blob: b725e63d68a3ab54a8d81529e75091b362a596b4 [file] [log] [blame]
/*
* Copyright 2018 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 "video/video_send_stream_impl.h"
#include <algorithm>
#include <string>
#include <utility>
#include "call/rtp_transport_controller_send_interface.h"
#include "modules/pacing/packet_router.h"
#include "modules/rtp_rtcp/source/rtp_sender.h"
#include "rtc_base/checks.h"
#include "rtc_base/experiments/alr_experiment.h"
#include "rtc_base/file.h"
#include "rtc_base/location.h"
#include "rtc_base/logging.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "rtc_base/trace_event.h"
#include "system_wrappers/include/field_trial.h"
namespace webrtc {
namespace internal {
namespace {
// Max positive size difference to treat allocations as "similar".
static constexpr int kMaxVbaSizeDifferencePercent = 10;
// Max time we will throttle similar video bitrate allocations.
static constexpr int64_t kMaxVbaThrottleTimeMs = 500;
bool TransportSeqNumExtensionConfigured(const VideoSendStream::Config& config) {
const std::vector<RtpExtension>& extensions = config.rtp.extensions;
return std::find_if(
extensions.begin(), extensions.end(), [](const RtpExtension& ext) {
return ext.uri == RtpExtension::kTransportSequenceNumberUri;
}) != extensions.end();
}
const char kForcedFallbackFieldTrial[] =
"WebRTC-VP8-Forced-Fallback-Encoder-v2";
absl::optional<int> GetFallbackMinBpsFromFieldTrial() {
if (!webrtc::field_trial::IsEnabled(kForcedFallbackFieldTrial))
return absl::nullopt;
std::string group =
webrtc::field_trial::FindFullName(kForcedFallbackFieldTrial);
if (group.empty())
return absl::nullopt;
int min_pixels;
int max_pixels;
int min_bps;
if (sscanf(group.c_str(), "Enabled-%d,%d,%d", &min_pixels, &max_pixels,
&min_bps) != 3) {
return absl::nullopt;
}
if (min_bps <= 0)
return absl::nullopt;
return min_bps;
}
int GetEncoderMinBitrateBps() {
const int kDefaultEncoderMinBitrateBps = 30000;
return GetFallbackMinBpsFromFieldTrial().value_or(
kDefaultEncoderMinBitrateBps);
}
// Calculate max padding bitrate for a multi layer codec.
int CalculateMaxPadBitrateBps(const std::vector<VideoStream>& streams,
int min_transmit_bitrate_bps,
bool pad_to_min_bitrate,
bool alr_probing) {
int pad_up_to_bitrate_bps = 0;
// Filter out only the active streams;
std::vector<VideoStream> active_streams;
for (const VideoStream& stream : streams) {
if (stream.active)
active_streams.emplace_back(stream);
}
if (active_streams.size() > 1) {
if (alr_probing) {
// With alr probing, just pad to the min bitrate of the lowest stream,
// probing will handle the rest of the rampup.
pad_up_to_bitrate_bps = active_streams[0].min_bitrate_bps;
} else {
// Pad to min bitrate of the highest layer.
pad_up_to_bitrate_bps =
active_streams[active_streams.size() - 1].min_bitrate_bps;
// Add target_bitrate_bps of the lower layers.
