blob: c516ddf796ea5f1b15144829f0968dd51e39b51a [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 "test/scenario/video_stream.h"
#include <algorithm>
#include <utility>
#include "absl/memory/memory.h"
#include "api/test/video/function_video_encoder_factory.h"
#include "api/video/builtin_video_bitrate_allocator_factory.h"
#include "media/base/media_constants.h"
#include "media/engine/internal_decoder_factory.h"
#include "media/engine/internal_encoder_factory.h"
#include "media/engine/webrtc_video_engine.h"
#include "test/call_test.h"
#include "test/fake_encoder.h"
#include "test/scenario/hardware_codecs.h"
#include "test/testsupport/file_utils.h"
namespace webrtc {
namespace test {
namespace {
enum : int { // The first valid value is 1.
kTransportSequenceNumberExtensionId = 1,
kAbsSendTimeExtensionId,
kVideoContentTypeExtensionId,
kVideoRotationRtpExtensionId,
};
constexpr int kDefaultMaxQp = cricket::WebRtcVideoChannel::kDefaultQpMax;
uint8_t CodecTypeToPayloadType(VideoCodecType codec_type) {
switch (codec_type) {
case VideoCodecType::kVideoCodecGeneric:
return CallTest::kFakeVideoSendPayloadType;
case VideoCodecType::kVideoCodecVP8:
return CallTest::kPayloadTypeVP8;
case VideoCodecType::kVideoCodecVP9:
return CallTest::kPayloadTypeVP9;
case VideoCodecType::kVideoCodecH264:
return CallTest::kPayloadTypeH264;
default:
RTC_NOTREACHED();
}
return {};
}
std::string CodecTypeToCodecName(VideoCodecType codec_type) {
switch (codec_type) {
case VideoCodecType::kVideoCodecGeneric:
return "";
case VideoCodecType::kVideoCodecVP8:
return cricket::kVp8CodecName;
case VideoCodecType::kVideoCodecVP9:
return cricket::kVp9CodecName;
case VideoCodecType::kVideoCodecH264:
return cricket::kH264CodecName;
default:
RTC_NOTREACHED();
}
return {};
}
VideoEncoderConfig::ContentType ConvertContentType(
VideoStreamConfig::Encoder::ContentType content_type) {
switch (content_type) {
case VideoStreamConfig::Encoder::ContentType::kVideo:
return VideoEncoderConfig::ContentType::kRealtimeVideo;
break;
case VideoStreamConfig::Encoder::ContentType::kScreen:
return VideoEncoderConfig::ContentType::kScreen;
}
}
InterLayerPredMode ToInterLayerPredMode(
VideoStreamConfig::Encoder::Layers::Prediction value) {
using Pred = VideoStreamConfig::Encoder::Layers::Prediction;
switch (value) {
case Pred::kTemporalOnly:
return InterLayerPredMode::kOff;
case Pred::kSpatialOnKey:
return InterLayerPredMode::kOnKeyPic;
case Pred::kFull:
return InterLayerPredMode::kOn;
}
}
std::vector<RtpExtension> GetVideoRtpExtensions(
const VideoStreamConfig config) {
std::vector<RtpExtension> res = {
RtpExtension(RtpExtension::kVideoContentTypeUri,
kVideoContentTypeExtensionId),
RtpExtension(RtpExtension::kVideoRotationUri,
kVideoRotationRtpExtensionId)};
if (config.stream.packet_feedback) {
res.push_back(RtpExtension(RtpExtension::kTransportSequenceNumberUri,
kTransportSequenceNumberExtensionId));
}
if (config.stream.abs_send_time) {
res.push_back(
RtpExtension(RtpExtension::kAbsSendTimeUri, kAbsSendTimeExtensionId));
}
return res;
}
std::string TransformFilePath(std::string path) {
static const std::string resource_prefix = "res://";
int ext_pos = path.rfind(".");
if (ext_pos < 0) {
return test::ResourcePath(path, "yuv");
} else if (path.find(resource_prefix) == 0) {
std::string name = path.substr(resource_prefix.length(), ext_pos);
std::string ext = path.substr(ext_pos, path.size());
return test::ResourcePath(name, ext);
}
return path;
}
