Experiment for the nack module.

webrtc/modules/video_coding/jitter_buffer.cc

 /*
  *  Copyright (c) 2012 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/modules/video_coding/jitter_buffer.h"
 
 #include <assert.h>
 
 #include <algorithm>
+#include <limits>
 #include <utility>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/trace_event.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/modules/video_coding/include/video_coding.h"
 #include "webrtc/modules/video_coding/frame_buffer.h"
 #include "webrtc/modules/video_coding/inter_frame_delay.h"
 #include "webrtc/modules/video_coding/internal_defines.h"
 #include "webrtc/modules/video_coding/jitter_buffer_common.h"
 #include "webrtc/modules/video_coding/jitter_estimator.h"
 #include "webrtc/modules/video_coding/packet.h"
 #include "webrtc/system_wrappers/include/clock.h"
 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/include/event_wrapper.h"
+#include "webrtc/system_wrappers/include/field_trial.h"
 #include "webrtc/system_wrappers/include/metrics.h"
 
 namespace webrtc {
-
 // Interval for updating SS data.
 static const uint32_t kSsCleanupIntervalSec = 60;
 
 // Use this rtt if no value has been reported.
 static const int64_t kDefaultRtt = 200;
 
 // Request a keyframe if no continuous frame has been received for this
 // number of milliseconds and NACKs are disabled.
 static const int64_t kMaxDiscontinuousFramesTime = 1000;
 
@@ skipping 162 matching lines @@
     SsMap::iterator ss_it;
     if (Find(frame_it.second->TimeStamp(), &ss_it)) {
       if (gof_idx >= ss_it->second.num_frames_in_gof) {
         continue;  // Assume corresponding SS not yet received.
       }
       frame_it.second->SetGofInfo(ss_it->second, gof_idx);
     }
   }
 }
 
+static NackModule*
+MaybeCreateNackModule(Clock* clock,
+                      NackSender* nack_sender,
+                      KeyFrameRequestSender* keyframe_request_sender) {
+if (field_trial::FindFullName("WebRTC-NewVideoJitterBuffer") == "Enabled") {
+    // Only create a nack module if a nack sender is available.
+    if (nack_sender) {
+      RTC_DCHECK(keyframe_request_sender);
+      return new NackModule(clock, nack_sender, keyframe_request_sender);
+    }
+  }
+  return nullptr;
+}
+
 VCMJitterBuffer::VCMJitterBuffer(Clock* clock,
-                                 std::unique_ptr<EventWrapper> event)
+                                 std::unique_ptr<EventWrapper> event,
+                                 NackSender* nack_sender,
+                                 KeyFrameRequestSender* keyframe_request_sender)
     : clock_(clock),
       running_(false),
       crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
       frame_event_(std::move(event)),
       max_number_of_frames_(kStartNumberOfFrames),
       free_frames_(),
       decodable_frames_(),
       incomplete_frames_(),
       last_decoded_state_(),
       first_packet_since_reset_(true),
@@ skipping 13 matching lines @@
       rtt_ms_(kDefaultRtt),
       nack_mode_(kNoNack),
       low_rtt_nack_threshold_ms_(-1),
       high_rtt_nack_threshold_ms_(-1),
       missing_sequence_numbers_(SequenceNumberLessThan()),
       max_nack_list_size_(0),
       max_packet_age_to_nack_(0),
       max_incomplete_time_ms_(0),
       decode_error_mode_(kNoErrors),
       average_packets_per_frame_(0.0f),
-      frame_counter_(0) {
+      frame_counter_(0),
+      nack_module_(MaybeCreateNackModule(clock,
+                                         nack_sender,
+                                         keyframe_request_sender)) {
   for (int i = 0; i < kStartNumberOfFrames; i++)
     free_frames_.push_back(new VCMFrameBuffer());
 }
 
 VCMJitterBuffer::~VCMJitterBuffer() {
   Stop();
   for (UnorderedFrameList::iterator it = free_frames_.begin();
        it != free_frames_.end(); ++it) {
     delete *it;
   }
@@ skipping 59 matching lines @@
   first_packet_since_reset_ = true;
   rtt_ms_ = kDefaultRtt;
   last_decoded_state_.Reset();
 }
 
 void VCMJitterBuffer::Stop() {
   crit_sect_->Enter();
   UpdateHistograms();
   running_ = false;
   last_decoded_state_.Reset();
+  if (nack_module_)
+    nack_module_->Stop();
 
   // Make sure all frames are free and reset.
   for (FrameList::iterator it = decodable_frames_.begin();
        it != decodable_frames_.end(); ++it) {
     free_frames_.push_back(it->second);
   }
   for (FrameList::iterator it = incomplete_frames_.begin();
        it != incomplete_frames_.end(); ++it) {
     free_frames_.push_back(it->second);
   }
@@ skipping 20 matching lines @@
   last_decoded_state_.Reset();  // TODO(mikhal): sync reset.
   num_consecutive_old_packets_ = 0;
   // Also reset the jitter and delay estimates
   jitter_estimate_.Reset();
   inter_frame_delay_.Reset(clock_->TimeInMilliseconds());
   waiting_for_completion_.frame_size = 0;
   waiting_for_completion_.timestamp = 0;
   waiting_for_completion_.latest_packet_time = -1;
   first_packet_since_reset_ = true;
   missing_sequence_numbers_.clear();
+  if (nack_module_)
+    nack_module_->Clear();
 }
 
