1# 音频录制流管理
2
3对于录制音频类的应用,开发者需要关注该应用的音频流的状态以做出相应的操作,比如监听到状态为结束时,及时提示用户录制已结束。
4
5## 读取或监听应用内音频流状态变化
6
7参考[使用AudioCapturer开发音频录制功能](using-audiocapturer-for-recording.md)或[audio.createAudioCapturer](../../reference/apis-audio-kit/js-apis-audio.md#audiocreateaudiocapturer8),完成AudioCapturer的创建,然后可以通过以下两种方式查看音频流状态的变化:
8
9- 方法1:直接查看AudioCapturer的[state](../../reference/apis-audio-kit/js-apis-audio.md#属性):
10
11  ```ts
12  let audioCapturerState: audio.AudioState = audioCapturer.state;
13  console.info(`Current state is: ${audioCapturerState }`)
14  ```
15
16- 方法2:注册stateChange监听AudioCapturer的状态变化:
17
18  ```ts
19  audioCapturer.on('stateChange', (capturerState: audio.AudioState) => {
20    console.info(`State change to: ${capturerState}`)
21  });
22  ```
23
24获取state后可对照[AudioState](../../reference/apis-audio-kit/js-apis-audio.md#audiostate8)来进行相应的操作,比如显示录制结束的提示等。
25
26## 读取或监听所有录制流的变化
27
28如果部分应用需要查询获取所有音频流的变化信息,可以通过AudioStreamManager读取或监听所有音频流的变化。
29
30<!--Del-->
31> **说明:**
32>
33> 对于标记为系统接口(system api)的音频流变化信息需要系统级别应用才可查看,若应用不是系统应用,将无法获取准确信息。
34<!--DelEnd-->
35
36如下为音频流管理调用关系图:
37
38![Invoking relationship of recording stream management](figures/invoking-relationship-recording-stream-mgmt.png)
39
40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('audioCapturerChange')监听音频流的变化,在音频流状态变化、设备变化时获得通知,同时可通过off('audioCapturerChange')取消相关事件的监听。另外,开发者可以通过主动调用getCurrentAudioCapturerInfoArray()查询录制流的唯一ID、录制流客户端的UID、以及流状态等信息。
41
42详细API含义可参考[AudioStreamManager](../../reference/apis-audio-kit/js-apis-audio.md#audiostreammanager9)。
43
44
45## 开发步骤及注意事项
46
471. 创建AudioStreamManager实例。
48     在使用AudioStreamManager的API前,需要使用getStreamManager()创建一个AudioStreamManager实例。
49
50   ```ts
51   import { audio } from '@kit.AudioKit';
52   import { BusinessError } from '@kit.BasicServicesKit';
53
54   let audioManager = audio.getAudioManager();
55   let audioStreamManager = audioManager.getStreamManager();
56   ```
57
582. 使用on('audioCapturerChange')监听音频录制流更改事件。 如果音频流监听应用需要在音频录制流状态变化、设备变化时获取通知,可以订阅该事件。
59
60   ```ts
61   audioStreamManager.on('audioCapturerChange', (AudioCapturerChangeInfoArray: audio.AudioCapturerChangeInfoArray) =>  {
62     for (let i = 0; i < AudioCapturerChangeInfoArray.length; i++) {
63       console.info(`## CapChange on is called for element ${i} ##`);
64       console.info(`StreamId for ${i} is: ${AudioCapturerChangeInfoArray[i].streamId}`);
65       console.info(`Source for ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.source}`);
66       console.info(`Flag  ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.capturerFlags}`);
67       let devDescriptor: audio.AudioDeviceDescriptors = AudioCapturerChangeInfoArray[i].deviceDescriptors;
68       for (let j = 0; j < AudioCapturerChangeInfoArray[i].deviceDescriptors.length; j++) {
69         console.info(`Id: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].id}`);
70         console.info(`Type: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceType}`);
71         console.info(`Role: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceRole}`);
72         console.info(`Name: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].name}`);
73         console.info(`Address: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].address}`);
74         console.info(`SampleRates: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].sampleRates[0]}`);
75         console.info(`ChannelCounts ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelCounts[0]}`);
76         console.info(`ChannelMask: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelMasks}`);
77       }
78     }
79   });
80   ```
81
823. (可选)使用off('audioCapturerChange')取消监听音频录制流变化。
83
84   ```ts
85   audioStreamManager.off('audioCapturerChange');
86   console.info('CapturerChange Off is called');
87   ```
88
894. (可选)使用getCurrentAudioCapturerInfoArray()获取当前音频录制流的信息。
90     该接口可获取音频录制流唯一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。
91   > **说明:**
92   > 对所有音频流状态进行监听的应用需要[声明权限](../../security/AccessToken/declare-permissions.md)ohos.permission.USE_BLUETOOTH,否则无法获得实际的设备名称和设备地址信息,查询到的设备名称和设备地址(蓝牙设备的相关属性)将为空字符串。
93
94   ```ts
95   async function getCurrentAudioCapturerInfoArray(){
96     await audioStreamManager.getCurrentAudioCapturerInfoArray().then((AudioCapturerChangeInfoArray: audio.AudioCapturerChangeInfoArray) => {
97       console.info('getCurrentAudioCapturerInfoArray  Get Promise Called ');
98       if (AudioCapturerChangeInfoArray != null) {
99         for (let i = 0; i < AudioCapturerChangeInfoArray.length; i++) {
100           console.info(`StreamId for ${i} is: ${AudioCapturerChangeInfoArray[i].streamId}`);
101           console.info(`Source for ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.source}`);
102           console.info(`Flag  ${i} is: ${AudioCapturerChangeInfoArray[i].capturerInfo.capturerFlags}`);
103           for (let j = 0; j < AudioCapturerChangeInfoArray[i].deviceDescriptors.length; j++) {
104             console.info(`Id: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].id}`);
105             console.info(`Type: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceType}`);
106             console.info(`Role: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].deviceRole}`);
107             console.info(`Name: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].name}`);
108             console.info(`Address: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].address}`);
109             console.info(`SampleRates: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].sampleRates[0]}`);
110             console.info(`ChannelCounts ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelCounts[0]}`);
111             console.info(`ChannelMask: ${i} : ${AudioCapturerChangeInfoArray[i].deviceDescriptors[j].channelMasks}`);
112           }
113         }
114       }
115     }).catch((err: BusinessError) => {
116       console.error(`Invoke getCurrentAudioCapturerInfoArray failed, code is ${err.code}, message is ${err.message}`);
117     });
118   }
119   ```
120