Repo created

TMessagesProj/jni/voip/webrtc/audio/audio_send_stream.cc

@@ -0,0 +1,891 @@
+/*
+ *  Copyright (c) 2015 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 "audio/audio_send_stream.h"
+
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "api/audio_codecs/audio_encoder.h"
+#include "api/audio_codecs/audio_encoder_factory.h"
+#include "api/audio_codecs/audio_format.h"
+#include "api/call/transport.h"
+#include "api/crypto/frame_encryptor_interface.h"
+#include "api/function_view.h"
+#include "api/rtc_event_log/rtc_event_log.h"
+#include "api/task_queue/task_queue_base.h"
+#include "audio/audio_state.h"
+#include "audio/channel_send.h"
+#include "audio/conversion.h"
+#include "call/rtp_config.h"
+#include "call/rtp_transport_controller_send_interface.h"
+#include "common_audio/vad/include/vad.h"
+#include "logging/rtc_event_log/events/rtc_event_audio_send_stream_config.h"
+#include "logging/rtc_event_log/rtc_stream_config.h"
+#include "media/base/media_channel.h"
+#include "modules/audio_coding/codecs/cng/audio_encoder_cng.h"
+#include "modules/audio_coding/codecs/red/audio_encoder_copy_red.h"
+#include "modules/audio_processing/include/audio_processing.h"
+#include "modules/rtp_rtcp/source/rtp_header_extensions.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/strings/audio_format_to_string.h"
+#include "rtc_base/trace_event.h"
+
+namespace webrtc {
+namespace {
+
+void UpdateEventLogStreamConfig(RtcEventLog* event_log,
+                                const AudioSendStream::Config& config,
+                                const AudioSendStream::Config* old_config) {
+  using SendCodecSpec = AudioSendStream::Config::SendCodecSpec;
+  // Only update if any of the things we log have changed.
+  auto payload_types_equal = [](const absl::optional<SendCodecSpec>& a,
+                                const absl::optional<SendCodecSpec>& b) {
+    if (a.has_value() && b.has_value()) {
+      return a->format.name == b->format.name &&
+             a->payload_type == b->payload_type;
+    }
+    return !a.has_value() && !b.has_value();
+  };
+
+  if (old_config && config.rtp.ssrc == old_config->rtp.ssrc &&
+      config.rtp.extensions == old_config->rtp.extensions &&
+      payload_types_equal(config.send_codec_spec,
+                          old_config->send_codec_spec)) {
+    return;
+  }
+
+  auto rtclog_config = std::make_unique<rtclog::StreamConfig>();
+  rtclog_config->local_ssrc = config.rtp.ssrc;
+  rtclog_config->rtp_extensions = config.rtp.extensions;
+  if (config.send_codec_spec) {
+    rtclog_config->codecs.emplace_back(config.send_codec_spec->format.name,
+                                       config.send_codec_spec->payload_type, 0);
+  }
+  event_log->Log(std::make_unique<RtcEventAudioSendStreamConfig>(
+      std::move(rtclog_config)));
+}
+
+}  // namespace
+
+constexpr char AudioAllocationConfig::kKey[];
+
+std::unique_ptr<StructParametersParser> AudioAllocationConfig::Parser() {
+  return StructParametersParser::Create(       //
+      "min", &min_bitrate,                     //
+      "max", &max_bitrate,                     //
+      "prio_rate", &priority_bitrate,          //
+      "prio_rate_raw", &priority_bitrate_raw,  //
+      "rate_prio", &bitrate_priority);
+}
+
+AudioAllocationConfig::AudioAllocationConfig(
+    const FieldTrialsView& field_trials) {
+  Parser()->Parse(field_trials.Lookup(kKey));
+  if (priority_bitrate_raw && !priority_bitrate.IsZero()) {
+    RTC_LOG(LS_WARNING) << "'priority_bitrate' and '_raw' are mutually "
+                           "exclusive but both were configured.";
+  }
+}
+
+namespace internal {
+AudioSendStream::AudioSendStream(
+    Clock* clock,
+    const webrtc::AudioSendStream::Config& config,
+    const rtc::scoped_refptr<webrtc::AudioState>& audio_state,
+    TaskQueueFactory* task_queue_factory,
+    RtpTransportControllerSendInterface* rtp_transport,
+    BitrateAllocatorInterface* bitrate_allocator,
+    RtcEventLog* event_log,
+    RtcpRttStats* rtcp_rtt_stats,
+    const absl::optional<RtpState>& suspended_rtp_state,
+    const FieldTrialsView& field_trials)
+    : AudioSendStream(clock,
+                      config,
+                      audio_state,
+                      task_queue_factory,
+                      rtp_transport,
+                      bitrate_allocator,
+                      event_log,
+                      suspended_rtp_state,
+                      voe::CreateChannelSend(clock,
+                                             task_queue_factory,
+                                             config.send_transport,