 // Get received key and delta frames
 FrameCounts VCMJitterBuffer::FrameStatistics() const {
   CriticalSectionScoped cs(crit_sect_);
   return receive_statistics_;
 }
 
 int VCMJitterBuffer::num_packets() const {
   CriticalSectionScoped cs(crit_sect_);
@@ skipping 216 matching lines @@
   // decoder. Propagates the missing_frame bit.
   frame->PrepareForDecode(continuous);
 
   // We have a frame - update the last decoded state and nack list.
   last_decoded_state_.SetState(frame);
   DropPacketsFromNackList(last_decoded_state_.sequence_num());
 
   if ((*frame).IsSessionComplete())
     UpdateAveragePacketsPerFrame(frame->NumPackets());
 
+  if (nack_module_)
+    nack_module_->ClearUpTo(frame->GetHighSeqNum());
   return frame;
 }
 
 // Release frame when done with decoding. Should never be used to release
 // frames from within the jitter buffer.
 void VCMJitterBuffer::ReleaseFrame(VCMEncodedFrame* frame) {
   CriticalSectionScoped cs(crit_sect_);
   VCMFrameBuffer* frame_buffer = static_cast<VCMFrameBuffer*>(frame);
   if (frame_buffer) {
     free_frames_.push_back(frame_buffer);
@@ skipping 40 matching lines @@
   const VCMFrameBuffer* frame_buffer =
       static_cast<const VCMFrameBuffer*>(frame);
   *retransmitted = (frame_buffer->GetNackCount() > 0);
   return frame_buffer->LatestPacketTimeMs();
 }
 
 VCMFrameBufferEnum VCMJitterBuffer::InsertPacket(const VCMPacket& packet,
                                                  bool* retransmitted) {
   CriticalSectionScoped cs(crit_sect_);
 
+  if (nack_module_)
+    nack_module_->OnReceivedPacket(packet);
+
   ++num_packets_;
   if (num_packets_ == 1) {
     time_first_packet_ms_ = clock_->TimeInMilliseconds();
   }
   // Does this packet belong to an old frame?
   if (last_decoded_state_.IsOldPacket(&packet)) {
     // Account only for media packets.
     if (packet.sizeBytes > 0) {
       num_discarded_packets_++;
       num_consecutive_old_packets_++;
@@ skipping 242 matching lines @@
     // when waiting for retransmissions.
     rtt_mult = 0.0f;
   }
   return jitter_estimate_.GetJitterEstimate(rtt_mult);
 }
 
 void VCMJitterBuffer::UpdateRtt(int64_t rtt_ms) {
   CriticalSectionScoped cs(crit_sect_);
   rtt_ms_ = rtt_ms;
   jitter_estimate_.UpdateRtt(rtt_ms);
+  if (nack_module_)
+    nack_module_->UpdateRtt(rtt_ms);
 }
 
 void VCMJitterBuffer::SetNackMode(VCMNackMode mode,
                                   int64_t low_rtt_nack_threshold_ms,
                                   int64_t high_rtt_nack_threshold_ms) {
   CriticalSectionScoped cs(crit_sect_);
   nack_mode_ = mode;
   if (mode == kNoNack) {
     missing_sequence_numbers_.clear();
   }
@@ skipping 99 matching lines @@
       } else {
         // Skip to the last key frame. If it's incomplete we will start
         // NACKing it.
         // Note that the estimated low sequence number is correct for VP8
         // streams because only the first packet of a key frame is marked.
         last_decoded_state_.Reset();
         DropPacketsFromNackList(EstimatedLowSequenceNumber(*rit->second));
       }
     }
   }
+  // The experiment is running, the nack module will send Nacks.
+  // The reason we allow the major part of the GetNackList function to
+  // run even if we are running the experiment is because this
+  // function is also used to signal that the jitter buffer wants to
+  // request a keyframe.
+  if (nack_module_)
+    return std::vector<uint16_t>();
+
   std::vector<uint16_t> nack_list(missing_sequence_numbers_.begin(),
                                   missing_sequence_numbers_.end());
   return nack_list;
 }
 
 void VCMJitterBuffer::SetDecodeErrorMode(VCMDecodeErrorMode error_mode) {
   CriticalSectionScoped cs(crit_sect_);
   decode_error_mode_ = error_mode;
 }
 
@@ skipping 277 matching lines @@
     return false;
   }
   // Evaluate if the RTT is higher than |high_rtt_nack_threshold_ms_|, and in
   // that case we don't wait for retransmissions.
   if (high_rtt_nack_threshold_ms_ >= 0 &&
       rtt_ms_ >= high_rtt_nack_threshold_ms_) {
     return false;
   }
   return true;
 }
+
+int64_t VCMJitterBuffer::TimeUntilNextProcess() {
+  if (nack_module_)
+    return nack_module_->TimeUntilNextProcess();
+  return std::numeric_limits<int64_t>::max();
+}
+
+void VCMJitterBuffer::Process() {
+  if (nack_module_)
+    nack_module_->Process();
+}
 }  // namespace webrtc