audio-stream-manager.md

# 音频流管理开发指导

## 场景介绍

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

### 工作流程

在进行应用开发的过程中，建议开发者通过on('stateChange')方法订阅AudioCapturer的状态变更。因为针对AudioCapturer的某些操作，仅在音频采集器在固定状态时才能执行。如果应用在音频采集器处于错误状态时执行操作，系统可能会抛出异常或生成其他未定义的行为。

详细API含义可参考：[音频管理API文档AudioStreamManager](../reference/apis/js-apis-audio.md#AudioStreamManager9)

**图1** 音频流管理调用关系图

![](figures/zh-ch_image_audio_stream_manager.png)

## 开发步骤

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。

   ```js
  var audioStreamManager = audio.getStreamManager();
   ```

2. （可选）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](../reference/apis/js-apis-audio.md)。

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

   ```js
audioStreamManager.off('audioRendererChange');
console.info('[RENDERER-CHANGE-ON-001] ######### RendererChange Off is called #########');
   ```   

4. （可选）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](../reference/apis/js-apis-audio.md)。

   ```js
audioStreamManager.on('audioCapturerChange', (AudioCapturerChangeInfoArray) =>  {
  for (let i = 0; i < AudioCapturerChangeInfoArray.length; i++) {
    console.info(' ## CapChange 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. （可选）使用off（'audioCapturerChange'）取消监听音频捕获器更改事件。

   ```js
audioStreamManager.off('audioCapturerChange');
console.info('[GET_CAPTURER_STATE_2_PROMISE] ######### CapturerChange Off is called #########');
    ```  
6. （可选）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相关权限，则查询到的音频状态为0，音频播放器其他信息为null。
   ```js
await audioStreamManager.getCurrentAudioRendererInfoArray().then( function (AudioRendererChangeInfoArray) {
  console.info('[GET_RENDERER_STATE_3_PROMISE] ######### 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('ChannnelMask:' + i + ':' + AudioRendererChangeInfo.deviceDescriptors[j].channelMasks);
      }
    }
  }
}).catch((err) => {
  console.log('getCurrentAudioRendererInfoArray :ERROR: ' + err.message);
});
   ``` 

7. （可选）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相关权限，则查询到的音频状态为0，音频捕获器其他信息为null。
   ```js
await audioStreamManager.getCurrentAudioCapturerInfoArray().then( function (AudioCapturerChangeInfoArray) {
  console.info('AFCapturerChangeLog: [GET_CAP_STA_1_PR] **** 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);
});
   ```