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/*
* 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 "modules/audio_processing/aec/aec_core.h"
#include "modules/audio_processing/aec/echo_cancellation.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "test/gtest.h"
#include "typedefs.h" // NOLINT(build/include)
namespace webrtc {
namespace {
class SystemDelayTest : public ::testing::Test {
protected:
SystemDelayTest();
virtual void SetUp();
virtual void TearDown();
// Initialization of AEC handle with respect to |sample_rate_hz|. Since the
// device sample rate is unimportant we set that value to 48000 Hz.
void Init(int sample_rate_hz);
// Makes one render call and one capture call in that specific order.
void RenderAndCapture(int device_buffer_ms);
// Fills up the far-end buffer with respect to the default device buffer size.
size_t BufferFillUp();
// Runs and verifies the behavior in a stable startup procedure.
void RunStableStartup();
// Maps buffer size in ms into samples, taking the unprocessed frame into
// account.
int MapBufferSizeToSamples(int size_in_ms, bool extended_filter);
void* handle_;
Aec* self_;
size_t samples_per_frame_;
// Dummy input/output speech data.
static const int kSamplesPerChunk = 160;
float far_[kSamplesPerChunk];
float near_[kSamplesPerChunk];
float out_[kSamplesPerChunk];
const float* near_ptr_;
float* out_ptr_;
};
SystemDelayTest::SystemDelayTest()
: handle_(NULL), self_(NULL), samples_per_frame_(0) {
// Dummy input data are set with more or less arbitrary non-zero values.
for (int i = 0; i < kSamplesPerChunk; i++) {
far_[i] = 257.0;
near_[i] = 514.0;
}
memset(out_, 0, sizeof(out_));
near_ptr_ = near_;
out_ptr_ = out_;
}
void SystemDelayTest::SetUp() {
handle_ = WebRtcAec_Create();
ASSERT_TRUE(handle_);
self_ = reinterpret_cast<Aec*>(handle_);
}
void SystemDelayTest::TearDown() {
// Free AEC
WebRtcAec_Free(handle_);
handle_ = NULL;
}
// In SWB mode nothing is added to the buffer handling with respect to
// functionality compared to WB. We therefore only verify behavior in NB and WB.
static const int kSampleRateHz[] = {8000, 16000};
static const size_t kNumSampleRates =
sizeof(kSampleRateHz) / sizeof(*kSampleRateHz);
// Default audio device buffer size used.
static const int kDeviceBufMs = 100;
// Requirement for a stable device convergence time in ms. Should converge in
// less than |kStableConvergenceMs|.
static const int kStableConvergenceMs = 100;
// Maximum convergence time in ms. This means that we should leave the startup
// phase after |kMaxConvergenceMs| independent of device buffer stability
// conditions.
static const int kMaxConvergenceMs = 500;
void SystemDelayTest::Init(int sample_rate_hz) {
// Initialize AEC
EXPECT_EQ(0, WebRtcAec_Init(handle_, sample_rate_hz, 48000));
EXPECT_EQ(0, WebRtcAec_system_delay(self_->aec));
// One frame equals 10 ms of data.
samples_per_frame_ = static_cast<size_t>(sample_rate_hz / 100);
}
void SystemDelayTest::RenderAndCapture(int device_buffer_ms) {
EXPECT_EQ(0, WebRtcAec_BufferFarend(handle_, far_, samples_per_frame_));
EXPECT_EQ(0, WebRtcAec_Process(handle_, &near_ptr_, 1, &out_ptr_,
samples_per_frame_, device_buffer_ms, 0));
}
size_t SystemDelayTest::BufferFillUp() {
// To make sure we have a full buffer when we verify stability we first fill
// up the far-end buffer with the same amount as we will report in through
// Process().
size_t buffer_size = 0;
for (int i = 0; i < kDeviceBufMs / 10; i++) {
EXPECT_EQ(0, WebRtcAec_BufferFarend(handle_, far_, samples_per_frame_));
buffer_size += samples_per_frame_;
EXPECT_EQ(static_cast<int>(buffer_size),
WebRtcAec_system_delay(self_->aec));
}
return buffer_size;
}
void SystemDelayTest::RunStableStartup() {
// To make sure we have a full buffer when we verify stability we first fill
// up the far-end buffer with the same amount as we will report in through
// Process().
size_t buffer_size = BufferFillUp();
if (WebRtcAec_delay_agnostic_enabled(self_->aec) == 1) {
// In extended_filter mode we set the buffer size after the first processed
// 10 ms chunk. Hence, we don't need to wait for the reported system delay
// values to become stable.
