increase bitrate precision of the network tester.

webrtc/tools/network_tester/packet_sender.cc

 /*
  *  Copyright 2017 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/tools/network_tester/packet_sender.h"
 
+#include <algorithm>
 #include <string>
 #include <utility>
 
 #include "webrtc/base/timeutils.h"
 #include "webrtc/tools/network_tester/config_reader.h"
 #include "webrtc/tools/network_tester/test_controller.h"
 
 namespace webrtc {
 
 namespace {
 
 class SendPacketTask : public rtc::QueuedTask {
  public:
   explicit SendPacketTask(PacketSender* packet_sender)
-      : packet_sender_(packet_sender) {}
+      : target_time_ms_(rtc::TimeMillis()), packet_sender_(packet_sender) {}
 
  private:
   bool Run() override {
     if (packet_sender_->IsSending()) {
       packet_sender_->SendPacket();
+      target_time_ms_ += packet_sender_->GetSendIntervalMs();
+      int64_t delay_ms = std::max(static_cast<int64_t>(0),
+                                  target_time_ms_ - rtc::TimeMillis());
       rtc::TaskQueue::Current()->PostDelayedTask(
-          std::unique_ptr<QueuedTask>(this),
-          packet_sender_->GetSendIntervalMs());
+          std::unique_ptr<QueuedTask>(this), delay_ms);
       return false;
     } else {
       return true;
     }
   }
+  int64_t target_time_ms_;
   PacketSender* const packet_sender_;
 };
 
 class UpdateTestSettingTask : public rtc::QueuedTask {
  public:
   UpdateTestSettingTask(PacketSender* packet_sender,
                         std::unique_ptr<ConfigReader> config_reader)
       : packet_sender_(packet_sender),
         config_reader_(std::move(config_reader)) {}
 
@@ skipping 69 matching lines @@
 }
 
 void PacketSender::UpdateTestSetting(size_t packet_size,
                                      int64_t send_interval_ms) {
   RTC_DCHECK_CALLED_SEQUENTIALLY(&worker_queue_checker_);
   send_interval_ms_ = send_interval_ms;
   packet_size_ = packet_size;
 }
 
 }  // namespace webrtc