[Chromoting] Move DefaultAudioDeviceChangeDetector out of AudioCapturerWin

remoting/host/audio_capturer_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/host/audio_capturer_win.h"
 
 #include <avrt.h>
 #include <mmreg.h>
 #include <mmsystem.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <windows.h>
 
 #include <algorithm>
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/synchronization/lock.h"
+#include "remoting/host/win/default_audio_device_change_detector.h"
 
 namespace {
 const int kChannels = 2;
 const int kBytesPerSample = 2;
 const int kBitsPerSample = kBytesPerSample * 8;
 // Conversion factor from 100ns to 1ms.
 const int k100nsPerMillisecond = 10000;
 
 // Tolerance for catching packets of silence. If all samples have absolute
 // value less than this threshold, the packet will be counted as a packet of
 // silence. A value of 2 was chosen, because Windows can give samples of 1 and
 // -1, even when no audio is playing.
 const int kSilenceThreshold = 2;
 
 // Lower bound for timer intervals, in milliseconds.
 const int kMinTimerInterval = 30;
 
 // Upper bound for the timer precision error, in milliseconds.
 // Timers are supposed to be accurate to 20ms, so we use 30ms to be safe.
 const int kMaxExpectedTimerLag = 30;
 }  // namespace
 
 namespace remoting {
 
-class AudioCapturerWin::MMNotificationClient : public IMMNotificationClient {
- public:
-  HRESULT __stdcall OnDefaultDeviceChanged(
-      EDataFlow flow,
-      ERole role,
-      LPCWSTR pwstrDefaultDevice) override {
-    base::AutoLock lock(lock_);
-    default_audio_device_changed_ = true;
-    return S_OK;
-  }
-
-  HRESULT __stdcall QueryInterface(REFIID iid, void** object) override {
-    if (iid == IID_IUnknown || iid == __uuidof(IMMNotificationClient)) {
-      *object = static_cast<IMMNotificationClient*>(this);
-      return S_OK;
-    }
-    *object = nullptr;
-    return E_NOINTERFACE;
-  }
-
-  // No Ops overrides.
-  HRESULT __stdcall OnDeviceAdded(LPCWSTR pwstrDeviceId) override {
-    return S_OK;
-  }
-  HRESULT __stdcall OnDeviceRemoved(LPCWSTR pwstrDeviceId) override {
-    return S_OK;
-  }
-  HRESULT __stdcall OnDeviceStateChanged(LPCWSTR pwstrDeviceId,
-                                         DWORD dwNewState) override {
-    return S_OK;
-  }
-  HRESULT __stdcall OnPropertyValueChanged(LPCWSTR pwstrDeviceId,
-                                           const PROPERTYKEY key) override {
-    return S_OK;
-  }
-  ULONG __stdcall AddRef() override { return 1; }
-  ULONG __stdcall Release() override { return 1; }
-
-  bool GetAndResetDefaultAudioDeviceChanged() {
-    base::AutoLock lock(lock_);
-    if (default_audio_device_changed_) {
-      default_audio_device_changed_ = false;
-      return true;
-    }
-    return false;
-  }
-
- private:
-  // |lock_| musted be locked when accessing |default_audio_device_changed_|.
-  bool default_audio_device_changed_ = false;
-  base::Lock lock_;
-};
-
 AudioCapturerWin::AudioCapturerWin()
     : sampling_rate_(AudioPacket::SAMPLING_RATE_INVALID),
       silence_detector_(kSilenceThreshold),
-      mm_notification_client_(new MMNotificationClient()),
       last_capture_error_(S_OK) {
   thread_checker_.DetachFromThread();
 }
 