+                                             rtcp_rtt_stats,
+                                             event_log,
+                                             config.frame_encryptor.get(),
+                                             config.crypto_options,
+                                             config.rtp.extmap_allow_mixed,
+                                             config.rtcp_report_interval_ms,
+                                             config.rtp.ssrc,
+                                             config.frame_transformer,
+                                             rtp_transport,
+                                             field_trials),
+                      field_trials) {}
+
+AudioSendStream::AudioSendStream(
+    Clock* clock,
+    const webrtc::AudioSendStream::Config& config,
+    const rtc::scoped_refptr<webrtc::AudioState>& audio_state,
+    TaskQueueFactory* task_queue_factory,
+    RtpTransportControllerSendInterface* rtp_transport,
+    BitrateAllocatorInterface* bitrate_allocator,
+    RtcEventLog* event_log,
+    const absl::optional<RtpState>& suspended_rtp_state,
+    std::unique_ptr<voe::ChannelSendInterface> channel_send,
+    const FieldTrialsView& field_trials)
+    : clock_(clock),
+      field_trials_(field_trials),
+      allocate_audio_without_feedback_(
+          field_trials_.IsEnabled("WebRTC-Audio-ABWENoTWCC")),
+      enable_audio_alr_probing_(
+          !field_trials_.IsDisabled("WebRTC-Audio-AlrProbing")),
+      allocation_settings_(field_trials_),
+      config_(Config(/*send_transport=*/nullptr)),
+      audio_state_(audio_state),
+      channel_send_(std::move(channel_send)),
+      event_log_(event_log),
+      use_legacy_overhead_calculation_(
+          field_trials_.IsEnabled("WebRTC-Audio-LegacyOverhead")),
+      enable_priority_bitrate_(
+          !field_trials_.IsDisabled("WebRTC-Audio-PriorityBitrate")),
+      bitrate_allocator_(bitrate_allocator),
+      rtp_transport_(rtp_transport),
+      rtp_rtcp_module_(channel_send_->GetRtpRtcp()),
+      suspended_rtp_state_(suspended_rtp_state) {
+  RTC_LOG(LS_INFO) << "AudioSendStream: " << config.rtp.ssrc;
+  RTC_DCHECK(audio_state_);
+  RTC_DCHECK(channel_send_);
+  RTC_DCHECK(bitrate_allocator_);
+  RTC_DCHECK(rtp_transport);
+
+  RTC_DCHECK(rtp_rtcp_module_);
+
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  ConfigureStream(config, true, nullptr);
+}
+
+AudioSendStream::~AudioSendStream() {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  RTC_LOG(LS_INFO) << "~AudioSendStream: " << config_.rtp.ssrc;
+  RTC_DCHECK(!sending_);
+  channel_send_->ResetSenderCongestionControlObjects();
+}
+
+const webrtc::AudioSendStream::Config& AudioSendStream::GetConfig() const {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  return config_;
+}
+
+void AudioSendStream::Reconfigure(
+    const webrtc::AudioSendStream::Config& new_config,
+    SetParametersCallback callback) {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  ConfigureStream(new_config, false, std::move(callback));
+}
+
+AudioSendStream::ExtensionIds AudioSendStream::FindExtensionIds(
+    const std::vector<RtpExtension>& extensions) {
+  ExtensionIds ids;
+  for (const auto& extension : extensions) {
+    if (extension.uri == RtpExtension::kAudioLevelUri) {
+      ids.audio_level = extension.id;
+    } else if (extension.uri == RtpExtension::kAbsSendTimeUri) {
+      ids.abs_send_time = extension.id;
+    } else if (extension.uri == RtpExtension::kTransportSequenceNumberUri) {
+      ids.transport_sequence_number = extension.id;
+    } else if (extension.uri == RtpExtension::kMidUri) {
+      ids.mid = extension.id;
+    } else if (extension.uri == RtpExtension::kRidUri) {
+      ids.rid = extension.id;
+    } else if (extension.uri == RtpExtension::kRepairedRidUri) {
+      ids.repaired_rid = extension.id;
+    } else if (extension.uri == RtpExtension::kAbsoluteCaptureTimeUri) {
+      ids.abs_capture_time = extension.id;
+    }
+  }
+  return ids;
+}
+
+int AudioSendStream::TransportSeqNumId(const AudioSendStream::Config& config) {
+  return FindExtensionIds(config.rtp.extensions).transport_sequence_number;
+}
+
+void AudioSendStream::ConfigureStream(
+    const webrtc::AudioSendStream::Config& new_config,
+    bool first_time,
+    SetParametersCallback callback) {
+  RTC_LOG(LS_INFO) << "AudioSendStream::ConfigureStream: "
+                   << new_config.ToString();
+  UpdateEventLogStreamConfig(event_log_, new_config,
+                             first_time ? nullptr : &config_);
+
+  const auto& old_config = config_;
+
+  // Configuration parameters which cannot be changed.
