webrtc/modules/audio_processing/echo_control_mobile_impl.cc - src - Git at Google

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */

 #include "webrtc/modules/audio_processing/echo_control_mobile_impl.h"

 #include <string.h>

 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/audio_processing/aecm/echo_control_mobile.h"
 #include "webrtc/modules/audio_processing/audio_buffer.h"
 #include "webrtc/system_wrappers/include/logging.h"

 namespace webrtc {

 namespace {
 int16_t MapSetting(EchoControlMobile::RoutingMode mode) {
   switch (mode) {
     case EchoControlMobile::kQuietEarpieceOrHeadset:
       return 0;
     case EchoControlMobile::kEarpiece:
       return 1;
     case EchoControlMobile::kLoudEarpiece:
       return 2;
     case EchoControlMobile::kSpeakerphone:
       return 3;
     case EchoControlMobile::kLoudSpeakerphone:
       return 4;
   }
   RTC_DCHECK(false);
   return -1;
 }

 AudioProcessing::Error MapError(int err) {
   switch (err) {
     case AECM_UNSUPPORTED_FUNCTION_ERROR:
       return AudioProcessing::kUnsupportedFunctionError;
     case AECM_NULL_POINTER_ERROR:
       return AudioProcessing::kNullPointerError;
     case AECM_BAD_PARAMETER_ERROR:
       return AudioProcessing::kBadParameterError;
     case AECM_BAD_PARAMETER_WARNING:
       return AudioProcessing::kBadStreamParameterWarning;
     default:
       // AECM_UNSPECIFIED_ERROR
       // AECM_UNINITIALIZED_ERROR
       return AudioProcessing::kUnspecifiedError;
   }
 }
 // Maximum length that a frame of samples can have.
 static const size_t kMaxAllowedValuesOfSamplesPerFrame = 160;
 // Maximum number of frames to buffer in the render queue.
 // TODO(peah): Decrease this once we properly handle hugely unbalanced
 // reverse and forward call numbers.
 static const size_t kMaxNumFramesToBuffer = 100;
 }  // namespace

 size_t EchoControlMobile::echo_path_size_bytes() {
   return WebRtcAecm_echo_path_size_bytes();
 }

 struct EchoControlMobileImpl::StreamProperties {
   StreamProperties() = delete;
   StreamProperties(int sample_rate_hz,
                    size_t num_reverse_channels,
                    size_t num_output_channels)
       : sample_rate_hz(sample_rate_hz),
         num_reverse_channels(num_reverse_channels),
         num_output_channels(num_output_channels) {}

   int sample_rate_hz;
   size_t num_reverse_channels;
   size_t num_output_channels;
 };

 class EchoControlMobileImpl::Canceller {
  public:
   Canceller() {
     state_ = WebRtcAecm_Create();
     RTC_CHECK(state_);
   }

   ~Canceller() {
     RTC_DCHECK(state_);
     WebRtcAecm_Free(state_);
   }

   void* state() {
     RTC_DCHECK(state_);
     return state_;
   }

   void Initialize(int sample_rate_hz,
                   unsigned char* external_echo_path,
                   size_t echo_path_size_bytes) {
     RTC_DCHECK(state_);
     int error = WebRtcAecm_Init(state_, sample_rate_hz);
     RTC_DCHECK_EQ(AudioProcessing::kNoError, error);
     if (external_echo_path != NULL) {
       error = WebRtcAecm_InitEchoPath(state_, external_echo_path,
                                       echo_path_size_bytes);
       RTC_DCHECK_EQ(AudioProcessing::kNoError, error);
     }
   }

  private:
   void* state_;
   RTC_DISALLOW_COPY_AND_ASSIGN(Canceller);
 };

 EchoControlMobileImpl::EchoControlMobileImpl(rtc::CriticalSection* crit_render,
                                              rtc::CriticalSection* crit_capture)
     : crit_render_(crit_render),
       crit_capture_(crit_capture),
       routing_mode_(kSpeakerphone),
       comfort_noise_enabled_(true),
       external_echo_path_(NULL),
       render_queue_element_max_size_(0) {
   RTC_DCHECK(crit_render);
   RTC_DCHECK(crit_capture);
 }