RenderAndCapture(kDeviceBufMs);
buffer_size += samples_per_frame_;
EXPECT_EQ(0, self_->startup_phase);
} else {
// A stable device should be accepted and put in a regular process mode
// within |kStableConvergenceMs|.
int process_time_ms = 0;
for (; process_time_ms < kStableConvergenceMs; process_time_ms += 10) {
RenderAndCapture(kDeviceBufMs);
buffer_size += samples_per_frame_;
if (self_->startup_phase == 0) {
// We have left the startup phase.
break;
}
}
// Verify convergence time.
EXPECT_GT(kStableConvergenceMs, process_time_ms);
}
// Verify that the buffer has been flushed.
EXPECT_GE(static_cast<int>(buffer_size), WebRtcAec_system_delay(self_->aec));
}
int SystemDelayTest::MapBufferSizeToSamples(int size_in_ms,
bool extended_filter) {
// If extended_filter is disabled we add an extra 10 ms for the unprocessed
// frame. That is simply how the algorithm is constructed.
return static_cast<int>((size_in_ms + (extended_filter ? 0 : 10)) *
samples_per_frame_ / 10);
}
// The tests should meet basic requirements and not be adjusted to what is
// actually implemented. If we don't get good code coverage this way we either
// lack in tests or have unnecessary code.
// General requirements:
// 1) If we add far-end data the system delay should be increased with the same
// amount we add.
// 2) If the far-end buffer is full we should flush the oldest data to make room
// for the new. In this case the system delay is unaffected.
// 3) There should exist a startup phase in which the buffer size is to be
// determined. In this phase no cancellation should be performed.
// 4) Under stable conditions (small variations in device buffer sizes) the AEC
// should determine an appropriate local buffer size within
// |kStableConvergenceMs| ms.
// 5) Under unstable conditions the AEC should make a decision within
// |kMaxConvergenceMs| ms.
// 6) If the local buffer runs out of data we should stuff the buffer with older
// frames.
// 7) The system delay should within |kMaxConvergenceMs| ms heal from
// disturbances like drift, data glitches, toggling events and outliers.
// 8) The system delay should never become negative.
TEST_F(SystemDelayTest, CorrectIncreaseWhenBufferFarend) {
// When we add data to the AEC buffer the internal system delay should be
// incremented with the same amount as the size of data.
// This process should be independent of DA-AEC and extended_filter mode.
for (int extended_filter = 0; extended_filter <= 1; ++extended_filter) {
WebRtcAec_enable_extended_filter(self_->aec, extended_filter);
EXPECT_EQ(extended_filter, WebRtcAec_extended_filter_enabled(self_->aec));
for (int da_aec = 0; da_aec <= 1; ++da_aec) {
WebRtcAec_enable_delay_agnostic(self_->aec, da_aec);
EXPECT_EQ(da_aec, WebRtcAec_delay_agnostic_enabled(self_->aec));
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
// Loop through a couple of calls to make sure the system delay
// increments correctly.
for (int j = 1; j <= 5; j++) {
EXPECT_EQ(0,
WebRtcAec_BufferFarend(handle_, far_, samples_per_frame_));
EXPECT_EQ(static_cast<int>(j * samples_per_frame_),
WebRtcAec_system_delay(self_->aec));
}
}
}
}
}
// TODO(bjornv): Add a test to verify behavior if the far-end buffer is full
// when adding new data.
TEST_F(SystemDelayTest, CorrectDelayAfterStableStartup) {
// We run the system in a stable startup. After that we verify that the system
// delay meets the requirements.