VideoSendStream::Config CreateVideoSendStreamConfig(VideoStreamConfig config,
std::vector<uint32_t> ssrcs,
Transport* send_transport) {
VideoSendStream::Config send_config(send_transport);
send_config.rtp.payload_name = CodecTypeToPayloadString(config.encoder.codec);
send_config.rtp.payload_type = CodecTypeToPayloadType(config.encoder.codec);
send_config.rtp.ssrcs = ssrcs;
send_config.rtp.extensions = GetVideoRtpExtensions(config);
if (config.stream.use_flexfec) {
send_config.rtp.flexfec.payload_type = CallTest::kFlexfecPayloadType;
send_config.rtp.flexfec.ssrc = CallTest::kFlexfecSendSsrc;
send_config.rtp.flexfec.protected_media_ssrcs = ssrcs;
}
if (config.stream.use_ulpfec) {
send_config.rtp.ulpfec.red_payload_type = CallTest::kRedPayloadType;
send_config.rtp.ulpfec.ulpfec_payload_type = CallTest::kUlpfecPayloadType;
send_config.rtp.ulpfec.red_rtx_payload_type = CallTest::kRtxRedPayloadType;
}
return send_config;
}
rtc::scoped_refptr<VideoEncoderConfig::EncoderSpecificSettings>
CreateVp9SpecificSettings(VideoStreamConfig video_config) {
constexpr auto kScreen = VideoStreamConfig::Encoder::ContentType::kScreen;
VideoStreamConfig::Encoder conf = video_config.encoder;
VideoCodecVP9 vp9 = VideoEncoder::GetDefaultVp9Settings();
vp9.frameDroppingOn = conf.frame_dropping;
vp9.keyFrameInterval = conf.key_frame_interval.value_or(0);
vp9.numberOfTemporalLayers = static_cast<uint8_t>(conf.layers.temporal);
vp9.numberOfSpatialLayers = static_cast<uint8_t>(conf.layers.spatial);
vp9.interLayerPred = ToInterLayerPredMode(conf.layers.prediction);
if (conf.content_type == kScreen &&
(video_config.source.framerate > 5 || conf.layers.spatial >= 3)) {
vp9.flexibleMode = true;
}
if (conf.content_type == kScreen ||
conf.layers.temporal * conf.layers.spatial) {
vp9.automaticResizeOn = false;
vp9.denoisingOn = false;
} else {
vp9.automaticResizeOn = conf.single.automatic_scaling;
vp9.denoisingOn = conf.single.denoising;
}
return new rtc::RefCountedObject<
VideoEncoderConfig::Vp9EncoderSpecificSettings>(vp9);
}
rtc::scoped_refptr<VideoEncoderConfig::EncoderSpecificSettings>
CreateVp8SpecificSettings(VideoStreamConfig config) {
VideoCodecVP8 vp8_settings = VideoEncoder::GetDefaultVp8Settings();
vp8_settings.frameDroppingOn = config.encoder.frame_dropping;
vp8_settings.keyFrameInterval = config.encoder.key_frame_interval.value_or(0);
vp8_settings.numberOfTemporalLayers = config.encoder.layers.temporal;
if (config.encoder.layers.spatial * config.encoder.layers.temporal > 1) {
vp8_settings.automaticResizeOn = false;
vp8_settings.denoisingOn = false;
} else {
vp8_settings.automaticResizeOn = config.encoder.single.automatic_scaling;
vp8_settings.denoisingOn = config.encoder.single.denoising;
}
return new rtc::RefCountedObject<
VideoEncoderConfig::Vp8EncoderSpecificSettings>(vp8_settings);
}
rtc::scoped_refptr<VideoEncoderConfig::EncoderSpecificSettings>
CreateH264SpecificSettings(VideoStreamConfig config) {
RTC_DCHECK_EQ(config.encoder.layers.temporal, 1);
RTC_DCHECK_EQ(config.encoder.layers.spatial, 1);
VideoCodecH264 h264_settings = VideoEncoder::GetDefaultH264Settings();
h264_settings.frameDroppingOn = config.encoder.frame_dropping;
h264_settings.keyFrameInterval =
config.encoder.key_frame_interval.value_or(0);
return new rtc::RefCountedObject<
VideoEncoderConfig::H264EncoderSpecificSettings>(h264_settings);
}
rtc::scoped_refptr<VideoEncoderConfig::EncoderSpecificSettings>
CreateEncoderSpecificSettings(VideoStreamConfig config) {