+  RTC_DCHECK(first_time ||
+             old_config.send_transport == new_config.send_transport);
+  RTC_DCHECK(first_time || old_config.rtp.ssrc == new_config.rtp.ssrc);
+  if (suspended_rtp_state_ && first_time) {
+    rtp_rtcp_module_->SetRtpState(*suspended_rtp_state_);
+  }
+  if (first_time || old_config.rtp.c_name != new_config.rtp.c_name) {
+    channel_send_->SetRTCP_CNAME(new_config.rtp.c_name);
+  }
+
+  // Enable the frame encryptor if a new frame encryptor has been provided.
+  if (first_time || new_config.frame_encryptor != old_config.frame_encryptor) {
+    channel_send_->SetFrameEncryptor(new_config.frame_encryptor);
+  }
+
+  if (first_time ||
+      new_config.frame_transformer != old_config.frame_transformer) {
+    channel_send_->SetEncoderToPacketizerFrameTransformer(
+        new_config.frame_transformer);
+  }
+
+  if (first_time ||
+      new_config.rtp.extmap_allow_mixed != old_config.rtp.extmap_allow_mixed) {
+    rtp_rtcp_module_->SetExtmapAllowMixed(new_config.rtp.extmap_allow_mixed);
+  }
+
+  const ExtensionIds old_ids = FindExtensionIds(old_config.rtp.extensions);
+  const ExtensionIds new_ids = FindExtensionIds(new_config.rtp.extensions);
+
+  // Audio level indication
+  if (first_time || new_ids.audio_level != old_ids.audio_level) {
+    channel_send_->SetSendAudioLevelIndicationStatus(new_ids.audio_level != 0,
+                                                     new_ids.audio_level);
+  }
+
+  if (first_time || new_ids.abs_send_time != old_ids.abs_send_time) {
+    absl::string_view uri = AbsoluteSendTime::Uri();
+    rtp_rtcp_module_->DeregisterSendRtpHeaderExtension(uri);
+    if (new_ids.abs_send_time) {
+      rtp_rtcp_module_->RegisterRtpHeaderExtension(uri, new_ids.abs_send_time);
+    }
+  }
+
+  bool transport_seq_num_id_changed =
+      new_ids.transport_sequence_number != old_ids.transport_sequence_number;
+  if (first_time ||
+      (transport_seq_num_id_changed && !allocate_audio_without_feedback_)) {
+    if (!first_time) {
+      channel_send_->ResetSenderCongestionControlObjects();
+    }
+
+    if (!allocate_audio_without_feedback_ &&
+        new_ids.transport_sequence_number != 0) {
+      rtp_rtcp_module_->RegisterRtpHeaderExtension(
+          TransportSequenceNumber::Uri(), new_ids.transport_sequence_number);
+      // Probing in application limited region is only used in combination with
+      // send side congestion control, wich depends on feedback packets which
+      // requires transport sequence numbers to be enabled.
+      // Optionally request ALR probing but do not override any existing
+      // request from other streams.
+      if (enable_audio_alr_probing_) {
+        rtp_transport_->EnablePeriodicAlrProbing(true);
+      }
+    }
+    channel_send_->RegisterSenderCongestionControlObjects(rtp_transport_);
+  }
+  // MID RTP header extension.
+  if ((first_time || new_ids.mid != old_ids.mid ||
+       new_config.rtp.mid != old_config.rtp.mid) &&
+      new_ids.mid != 0 && !new_config.rtp.mid.empty()) {
+    rtp_rtcp_module_->RegisterRtpHeaderExtension(RtpMid::Uri(), new_ids.mid);
+    rtp_rtcp_module_->SetMid(new_config.rtp.mid);
+  }
+
+  if (first_time || new_ids.abs_capture_time != old_ids.abs_capture_time) {
+    absl::string_view uri = AbsoluteCaptureTimeExtension::Uri();
+    rtp_rtcp_module_->DeregisterSendRtpHeaderExtension(uri);
+    if (new_ids.abs_capture_time) {
+      rtp_rtcp_module_->RegisterRtpHeaderExtension(uri,
+                                                   new_ids.abs_capture_time);
+    }
+  }
+
+  if (!ReconfigureSendCodec(new_config)) {
+    RTC_LOG(LS_ERROR) << "Failed to set up send codec state.";
+
+    webrtc::InvokeSetParametersCallback(
+        callback, webrtc::RTCError(webrtc::RTCErrorType::INTERNAL_ERROR,
+                                   "Failed to set up send codec state."));
+  }
+
+  // Set currently known overhead (used in ANA, opus only).