 EchoControlMobileImpl::~EchoControlMobileImpl() {
     if (external_echo_path_ != NULL) {
       delete [] external_echo_path_;
       external_echo_path_ = NULL;
     }
 }

 int EchoControlMobileImpl::ProcessRenderAudio(const AudioBuffer* audio) {
   rtc::CritScope cs_render(crit_render_);
   if (!enabled_) {
     return AudioProcessing::kNoError;
   }

   RTC_DCHECK(stream_properties_);
   RTC_DCHECK_GE(160u, audio->num_frames_per_band());
   RTC_DCHECK_EQ(audio->num_channels(),
                 stream_properties_->num_reverse_channels);
   RTC_DCHECK_GE(cancellers_.size(), stream_properties_->num_output_channels *
                                         audio->num_channels());

   int err = AudioProcessing::kNoError;
   // The ordering convention must be followed to pass to the correct AECM.
   render_queue_buffer_.clear();
   int render_channel = 0;
   for (auto& canceller : cancellers_) {
     err = WebRtcAecm_GetBufferFarendError(
         canceller->state(),
         audio->split_bands_const(render_channel)[kBand0To8kHz],
         audio->num_frames_per_band());

     if (err != AudioProcessing::kNoError)
       return MapError(err);  // TODO(ajm): warning possible?);

     // Buffer the samples in the render queue.
     render_queue_buffer_.insert(
         render_queue_buffer_.end(),
         audio->split_bands_const(render_channel)[kBand0To8kHz],
         (audio->split_bands_const(render_channel)[kBand0To8kHz] +
          audio->num_frames_per_band()));
     render_channel = (render_channel + 1) % audio->num_channels();
   }

   // Insert the samples into the queue.
   if (!render_signal_queue_->Insert(&render_queue_buffer_)) {
     // The data queue is full and needs to be emptied.
     ReadQueuedRenderData();

     // Retry the insert (should always work).
     RTC_DCHECK_EQ(render_signal_queue_->Insert(&render_queue_buffer_), true);
   }

   return AudioProcessing::kNoError;
 }

 // Read chunks of data that were received and queued on the render side from
 // a queue. All the data chunks are buffered into the farend signal of the AEC.
 void EchoControlMobileImpl::ReadQueuedRenderData() {
   rtc::CritScope cs_capture(crit_capture_);
   RTC_DCHECK(stream_properties_);

   if (!enabled_) {
     return;
   }

   while (render_signal_queue_->Remove(&capture_queue_buffer_)) {
     size_t buffer_index = 0;
     size_t num_frames_per_band = capture_queue_buffer_.size() /
                                  (stream_properties_->num_output_channels *
                                   stream_properties_->num_reverse_channels);

     for (auto& canceller : cancellers_) {
       WebRtcAecm_BufferFarend(canceller->state(),
                               &capture_queue_buffer_[buffer_index],
                               num_frames_per_band);

       buffer_index += num_frames_per_band;
     }
   }
 }

 int EchoControlMobileImpl::ProcessCaptureAudio(AudioBuffer* audio,
                                                int stream_delay_ms) {
   rtc::CritScope cs_capture(crit_capture_);
   if (!enabled_) {
     return AudioProcessing::kNoError;
   }

   RTC_DCHECK(stream_properties_);
   RTC_DCHECK_GE(160u, audio->num_frames_per_band());
   RTC_DCHECK_EQ(audio->num_channels(), stream_properties_->num_output_channels);
   RTC_DCHECK_GE(cancellers_.size(), stream_properties_->num_reverse_channels *
                                         audio->num_channels());

   int err = AudioProcessing::kNoError;

   // The ordering convention must be followed to pass to the correct AECM.
   size_t handle_index = 0;
   for (size_t capture = 0; capture < audio->num_channels(); ++capture) {
     // TODO(ajm): improve how this works, possibly inside AECM.
     //            This is kind of hacked up.
     const int16_t* noisy = audio->low_pass_reference(capture);
     const int16_t* clean = audio->split_bands_const(capture)[kBand0To8kHz];
     if (noisy == NULL) {
       noisy = clean;
       clean = NULL;
     }
     for (size_t render = 0; render < stream_properties_->num_reverse_channels;
          ++render) {
       err = WebRtcAecm_Process(cancellers_[handle_index]->state(), noisy, clean,
                                audio->split_bands(capture)[kBand0To8kHz],
                                audio->num_frames_per_band(), stream_delay_ms);