 AudioCapturerWin::~AudioCapturerWin() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  if (audio_client_) {
-    audio_client_->Stop();
-  }
+  Deinitialize();
 }
 
 bool AudioCapturerWin::Start(const PacketCapturedCallback& callback) {
   callback_ = callback;
 
   if (!Initialize()) {
     return false;
   }
 
   // Initialize the capture timer and start capturing. Note, this timer won't
@@ skipping 11 matching lines @@
   if (!Initialize()) {
     Deinitialize();
     return false;
   }
   return true;
 }
 
 void AudioCapturerWin::Deinitialize() {
   DCHECK(thread_checker_.CalledOnValidThread());
   wave_format_ex_.Reset(nullptr);
-  mm_device_enumerator_.Reset();
+  default_device_detector_.reset();
   audio_capture_client_.Reset();
+  if (audio_client_) {
+    audio_client_->Stop();
+  }
   audio_client_.Reset();
   mm_device_.Reset();
   audio_volume_.Reset();
 }
 
 bool AudioCapturerWin::Initialize() {
   DCHECK(!audio_capture_client_.get());
   DCHECK(!audio_client_.get());
   DCHECK(!mm_device_.get());
   DCHECK(!audio_volume_.get());
   DCHECK(static_cast<PWAVEFORMATEX>(wave_format_ex_) == nullptr);
   DCHECK(thread_checker_.CalledOnValidThread());
 
   HRESULT hr = S_OK;
-  hr = mm_device_enumerator_.CreateInstance(__uuidof(MMDeviceEnumerator));
+  base::win::ScopedComPtr<IMMDeviceEnumerator> mm_device_enumerator;
+  hr = mm_device_enumerator.CreateInstance(__uuidof(MMDeviceEnumerator));
   if (FAILED(hr)) {
     LOG(ERROR) << "Failed to create IMMDeviceEnumerator. Error " << hr;
     return false;
   }
 
-  hr = mm_device_enumerator_->RegisterEndpointNotificationCallback(
-      mm_notification_client_.get());
-  if (FAILED(hr)) {
-    // We cannot predict which kind of error the API may return, but this is
-    // not a fatal error.
-    LOG(ERROR) << "Failed to register IMMNotificationClient. Error " << hr;
-  }
+  default_device_detector_.reset(
+      new DefaultAudioDeviceChangeDetector(mm_device_enumerator));
 
   // Get the audio endpoint.
-  hr = mm_device_enumerator_->GetDefaultAudioEndpoint(eRender, eConsole,
-                                                      mm_device_.Receive());
+  hr = mm_device_enumerator->GetDefaultAudioEndpoint(eRender, eConsole,
+                                                     mm_device_.Receive());
   if (FAILED(hr)) {
     LOG(ERROR) << "Failed to get IMMDevice. Error " << hr;
     return false;
   }
 
   // Get an audio client.
   hr = mm_device_->Activate(__uuidof(IAudioClient),
                             CLSCTX_ALL,
                             nullptr,
                             audio_client_.ReceiveVoid());
@@ skipping 184 matching lines @@
   packet->set_bytes_per_sample(AudioPacket::BYTES_PER_SAMPLE_2);
   packet->set_channels(AudioPacket::CHANNELS_STEREO);
 
   callback_.Run(std::move(packet));
 }
 
 void AudioCapturerWin::DoCapture() {
   DCHECK(AudioCapturer::IsValidSampleRate(sampling_rate_));
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  if (!is_initialized() ||
-      mm_notification_client_->GetAndResetDefaultAudioDeviceChanged()) {
+  if (!is_initialized() || default_device_detector_->GetAndReset()) {
     if (!ResetAndInitialize()) {
       // Initialization failed, we should wait for next DoCapture call.
       return;
     }
   }
 
   // Fetch all packets from the audio capture endpoint buffer.
   HRESULT hr = S_OK;
   while (true) {
     UINT32 next_packet_size;
@@ skipping 35 matching lines @@
 
 bool AudioCapturer::IsSupported() {
   return true;
 }
 
 std::unique_ptr<AudioCapturer> AudioCapturer::Create() {
   return base::WrapUnique(new AudioCapturerWin());
 }
 
 }  // namespace remoting