+  UpdateOverheadPerPacket();
+
+  channel_send_->CallEncoder([this](AudioEncoder* encoder) {
+    RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+    if (!encoder) {
+      return;
+    }
+    frame_length_range_ = encoder->GetFrameLengthRange();
+    bitrate_range_ = encoder->GetBitrateRange();
+  });
+
+  if (sending_) {
+    ReconfigureBitrateObserver(new_config);
+  }
+
+  config_ = new_config;
+
+  webrtc::InvokeSetParametersCallback(callback, webrtc::RTCError::OK());
+}
+
+void AudioSendStream::Start() {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  if (sending_) {
+    return;
+  }
+  RTC_LOG(LS_INFO) << "AudioSendStream::Start: " << config_.rtp.ssrc;
+  if (!config_.has_dscp && config_.min_bitrate_bps != -1 &&
+      config_.max_bitrate_bps != -1 &&
+      (allocate_audio_without_feedback_ || TransportSeqNumId(config_) != 0)) {
+    rtp_transport_->AccountForAudioPacketsInPacedSender(true);
+    rtp_transport_->IncludeOverheadInPacedSender();
+    rtp_rtcp_module_->SetAsPartOfAllocation(true);
+    ConfigureBitrateObserver();
+  } else {
+    rtp_rtcp_module_->SetAsPartOfAllocation(false);
+  }
+  channel_send_->StartSend();
+  sending_ = true;
+  audio_state()->AddSendingStream(this, encoder_sample_rate_hz_,
+                                  encoder_num_channels_);
+}
+
+void AudioSendStream::Stop() {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  if (!sending_) {
+    return;
+  }
+  RTC_LOG(LS_INFO) << "AudioSendStream::Stop: " << config_.rtp.ssrc;
+  RemoveBitrateObserver();
+  channel_send_->StopSend();
+  sending_ = false;
+  audio_state()->RemoveSendingStream(this);
+}
+
+void AudioSendStream::SendAudioData(std::unique_ptr<AudioFrame> audio_frame) {
+  RTC_CHECK_RUNS_SERIALIZED(&audio_capture_race_checker_);
+  RTC_DCHECK_GT(audio_frame->sample_rate_hz_, 0);
+  TRACE_EVENT0("webrtc", "AudioSendStream::SendAudioData");
+  double duration = static_cast<double>(audio_frame->samples_per_channel_) /
+                    audio_frame->sample_rate_hz_;
+  {
+    // Note: SendAudioData() passes the frame further down the pipeline and it
+    // may eventually get sent. But this method is invoked even if we are not
+    // connected, as long as we have an AudioSendStream (created as a result of
+    // an O/A exchange). This means that we are calculating audio levels whether
+    // or not we are sending samples.
+    // TODO(https://crbug.com/webrtc/10771): All "media-source" related stats
+    // should move from send-streams to the local audio sources or tracks; a
+    // send-stream should not be required to read the microphone audio levels.
+    MutexLock lock(&audio_level_lock_);
+    audio_level_.ComputeLevel(*audio_frame, duration);
+  }
+  channel_send_->ProcessAndEncodeAudio(std::move(audio_frame));
+}
+
+bool AudioSendStream::SendTelephoneEvent(int payload_type,
+                                         int payload_frequency,
+                                         int event,
+                                         int duration_ms) {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  channel_send_->SetSendTelephoneEventPayloadType(payload_type,
+                                                  payload_frequency);
+  return channel_send_->SendTelephoneEventOutband(event, duration_ms);
+}
+
+void AudioSendStream::SetMuted(bool muted) {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  channel_send_->SetInputMute(muted);
+}
+
+webrtc::AudioSendStream::Stats AudioSendStream::GetStats() const {
+  return GetStats(true);
+}
+
+webrtc::AudioSendStream::Stats AudioSendStream::GetStats(
+    bool has_remote_tracks) const {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  webrtc::AudioSendStream::Stats stats;
+  stats.local_ssrc = config_.rtp.ssrc;
+  stats.target_bitrate_bps = channel_send_->GetTargetBitrate();
+
+  webrtc::CallSendStatistics call_stats = channel_send_->GetRTCPStatistics();
+  stats.payload_bytes_sent = call_stats.payload_bytes_sent;
+  stats.header_and_padding_bytes_sent =
+      call_stats.header_and_padding_bytes_sent;
+  stats.retransmitted_bytes_sent = call_stats.retransmitted_bytes_sent;
+  stats.packets_sent = call_stats.packetsSent;
+  stats.total_packet_send_delay = call_stats.total_packet_send_delay;
+  stats.retransmitted_packets_sent = call_stats.retransmitted_packets_sent;
+  // RTT isn't known until a RTCP report is received. Until then, VoiceEngine
+  // returns 0 to indicate an error value.
+  if (call_stats.rttMs > 0) {
+    stats.rtt_ms = call_stats.rttMs;
+  }
+  if (config_.send_codec_spec) {
+    const auto& spec = *config_.send_codec_spec;
+    stats.codec_name = spec.format.name;
+    stats.codec_payload_type = spec.payload_type;
+
+    // Get data from the last remote RTCP report.