for (size_t i = 0; i < active_streams.size() - 1; ++i)
pad_up_to_bitrate_bps += active_streams[i].target_bitrate_bps;
}
} else if (!active_streams.empty() && pad_to_min_bitrate) {
pad_up_to_bitrate_bps = active_streams[0].min_bitrate_bps;
}
pad_up_to_bitrate_bps =
std::max(pad_up_to_bitrate_bps, min_transmit_bitrate_bps);
return pad_up_to_bitrate_bps;
}
RtpSenderObservers CreateObservers(CallStats* call_stats,
EncoderRtcpFeedback* encoder_feedback,
SendStatisticsProxy* stats_proxy,
SendDelayStats* send_delay_stats) {
RtpSenderObservers observers;
observers.rtcp_rtt_stats = call_stats;
observers.intra_frame_callback = encoder_feedback;
observers.rtcp_stats = stats_proxy;
observers.rtp_stats = stats_proxy;
observers.bitrate_observer = stats_proxy;
observers.frame_count_observer = stats_proxy;
observers.rtcp_type_observer = stats_proxy;
observers.send_delay_observer = stats_proxy;
observers.send_packet_observer = send_delay_stats;
return observers;
}
absl::optional<AlrExperimentSettings> GetAlrSettings(
VideoEncoderConfig::ContentType content_type) {
if (content_type == VideoEncoderConfig::ContentType::kScreen) {
return AlrExperimentSettings::CreateFromFieldTrial(
AlrExperimentSettings::kScreenshareProbingBweExperimentName);
}
return AlrExperimentSettings::CreateFromFieldTrial(
AlrExperimentSettings::kStrictPacingAndProbingExperimentName);
}
bool SameStreamsEnabled(const VideoBitrateAllocation& lhs,
const VideoBitrateAllocation& rhs) {
for (size_t si = 0; si < kMaxSpatialLayers; ++si) {
for (size_t ti = 0; ti < kMaxTemporalStreams; ++ti) {
if (lhs.HasBitrate(si, ti) != rhs.HasBitrate(si, ti)) {
return false;
}
}
}
return true;
}
} // namespace
// CheckEncoderActivityTask is used for tracking when the encoder last produced
// and encoded video frame. If the encoder has not produced anything the last
// kEncoderTimeOutMs we also want to stop sending padding.
class VideoSendStreamImpl::CheckEncoderActivityTask : public rtc::QueuedTask {
public:
static const int kEncoderTimeOutMs = 2000;
explicit CheckEncoderActivityTask(
const rtc::WeakPtr<VideoSendStreamImpl>& send_stream)
: activity_(0), send_stream_(std::move(send_stream)), timed_out_(false) {}
void Stop() {
RTC_CHECK(task_checker_.CalledSequentially());
send_stream_.reset();
}
void UpdateEncoderActivity() {
// UpdateEncoderActivity is called from VideoSendStreamImpl::Encoded on
// whatever thread the real encoder implementation run on. In the case of
// hardware encoders, there might be several encoders
// running in parallel on different threads.
rtc::AtomicOps::ReleaseStore(&activity_, 1);
}
private:
bool Run() override {
RTC_CHECK(task_checker_.CalledSequentially());
if (!send_stream_)
return true;
if (!rtc::AtomicOps::AcquireLoad(&activity_)) {
if (!timed_out_) {
send_stream_->SignalEncoderTimedOut();
}
timed_out_ = true;
} else if (timed_out_) {
send_stream_->SignalEncoderActive();
timed_out_ = false;
}
rtc::AtomicOps::ReleaseStore(&activity_, 0);
rtc::TaskQueue::Current()->PostDelayedTask(
std::unique_ptr<rtc::QueuedTask>(this), kEncoderTimeOutMs);
// Return false to prevent this task from being deleted. Ownership has been
// transferred to the task queue when PostDelayedTask was called.
return false;
}
volatile int activity_;
rtc::SequencedTaskChecker task_checker_;
rtc::WeakPtr<VideoSendStreamImpl> send_stream_;
bool timed_out_;
};
VideoSendStreamImpl::VideoSendStreamImpl(
SendStatisticsProxy* stats_proxy,
rtc::TaskQueue* worker_queue,
CallStats* call_stats,
RtpTransportControllerSendInterface* transport,
BitrateAllocatorInterface* bitrate_allocator,
SendDelayStats* send_delay_stats,
VideoStreamEncoderInterface* video_stream_encoder,
RtcEventLog* event_log,