       if (err != AudioProcessing::kNoError) {
         return MapError(err);
       }

       ++handle_index;
     }
     for (size_t band = 1u; band < audio->num_bands(); ++band) {
       memset(audio->split_bands(capture)[band],
              0,
              audio->num_frames_per_band() *
                  sizeof(audio->split_bands(capture)[band][0]));
     }
   }
   return AudioProcessing::kNoError;
 }

 int EchoControlMobileImpl::Enable(bool enable) {
   // Ensure AEC and AECM are not both enabled.
   rtc::CritScope cs_render(crit_render_);
   rtc::CritScope cs_capture(crit_capture_);
   RTC_DCHECK(stream_properties_);

   if (enable &&
       stream_properties_->sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
     return AudioProcessing::kBadSampleRateError;
   }

   if (enable && !enabled_) {
     enabled_ = enable;  // Must be set before Initialize() is called.

     // TODO(peah): Simplify once the Enable function has been removed from
     // the public APM API.
     Initialize(stream_properties_->sample_rate_hz,
                stream_properties_->num_reverse_channels,
                stream_properties_->num_output_channels);
   } else {
     enabled_ = enable;
   }
   return AudioProcessing::kNoError;
 }

 bool EchoControlMobileImpl::is_enabled() const {
   rtc::CritScope cs(crit_capture_);
   return enabled_;
 }

 int EchoControlMobileImpl::set_routing_mode(RoutingMode mode) {
   if (MapSetting(mode) == -1) {
     return AudioProcessing::kBadParameterError;
   }

   {
     rtc::CritScope cs(crit_capture_);
     routing_mode_ = mode;
   }
   return Configure();
 }

 EchoControlMobile::RoutingMode EchoControlMobileImpl::routing_mode()
     const {
   rtc::CritScope cs(crit_capture_);
   return routing_mode_;
 }

 int EchoControlMobileImpl::enable_comfort_noise(bool enable) {
   {
     rtc::CritScope cs(crit_capture_);
     comfort_noise_enabled_ = enable;
   }
   return Configure();
 }

 bool EchoControlMobileImpl::is_comfort_noise_enabled() const {
   rtc::CritScope cs(crit_capture_);
   return comfort_noise_enabled_;
 }

 int EchoControlMobileImpl::SetEchoPath(const void* echo_path,
                                        size_t size_bytes) {
   {
     rtc::CritScope cs_render(crit_render_);
     rtc::CritScope cs_capture(crit_capture_);
     if (echo_path == NULL) {
       return AudioProcessing::kNullPointerError;
     }
     if (size_bytes != echo_path_size_bytes()) {
       // Size mismatch
       return AudioProcessing::kBadParameterError;
     }

     if (external_echo_path_ == NULL) {
       external_echo_path_ = new unsigned char[size_bytes];
     }
     memcpy(external_echo_path_, echo_path, size_bytes);
   }

   // TODO(peah): Simplify once the Enable function has been removed from
   // the public APM API.
   RTC_DCHECK(stream_properties_);
   Initialize(stream_properties_->sample_rate_hz,
              stream_properties_->num_reverse_channels,
              stream_properties_->num_output_channels);
   return AudioProcessing::kNoError;
 }

 int EchoControlMobileImpl::GetEchoPath(void* echo_path,
                                        size_t size_bytes) const {
   rtc::CritScope cs(crit_capture_);
   if (echo_path == NULL) {
     return AudioProcessing::kNullPointerError;
   }
   if (size_bytes != echo_path_size_bytes()) {
     // Size mismatch
     return AudioProcessing::kBadParameterError;
   }
   if (!enabled_) {
     return AudioProcessing::kNotEnabledError;
   }

   // Get the echo path from the first channel
   int32_t err =
       WebRtcAecm_GetEchoPath(cancellers_[0]->state(), echo_path, size_bytes);
   if (err != 0) {
     return MapError(err);
   }

   return AudioProcessing::kNoError;
 }

 void EchoControlMobileImpl::Initialize(int sample_rate_hz,
                                        size_t num_reverse_channels,
                                        size_t num_output_channels) {
   rtc::CritScope cs_render(crit_render_);
   rtc::CritScope cs_capture(crit_capture_);

   stream_properties_.reset(new StreamProperties(
       sample_rate_hz, num_reverse_channels, num_output_channels));

   if (!enabled_) {
     return;
   }

   if (stream_properties_->sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
     LOG(LS_ERROR) << "AECM only supports 16 kHz or lower sample rates";
   }

   cancellers_.resize(num_handles_required());
   for (auto& canceller : cancellers_) {
     if (!canceller) {
       canceller.reset(new Canceller());
     }
     canceller->Initialize(sample_rate_hz, external_echo_path_,
                           echo_path_size_bytes());
   }

