harmony 鸿蒙Microphone Management

2023-06-24
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Microphone Management

The microphone is used to record audio data. To deliver an optimal recording effect, you are advised to query the microphone state before starting recording and listen for state changes during recording.

If the user mutes the microphone during audio recording, the recording process is normal, the size of the recorded file increases with the recording duration, but the data volume written into the file is 0.

How to Develop

The AudioVolumeGroupManager class provides APIs for managing the microphone state. For details, see API Reference.

Create an audioVolumeGroupManager object.

   import audio from '@ohos.multimedia.audio';

   let audioVolumeGroupManager: audio.AudioVolumeGroupManager;
   async function loadVolumeGroupManager() { // Create an audioVolumeGroupManager object.
     const groupid = audio.DEFAULT_VOLUME_GROUP_ID;
     audioVolumeGroupManager = await audio.getAudioManager().getVolumeManager().getVolumeGroupManager(groupid);
     console.info('audioVolumeGroupManager create success.');
   }

Call on(‘micStateChange’) to listen for microphone state changes. When the microphone state changes, the application will be notified of the change.

Currently, when multiple AudioManager instances are used in a single process, only the subscription of the last instance takes effect, and the subscription of other instances is overwritten (even if the last instance does not initiate a subscription). Therefore, you are advised to use a single AudioManager instance.

   async function on() {   // Subscribe to microphone state changes.
     audioVolumeGroupManager.on('micStateChange', (micStateChange: audio.MicStateChangeEvent) => {
       console.info(`Current microphone status is: ${micStateChange.mute} `);
     });
   }

Call isMicrophoneMute to check whether the microphone is muted. If the return value is true, the microphone is muted; otherwise, the microphone is not muted.

   async function isMicrophoneMute() { // Check whether the microphone is muted.
     await audioVolumeGroupManager.isMicrophoneMute().then((value: boolean) => {
       console.info(`isMicrophoneMute is: ${value}.`);
     });
   }

Call setMicrophoneMute to mute or unmute the microphone. To mute the microphone, pass in true. To unmute the microphone, pass in false.

   async function setMicrophoneMuteTrue() { // Pass in true to mute the microphone.
     await audioVolumeGroupManager.setMicrophoneMute(true).then(() => {
       console.info('setMicrophoneMute to mute.');
     });
   }
   async function setMicrophoneMuteFalse() { // Pass in false to unmute the microphone.
     await audioVolumeGroupManager.setMicrophoneMute(false).then(() => {
       console.info('setMicrophoneMute to not mute.');
     });
   }

Sample Code

Refer to the sample code below to complete the process of muting and unmuting the microphone.

   import audio from '@ohos.multimedia.audio';
   
   let audioVolumeGroupManager: audio.AudioVolumeGroupManager;
   
   async function loadVolumeGroupManager() {
        const groupid = audio.DEFAULT_VOLUME_GROUP_ID;
        audioVolumeGroupManager = await audio.getAudioManager().getVolumeManager().getVolumeGroupManager(groupid);
        console.info('audioVolumeGroupManager------create-------success.');
   }
   
   async function on() {   // Subscribe to microphone state changes.
     await loadVolumeGroupManager();
     audioVolumeGroupManager.on('micStateChange', (micStateChange) => {
       console.info(`Current microphone status is: ${micStateChange.mute} `);
     });
   }
   async function isMicrophoneMute() { // Check whether the microphone is muted.
     await audioVolumeGroupManager.isMicrophoneMute().then((value) => {
       console.info(`isMicrophoneMute is: ${value}.`);
     });
   }
   async function setMicrophoneMuteTrue() { // Mute the microphone.
     await loadVolumeGroupManager();
     await audioVolumeGroupManager.setMicrophoneMute(true).then(() => {
       console.info('setMicrophoneMute to mute.');
     });
   }
   async function setMicrophoneMuteFalse() { // Unmute the microphone.
     await loadVolumeGroupManager();
     await audioVolumeGroupManager.setMicrophoneMute(false).then(() => {
       console.info('setMicrophoneMute to not mute.');
     });
   }
   async function test(){
     await on();
     await isMicrophoneMute();
     await setMicrophoneMuteTrue();
     await isMicrophoneMute();
     await setMicrophoneMuteFalse();
     await isMicrophoneMute();
     await setMicrophoneMuteTrue();
     await isMicrophoneMute();
   }