) {
     case kProtectionNack: {
       RTC_DCHECK(enable);
       _receiver.SetNackMode(kNack, -1, -1);
       break;
     }
 
     case kProtectionNackFEC: {
       rtc::CritScope cs(&receive_crit_);
       RTC_DCHECK(enable);
-      _receiver.SetNackMode(kNack, media_optimization::kLowRttNackMs, -1);
+      _receiver.SetNackMode(kNack, media_optimization::kLowRttNackMs, 500);

[stefan-webrtc, 2016/05/04 09:30:48]

500 should be a named constant. What does it represent? The rtt above which nack
is disabled? In that case I think -1 is correct, i.e., we never disable nack. Or
does it mean that we don't add an extra rtt above that threshold?

[philipel, 2016/05/04 10:56:05]

This value represent the threshold rtt after which an rtt is no longer added to
the jitter buffer delay in the case of to many frames having at least on of
their packets nacked.

Maybe name it to something like "kMaxRttDelayThreshold"?

       _receiver.SetDecodeErrorMode(kNoErrors);
       break;
     }
     case kProtectionFEC:
     case kProtectionNone:
       // No receiver-side protection.
       RTC_DCHECK(enable);
       _receiver.SetNackMode(kNoNack, -1, -1);
       _receiver.SetDecodeErrorMode(kWithErrors);
       break;
@@ skipping 327 matching lines @@
   _receiver.SetNackSettings(max_nack_list_size, max_packet_age_to_nack,
                             max_incomplete_time_ms);
 }
 
 int VideoReceiver::SetMinReceiverDelay(int desired_delay_ms) {
   return _receiver.SetMinReceiverDelay(desired_delay_ms);
 }
 
 }  // namespace vcm
 }  // namespace webrtc