const VideoSendStream::Config* config,
int initial_encoder_max_bitrate,
double initial_encoder_bitrate_priority,
std::map<uint32_t, RtpState> suspended_ssrcs,
std::map<uint32_t, RtpPayloadState> suspended_payload_states,
VideoEncoderConfig::ContentType content_type,
std::unique_ptr<FecController> fec_controller)
: has_alr_probing_(config->periodic_alr_bandwidth_probing ||
GetAlrSettings(content_type)),
stats_proxy_(stats_proxy),
config_(config),
worker_queue_(worker_queue),
check_encoder_activity_task_(nullptr),
call_stats_(call_stats),
transport_(transport),
bitrate_allocator_(bitrate_allocator),
max_padding_bitrate_(0),
encoder_min_bitrate_bps_(0),
encoder_target_rate_bps_(0),
encoder_bitrate_priority_(initial_encoder_bitrate_priority),
has_packet_feedback_(false),
video_stream_encoder_(video_stream_encoder),
encoder_feedback_(Clock::GetRealTimeClock(),
config_->rtp.ssrcs,
video_stream_encoder),
bandwidth_observer_(transport->GetBandwidthObserver()),
rtp_video_sender_(
transport_->CreateRtpVideoSender(config_->rtp.ssrcs,
suspended_ssrcs,
suspended_payload_states,
config_->rtp,
config_->rtcp,
config_->send_transport,
CreateObservers(call_stats,
&encoder_feedback_,
stats_proxy_,
send_delay_stats),
event_log,
std::move(fec_controller))),
weak_ptr_factory_(this) {
RTC_DCHECK_RUN_ON(worker_queue_);
RTC_LOG(LS_INFO) << "VideoSendStreamInternal: " << config_->ToString();
weak_ptr_ = weak_ptr_factory_.GetWeakPtr();
RTC_DCHECK(!config_->rtp.ssrcs.empty());
RTC_DCHECK(call_stats_);
RTC_DCHECK(transport_);
RTC_DCHECK_NE(initial_encoder_max_bitrate, 0);
if (initial_encoder_max_bitrate > 0) {
encoder_max_bitrate_bps_ =
rtc::dchecked_cast<uint32_t>(initial_encoder_max_bitrate);
} else {
// TODO(srte): Make sure max bitrate is not set to negative values. We don't
// have any way to handle unset values in downstream code, such as the
// bitrate allocator. Previously -1 was implicitly casted to UINT32_MAX, a
// behaviour that is not safe. Converting to 10 Mbps should be safe for
// reasonable use cases as it allows adding the max of multiple streams
// without wrappping around.
const int kFallbackMaxBitrateBps = 10000000;
RTC_DLOG(LS_ERROR) << "ERROR: Initial encoder max bitrate = "
<< initial_encoder_max_bitrate << " which is <= 0!";
RTC_DLOG(LS_INFO) << "Using default encoder max bitrate = 10 Mbps";
encoder_max_bitrate_bps_ = kFallbackMaxBitrateBps;
}
RTC_CHECK(AlrExperimentSettings::MaxOneFieldTrialEnabled());
// If send-side BWE is enabled, check if we should apply updated probing and
// pacing settings.
if (TransportSeqNumExtensionConfigured(*config_)) {
has_packet_feedback_ = true;
absl::optional<AlrExperimentSettings> alr_settings =
GetAlrSettings(content_type);
if (alr_settings) {
transport->EnablePeriodicAlrProbing(true);
transport->SetPacingFactor(alr_settings->pacing_factor);
configured_pacing_factor_ = alr_settings->pacing_factor;
transport->SetQueueTimeLimit(alr_settings->max_paced_queue_time);
} else {
transport->EnablePeriodicAlrProbing(false);
transport->SetPacingFactor(PacedSender::kDefaultPaceMultiplier);
configured_pacing_factor_ = PacedSender::kDefaultPaceMultiplier;
transport->SetQueueTimeLimit(PacedSender::kMaxQueueLengthMs);
}
}
if (config_->periodic_alr_bandwidth_probing) {
transport->EnablePeriodicAlrProbing(true);
}
RTC_DCHECK_GE(config_->rtp.payload_type, 0);
RTC_DCHECK_LE(config_->rtp.payload_type, 127);
video_stream_encoder_->SetStartBitrate(
bitrate_allocator_->GetStartBitrate(this));
// Only request rotation at the source when we positively know that the remote
// side doesn't support the rotation extension. This allows us to prepare the
// encoder in the expectation that rotation is supported - which is the common
// case.