+    for (const ReportBlockData& block :
+         channel_send_->GetRemoteRTCPReportBlocks()) {
+      // Lookup report for send ssrc only.
+      if (block.source_ssrc() == stats.local_ssrc) {
+        stats.packets_lost = block.cumulative_lost();
+        stats.fraction_lost = block.fraction_lost();
+        if (spec.format.clockrate_hz > 0) {
+          stats.jitter_ms = block.jitter(spec.format.clockrate_hz).ms();
+        }
+        break;
+      }
+    }
+  }
+
+  {
+    MutexLock lock(&audio_level_lock_);
+    stats.audio_level = audio_level_.LevelFullRange();
+    stats.total_input_energy = audio_level_.TotalEnergy();
+    stats.total_input_duration = audio_level_.TotalDuration();
+  }
+
+  stats.ana_statistics = channel_send_->GetANAStatistics();
+
+  AudioProcessing* ap = audio_state_->audio_processing();
+  if (ap) {
+    stats.apm_statistics = ap->GetStatistics(has_remote_tracks);
+  }
+
+  stats.report_block_datas = std::move(call_stats.report_block_datas);
+
+  stats.nacks_received = call_stats.nacks_received;
+
+  return stats;
+}
+
+void AudioSendStream::DeliverRtcp(const uint8_t* packet, size_t length) {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  channel_send_->ReceivedRTCPPacket(packet, length);
+  // Poll if overhead has changed, which it can do if ack triggers us to stop
+  // sending mid/rid.
+  UpdateOverheadPerPacket();
+}
+
+uint32_t AudioSendStream::OnBitrateUpdated(BitrateAllocationUpdate update) {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  // Pick a target bitrate between the constraints. Overrules the allocator if
+  // it 1) allocated a bitrate of zero to disable the stream or 2) allocated a
+  // higher than max to allow for e.g. extra FEC.
+  absl::optional<TargetAudioBitrateConstraints> constraints =
+      GetMinMaxBitrateConstraints();
+  if (constraints) {
+    update.target_bitrate.Clamp(constraints->min, constraints->max);
+    update.stable_target_bitrate.Clamp(constraints->min, constraints->max);
+  }
+  channel_send_->OnBitrateAllocation(update);
+  // The amount of audio protection is not exposed by the encoder, hence
+  // always returning 0.
+  return 0;
+}
+
+void AudioSendStream::SetTransportOverhead(
+    int transport_overhead_per_packet_bytes) {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  transport_overhead_per_packet_bytes_ = transport_overhead_per_packet_bytes;
+  UpdateOverheadPerPacket();
+}
+
+void AudioSendStream::UpdateOverheadPerPacket() {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  size_t overhead_per_packet_bytes =
+      transport_overhead_per_packet_bytes_ +
+      rtp_rtcp_module_->ExpectedPerPacketOverhead();
+  if (overhead_per_packet_ == overhead_per_packet_bytes) {
+    return;
+  }
+  overhead_per_packet_ = overhead_per_packet_bytes;
+  channel_send_->CallEncoder([&](AudioEncoder* encoder) {
+    encoder->OnReceivedOverhead(overhead_per_packet_bytes);
+  });
+  if (registered_with_allocator_) {
+    ConfigureBitrateObserver();
+  }
+}
+
+size_t AudioSendStream::TestOnlyGetPerPacketOverheadBytes() const {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  return overhead_per_packet_;
+}
+
+RtpState AudioSendStream::GetRtpState() const {
+  return rtp_rtcp_module_->GetRtpState();
+}
+
+const voe::ChannelSendInterface* AudioSendStream::GetChannel() const {
+  return channel_send_.get();
+}
+
+internal::AudioState* AudioSendStream::audio_state() {
+  internal::AudioState* audio_state =
+      static_cast<internal::AudioState*>(audio_state_.get());
+  RTC_DCHECK(audio_state);
+  return audio_state;
+}
+
+const internal::AudioState* AudioSendStream::audio_state() const {
+  internal::AudioState* audio_state =
+      static_cast<internal::AudioState*>(audio_state_.get());
+  RTC_DCHECK(audio_state);
+  return audio_state;
+}
+
+void AudioSendStream::StoreEncoderProperties(int sample_rate_hz,
+                                             size_t num_channels) {
+  encoder_sample_rate_hz_ = sample_rate_hz;
+  encoder_num_channels_ = num_channels;
+  if (sending_) {
+    // Update AudioState's information about the stream.
+    audio_state()->AddSendingStream(this, sample_rate_hz, num_channels);
+  }
+}
+
+// Apply current codec settings to a single voe::Channel used for sending.