// This process should be independent of DA-AEC and extended_filter mode.
for (int extended_filter = 0; extended_filter <= 1; ++extended_filter) {
WebRtcAec_enable_extended_filter(self_->aec, extended_filter);
EXPECT_EQ(extended_filter, WebRtcAec_extended_filter_enabled(self_->aec));
for (int da_aec = 0; da_aec <= 1; ++da_aec) {
WebRtcAec_enable_delay_agnostic(self_->aec, da_aec);
EXPECT_EQ(da_aec, WebRtcAec_delay_agnostic_enabled(self_->aec));
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
RunStableStartup();
// Verify system delay with respect to requirements, i.e., the
// |system_delay| is in the interval [75%, 100%] of what's reported on
// the average.
// In extended_filter mode we target 50% and measure after one processed
// 10 ms chunk.
int average_reported_delay =
static_cast<int>(kDeviceBufMs * samples_per_frame_ / 10);
EXPECT_GE(average_reported_delay, WebRtcAec_system_delay(self_->aec));
int lower_bound = WebRtcAec_extended_filter_enabled(self_->aec)
? (average_reported_delay / 2 -
rtc::checked_cast<int>(samples_per_frame_))
: average_reported_delay * 3 / 4;
EXPECT_LE(lower_bound, WebRtcAec_system_delay(self_->aec));
}
}
}
}
TEST_F(SystemDelayTest, CorrectDelayAfterUnstableStartup) {
// This test does not apply in extended_filter mode, since we only use the
// the first 10 ms chunk to determine a reasonable buffer size. Neither does
// it apply if DA-AEC is on because that overrides the startup procedure.
WebRtcAec_enable_extended_filter(self_->aec, 0);
EXPECT_EQ(0, WebRtcAec_extended_filter_enabled(self_->aec));
WebRtcAec_enable_delay_agnostic(self_->aec, 0);
EXPECT_EQ(0, WebRtcAec_delay_agnostic_enabled(self_->aec));
// In an unstable system we would start processing after |kMaxConvergenceMs|.
// On the last frame the AEC buffer is adjusted to 60% of the last reported
// device buffer size.
// We construct an unstable system by altering the device buffer size between
// two values |kDeviceBufMs| +- 25 ms.
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
// To make sure we have a full buffer when we verify stability we first fill
// up the far-end buffer with the same amount as we will report in on the
// average through Process().
size_t buffer_size = BufferFillUp();
int buffer_offset_ms = 25;
int reported_delay_ms = 0;
int process_time_ms = 0;
for (; process_time_ms <= kMaxConvergenceMs; process_time_ms += 10) {
reported_delay_ms = kDeviceBufMs + buffer_offset_ms;
RenderAndCapture(reported_delay_ms);
buffer_size += samples_per_frame_;
buffer_offset_ms = -buffer_offset_ms;
if (self_->startup_phase == 0) {
// We have left the startup phase.
break;
}
}
// Verify convergence time.
EXPECT_GE(kMaxConvergenceMs, process_time_ms);
// Verify that the buffer has been flushed.
EXPECT_GE(static_cast<int>(buffer_size),
WebRtcAec_system_delay(self_->aec));
// Verify system delay with respect to requirements, i.e., the
// |system_delay| is in the interval [60%, 100%] of what's last reported.
EXPECT_GE(static_cast<int>(reported_delay_ms * samples_per_frame_ / 10),
WebRtcAec_system_delay(self_->aec));
EXPECT_LE(
static_cast<int>(reported_delay_ms * samples_per_frame_ / 10 * 3 / 5),
WebRtcAec_system_delay(self_->aec));
}
}
TEST_F(SystemDelayTest, CorrectDelayAfterStableBufferBuildUp) {
// This test does not apply in extended_filter mode, since we only use the
// the first 10 ms chunk to determine a reasonable buffer size. Neither does
// it apply if DA-AEC is on because that overrides the startup procedure.