   Configure();

   AllocateRenderQueue();
 }

 void EchoControlMobileImpl::AllocateRenderQueue() {
   const size_t new_render_queue_element_max_size = std::max<size_t>(
       static_cast<size_t>(1),
       kMaxAllowedValuesOfSamplesPerFrame * num_handles_required());

   rtc::CritScope cs_render(crit_render_);
   rtc::CritScope cs_capture(crit_capture_);

   // Reallocate the queue if the queue item size is too small to fit the
   // data to put in the queue.
   if (render_queue_element_max_size_ < new_render_queue_element_max_size) {
     render_queue_element_max_size_ = new_render_queue_element_max_size;

     std::vector<int16_t> template_queue_element(render_queue_element_max_size_);

     render_signal_queue_.reset(
         new SwapQueue<std::vector<int16_t>, RenderQueueItemVerifier<int16_t>>(
             kMaxNumFramesToBuffer, template_queue_element,
             RenderQueueItemVerifier<int16_t>(render_queue_element_max_size_)));

     render_queue_buffer_.resize(render_queue_element_max_size_);
     capture_queue_buffer_.resize(render_queue_element_max_size_);
   } else {
     render_signal_queue_->Clear();
   }
 }

 int EchoControlMobileImpl::Configure() {
   rtc::CritScope cs_render(crit_render_);
   rtc::CritScope cs_capture(crit_capture_);
   AecmConfig config;
   config.cngMode = comfort_noise_enabled_;
   config.echoMode = MapSetting(routing_mode_);
   int error = AudioProcessing::kNoError;
   for (auto& canceller : cancellers_) {
     int handle_error = WebRtcAecm_set_config(canceller->state(), config);
     if (handle_error != AudioProcessing::kNoError) {
       error = handle_error;
     }
   }
   return error;
 }

 size_t EchoControlMobileImpl::num_handles_required() const {
   RTC_DCHECK(stream_properties_);
   return stream_properties_->num_output_channels *
          stream_properties_->num_reverse_channels;
 }
 }  // namespace webrtc
	/*
	* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/

	#include "webrtc/modules/audio_processing/echo_control_mobile_impl.h"

	#include <string.h>

	#include "webrtc/base/constructormagic.h"
	#include "webrtc/modules/audio_processing/aecm/echo_control_mobile.h"
	#include "webrtc/modules/audio_processing/audio_buffer.h"
	#include "webrtc/system_wrappers/include/logging.h"

	namespace webrtc {

	namespace {
	int16_t MapSetting(EchoControlMobile::RoutingMode mode) {
	switch (mode) {
	case EchoControlMobile::kQuietEarpieceOrHeadset:
	return 0;
	case EchoControlMobile::kEarpiece:
	return 1;
	case EchoControlMobile::kLoudEarpiece:
	return 2;
	case EchoControlMobile::kSpeakerphone:
	return 3;
	case EchoControlMobile::kLoudSpeakerphone:
	return 4;
	}
	RTC_DCHECK(false);
	return -1;
	}

	AudioProcessing::Error MapError(int err) {
	switch (err) {
	case AECM_UNSUPPORTED_FUNCTION_ERROR:
	return AudioProcessing::kUnsupportedFunctionError;
	case AECM_NULL_POINTER_ERROR:
	return AudioProcessing::kNullPointerError;
	case AECM_BAD_PARAMETER_ERROR:
	return AudioProcessing::kBadParameterError;
	case AECM_BAD_PARAMETER_WARNING:
	return AudioProcessing::kBadStreamParameterWarning;
	default:
	// AECM_UNSPECIFIED_ERROR
	// AECM_UNINITIALIZED_ERROR
	return AudioProcessing::kUnspecifiedError;
	}
	}
	// Maximum length that a frame of samples can have.
	static const size_t kMaxAllowedValuesOfSamplesPerFrame = 160;
	// Maximum number of frames to buffer in the render queue.
	// TODO(peah): Decrease this once we properly handle hugely unbalanced
	// reverse and forward call numbers.
	static const size_t kMaxNumFramesToBuffer = 100;
	} // namespace

	size_t EchoControlMobile::echo_path_size_bytes() {
	return WebRtcAecm_echo_path_size_bytes();
	}

