text: /*
   *  Copyright (c) 2019 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.
   */
  
  #ifndef TEST_PC_E2E_ECHO_ECHO_EMULATION_H_
  #define TEST_PC_E2E_ECHO_ECHO_EMULATION_H_
  
  #include <atomic>
  #include <deque>
  #include <memory>
  #include <vector>
  
  #include "api/test/peerconnection_quality_test_fixture.h"
  #include "modules/audio_device/include/test_audio_device.h"
  #include "rtc_base/swap_queue.h"
  
  namespace webrtc {
  namespace webrtc_pc_e2e {
  
  // Reduces audio input strength from provided capturer twice and adds input
  // provided into EchoEmulatingCapturer::OnAudioRendered(...).
  class EchoEmulatingCapturer : public TestAudioDeviceModule::Capturer {
   public:
    EchoEmulatingCapturer(
        std::unique_ptr<TestAudioDeviceModule::Capturer> capturer,
        PeerConnectionE2EQualityTestFixture::EchoEmulationConfig config);
  
    void OnAudioRendered(rtc::ArrayView<const int16_t> data);
  
    int SamplingFrequency() const override {
      return delegate_->SamplingFrequency();
    }
    int NumChannels() const override { return delegate_->NumChannels(); }
    bool Capture(rtc::BufferT<int16_t>* buffer) override;
  
   private:
    std::unique_ptr<TestAudioDeviceModule::Capturer> delegate_;
    const PeerConnectionE2EQualityTestFixture::EchoEmulationConfig config_;
  
    SwapQueue<std::vector<int16_t>> renderer_queue_;
  
    SequenceChecker renderer_thread_;
    std::vector<int16_t> queue_input_ RTC_GUARDED_BY(renderer_thread_);
    bool recording_started_ RTC_GUARDED_BY(renderer_thread_) = false;
  
    SequenceChecker capturer_thread_;
    std::vector<int16_t> queue_output_ RTC_GUARDED_BY(capturer_thread_);
    bool delay_accumulated_ RTC_GUARDED_BY(capturer_thread_) = false;
  };
  
  // Renders output into provided renderer and also copy output into provided
  // EchoEmulationCapturer.
  class EchoEmulatingRenderer : public TestAudioDeviceModule::Renderer {
   public:
    EchoEmulatingRenderer(
        std::unique_ptr<TestAudioDeviceModule::Renderer> renderer,
        EchoEmulatingCapturer* echo_emulating_capturer);
  
    int SamplingFrequency() const override {
      return delegate_->SamplingFrequency();
    }
    int NumChannels() const override { return delegate_->NumChannels(); }
    bool Render(rtc::ArrayView<const int16_t> data) override;
  
   private:
    std::unique_ptr<TestAudioDeviceModule::Renderer> delegate_;
    EchoEmulatingCapturer* echo_emulating_capturer_;
  };
  
  }  // namespace webrtc_pc_e2e
  }  // namespace webrtc
  
  #endif  // TEST_PC_E2E_ECHO_ECHO_EMULATION_H_
  