Refactor NACK bitrate allocation

webrtc/modules/rtp_rtcp/source/bitrate.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/rtp_rtcp/source/bitrate.h"
-
-#include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
-
-namespace webrtc {
-
-Bitrate::Bitrate(Clock* clock, Observer* observer)
-    : clock_(clock),
-      packet_rate_(0),
-      bitrate_(0),
-      bitrate_next_idx_(0),
-      time_last_rate_update_(0),
-      bytes_count_(0),
-      packet_count_(0),
-      observer_(observer) {
-  memset(packet_rate_array_, 0, sizeof(packet_rate_array_));
-  memset(bitrate_diff_ms_, 0, sizeof(bitrate_diff_ms_));
-  memset(bitrate_array_, 0, sizeof(bitrate_array_));
-}
-
-Bitrate::~Bitrate() {}
-
-void Bitrate::Update(const size_t bytes) {
-  rtc::CritScope cs(&crit_);
-  bytes_count_ += bytes;
-  packet_count_++;
-}
-
-uint32_t Bitrate::PacketRate() const {
-  rtc::CritScope cs(&crit_);
-  return packet_rate_;
-}
-
-uint32_t Bitrate::BitrateLast() const {
-  rtc::CritScope cs(&crit_);
-  return bitrate_;
-}
-
-uint32_t Bitrate::BitrateNow() const {
-  rtc::CritScope cs(&crit_);
-  int64_t now = clock_->TimeInMilliseconds();
-  int64_t diff_ms = now - time_last_rate_update_;
-
-  if (diff_ms > 10000) {  // 10 seconds.
-    // Too high difference, ignore.
-    return bitrate_;
-  }
-  int64_t bits_since_last_rate_update = 8 * bytes_count_ * 1000;
-
-  // We have to consider the time when the measurement was done:
-  // ((bits/sec * sec) + (bits)) / sec.
-  int64_t bitrate = (static_cast<uint64_t>(bitrate_) * 1000 +
-                           bits_since_last_rate_update) / (1000 + diff_ms);
-  return static_cast<uint32_t>(bitrate);
-}
-
-int64_t Bitrate::time_last_rate_update() const {
-  rtc::CritScope cs(&crit_);
-  return time_last_rate_update_;
-}
-
-// Triggered by timer.
-void Bitrate::Process() {
-  BitrateStatistics stats;
-  {
-    rtc::CritScope cs(&crit_);
-    int64_t now = clock_->CurrentNtpInMilliseconds();
-    int64_t diff_ms = now - time_last_rate_update_;
-
-    if (diff_ms < 100) {
-      // Not enough data, wait...
-      return;
-    }
-    if (diff_ms > 10000) {  // 10 seconds.
-      // Too high difference, ignore.
-      time_last_rate_update_ = now;
-      bytes_count_ = 0;
-      packet_count_ = 0;
-      return;
-    }
-    packet_rate_array_[bitrate_next_idx_] = (packet_count_ * 1000) / diff_ms;
-    bitrate_array_[bitrate_next_idx_] = 8 * ((bytes_count_ * 1000) / diff_ms);
-    bitrate_diff_ms_[bitrate_next_idx_] = diff_ms;
-    bitrate_next_idx_++;
-    if (bitrate_next_idx_ >= 10) {
-      bitrate_next_idx_ = 0;
-    }
-    int64_t sum_diffMS = 0;
-    int64_t sum_bitrateMS = 0;
-    int64_t sum_packetrateMS = 0;
-    for (int i = 0; i < 10; i++) {
-      sum_diffMS += bitrate_diff_ms_[i];
-      sum_bitrateMS += bitrate_array_[i] * bitrate_diff_ms_[i];
-      sum_packetrateMS += packet_rate_array_[i] * bitrate_diff_ms_[i];
-    }
-    time_last_rate_update_ = now;
-    bytes_count_ = 0;
-    packet_count_ = 0;
-    packet_rate_ = static_cast<uint32_t>(sum_packetrateMS / sum_diffMS);
-    bitrate_ = static_cast<uint32_t>(sum_bitrateMS / sum_diffMS);
-
-    stats.bitrate_bps = bitrate_;
-    stats.packet_rate = packet_rate_;
-    stats.timestamp_ms = now;
-  }
-
-  if (observer_)
-    observer_->BitrateUpdated(stats);
-}
-
-}  // namespace webrtc