using Codec = VideoStreamConfig::Encoder::Codec;
switch (config.encoder.codec) {
case Codec::kVideoCodecH264:
return CreateH264SpecificSettings(config);
case Codec::kVideoCodecVP8:
return CreateVp8SpecificSettings(config);
case Codec::kVideoCodecVP9:
return CreateVp9SpecificSettings(config);
case Codec::kVideoCodecGeneric:
return nullptr;
case Codec::kVideoCodecMultiplex:
RTC_NOTREACHED();
return nullptr;
}
}
VideoEncoderConfig CreateVideoEncoderConfig(VideoStreamConfig config) {
VideoEncoderConfig encoder_config;
encoder_config.codec_type = config.encoder.codec;
encoder_config.content_type = ConvertContentType(config.encoder.content_type);
encoder_config.video_format =
SdpVideoFormat(CodecTypeToPayloadString(config.encoder.codec), {});
encoder_config.number_of_streams = 1;
if (config.encoder.codec == VideoStreamConfig::Encoder::Codec::kVideoCodecVP8)
encoder_config.number_of_streams =
static_cast<size_t>(config.encoder.layers.spatial);
encoder_config.simulcast_layers =
std::vector<VideoStream>(config.encoder.layers.spatial);
encoder_config.min_transmit_bitrate_bps = config.stream.pad_to_rate.bps();
std::string cricket_codec = CodecTypeToCodecName(config.encoder.codec);
if (!cricket_codec.empty()) {
bool screenshare = config.encoder.content_type ==
VideoStreamConfig::Encoder::ContentType::kScreen;
encoder_config.video_stream_factory =
new rtc::RefCountedObject<cricket::EncoderStreamFactory>(
cricket_codec, kDefaultMaxQp, screenshare, screenshare);
} else {
encoder_config.video_stream_factory =
new rtc::RefCountedObject<DefaultVideoStreamFactory>();
}
// TODO(srte): Base this on encoder capabilities.
encoder_config.max_bitrate_bps =
config.encoder.max_data_rate.value_or(DataRate::kbps(10000)).bps();
encoder_config.encoder_specific_settings =
CreateEncoderSpecificSettings(config);
if (config.encoder.max_framerate) {
for (auto& layer : encoder_config.simulcast_layers) {
layer.max_framerate = *config.encoder.max_framerate;
}
}
return encoder_config;
}
std::unique_ptr<FrameGenerator> CreateImageSlideGenerator(
Clock* clock,
VideoStreamConfig::Source::Slides slides,
int framerate) {
std::vector<std::string> paths = slides.images.paths;
for (std::string& path : paths)
path = TransformFilePath(path);
if (slides.images.crop.width || slides.images.crop.height) {
TimeDelta pause_duration =
slides.change_interval - slides.images.crop.scroll_duration;
RTC_CHECK_GE(pause_duration, TimeDelta::Zero());
int crop_width = slides.images.crop.width.value_or(slides.images.width);
int crop_height = slides.images.crop.height.value_or(slides.images.height);
RTC_CHECK_LE(crop_width, slides.images.width);
RTC_CHECK_LE(crop_height, slides.images.height);
return FrameGenerator::CreateScrollingInputFromYuvFiles(
clock, paths, slides.images.width, slides.images.height, crop_width,
crop_height, slides.images.crop.scroll_duration.ms(),
pause_duration.ms());
} else {
return FrameGenerator::CreateFromYuvFile(
paths, slides.images.width, slides.images.height,
slides.change_interval.seconds<double>() * framerate);
}
}
std::unique_ptr<FrameGenerator> CreateFrameGenerator(
Clock* clock,
VideoStreamConfig::Source source) {
using Capture = VideoStreamConfig::Source::Capture;
switch (source.capture) {
case Capture::kGenerator:
return FrameGenerator::CreateSquareGenerator(
source.generator.width, source.generator.height,
source.generator.pixel_format, /*num_squares*/ absl::nullopt);
case Capture::kVideoFile:
