Cast:Adding signaling and infrastructure for adjustable delay

media/cast/video_sender/video_sender.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/cast/video_sender/video_sender.h"
 
 #include <cstring>
 #include <list>
 
 #include "base/bind.h"
@@ skipping 99 matching lines @@
       last_skip_count_(0),
       congestion_control_(cast_environment->Clock(),
                           video_config.congestion_control_back_off,
                           video_config.max_bitrate,
                           video_config.min_bitrate,
                           video_config.start_bitrate),
       initialized_(false),
       active_session_(false),
       weak_factory_(this) {
   max_unacked_frames_ =
-      static_cast<uint8>(video_config.rtp_config.max_delay_ms *
-                         video_config.max_frame_rate / 1000) +
-      1;
+      1 + static_cast<uint8>(video_config.rtp_config.max_delay_ms *
+                             max_frame_rate_ / 1000);
   VLOG(1) << "max_unacked_frames " << static_cast<int>(max_unacked_frames_);
   DCHECK_GT(max_unacked_frames_, 0) << "Invalid argument";
 
   rtp_video_sender_statistics_.reset(
       new LocalRtpVideoSenderStatistics(transport_sender));
 
   if (video_config.use_external_encoder) {
     CHECK(gpu_factories);
     video_encoder_.reset(new ExternalVideoEncoder(
         cast_environment, video_config, gpu_factories));
@@ skipping 242 matching lines @@
 }
 
 void VideoSender::OnReceivedCastFeedback(const RtcpCastMessage& cast_feedback) {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
   base::TimeDelta rtt;
   base::TimeDelta avg_rtt;
   base::TimeDelta min_rtt;
   base::TimeDelta max_rtt;
   base::TimeTicks now = cast_environment_->Clock()->NowTicks();
 
+  // Update delay and max number of frames in flight based on the the new
+  // received target delay.
+  rtp_max_delay_ =
+      base::TimeDelta::FromMilliseconds(cast_feedback.target_delay_ms_);
+  max_unacked_frames_ = 1 + static_cast<uint8>(cast_feedback.target_delay_ms_ *
+                                               max_frame_rate_ / 1000);
   if (rtcp_->Rtt(&rtt, &avg_rtt, &min_rtt, &max_rtt)) {
     cast_environment_->Logging()->InsertGenericEvent(
         now, kRttMs, rtt.InMilliseconds());
     // Don't use a RTT lower than our average.
     rtt = std::max(rtt, avg_rtt);
   } else {
     // We have no measured value use default.
     rtt = base::TimeDelta::FromMilliseconds(kStartRttMs);
   }
   if (cast_feedback.missing_frames_and_packets_.empty()) {
@@ skipping 100 matching lines @@
 
 void VideoSender::ResendPacketsOnTransportThread(
     const transport::MissingFramesAndPacketsMap& missing_packets) {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::TRANSPORT));
   last_send_time_ = cast_environment_->Clock()->NowTicks();
   transport_sender_->ResendPackets(false, missing_packets);
 }
 
 }  // namespace cast
 }  // namespace media