	struct EchoControlMobileImpl::StreamProperties {
	StreamProperties() = delete;
	StreamProperties(int sample_rate_hz,
	size_t num_reverse_channels,
	size_t num_output_channels)
	: sample_rate_hz(sample_rate_hz),
	num_reverse_channels(num_reverse_channels),
	num_output_channels(num_output_channels) {}

	int sample_rate_hz;
	size_t num_reverse_channels;
	size_t num_output_channels;
	};

	class EchoControlMobileImpl::Canceller {
	public:
	Canceller() {
	state_ = WebRtcAecm_Create();
	RTC_CHECK(state_);
	}

	~Canceller() {
	RTC_DCHECK(state_);
	WebRtcAecm_Free(state_);
	}

	void* state() {
	RTC_DCHECK(state_);
	return state_;
	}

	void Initialize(int sample_rate_hz,
	unsigned char* external_echo_path,
	size_t echo_path_size_bytes) {
	RTC_DCHECK(state_);
	int error = WebRtcAecm_Init(state_, sample_rate_hz);
	RTC_DCHECK_EQ(AudioProcessing::kNoError, error);
	if (external_echo_path != NULL) {
	error = WebRtcAecm_InitEchoPath(state_, external_echo_path,
	echo_path_size_bytes);
	RTC_DCHECK_EQ(AudioProcessing::kNoError, error);
	}
	}

	private:
	void* state_;
	RTC_DISALLOW_COPY_AND_ASSIGN(Canceller);
	};

	EchoControlMobileImpl::EchoControlMobileImpl(rtc::CriticalSection* crit_render,
	rtc::CriticalSection* crit_capture)
	: crit_render_(crit_render),
	crit_capture_(crit_capture),
	routing_mode_(kSpeakerphone),
	comfort_noise_enabled_(true),
	external_echo_path_(NULL),
	render_queue_element_max_size_(0) {
	RTC_DCHECK(crit_render);
	RTC_DCHECK(crit_capture);
	}

	EchoControlMobileImpl::~EchoControlMobileImpl() {
	if (external_echo_path_ != NULL) {
	delete [] external_echo_path_;
	external_echo_path_ = NULL;
	}
	}

	int EchoControlMobileImpl::ProcessRenderAudio(const AudioBuffer* audio) {
	rtc::CritScope cs_render(crit_render_);
	if (!enabled_) {
	return AudioProcessing::kNoError;
	}

	RTC_DCHECK(stream_properties_);
	RTC_DCHECK_GE(160u, audio->num_frames_per_band());
	RTC_DCHECK_EQ(audio->num_channels(),
	stream_properties_->num_reverse_channels);
	RTC_DCHECK_GE(cancellers_.size(), stream_properties_->num_output_channels *
	audio->num_channels());

	int err = AudioProcessing::kNoError;
	// The ordering convention must be followed to pass to the correct AECM.
	render_queue_buffer_.clear();
	int render_channel = 0;
	for (auto& canceller : cancellers_) {
	err = WebRtcAecm_GetBufferFarendError(
	canceller->state(),
	audio->split_bands_const(render_channel)[kBand0To8kHz],
	audio->num_frames_per_band());

	if (err != AudioProcessing::kNoError)
	return MapError(err); // TODO(ajm): warning possible?);

	// Buffer the samples in the render queue.
	render_queue_buffer_.insert(
	render_queue_buffer_.end(),
	audio->split_bands_const(render_channel)[kBand0To8kHz],
	(audio->split_bands_const(render_channel)[kBand0To8kHz] +
	audio->num_frames_per_band()));
	render_channel = (render_channel + 1) % audio->num_channels();
	}

	// Insert the samples into the queue.
	if (!render_signal_queue_->Insert(&render_queue_buffer_)) {
	// The data queue is full and needs to be emptied.
	ReadQueuedRenderData();