+bool AudioSendStream::SetupSendCodec(const Config& new_config) {
+  RTC_DCHECK(new_config.send_codec_spec);
+  const auto& spec = *new_config.send_codec_spec;
+
+  RTC_DCHECK(new_config.encoder_factory);
+  std::unique_ptr<AudioEncoder> encoder =
+      new_config.encoder_factory->MakeAudioEncoder(
+          spec.payload_type, spec.format, new_config.codec_pair_id);
+
+  if (!encoder) {
+    RTC_DLOG(LS_ERROR) << "Unable to create encoder for "
+                       << rtc::ToString(spec.format);
+    return false;
+  }
+
+  // If a bitrate has been specified for the codec, use it over the
+  // codec's default.
+  if (spec.target_bitrate_bps) {
+    encoder->OnReceivedTargetAudioBitrate(*spec.target_bitrate_bps);
+  }
+
+  // Enable ANA if configured (currently only used by Opus).
+  if (new_config.audio_network_adaptor_config) {
+    if (encoder->EnableAudioNetworkAdaptor(
+            *new_config.audio_network_adaptor_config, event_log_)) {
+      RTC_LOG(LS_INFO) << "Audio network adaptor enabled on SSRC "
+                       << new_config.rtp.ssrc;
+    } else {
+      RTC_LOG(LS_INFO) << "Failed to enable Audio network adaptor on SSRC "
+                       << new_config.rtp.ssrc;
+    }
+  }
+
+  // Wrap the encoder in an AudioEncoderCNG, if VAD is enabled.
+  if (spec.cng_payload_type) {
+    AudioEncoderCngConfig cng_config;
+    cng_config.num_channels = encoder->NumChannels();
+    cng_config.payload_type = *spec.cng_payload_type;
+    cng_config.speech_encoder = std::move(encoder);
+    cng_config.vad_mode = Vad::kVadNormal;
+    encoder = CreateComfortNoiseEncoder(std::move(cng_config));
+
+    RegisterCngPayloadType(*spec.cng_payload_type,
+                           new_config.send_codec_spec->format.clockrate_hz);
+  }
+
+  // Wrap the encoder in a RED encoder, if RED is enabled.
+  SdpAudioFormat format = spec.format;
+  if (spec.red_payload_type) {
+    AudioEncoderCopyRed::Config red_config;
+    red_config.payload_type = *spec.red_payload_type;
+    red_config.speech_encoder = std::move(encoder);
+    encoder = std::make_unique<AudioEncoderCopyRed>(std::move(red_config),
+                                                    field_trials_);
+    format.name = cricket::kRedCodecName;
+  }
+
+  // Set currently known overhead (used in ANA, opus only).
+  // If overhead changes later, it will be updated in UpdateOverheadPerPacket.
+  if (overhead_per_packet_ > 0) {
+    encoder->OnReceivedOverhead(overhead_per_packet_);
+  }
+
+  StoreEncoderProperties(encoder->SampleRateHz(), encoder->NumChannels());
+  channel_send_->SetEncoder(new_config.send_codec_spec->payload_type, format,
+                            std::move(encoder));
+
+  return true;
+}
+
+bool AudioSendStream::ReconfigureSendCodec(const Config& new_config) {
+  const auto& old_config = config_;
+
+  if (!new_config.send_codec_spec) {
+    // We cannot de-configure a send codec. So we will do nothing.
+    // By design, the send codec should have not been configured.
+    RTC_DCHECK(!old_config.send_codec_spec);
+    return true;
+  }
+
+  if (new_config.send_codec_spec == old_config.send_codec_spec &&
+      new_config.audio_network_adaptor_config ==
+          old_config.audio_network_adaptor_config) {
+    return true;
+  }
+
+  // If we have no encoder, or the format or payload type's changed, create a
+  // new encoder.
+  if (!old_config.send_codec_spec ||
+      new_config.send_codec_spec->format !=
+          old_config.send_codec_spec->format ||
+      new_config.send_codec_spec->payload_type !=
+          old_config.send_codec_spec->payload_type ||
+      new_config.send_codec_spec->red_payload_type !=
+          old_config.send_codec_spec->red_payload_type) {
+    return SetupSendCodec(new_config);
+  }
+
+  const absl::optional<int>& new_target_bitrate_bps =
+      new_config.send_codec_spec->target_bitrate_bps;
+  // If a bitrate has been specified for the codec, use it over the
+  // codec's default.