bool rotation_applied =
std::find_if(config_->rtp.extensions.begin(),
config_->rtp.extensions.end(),
[](const RtpExtension& extension) {
return extension.uri == RtpExtension::kVideoRotationUri;
}) == config_->rtp.extensions.end();
video_stream_encoder_->SetSink(this, rotation_applied);
}
VideoSendStreamImpl::~VideoSendStreamImpl() {
RTC_DCHECK_RUN_ON(worker_queue_);
RTC_DCHECK(!rtp_video_sender_->IsActive())
<< "VideoSendStreamImpl::Stop not called";
RTC_LOG(LS_INFO) << "~VideoSendStreamInternal: " << config_->ToString();
transport_->DestroyRtpVideoSender(rtp_video_sender_);
}
void VideoSendStreamImpl::RegisterProcessThread(
ProcessThread* module_process_thread) {
rtp_video_sender_->RegisterProcessThread(module_process_thread);
}
void VideoSendStreamImpl::DeRegisterProcessThread() {
rtp_video_sender_->DeRegisterProcessThread();
}
bool VideoSendStreamImpl::DeliverRtcp(const uint8_t* packet, size_t length) {
// Runs on a network thread.
RTC_DCHECK(!worker_queue_->IsCurrent());
rtp_video_sender_->DeliverRtcp(packet, length);
return true;
}
void VideoSendStreamImpl::UpdateActiveSimulcastLayers(
const std::vector<bool> active_layers) {
RTC_DCHECK_RUN_ON(worker_queue_);
RTC_LOG(LS_INFO) << "VideoSendStream::UpdateActiveSimulcastLayers";
bool previously_active = rtp_video_sender_->IsActive();
rtp_video_sender_->SetActiveModules(active_layers);
if (!rtp_video_sender_->IsActive() && previously_active) {
// Payload router switched from active to inactive.
StopVideoSendStream();
} else if (rtp_video_sender_->IsActive() && !previously_active) {
// Payload router switched from inactive to active.
StartupVideoSendStream();
}
}
void VideoSendStreamImpl::Start() {
RTC_DCHECK_RUN_ON(worker_queue_);
RTC_LOG(LS_INFO) << "VideoSendStream::Start";
if (rtp_video_sender_->IsActive())
return;
TRACE_EVENT_INSTANT0("webrtc", "VideoSendStream::Start");
rtp_video_sender_->SetActive(true);
StartupVideoSendStream();
}
void VideoSendStreamImpl::StartupVideoSendStream() {
RTC_DCHECK_RUN_ON(worker_queue_);
bitrate_allocator_->AddObserver(
this,
MediaStreamAllocationConfig{
static_cast<uint32_t>(encoder_min_bitrate_bps_),
encoder_max_bitrate_bps_, static_cast<uint32_t>(max_padding_bitrate_),
!config_->suspend_below_min_bitrate, config_->track_id,
encoder_bitrate_priority_, has_packet_feedback_});
// Start monitoring encoder activity.
{
rtc::CritScope lock(&encoder_activity_crit_sect_);
RTC_DCHECK(!check_encoder_activity_task_);
check_encoder_activity_task_ = new CheckEncoderActivityTask(weak_ptr_);
worker_queue_->PostDelayedTask(
std::unique_ptr<rtc::QueuedTask>(check_encoder_activity_task_),
CheckEncoderActivityTask::kEncoderTimeOutMs);
}
video_stream_encoder_->SendKeyFrame();
}
void VideoSendStreamImpl::Stop() {
RTC_DCHECK_RUN_ON(worker_queue_);
RTC_LOG(LS_INFO) << "VideoSendStream::Stop";
if (!rtp_video_sender_->IsActive())
return;
TRACE_EVENT_INSTANT0("webrtc", "VideoSendStream::Stop");
rtp_video_sender_->SetActive(false);
StopVideoSendStream();
}
void VideoSendStreamImpl::StopVideoSendStream() {
bitrate_allocator_->RemoveObserver(this);
{
rtc::CritScope lock(&encoder_activity_crit_sect_);
check_encoder_activity_task_->Stop();
check_encoder_activity_task_ = nullptr;
}
video_stream_encoder_->OnBitrateUpdated(0, 0, 0);
stats_proxy_->OnSetEncoderTargetRate(0);
}
void VideoSendStreamImpl::SignalEncoderTimedOut() {
RTC_DCHECK_RUN_ON(worker_queue_);
// If the encoder has not produced anything the last kEncoderTimeOutMs and it
// is supposed to, deregister as BitrateAllocatorObserver. This can happen
// if a camera stops producing frames.
