Alexa SDK庖丁解牛-第五回：Speaker管理

最新推荐文章于 2024-09-11 09:50:19 发布

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本文介绍了Alexa Speaker Manager的工作原理，包括初始化过程、指令处理流程及音量调整、静音等核心功能实现方式。

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 本节我们介绍下alexa的speaker管理：

 
 引言：
 从代码逻辑看speaker相关的SetVolum、AdjustVolum和SetMute是不考虑扬声器的类型（audioSpeaker ，speakSpeaker ，alertsSpeaker ），指令是不区分操作对象的，但是speaker有LOCAL，AVS_SYNCED之分，所有的指令只处理AVS_SYNCED类型的speaker，并把状态更新通知到AVS_SYNCED类型的被观察者对象，其实就是alert speaker不在处理范围之内，audiospeaker和speakSpeaker具体如何初始化音量相关操作还需要具体分析：

 
 1.初始化过程：

  m_speakerManager = capabilityAgents::speakerManager::SpeakerManager::create(

  {speakSpeaker, audioSpeaker, alertsSpeaker}, contextManager, m_connectionManager, exceptionSender);

  SpeakerManager构造函数中，把speakSpeaker, audioSpeaker, alertsSpeaker存到map中：

  for (auto speaker : speakers) {

  m_speakerMap.insert(

  std::pair<SpeakerInterface::Type, std::shared_ptr<SpeakerInterface>>(speaker->getSpeakerType(), speaker));

}

  他们的原型是：

  std::shared_ptr<alexaClientSDK::avsCommon::sdkInterfaces::SpeakerInterface> speakSpeaker =

  std::static_pointer_cast<alexaClientSDK::avsCommon::sdkInterfaces::SpeakerInterface>(m_speakMediaPlayer);

  std::shared_ptr<alexaClientSDK::avsCommon::sdkInterfaces::SpeakerInterface> audioSpeaker =

  std::static_pointer_cast<alexaClientSDK::avsCommon::sdkInterfaces::SpeakerInterface>(m_audioMediaPlayer);

  std::shared_ptr<alexaClientSDK::avsCommon::sdkInterfaces::SpeakerInterface> alertsSpeaker =

  std::static_pointer_cast<alexaClientSDK::avsCommon::sdkInterfaces::SpeakerInterface>(m_alertsMediaPlayer);

  配置：

  configuration[SET_VOLUME] = BlockingPolicy::NON_BLOCKING;

  configuration[ADJUST_VOLUME] = BlockingPolicy::NON_BLOCKING;

  configuration[SET_MUTE] = BlockingPolicy::NON_BLOCKING;

  2. 添加到观察者：

  m_directiveSequencer->addDirectiveHandler(m_speakerManager)

  =》

  DirectiveRouter::addDirectiveHandler()

  3. 指令处理过程：

  void DirectiveSequencer::receiveDirectiveLocked(std::unique_lock<std::mutex>& lock)
 
  =》
 
  handled = m_directiveRouter.handleDirectiveWithPolicyHandleImmediately(directive);
 
  if (!handled) {
 
  ACSDK_INFO(LX("receiveDirectiveLocked").d("test", "444"));
 
  //因为speak设置的是noblock模式，所以走这个分支
 
  handled =
   m_directiveProcessor->onDirective
  (directive);
 
  }
 
  =》
 
  DirectiveRouter::preHandleDirective()
 
  =》
 
  m_handlingQueue.push_back(directive);
 
  m_wakeProcessingLoop.notify_one();
 
  =》激活m_wakeProcessingLoop.wait()
 
  bool DirectiveProcessor::handleDirectiveLocked(std::unique_lock<std::mutex>& lock) 
 
  =》
 
  m_directiveRouter->handleDirective(directive, &policy);
 
  bool DirectiveRouter::handleDirective(）
 
  =》
 
  auto handlerAndPolicy = getHandlerAndPolicyLocked(directive);
 
  HandlerCallScope scope(lock, this, handlerAndPolicy.handler);
 
  auto result = handlerAndPolicy.handler->handleDirective(directive->getMessageId());

  =》

  void SpeakerManager::handleDirectiveImmediately(std::shared_ptr<AVSDirective> directive) {

  handleDirective(std::make_shared<DirectiveInfo>(directive, nullptr));

};

  3.1 speakerManager指令处理逻辑：

  void SpeakerManager::handleDirective(std::shared_ptr<CapabilityAgent::DirectiveInfo> info) 

 
 1）case:SET_MUTE：处理函数为executeSetMute & executeSetVolume

  （1）bool SpeakerManager::executeSetMute()

  =>bool MediaPlayer::setMute(bool mute)

  =>void MediaPlayer::handleSetMute()

{

  g_object_set(m_pipeline.volume, "mute", static_cast<gboolean>(mute), NULL);

}

  （2） bool SpeakerManager::executeSetVolume ()

  =>bool MediaPlayer::setVolume(int8_t volume)

  =>void MediaPlayer::handleSetVolume()

{

  g_object_set(m_pipeline.volume, "volume", gstVolume, NULL);

}

 
 2）case:ADJUST_VOLUME 处理函数为executeSetMute & executeAdjustVolume(在原有的音量上上调、下调音量)

  bool MediaPlayer::adjustVolume(int8_t delta) 

  =>void MediaPlayer::handleAdjustVolume(std::promise<bool>* promise, int8_t delta)

{

  gdouble gstVolume;

  g_object_get(m_pipeline.volume, "volume", &gstVolume, NULL);

  gdouble gstDelta;

  if (!toGstDeltaVolume->normalize(delta, &gstDelta)) {

  ACSDK_ERROR(LX("adjustVolumeFailed").d("reason", "normalizeVolumeFailed"));

  promise->set_value(false);

  return;

}

  gstVolume += gstDelta;

  // If adjustment exceeds bounds, cap at max/min.

  gstVolume = std::min(gstVolume, static_cast<gdouble>(GST_SET_VOLUME_MAX));

  gstVolume = std::max(gstVolume, static_cast<gdouble>(GST_SET_VOLUME_MIN));

  g_object_set(m_pipeline.volume, "volume", gstVolume, NULL);

}

3）case：SET_MUTE 处理函数为executeSetMute

 
 4）状态更新通知到AVS_SYNCED类型的被观察者对象：

  bool SpeakerManager::updateContextManager(）

{

  if (SetStateResult::SUCCESS !=

 
 m_contextManager->setState(VOLUME_STATE, buffer.GetString(), StateRefreshPolicy::NEVER)) {

  ACSDK_ERROR(LX("updateContextManagerFailed").d("reason", "contextManagerSetStateFailed"));

  return false;

}

}

  SetStateResult ContextManager::setState(

  const NamespaceAndName& stateProviderName,

  const std::string& jsonState,

  const StateRefreshPolicy& refreshPolicy,

  const unsigned int stateRequestToken) 