OpenHarmony音频流管理开发

1、OpenHarmony音频流管理开发简介

        AudioStreamManager提供了音频流管理的方法。开发者可以通过本博文了解应用如何通过AudioStreamManager管理音频流。

 2、OpenHarmony音频流管理运作机制

        该模块提供了音频流管理调用关系图

  图1 音频流管理调用关系图

         说明：在进行应用开发的过程中，开发者需要使用getStreamManager()创建一个AudioStreamManager实例，进而通过该实例管理音频流。开发者可通过调用on('audioRendererChange')、on('audioCapturerChange')监听音频播放应用和音频录制应用，在应用状态变化、设备变化、音频属性变化时获得通知。同时可通过off('audioRendererChange')、off('audioCapturerChange')取消相关事件的监听。与此同时，开发者可以通过调用（可选）使用getCurrentAudioRendererInfoArray()获取当前音频播放应用的音频流唯一ID、音频播放客户端的UID、音频状态等信息，同理可调用getCurrentAudioCapturerInfoArray()获取音频录制应用的信息。

3、OpenHarmony音频流管理开发开发指导

        详细API含义可参考：音频管理API文档AudioStreamManager

(1).创建AudioStreamManager实例。

        在使用AudioStreamManager的API前，需要使用getStreamManager()创建一个AudioStreamManager实例。

var audioManager = audio.getAudioManager();
var audioStreamManager = audioManager.getStreamManager();

(2).使用on（'audioRendererChange'）监听音频渲染器更改事件。 如果音频流监听应用需要在音频播放应用状态变化、设备变化、音频属性变化时获取通知，可以订阅该事件。更多事件请参考API参考文档。

audioStreamManager.on('audioRendererChange',  (AudioRendererChangeInfoArray) => {
  for (let i = 0; i < AudioRendererChangeInfoArray.length; i++) {
    AudioRendererChangeInfo = AudioRendererChangeInfoArray[i];
    console.info('## RendererChange on is called for ' + i + ' ##');
    console.info('StreamId for ' + i + ' is:' + AudioRendererChangeInfo.streamId);
    console.info('ClientUid for ' + i + ' is:' + AudioRendererChangeInfo.clientUid);
    console.info('Content for ' + i + ' is:' + AudioRendererChangeInfo.rendererInfo.content);
    console.info('Stream for ' + i + ' is:' + AudioRendererChangeInfo.rendererInfo.usage);
    console.info('Flag ' + i + ' is:' + AudioRendererChangeInfo.rendererInfo.rendererFlags);
    console.info('State for ' + i + ' is:' + AudioRendererChangeInfo.rendererState);  
    var devDescriptor = AudioRendererChangeInfo.deviceDescriptors;
    for (let j = 0; j < AudioRendererChangeInfo.deviceDescriptors.length; j++) {
      console.info('Id:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].id);
      console.info('Type:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].deviceType);
      console.info('Role:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].deviceRole);
      console.info('Name:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].name);
      console.info('Address:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].address);
      console.info('SampleRates:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].sampleRates[0]);
      console.info('ChannelCounts' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].channelCounts[0]);
      console.info('ChannelMask:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].channelMasks);
    }
  }
});

(3).使用off（'audioRendererChange'）取消监听音频渲染器更改事件。

audioStreamManager.off('audioRendererChange');
console.info('######### RendererChange Off is called #########');

(4).使用on（'audioCapturerChange'）监听音频捕获器更改事件。 如果音频流监听应用需要在音频录制应用状态变化、设备变化、音频属性变化时获取通知，可以订阅该事件。更多事件请参考API参考文档。

audioStreamManager.on('audioCapturerChange', (AudioCapturerChangeInfoArray) =>  {
  for (let i = 0; i < AudioCapturerChangeInfoArray.length; i++) {
    console.info(' ## audioCapturerChange on is called for element ' + i + ' ##');
    console.info('StreamId for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].streamId);
    console.info('ClientUid for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].clientUid);
    console.info('Source for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].capturerInfo.source);
    console.info('Flag ' + i + 'is:' + AudioCapturerChangeInfoArray[i].capturerInfo.capturerFlags);
    console.info('State for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].capturerState);  
    for (let j = 0; j < AudioCapturerChangeInfoArray[i].deviceDescriptors.length; j++) {
      console.info('Id:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].id);
      console.info('Type:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceType);
      console.info('Role:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceRole);
      console.info('Name:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].name);
      console.info('Address:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].address);
      console.info('SampleRates:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].sampleRates[0]);
      console.info('ChannelCounts' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelCounts[0]);
      console.info('ChannelMask:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelMasks);
    }
  }
});