	// Retry the insert (should always work).
	RTC_DCHECK_EQ(render_signal_queue_->Insert(&render_queue_buffer_), true);
	}

	return AudioProcessing::kNoError;
	}

	// Read chunks of data that were received and queued on the render side from
	// a queue. All the data chunks are buffered into the farend signal of the AEC.
	void EchoControlMobileImpl::ReadQueuedRenderData() {
	rtc::CritScope cs_capture(crit_capture_);
	RTC_DCHECK(stream_properties_);

	if (!enabled_) {
	return;
	}

	while (render_signal_queue_->Remove(&capture_queue_buffer_)) {
	size_t buffer_index = 0;
	size_t num_frames_per_band = capture_queue_buffer_.size() /
	(stream_properties_->num_output_channels *
	stream_properties_->num_reverse_channels);

	for (auto& canceller : cancellers_) {
	WebRtcAecm_BufferFarend(canceller->state(),
	&capture_queue_buffer_[buffer_index],
	num_frames_per_band);

	buffer_index += num_frames_per_band;
	}
	}
	}

	int EchoControlMobileImpl::ProcessCaptureAudio(AudioBuffer* audio,
	int stream_delay_ms) {
	rtc::CritScope cs_capture(crit_capture_);
	if (!enabled_) {
	return AudioProcessing::kNoError;
	}

	RTC_DCHECK(stream_properties_);
	RTC_DCHECK_GE(160u, audio->num_frames_per_band());
	RTC_DCHECK_EQ(audio->num_channels(), stream_properties_->num_output_channels);
	RTC_DCHECK_GE(cancellers_.size(), stream_properties_->num_reverse_channels *
	audio->num_channels());

	int err = AudioProcessing::kNoError;

	// The ordering convention must be followed to pass to the correct AECM.
	size_t handle_index = 0;
	for (size_t capture = 0; capture < audio->num_channels(); ++capture) {
	// TODO(ajm): improve how this works, possibly inside AECM.
	// This is kind of hacked up.
	const int16_t* noisy = audio->low_pass_reference(capture);
	const int16_t* clean = audio->split_bands_const(capture)[kBand0To8kHz];
	if (noisy == NULL) {
	noisy = clean;
	clean = NULL;
	}
	for (size_t render = 0; render < stream_properties_->num_reverse_channels;
	++render) {
	err = WebRtcAecm_Process(cancellers_[handle_index]->state(), noisy, clean,
	audio->split_bands(capture)[kBand0To8kHz],
	audio->num_frames_per_band(), stream_delay_ms);

	if (err != AudioProcessing::kNoError) {
	return MapError(err);
	}

	++handle_index;
	}
	for (size_t band = 1u; band < audio->num_bands(); ++band) {
	memset(audio->split_bands(capture)[band],
	0,
	audio->num_frames_per_band() *
	sizeof(audio->split_bands(capture)[band][0]));
	}
	}
	return AudioProcessing::kNoError;
	}

	int EchoControlMobileImpl::Enable(bool enable) {
	// Ensure AEC and AECM are not both enabled.
	rtc::CritScope cs_render(crit_render_);
	rtc::CritScope cs_capture(crit_capture_);
	RTC_DCHECK(stream_properties_);

	if (enable &&
	stream_properties_->sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
	return AudioProcessing::kBadSampleRateError;
	}

	if (enable && !enabled_) {
	enabled_ = enable; // Must be set before Initialize() is called.

	// TODO(peah): Simplify once the Enable function has been removed from
	// the public APM API.
	Initialize(stream_properties_->sample_rate_hz,
	stream_properties_->num_reverse_channels,
	stream_properties_->num_output_channels);
	} else {
	enabled_ = enable;
	}
	return AudioProcessing::kNoError;
	}

	bool EchoControlMobileImpl::is_enabled() const {
	rtc::CritScope cs(crit_capture_);
	return enabled_;
	}

	int EchoControlMobileImpl::set_routing_mode(RoutingMode mode) {
	if (MapSetting(mode) == -1) {
	return AudioProcessing::kBadParameterError;
	}

	{
	rtc::CritScope cs(crit_capture_);
	routing_mode_ = mode;
	}
	return Configure();
	}

	EchoControlMobile::RoutingMode EchoControlMobileImpl::routing_mode()
	const {
	rtc::CritScope cs(crit_capture_);
	return routing_mode_;
	}

	int EchoControlMobileImpl::enable_comfort_noise(bool enable) {
	{
	rtc::CritScope cs(crit_capture_);
	comfort_noise_enabled_ = enable;
	}
	return Configure();
	}

	bool EchoControlMobileImpl::is_comfort_noise_enabled() const {
	rtc::CritScope cs(crit_capture_);
	return comfort_noise_enabled_;
	}

	int EchoControlMobileImpl::SetEchoPath(const void* echo_path,
	size_t size_bytes) {
	{
	rtc::CritScope cs_render(crit_render_);
	rtc::CritScope cs_capture(crit_capture_);
	if (echo_path == NULL) {
	return AudioProcessing::kNullPointerError;
	}
	if (size_bytes != echo_path_size_bytes()) {
	// Size mismatch
	return AudioProcessing::kBadParameterError;
	}

	if (external_echo_path_ == NULL) {
	external_echo_path_ = new unsigned char[size_bytes];
	}
	memcpy(external_echo_path_, echo_path, size_bytes);
	}