if (encoder_target_rate_bps_ > 0) {
RTC_LOG(LS_INFO) << "SignalEncoderTimedOut, Encoder timed out.";
bitrate_allocator_->RemoveObserver(this);
}
}
void VideoSendStreamImpl::OnBitrateAllocationUpdated(
const VideoBitrateAllocation& allocation) {
if (!worker_queue_->IsCurrent()) {
auto ptr = weak_ptr_;
worker_queue_->PostTask([=] {
if (!ptr.get())
return;
ptr->OnBitrateAllocationUpdated(allocation);
});
return;
}
RTC_DCHECK_RUN_ON(worker_queue_);
int64_t now_ms = rtc::TimeMillis();
if (encoder_target_rate_bps_ != 0) {
if (video_bitrate_allocation_context_) {
// If new allocation is within kMaxVbaSizeDifferencePercent larger than
// the previously sent allocation and the same streams are still enabled,
// it is considered "similar". We do not want send similar allocations
// more once per kMaxVbaThrottleTimeMs.
const VideoBitrateAllocation& last =
video_bitrate_allocation_context_->last_sent_allocation;
const bool is_similar =
allocation.get_sum_bps() >= last.get_sum_bps() &&
allocation.get_sum_bps() <
(last.get_sum_bps() * (100 + kMaxVbaSizeDifferencePercent)) /
100 &&
SameStreamsEnabled(allocation, last);
if (is_similar &&
(now_ms - video_bitrate_allocation_context_->last_send_time_ms) <
kMaxVbaThrottleTimeMs) {
// This allocation is too similar, cache it and return.
video_bitrate_allocation_context_->throttled_allocation = allocation;
return;
}
} else {
video_bitrate_allocation_context_.emplace();
}
video_bitrate_allocation_context_->last_sent_allocation = allocation;
video_bitrate_allocation_context_->throttled_allocation.reset();
video_bitrate_allocation_context_->last_send_time_ms = now_ms;
// Send bitrate allocation metadata only if encoder is not paused.
rtp_video_sender_->OnBitrateAllocationUpdated(allocation);
}
}
void VideoSendStreamImpl::SignalEncoderActive() {
RTC_DCHECK_RUN_ON(worker_queue_);
RTC_LOG(LS_INFO) << "SignalEncoderActive, Encoder is active.";
bitrate_allocator_->AddObserver(
this,
MediaStreamAllocationConfig{
static_cast<uint32_t>(encoder_min_bitrate_bps_),
encoder_max_bitrate_bps_, static_cast<uint32_t>(max_padding_bitrate_),
!config_->suspend_below_min_bitrate, config_->track_id,
encoder_bitrate_priority_, has_packet_feedback_});
}
void VideoSendStreamImpl::OnEncoderConfigurationChanged(
std::vector<VideoStream> streams,
int min_transmit_bitrate_bps) {
if (!worker_queue_->IsCurrent()) {
rtc::WeakPtr<VideoSendStreamImpl> send_stream = weak_ptr_;
worker_queue_->PostTask([send_stream, streams, min_transmit_bitrate_bps]() {
if (send_stream)
send_stream->OnEncoderConfigurationChanged(std::move(streams),
min_transmit_bitrate_bps);
});
return;
}
RTC_DCHECK_GE(config_->rtp.ssrcs.size(), streams.size());
TRACE_EVENT0("webrtc", "VideoSendStream::OnEncoderConfigurationChanged");
RTC_DCHECK_GE(config_->rtp.ssrcs.size(), streams.size());
RTC_DCHECK_RUN_ON(worker_queue_);
encoder_min_bitrate_bps_ =
std::max(streams[0].min_bitrate_bps, GetEncoderMinBitrateBps());
encoder_max_bitrate_bps_ = 0;
double stream_bitrate_priority_sum = 0;
for (const auto& stream : streams) {
// We don't want to allocate more bitrate than needed to inactive streams.