RTC_CHECK(source.video_file.width && source.video_file.height);
return FrameGenerator::CreateFromYuvFile(
{TransformFilePath(source.video_file.name)}, source.video_file.width,
source.video_file.height, /*frame_repeat_count*/ 1);
case Capture::kGenerateSlides:
return FrameGenerator::CreateSlideGenerator(
source.slides.generator.width, source.slides.generator.height,
source.slides.change_interval.seconds<double>() * source.framerate);
case Capture::kImageSlides:
return CreateImageSlideGenerator(clock, source.slides, source.framerate);
}
}
VideoReceiveStream::Config CreateVideoReceiveStreamConfig(
VideoStreamConfig config,
Transport* feedback_transport,
VideoReceiveStream::Decoder decoder,
rtc::VideoSinkInterface<VideoFrame>* renderer,
uint32_t local_ssrc,
uint32_t ssrc,
uint32_t rtx_ssrc) {
VideoReceiveStream::Config recv(feedback_transport);
recv.rtp.remb = !config.stream.packet_feedback;
recv.rtp.transport_cc = config.stream.packet_feedback;
recv.rtp.local_ssrc = local_ssrc;
recv.rtp.extensions = GetVideoRtpExtensions(config);
RTC_DCHECK(!config.stream.use_rtx ||
config.stream.nack_history_time > TimeDelta::Zero());
recv.rtp.nack.rtp_history_ms = config.stream.nack_history_time.ms();
recv.rtp.protected_by_flexfec = config.stream.use_flexfec;
recv.rtp.remote_ssrc = ssrc;
recv.decoders.push_back(decoder);
recv.renderer = renderer;
if (config.stream.use_rtx) {
recv.rtp.rtx_ssrc = rtx_ssrc;
recv.rtp.rtx_associated_payload_types[CallTest::kSendRtxPayloadType] =
CodecTypeToPayloadType(config.encoder.codec);
}
if (config.stream.use_ulpfec) {
recv.rtp.red_payload_type = CallTest::kRedPayloadType;
recv.rtp.ulpfec_payload_type = CallTest::kUlpfecPayloadType;
recv.rtp.rtx_associated_payload_types[CallTest::kRtxRedPayloadType] =
CallTest::kRedPayloadType;
}
recv.sync_group = config.render.sync_group;
return recv;
}
} // namespace
SendVideoStream::SendVideoStream(CallClient* sender,
VideoStreamConfig config,
Transport* send_transport,
VideoFrameMatcher* matcher)
: sender_(sender), config_(config) {
video_capturer_ = absl::make_unique<FrameGeneratorCapturer>(
sender_->clock_, CreateFrameGenerator(sender_->clock_, config.source),
config.source.framerate,
*sender->time_controller_->GetTaskQueueFactory());
video_capturer_->Init();
using Encoder = VideoStreamConfig::Encoder;
using Codec = VideoStreamConfig::Encoder::Codec;
switch (config.encoder.implementation) {
case Encoder::Implementation::kFake:
if (config.encoder.codec == Codec::kVideoCodecGeneric) {
encoder_factory_ =
absl::make_unique<FunctionVideoEncoderFactory>([this]() {
rtc::CritScope cs(&crit_);
auto encoder =
absl::make_unique<test::FakeEncoder>(sender_->clock_);
fake_encoders_.push_back(encoder.get());
if (config_.encoder.fake.max_rate.IsFinite())
encoder->SetMaxBitrate(config_.encoder.fake.max_rate.kbps());
return encoder;
});
} else {
RTC_NOTREACHED();
}
break;
case VideoStreamConfig::Encoder::Implementation::kSoftware:
encoder_factory_.reset(new InternalEncoderFactory());
break;
case VideoStreamConfig::Encoder::Implementation::kHardware:
encoder_factory_ = CreateHardwareEncoderFactory();
break;
}
RTC_CHECK(encoder_factory_);
bitrate_allocator_factory_ = CreateBuiltinVideoBitrateAllocatorFactory();
RTC_CHECK(bitrate_allocator_factory_);
VideoEncoderConfig encoder_config = CreateVideoEncoderConfig(config);
for (size_t i = 0; i < encoder_config.number_of_streams; ++i) {
ssrcs_.push_back(sender->GetNextVideoSsrc());
rtx_ssrcs_.push_back(sender->GetNextRtxSsrc());