WebRtcAec_enable_extended_filter(self_->aec, 0);
EXPECT_EQ(0, WebRtcAec_extended_filter_enabled(self_->aec));
WebRtcAec_enable_delay_agnostic(self_->aec, 0);
EXPECT_EQ(0, WebRtcAec_delay_agnostic_enabled(self_->aec));
// In this test we start by establishing the device buffer size during stable
// conditions, but with an empty internal far-end buffer. Once that is done we
// verify that the system delay is increased correctly until we have reach an
// internal buffer size of 75% of what's been reported.
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
// We assume that running |kStableConvergenceMs| calls will put the
// algorithm in a state where the device buffer size has been determined. We
// can make that assumption since we have a separate stability test.
int process_time_ms = 0;
for (; process_time_ms < kStableConvergenceMs; process_time_ms += 10) {
EXPECT_EQ(0, WebRtcAec_Process(handle_, &near_ptr_, 1, &out_ptr_,
samples_per_frame_, kDeviceBufMs, 0));
}
// Verify that a buffer size has been established.
EXPECT_EQ(0, self_->checkBuffSize);
// We now have established the required buffer size. Let us verify that we
// fill up before leaving the startup phase for normal processing.
size_t buffer_size = 0;
size_t target_buffer_size = kDeviceBufMs * samples_per_frame_ / 10 * 3 / 4;
process_time_ms = 0;
for (; process_time_ms <= kMaxConvergenceMs; process_time_ms += 10) {
RenderAndCapture(kDeviceBufMs);
buffer_size += samples_per_frame_;
if (self_->startup_phase == 0) {
// We have left the startup phase.
break;
}
}
// Verify convergence time.
EXPECT_GT(kMaxConvergenceMs, process_time_ms);
// Verify that the buffer has reached the desired size.
EXPECT_LE(static_cast<int>(target_buffer_size),
WebRtcAec_system_delay(self_->aec));
// Verify normal behavior (system delay is kept constant) after startup by
// running a couple of calls to BufferFarend() and Process().
for (int j = 0; j < 6; j++) {
int system_delay_before_calls = WebRtcAec_system_delay(self_->aec);
RenderAndCapture(kDeviceBufMs);
EXPECT_EQ(system_delay_before_calls, WebRtcAec_system_delay(self_->aec));
}
}
}
TEST_F(SystemDelayTest, CorrectDelayWhenBufferUnderrun) {
// Here we test a buffer under run scenario. If we keep on calling
// WebRtcAec_Process() we will finally run out of data, but should
// automatically stuff the buffer. We verify this behavior by checking if the
// system delay goes negative.
// This process should be independent of DA-AEC and extended_filter mode.
for (int extended_filter = 0; extended_filter <= 1; ++extended_filter) {
WebRtcAec_enable_extended_filter(self_->aec, extended_filter);
EXPECT_EQ(extended_filter, WebRtcAec_extended_filter_enabled(self_->aec));
for (int da_aec = 0; da_aec <= 1; ++da_aec) {
WebRtcAec_enable_delay_agnostic(self_->aec, da_aec);
EXPECT_EQ(da_aec, WebRtcAec_delay_agnostic_enabled(self_->aec));
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
RunStableStartup();
// The AEC has now left the Startup phase. We now have at most
// |kStableConvergenceMs| in the buffer. Keep on calling Process() until
// we run out of data and verify that the system delay is non-negative.
for (int j = 0; j <= kStableConvergenceMs; j += 10) {
EXPECT_EQ(0, WebRtcAec_Process(handle_, &near_ptr_, 1, &out_ptr_,
samples_per_frame_, kDeviceBufMs, 0));
EXPECT_LE(0, WebRtcAec_system_delay(self_->aec));
}
}
}
}
}
TEST_F(SystemDelayTest, CorrectDelayDuringDrift) {
// This drift test should verify that the system delay is never exceeding the
// device buffer. The drift is simulated by decreasing the reported device
// buffer size by 1 ms every 100 ms. If the device buffer size goes below 30
// ms we jump (add) 10 ms to give a repeated pattern.