encoder_max_bitrate_bps_ += stream.active ? stream.max_bitrate_bps : 0;
if (stream.bitrate_priority) {
RTC_DCHECK_GT(*stream.bitrate_priority, 0);
stream_bitrate_priority_sum += *stream.bitrate_priority;
}
}
RTC_DCHECK_GT(stream_bitrate_priority_sum, 0);
encoder_bitrate_priority_ = stream_bitrate_priority_sum;
encoder_max_bitrate_bps_ =
std::max(static_cast<uint32_t>(encoder_min_bitrate_bps_),
encoder_max_bitrate_bps_);
const VideoCodecType codec_type =
PayloadStringToCodecType(config_->rtp.payload_name);
if (codec_type == kVideoCodecVP9) {
max_padding_bitrate_ = streams[0].target_bitrate_bps;
} else {
max_padding_bitrate_ = CalculateMaxPadBitrateBps(
streams, min_transmit_bitrate_bps, config_->suspend_below_min_bitrate,
has_alr_probing_);
}
// Clear stats for disabled layers.
for (size_t i = streams.size(); i < config_->rtp.ssrcs.size(); ++i) {
stats_proxy_->OnInactiveSsrc(config_->rtp.ssrcs[i]);
}
const size_t num_temporal_layers =
streams.back().num_temporal_layers.value_or(1);
rtp_video_sender_->SetEncodingData(streams[0].width, streams[0].height,
num_temporal_layers);
if (rtp_video_sender_->IsActive()) {
// The send stream is started already. Update the allocator with new bitrate
// limits.
bitrate_allocator_->AddObserver(
this, MediaStreamAllocationConfig{
static_cast<uint32_t>(encoder_min_bitrate_bps_),
encoder_max_bitrate_bps_,
static_cast<uint32_t>(max_padding_bitrate_),
!config_->suspend_below_min_bitrate, config_->track_id,
encoder_bitrate_priority_, has_packet_feedback_});
}
}
EncodedImageCallback::Result VideoSendStreamImpl::OnEncodedImage(
const EncodedImage& encoded_image,
const CodecSpecificInfo* codec_specific_info,
const RTPFragmentationHeader* fragmentation) {
// Encoded is called on whatever thread the real encoder implementation run
// on. In the case of hardware encoders, there might be several encoders
// running in parallel on different threads.
{
rtc::CritScope lock(&encoder_activity_crit_sect_);
if (check_encoder_activity_task_)
check_encoder_activity_task_->UpdateEncoderActivity();
}
EncodedImageCallback::Result result = rtp_video_sender_->OnEncodedImage(
encoded_image, codec_specific_info, fragmentation);
// Check if there's a throttled VideoBitrateAllocation that we should try
// sending.
rtc::WeakPtr<VideoSendStreamImpl> send_stream = weak_ptr_;
auto update_task = [send_stream]() {
if (send_stream) {
RTC_DCHECK_RUN_ON(send_stream->worker_queue_);
auto& context = send_stream->video_bitrate_allocation_context_;
if (context && context->throttled_allocation) {
send_stream->OnBitrateAllocationUpdated(*context->throttled_allocation);
}
}
};
if (!worker_queue_->IsCurrent()) {
worker_queue_->PostTask(update_task);
} else {
update_task();
}
return result;
}
std::map<uint32_t, RtpState> VideoSendStreamImpl::GetRtpStates() const {
return rtp_video_sender_->GetRtpStates();
}
std::map<uint32_t, RtpPayloadState> VideoSendStreamImpl::GetRtpPayloadStates()
const {
return rtp_video_sender_->GetRtpPayloadStates();
}
uint32_t VideoSendStreamImpl::OnBitrateUpdated(uint32_t bitrate_bps,
uint8_t fraction_loss,
int64_t rtt,
int64_t probing_interval_ms) {
RTC_DCHECK_RUN_ON(worker_queue_);
RTC_DCHECK(rtp_video_sender_->IsActive())
<< "VideoSendStream::Start has not been called.";
rtp_video_sender_->OnBitrateUpdated(bitrate_bps, fraction_loss, rtt,
stats_proxy_->GetSendFrameRate());
encoder_target_rate_bps_ = rtp_video_sender_->GetPayloadBitrateBps();
encoder_target_rate_bps_ =
std::min(encoder_max_bitrate_bps_, encoder_target_rate_bps_);
video_stream_encoder_->OnBitrateUpdated(encoder_target_rate_bps_,
fraction_loss, rtt);
stats_proxy_->OnSetEncoderTargetRate(encoder_target_rate_bps_);
return rtp_video_sender_->GetProtectionBitrateBps();
}
} // namespace internal
} // namespace webrtc