}
VideoSendStream::Config send_config =
CreateVideoSendStreamConfig(config, ssrcs_, send_transport);
send_config.encoder_settings.encoder_factory = encoder_factory_.get();
send_config.encoder_settings.bitrate_allocator_factory =
bitrate_allocator_factory_.get();
sender_->SendTask([&] {
if (config.stream.fec_controller_factory) {
send_stream_ = sender_->call_->CreateVideoSendStream(
std::move(send_config), std::move(encoder_config),
config.stream.fec_controller_factory->CreateFecController());
} else {
send_stream_ = sender_->call_->CreateVideoSendStream(
std::move(send_config), std::move(encoder_config));
}
if (matcher->Active()) {
frame_tap_ = absl::make_unique<ForwardingCapturedFrameTap>(
sender_->clock_, matcher, video_capturer_.get());
send_stream_->SetSource(frame_tap_.get(),
config.encoder.degradation_preference);
} else {
send_stream_->SetSource(video_capturer_.get(),
config.encoder.degradation_preference);
}
});
}
SendVideoStream::~SendVideoStream() {
sender_->SendTask(
[this] { sender_->call_->DestroyVideoSendStream(send_stream_); });
}
void SendVideoStream::Start() {
sender_->SendTask([this] {
send_stream_->Start();
sender_->call_->SignalChannelNetworkState(MediaType::VIDEO, kNetworkUp);
});
}
void SendVideoStream::Stop() {
sender_->SendTask([this] { send_stream_->Stop(); });
}
void SendVideoStream::UpdateConfig(
std::function<void(VideoStreamConfig*)> modifier) {
sender_->SendTask([&] {
rtc::CritScope cs(&crit_);
VideoStreamConfig prior_config = config_;
modifier(&config_);
if (prior_config.encoder.fake.max_rate != config_.encoder.fake.max_rate) {
for (auto* encoder : fake_encoders_) {
encoder->SetMaxBitrate(config_.encoder.fake.max_rate.kbps());
}
}
// TODO(srte): Add more conditions that should cause reconfiguration.
if (prior_config.encoder.max_framerate != config_.encoder.max_framerate) {
VideoEncoderConfig encoder_config = CreateVideoEncoderConfig(config_);
send_stream_->ReconfigureVideoEncoder(std::move(encoder_config));
}
if (prior_config.source.framerate != config_.source.framerate) {
SetCaptureFramerate(config_.source.framerate);
}
});
}
void SendVideoStream::UpdateActiveLayers(std::vector<bool> active_layers) {
sender_->task_queue_.PostTask([=] {
rtc::CritScope cs(&crit_);
if (config_.encoder.codec ==
VideoStreamConfig::Encoder::Codec::kVideoCodecVP8) {
send_stream_->UpdateActiveSimulcastLayers(active_layers);
} else {
VideoEncoderConfig encoder_config = CreateVideoEncoderConfig(config_);
RTC_CHECK_EQ(encoder_config.simulcast_layers.size(),
active_layers.size());
for (size_t i = 0; i < encoder_config.simulcast_layers.size(); ++i)
encoder_config.simulcast_layers[i].active = active_layers[i];
send_stream_->ReconfigureVideoEncoder(std::move(encoder_config));
}
});
}
void SendVideoStream::SetCaptureFramerate(int framerate) {
sender_->SendTask([&] { video_capturer_->ChangeFramerate(framerate); });
}
VideoSendStream::Stats SendVideoStream::GetStats() const {
return send_stream_->GetStats();
}
ColumnPrinter SendVideoStream::StatsPrinter() {
return ColumnPrinter::Lambda(
"video_target_rate video_sent_rate width height",
[this](rtc::SimpleStringBuilder& sb) {
VideoSendStream::Stats video_stats = send_stream_->GetStats();
int width = 0;
int height = 0;
for (const auto& stream_stat : video_stats.substreams) {
width = std::max(width, stream_stat.second.width);
height = std::max(height, stream_stat.second.height);
}
sb.AppendFormat("%.0lf %.0lf %i %i",
video_stats.target_media_bitrate_bps / 8.0,