// This process should be independent of DA-AEC and extended_filter mode.
for (int extended_filter = 0; extended_filter <= 1; ++extended_filter) {
WebRtcAec_enable_extended_filter(self_->aec, extended_filter);
EXPECT_EQ(extended_filter, WebRtcAec_extended_filter_enabled(self_->aec));
for (int da_aec = 0; da_aec <= 1; ++da_aec) {
WebRtcAec_enable_delay_agnostic(self_->aec, da_aec);
EXPECT_EQ(da_aec, WebRtcAec_delay_agnostic_enabled(self_->aec));
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
RunStableStartup();
// We have left the startup phase and proceed with normal processing.
int jump = 0;
for (int j = 0; j < 1000; j++) {
// Drift = -1 ms per 100 ms of data.
int device_buf_ms = kDeviceBufMs - (j / 10) + jump;
int device_buf =
MapBufferSizeToSamples(device_buf_ms, extended_filter == 1);
if (device_buf_ms < 30) {
// Add 10 ms data, taking affect next frame.
jump += 10;
}
RenderAndCapture(device_buf_ms);
// Verify that the system delay does not exceed the device buffer.
EXPECT_GE(device_buf, WebRtcAec_system_delay(self_->aec));
// Verify that the system delay is non-negative.
EXPECT_LE(0, WebRtcAec_system_delay(self_->aec));
}
}
}
}
}
TEST_F(SystemDelayTest, ShouldRecoverAfterGlitch) {
// This glitch test should verify that the system delay recovers if there is
// a glitch in data. The data glitch is constructed as 200 ms of buffering
// after which the stable procedure continues. The glitch is never reported by
// the device.
// The system is said to be in a non-causal state if the difference between
// the device buffer and system delay is less than a block (64 samples).
// This process should be independent of DA-AEC and extended_filter mode.
for (int extended_filter = 0; extended_filter <= 1; ++extended_filter) {
WebRtcAec_enable_extended_filter(self_->aec, extended_filter);
EXPECT_EQ(extended_filter, WebRtcAec_extended_filter_enabled(self_->aec));
for (int da_aec = 0; da_aec <= 1; ++da_aec) {
WebRtcAec_enable_delay_agnostic(self_->aec, da_aec);
EXPECT_EQ(da_aec, WebRtcAec_delay_agnostic_enabled(self_->aec));
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
RunStableStartup();
int device_buf =
MapBufferSizeToSamples(kDeviceBufMs, extended_filter == 1);
// Glitch state.
for (int j = 0; j < 20; j++) {
EXPECT_EQ(0,
WebRtcAec_BufferFarend(handle_, far_, samples_per_frame_));
// No need to verify system delay, since that is done in a separate
// test.
}
// Verify that we are in a non-causal state, i.e.,
// |system_delay| > |device_buf|.
EXPECT_LT(device_buf, WebRtcAec_system_delay(self_->aec));
// Recover state. Should recover at least 4 ms of data per 10 ms, hence
// a glitch of 200 ms will take at most 200 * 10 / 4 = 500 ms to recover
// from.
bool non_causal = true; // We are currently in a non-causal state.
for (int j = 0; j < 50; j++) {
int system_delay_before = WebRtcAec_system_delay(self_->aec);
RenderAndCapture(kDeviceBufMs);
int system_delay_after = WebRtcAec_system_delay(self_->aec);
// We have recovered if
// |device_buf| - |system_delay_after| >= PART_LEN (1 block).
// During recovery, |system_delay_after| < |system_delay_before|,
// otherwise they are equal.
if (non_causal) {
EXPECT_LT(system_delay_after, system_delay_before);
if (device_buf - system_delay_after >= PART_LEN) {
non_causal = false;
}
} else {
EXPECT_EQ(system_delay_before, system_delay_after);
}
// Verify that the system delay is non-negative.
EXPECT_LE(0, WebRtcAec_system_delay(self_->aec));
}
// Check that we have recovered.