+  if (new_target_bitrate_bps &&
+      new_target_bitrate_bps !=
+          old_config.send_codec_spec->target_bitrate_bps) {
+    channel_send_->CallEncoder([&](AudioEncoder* encoder) {
+      encoder->OnReceivedTargetAudioBitrate(*new_target_bitrate_bps);
+    });
+  }
+
+  ReconfigureANA(new_config);
+  ReconfigureCNG(new_config);
+
+  return true;
+}
+
+void AudioSendStream::ReconfigureANA(const Config& new_config) {
+  if (new_config.audio_network_adaptor_config ==
+      config_.audio_network_adaptor_config) {
+    return;
+  }
+  if (new_config.audio_network_adaptor_config) {
+    channel_send_->CallEncoder([&](AudioEncoder* encoder) {
+      RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+      if (encoder->EnableAudioNetworkAdaptor(
+              *new_config.audio_network_adaptor_config, event_log_)) {
+        RTC_LOG(LS_INFO) << "Audio network adaptor enabled on SSRC "
+                         << new_config.rtp.ssrc;
+        if (overhead_per_packet_ > 0) {
+          encoder->OnReceivedOverhead(overhead_per_packet_);
+        }
+      } else {
+        RTC_LOG(LS_INFO) << "Failed to enable Audio network adaptor on SSRC "
+                         << new_config.rtp.ssrc;
+      }
+    });
+  } else {
+    channel_send_->CallEncoder(
+        [&](AudioEncoder* encoder) { encoder->DisableAudioNetworkAdaptor(); });
+    RTC_LOG(LS_INFO) << "Audio network adaptor disabled on SSRC "
+                     << new_config.rtp.ssrc;
+  }
+}
+
+void AudioSendStream::ReconfigureCNG(const Config& new_config) {
+  if (new_config.send_codec_spec->cng_payload_type ==
+      config_.send_codec_spec->cng_payload_type) {
+    return;
+  }
+
+  // Register the CNG payload type if it's been added, don't do anything if CNG
+  // is removed. Payload types must not be redefined.
+  if (new_config.send_codec_spec->cng_payload_type) {
+    RegisterCngPayloadType(*new_config.send_codec_spec->cng_payload_type,
+                           new_config.send_codec_spec->format.clockrate_hz);
+  }
+
+  // Wrap or unwrap the encoder in an AudioEncoderCNG.
+  channel_send_->ModifyEncoder([&](std::unique_ptr<AudioEncoder>* encoder_ptr) {
+    std::unique_ptr<AudioEncoder> old_encoder(std::move(*encoder_ptr));
+    auto sub_encoders = old_encoder->ReclaimContainedEncoders();
+    if (!sub_encoders.empty()) {
+      // Replace enc with its sub encoder. We need to put the sub
+      // encoder in a temporary first, since otherwise the old value
+      // of enc would be destroyed before the new value got assigned,
+      // which would be bad since the new value is a part of the old
+      // value.
+      auto tmp = std::move(sub_encoders[0]);
+      old_encoder = std::move(tmp);
+    }
+    if (new_config.send_codec_spec->cng_payload_type) {
+      AudioEncoderCngConfig config;
+      config.speech_encoder = std::move(old_encoder);
+      config.num_channels = config.speech_encoder->NumChannels();
+      config.payload_type = *new_config.send_codec_spec->cng_payload_type;
+      config.vad_mode = Vad::kVadNormal;
+      *encoder_ptr = CreateComfortNoiseEncoder(std::move(config));
+    } else {
+      *encoder_ptr = std::move(old_encoder);
+    }
+  });
+}
+
+void AudioSendStream::ReconfigureBitrateObserver(
+    const webrtc::AudioSendStream::Config& new_config) {
+  // Since the Config's default is for both of these to be -1, this test will
+  // allow us to configure the bitrate observer if the new config has bitrate
+  // limits set, but would only have us call RemoveBitrateObserver if we were
+  // previously configured with bitrate limits.
+  if (config_.min_bitrate_bps == new_config.min_bitrate_bps &&
+      config_.max_bitrate_bps == new_config.max_bitrate_bps &&
+      config_.bitrate_priority == new_config.bitrate_priority &&
+      TransportSeqNumId(config_) == TransportSeqNumId(new_config) &&
+      config_.audio_network_adaptor_config ==
+          new_config.audio_network_adaptor_config) {
+    return;
+  }
+
+  if (!new_config.has_dscp && new_config.min_bitrate_bps != -1 &&
+      new_config.max_bitrate_bps != -1 && TransportSeqNumId(new_config) != 0) {
+    rtp_transport_->AccountForAudioPacketsInPacedSender(true);
+    rtp_transport_->IncludeOverheadInPacedSender();
+    // We may get a callback immediately as the observer is registered, so
+    // make sure the bitrate limits in config_ are up-to-date.
+    config_.min_bitrate_bps = new_config.min_bitrate_bps;
+    config_.max_bitrate_bps = new_config.max_bitrate_bps;
+
+    config_.bitrate_priority = new_config.bitrate_priority;
+    ConfigureBitrateObserver();
+    rtp_rtcp_module_->SetAsPartOfAllocation(true);
+  } else {
+    rtp_transport_->AccountForAudioPacketsInPacedSender(false);
+    RemoveBitrateObserver();
+    rtp_rtcp_module_->SetAsPartOfAllocation(false);
+  }
+}
+
+void AudioSendStream::ConfigureBitrateObserver() {
+  RTC_DCHECK_RUN_ON(&worker_thread_checker_);
+  // This either updates the current observer or adds a new observer.