	// TODO(peah): Simplify once the Enable function has been removed from
	// the public APM API.
	RTC_DCHECK(stream_properties_);
	Initialize(stream_properties_->sample_rate_hz,
	stream_properties_->num_reverse_channels,
	stream_properties_->num_output_channels);
	return AudioProcessing::kNoError;
	}

	int EchoControlMobileImpl::GetEchoPath(void* echo_path,
	size_t size_bytes) const {
	rtc::CritScope cs(crit_capture_);
	if (echo_path == NULL) {
	return AudioProcessing::kNullPointerError;
	}
	if (size_bytes != echo_path_size_bytes()) {
	// Size mismatch
	return AudioProcessing::kBadParameterError;
	}
	if (!enabled_) {
	return AudioProcessing::kNotEnabledError;
	}

	// Get the echo path from the first channel
	int32_t err =
	WebRtcAecm_GetEchoPath(cancellers_[0]->state(), echo_path, size_bytes);
	if (err != 0) {
	return MapError(err);
	}

	return AudioProcessing::kNoError;
	}

	void EchoControlMobileImpl::Initialize(int sample_rate_hz,
	size_t num_reverse_channels,
	size_t num_output_channels) {
	rtc::CritScope cs_render(crit_render_);
	rtc::CritScope cs_capture(crit_capture_);

	stream_properties_.reset(new StreamProperties(
	sample_rate_hz, num_reverse_channels, num_output_channels));

	if (!enabled_) {
	return;
	}

	if (stream_properties_->sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
	LOG(LS_ERROR) << "AECM only supports 16 kHz or lower sample rates";
	}

	cancellers_.resize(num_handles_required());
	for (auto& canceller : cancellers_) {
	if (!canceller) {
	canceller.reset(new Canceller());
	}
	canceller->Initialize(sample_rate_hz, external_echo_path_,
	echo_path_size_bytes());
	}

	Configure();

	AllocateRenderQueue();
	}

	void EchoControlMobileImpl::AllocateRenderQueue() {
	const size_t new_render_queue_element_max_size = std::max<size_t>(
	static_cast<size_t>(1),
	kMaxAllowedValuesOfSamplesPerFrame * num_handles_required());

	rtc::CritScope cs_render(crit_render_);
	rtc::CritScope cs_capture(crit_capture_);

	// Reallocate the queue if the queue item size is too small to fit the
	// data to put in the queue.
	if (render_queue_element_max_size_ < new_render_queue_element_max_size) {
	render_queue_element_max_size_ = new_render_queue_element_max_size;

	std::vector<int16_t> template_queue_element(render_queue_element_max_size_);

	render_signal_queue_.reset(
	new SwapQueue<std::vector<int16_t>, RenderQueueItemVerifier<int16_t>>(
	kMaxNumFramesToBuffer, template_queue_element,
	RenderQueueItemVerifier<int16_t>(render_queue_element_max_size_)));

	render_queue_buffer_.resize(render_queue_element_max_size_);
	capture_queue_buffer_.resize(render_queue_element_max_size_);
	} else {
	render_signal_queue_->Clear();
	}
	}

	int EchoControlMobileImpl::Configure() {
	rtc::CritScope cs_render(crit_render_);
	rtc::CritScope cs_capture(crit_capture_);
	AecmConfig config;
	config.cngMode = comfort_noise_enabled_;
	config.echoMode = MapSetting(routing_mode_);
	int error = AudioProcessing::kNoError;
	for (auto& canceller : cancellers_) {
	int handle_error = WebRtcAecm_set_config(canceller->state(), config);
	if (handle_error != AudioProcessing::kNoError) {
	error = handle_error;
	}
	}
	return error;
	}

	size_t EchoControlMobileImpl::num_handles_required() const {
	RTC_DCHECK(stream_properties_);
	return stream_properties_->num_output_channels *
	stream_properties_->num_reverse_channels;
	}
	} // namespace webrtc