EXPECT_FALSE(non_causal);
}
}
}
}
TEST_F(SystemDelayTest, UnaffectedWhenSpuriousDeviceBufferValues) {
// This test does not apply in extended_filter mode, since we only use the
// the first 10 ms chunk to determine a reasonable buffer size.
const int extended_filter = 0;
WebRtcAec_enable_extended_filter(self_->aec, extended_filter);
EXPECT_EQ(extended_filter, WebRtcAec_extended_filter_enabled(self_->aec));
// Should be DA-AEC independent.
for (int da_aec = 0; da_aec <= 1; ++da_aec) {
WebRtcAec_enable_delay_agnostic(self_->aec, da_aec);
EXPECT_EQ(da_aec, WebRtcAec_delay_agnostic_enabled(self_->aec));
// This spurious device buffer data test aims at verifying that the system
// delay is unaffected by large outliers.
// The system is said to be in a non-causal state if the difference between
// the device buffer and system delay is less than a block (64 samples).
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
RunStableStartup();
int device_buf =
MapBufferSizeToSamples(kDeviceBufMs, extended_filter == 1);
// Normal state. We are currently not in a non-causal state.
bool non_causal = false;
// Run 1 s and replace device buffer size with 500 ms every 100 ms.
for (int j = 0; j < 100; j++) {
int system_delay_before_calls = WebRtcAec_system_delay(self_->aec);
int device_buf_ms = j % 10 == 0 ? 500 : kDeviceBufMs;
RenderAndCapture(device_buf_ms);
// Check for non-causality.
if (device_buf - WebRtcAec_system_delay(self_->aec) < PART_LEN) {
non_causal = true;
}
EXPECT_FALSE(non_causal);
EXPECT_EQ(system_delay_before_calls,
WebRtcAec_system_delay(self_->aec));
// Verify that the system delay is non-negative.
EXPECT_LE(0, WebRtcAec_system_delay(self_->aec));
}
}
}
}
TEST_F(SystemDelayTest, CorrectImpactWhenTogglingDeviceBufferValues) {
// This test aims at verifying that the system delay is "unaffected" by
// toggling values reported by the device.
// The test is constructed such that every other device buffer value is zero
// and then 2 * |kDeviceBufMs|, hence the size is constant on the average. The
// zero values will force us into a non-causal state and thereby lowering the
// system delay until we basically run out of data. Once that happens the
// buffer will be stuffed.
// TODO(bjornv): This test will have a better impact if we verified that the
// delay estimate goes up when the system delay goes down to meet the average
// device buffer size.
// This test does not apply if DA-AEC is enabled and extended_filter mode
// disabled.
for (int extended_filter = 0; extended_filter <= 1; ++extended_filter) {
WebRtcAec_enable_extended_filter(self_->aec, extended_filter);
EXPECT_EQ(extended_filter, WebRtcAec_extended_filter_enabled(self_->aec));
for (int da_aec = 0; da_aec <= 1; ++da_aec) {
WebRtcAec_enable_delay_agnostic(self_->aec, da_aec);
EXPECT_EQ(da_aec, WebRtcAec_delay_agnostic_enabled(self_->aec));
if (extended_filter == 0 && da_aec == 1) {
continue;
}
for (size_t i = 0; i < kNumSampleRates; i++) {
Init(kSampleRateHz[i]);
RunStableStartup();
const int device_buf =
MapBufferSizeToSamples(kDeviceBufMs, extended_filter == 1);
// Normal state. We are currently not in a non-causal state.
bool non_causal = false;
// Loop through 100 frames (both render and capture), which equals 1 s
// of data. Every odd frame we set the device buffer size to
// 2 * |kDeviceBufMs| and even frames we set the device buffer size to
// zero.
for (int j = 0; j < 100; j++) {
int system_delay_before_calls = WebRtcAec_system_delay(self_->aec);
int device_buf_ms = 2 * (j % 2) * kDeviceBufMs;
RenderAndCapture(device_buf_ms);
// Check for non-causality, compared with the average device buffer
// size.
non_causal |= (device_buf - WebRtcAec_system_delay(self_->aec) < 64);
EXPECT_GE(system_delay_before_calls,
WebRtcAec_system_delay(self_->aec));
// Verify that the system delay is non-negative.
EXPECT_LE(0, WebRtcAec_system_delay(self_->aec));
}
// Verify we are not in a non-causal state.
EXPECT_FALSE(non_causal);
}
}
}
}
} // namespace
} // namespace webrtc