音頻錄制流管理

讀取或監(jiān)聽?wèi)?yīng)用內(nèi)音頻流狀態(tài)變化

參考使用AudioCapturer開發(fā)音頻錄制功能或audio.createAudioCapturer，完成AudioCapturer的創(chuàng)建，然后可以通過以下兩種方式查看音頻流狀態(tài)的變化：

• 方法1：直接查看AudioCapturer的state：

  let audioCapturerState = audioCapturer.state;
  console.info(`Current state is: ${audioCapturerState }`)

• 方法2：注冊stateChange監(jiān)聽AudioCapturer的狀態(tài)變化：

  audioCapturer.on('stateChange', (capturerState) => {
    console.info(`State change to: ${capturerState}`)
  });

獲取state后可對照AudioState來進(jìn)行相應(yīng)的操作，比如顯示錄制結(jié)束的提示等。

讀取或監(jiān)聽所有錄制流的變化

如果部分應(yīng)用需要查詢獲取所有音頻流的變化信息，可以通過AudioStreamManager讀取或監(jiān)聽所有音頻流的變化。

如下為音頻流管理調(diào)用關(guān)系圖：

在進(jìn)行應(yīng)用開發(fā)的過程中，開發(fā)者需要使用getStreamManager()創(chuàng)建一個AudioStreamManager實(shí)例，進(jìn)而通過該實(shí)例管理音頻流。開發(fā)者可通過調(diào)用on('audioCapturerChange')監(jiān)聽音頻流的變化，在音頻流狀態(tài)變化、設(shè)備變化時獲得通知，同時可通過off('audioCapturerChange')取消相關(guān)事件的監(jiān)聽。另外，開發(fā)者可以通過主動調(diào)用getCurrentAudioCapturerInfoArray()查詢錄制流的唯一ID、錄制流客戶端的UID、以及流狀態(tài)等信息。

詳細(xì)API含義可參考音頻管理API文檔AudioStreamManager。

開發(fā)步驟及注意事項(xiàng)

1. 創(chuàng)建AudioStreamManager實(shí)例。
   在使用AudioStreamManager的API前，需要使用getStreamManager()創(chuàng)建一個AudioStreamManager實(shí)例。

   import audio from '@ohos.multimedia.audio';
   let audioManager = audio.getAudioManager();
   let audioStreamManager = audioManager.getStreamManager();

2. 使用on('audioCapturerChange')監(jiān)聽音頻錄制流更改事件。 如果音頻流監(jiān)聽?wèi)?yīng)用需要在音頻錄制流狀態(tài)變化、設(shè)備變化時獲取通知，可以訂閱該事件。

   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(`Source for ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.source}`);
       console.info(`Flag  ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.capturerFlags}`);
       let 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}`);
       }
     }
   });

3. （可選）使用off('audioCapturerChange')取消監(jiān)聽音頻錄制流變化。

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

4. （可選）使用getCurrentAudioCapturerInfoArray()獲取當(dāng)前音頻錄制流的信息。
   該接口可獲取音頻錄制流唯一ID，音頻錄制客戶端的UID，音頻狀態(tài)以及音頻捕獲器的其他信息。

   說明

   對所有音頻流狀態(tài)進(jìn)行監(jiān)聽的應(yīng)用需要申請權(quán)限ohos.permission.USE_BLUETOOTH，否則無法獲得實(shí)際的設(shè)備名稱和設(shè)備地址信息，查詢到的設(shè)備名稱和設(shè)備地址（藍(lán)牙設(shè)備的相關(guān)屬性）將為空字符串。

   async function getCurrentAudioCapturerInfoArray(){
     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(`Source for ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.source}`);
           console.info(`Flag  ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.capturerFlags}`);
           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.error(`Invoke getCurrentAudioCapturerInfoArray failed, code is ${err.code}, message is ${err.message}`);
     });
   }