video_stats.media_bitrate_bps / 8.0, width, height);
},
64);
}
ReceiveVideoStream::ReceiveVideoStream(CallClient* receiver,
VideoStreamConfig config,
SendVideoStream* send_stream,
size_t chosen_stream,
Transport* feedback_transport,
VideoFrameMatcher* matcher)
: receiver_(receiver), config_(config) {
if (config.encoder.codec ==
VideoStreamConfig::Encoder::Codec::kVideoCodecGeneric) {
decoder_factory_ = absl::make_unique<FunctionVideoDecoderFactory>(
[]() { return absl::make_unique<FakeDecoder>(); });
} else {
decoder_factory_ = absl::make_unique<InternalDecoderFactory>();
}
VideoReceiveStream::Decoder decoder =
CreateMatchingDecoder(CodecTypeToPayloadType(config.encoder.codec),
CodecTypeToPayloadString(config.encoder.codec));
decoder.decoder_factory = decoder_factory_.get();
size_t num_streams = 1;
if (config.encoder.codec == VideoStreamConfig::Encoder::Codec::kVideoCodecVP8)
num_streams = config.encoder.layers.spatial;
for (size_t i = 0; i < num_streams; ++i) {
rtc::VideoSinkInterface<VideoFrame>* renderer = &fake_renderer_;
if (matcher->Active()) {
render_taps_.emplace_back(absl::make_unique<DecodedFrameTap>(matcher, i));
renderer = render_taps_.back().get();
}
auto recv_config = CreateVideoReceiveStreamConfig(
config, feedback_transport, decoder, renderer,
receiver_->GetNextVideoLocalSsrc(), send_stream->ssrcs_[i],
send_stream->rtx_ssrcs_[i]);
if (config.stream.use_flexfec) {
RTC_DCHECK(num_streams == 1);
FlexfecReceiveStream::Config flexfec(feedback_transport);
flexfec.payload_type = CallTest::kFlexfecPayloadType;
flexfec.remote_ssrc = CallTest::kFlexfecSendSsrc;
flexfec.protected_media_ssrcs = send_stream->rtx_ssrcs_;
flexfec.local_ssrc = recv_config.rtp.local_ssrc;
receiver_->ssrc_media_types_[flexfec.remote_ssrc] = MediaType::VIDEO;
flecfec_stream_ = receiver_->call_->CreateFlexfecReceiveStream(flexfec);
}
receiver_->ssrc_media_types_[recv_config.rtp.remote_ssrc] =
MediaType::VIDEO;
if (config.stream.use_rtx)
receiver_->ssrc_media_types_[recv_config.rtp.rtx_ssrc] = MediaType::VIDEO;
receiver_->SendTask([this, &recv_config] {
receive_streams_.push_back(
receiver_->call_->CreateVideoReceiveStream(std::move(recv_config)));
});
}
}
ReceiveVideoStream::~ReceiveVideoStream() {
receiver_->SendTask([this] {
for (auto* recv_stream : receive_streams_)
receiver_->call_->DestroyVideoReceiveStream(recv_stream);
if (flecfec_stream_)
receiver_->call_->DestroyFlexfecReceiveStream(flecfec_stream_);
});
}
void ReceiveVideoStream::Start() {
receiver_->SendTask([this] {
for (auto* recv_stream : receive_streams_)
recv_stream->Start();
receiver_->call_->SignalChannelNetworkState(MediaType::VIDEO, kNetworkUp);
});
}
void ReceiveVideoStream::Stop() {
receiver_->SendTask([this] {
for (auto* recv_stream : receive_streams_)
recv_stream->Stop();
});
}
VideoReceiveStream::Stats ReceiveVideoStream::GetStats() const {
if (receive_streams_.empty())
return VideoReceiveStream::Stats();
// TODO(srte): Handle multiple receive streams.
return receive_streams_.front()->GetStats();
}
VideoStreamPair::~VideoStreamPair() = default;
VideoStreamPair::VideoStreamPair(CallClient* sender,
CallClient* receiver,
VideoStreamConfig config)
: config_(config),
matcher_(config.hooks.frame_pair_handlers),
send_stream_(sender, config, sender->transport_.get(), &matcher_),
receive_stream_(receiver,
config,
&send_stream_,
/*chosen_stream=*/0,
receiver->transport_.get(),
&matcher_) {}
} // namespace test
} // namespace webrtc