(5).使用off（'audioCapturerChange'）取消监听音频捕获器更改事件。

audioStreamManager.off('audioCapturerChange');
console.info('######### CapturerChange Off is called #########');

(6).使用getCurrentAudioRendererInfoArray()获取当前音频渲染器的信息。 该接口可获取音频流唯一ID，音频播放客户端的UID，音频状态以及音频播放器的其他信息。需注意的是若对第三方音频流监听应用未配置ohos.permission.USE_BLUETOOTH权限，则查询到的设备名称和设备地址为空字符串，若正确配置权限，则显示的实际的设备名称和设备地址信息。

await audioStreamManager.getCurrentAudioRendererInfoArray().then( function (AudioRendererChangeInfoArray) {
  console.info('######### Get Promise is called ##########');
  if (AudioRendererChangeInfoArray != null) {
    for (let i = 0; i < AudioRendererChangeInfoArray.length; i++) {
      AudioRendererChangeInfo = AudioRendererChangeInfoArray[i];
      console.info('StreamId for ' + i +' is:' + AudioRendererChangeInfo.streamId);
      console.info('ClientUid for ' + i + ' is:' + AudioRendererChangeInfo.clientUid);
      console.info('Content ' + i + ' is:' + AudioRendererChangeInfo.rendererInfo.content);
      console.info('Stream' + i +' is:' + AudioRendererChangeInfo.rendererInfo.usage);
      console.info('Flag' + i + ' is:' + AudioRendererChangeInfo.rendererInfo.rendererFlags); 
      console.info('State for ' + i + ' is:' + AudioRendererChangeInfo.rendererState);  
      var devDescriptor = AudioRendererChangeInfo.deviceDescriptors;
      for (let j = 0; j < AudioRendererChangeInfo.deviceDescriptors.length; j++) {
        console.info('Id:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].id);
        console.info('Type:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].deviceType);
        console.info('Role:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].deviceRole);
        console.info('Name:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].name);
        console.info('Address:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].address);
        console.info('SampleRates:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].sampleRates[0]);
        console.info('ChannelCounts' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].channelCounts[0]);
        console.info('ChannelMask:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].channelMasks);
      }
    }
  }
}).catch((err) => {
  console.log('getCurrentAudioRendererInfoArray :ERROR: ' + err.message);
});

(7).使用getCurrentAudioCapturerInfoArray()获取当前音频捕获器的信息。 该接口可获取音频流唯一ID，音频录制客户端的UID，音频状态以及音频捕获器的其他信息。需注意的是若对第三方音频流监听应用未配置ohos.permission.USE_BLUETOOTH权限，则查询到的设备名称和设备地址为空字符串，若正确配置权限，则显示的实际的设备名称和设备地址信息。

await audioStreamManager.getCurrentAudioCapturerInfoArray().then( function (AudioCapturerChangeInfoArray) {
  console.info('getCurrentAudioCapturerInfoArray： **** Get Promise Called ****');
  if (AudioCapturerChangeInfoArray != null) {
    for (let i = 0; i < AudioCapturerChangeInfoArray.length; i++) {
      console.info('StreamId for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].streamId);
      console.info('ClientUid for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].clientUid);
      console.info('Source for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].capturerInfo.source);
      console.info('Flag ' + i + 'is:' + AudioCapturerChangeInfoArray[i].capturerInfo.capturerFlags);
      console.info('State for ' + i + 'is:' + AudioCapturerChangeInfoArray[i].capturerState);  
      var devDescriptor = AudioCapturerChangeInfoArray[i].deviceDescriptors;
      for (let j = 0; j < AudioCapturerChangeInfoArray[i].deviceDescriptors.length; j++) {
        console.info('Id:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].id);
        console.info('Type:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceType);
        console.info('Role:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceRole);
        console.info('Name:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].name)
        console.info('Address:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].address);
        console.info('SampleRates:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].sampleRates[0]);
        console.info('ChannelCounts' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelCounts[0]);
        console.info('ChannelMask:' + i + ':' + AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelMasks);
      }
    }
  }
}).catch((err) => {
  console.log('getCurrentAudioCapturerInfoArray :ERROR: ' + err.message);
});