+  // TODO(srte): Add overhead compensation here.
+  auto constraints = GetMinMaxBitrateConstraints();
+  RTC_DCHECK(constraints.has_value());
+
+  DataRate priority_bitrate = allocation_settings_.priority_bitrate;
+  if (use_legacy_overhead_calculation_) {
+    // OverheadPerPacket = Ipv4(20B) + UDP(8B) + SRTP(10B) + RTP(12)
+    constexpr int kOverheadPerPacket = 20 + 8 + 10 + 12;
+    const TimeDelta kMinPacketDuration = TimeDelta::Millis(20);
+    DataRate max_overhead =
+        DataSize::Bytes(kOverheadPerPacket) / kMinPacketDuration;
+    priority_bitrate += max_overhead;
+  } else {
+    RTC_DCHECK(frame_length_range_);
+    const DataSize overhead_per_packet = DataSize::Bytes(overhead_per_packet_);
+    DataRate min_overhead = overhead_per_packet / frame_length_range_->second;
+    priority_bitrate += min_overhead;
+  }
+
+  if (allocation_settings_.priority_bitrate_raw) {
+    priority_bitrate = *allocation_settings_.priority_bitrate_raw;
+  }
+
+  if (!enable_priority_bitrate_) {
+    priority_bitrate = DataRate::BitsPerSec(0);
+  }
+
+  bitrate_allocator_->AddObserver(
+      this,
+      MediaStreamAllocationConfig{
+          constraints->min.bps<uint32_t>(), constraints->max.bps<uint32_t>(), 0,
+          priority_bitrate.bps(), true,
+          allocation_settings_.bitrate_priority.value_or(
+              config_.bitrate_priority)});
+
+  registered_with_allocator_ = true;
+}
+
+void AudioSendStream::RemoveBitrateObserver() {
+  registered_with_allocator_ = false;
+  bitrate_allocator_->RemoveObserver(this);
+}
+
+absl::optional<AudioSendStream::TargetAudioBitrateConstraints>
+AudioSendStream::GetMinMaxBitrateConstraints() const {
+  if (config_.min_bitrate_bps < 0 || config_.max_bitrate_bps < 0) {
+    RTC_LOG(LS_WARNING) << "Config is invalid: min_bitrate_bps="
+                        << config_.min_bitrate_bps
+                        << "; max_bitrate_bps=" << config_.max_bitrate_bps
+                        << "; both expected greater or equal to 0";
+    return absl::nullopt;
+  }
+  TargetAudioBitrateConstraints constraints{
+      DataRate::BitsPerSec(config_.min_bitrate_bps),
+      DataRate::BitsPerSec(config_.max_bitrate_bps)};
+
+  // If bitrates were explicitly overriden via field trial, use those values.
+  if (allocation_settings_.min_bitrate)
+    constraints.min = *allocation_settings_.min_bitrate;
+  if (allocation_settings_.max_bitrate)
+    constraints.max = *allocation_settings_.max_bitrate;
+
+  // Use encoder defined bitrate range if available.
+  if (bitrate_range_) {
+    constraints.min = bitrate_range_->first;
+    constraints.max = bitrate_range_->second;
+  }
+
+  RTC_DCHECK_GE(constraints.min, DataRate::Zero());
+  RTC_DCHECK_GE(constraints.max, DataRate::Zero());
+  if (constraints.max < constraints.min) {
+    RTC_LOG(LS_WARNING) << "TargetAudioBitrateConstraints::max is less than "
+                        << "TargetAudioBitrateConstraints::min";
+    return absl::nullopt;
+  }
+  if (use_legacy_overhead_calculation_) {
+    // OverheadPerPacket = Ipv4(20B) + UDP(8B) + SRTP(10B) + RTP(12)
+    const DataSize kOverheadPerPacket = DataSize::Bytes(20 + 8 + 10 + 12);
+    const TimeDelta kMaxFrameLength =
+        TimeDelta::Millis(60);  // Based on Opus spec
+    const DataRate kMinOverhead = kOverheadPerPacket / kMaxFrameLength;
+    constraints.min += kMinOverhead;
+    constraints.max += kMinOverhead;
+  } else {
+    if (!frame_length_range_.has_value()) {
+      RTC_LOG(LS_WARNING) << "frame_length_range_ is not set";
+      return absl::nullopt;
+    }
+    const DataSize overhead_per_packet = DataSize::Bytes(overhead_per_packet_);
+    constraints.min += overhead_per_packet / frame_length_range_->second;
+    constraints.max += overhead_per_packet / frame_length_range_->first;
+  }
+  return constraints;
+}
+
+void AudioSendStream::RegisterCngPayloadType(int payload_type,
+                                             int clockrate_hz) {
+  channel_send_->RegisterCngPayloadType(payload_type, clockrate_hz);
+}
+
+}  // namespace internal
+}  // namespace webrtc