应用可通过配置合适的音频流类型StreamUsage，根据系统默认的音频焦点策略，达到降低音量或同时播放的效果。
例如先播放STREAM_USAGE_MUSIC音乐音频，后播STREAM_USAGE_NAVIGATION导航音频可实现降低先播音频音量效果，详情可参考系统默认焦点策略表。
当系统默认焦点策略不满足应用焦点需求时，可通过音频会话（AudioSession）自定义本应用的焦点策略。
系统预设四种并发模式可按需选择：
详细使用步骤可参考官网使用AudioSession管理应用音频焦点(ArkTS)或者使用AudioSession管理应用音频焦点(C/C++)。
import { audio } from '@kit.AudioKit';
import { common } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';
let audioRenderer: audio.AudioRenderer;
let audioStreamInfo: audio.AudioStreamInfo = {
samplingRate: audio.AudioSamplingRate.SAMPLE_RATE_8000, // 采样率。
channels: audio.AudioChannel.CHANNEL_1, // 通道。
sampleFormat: audio.AudioSampleFormat.SAMPLE_FORMAT_S16LE, // 采样格式。
encodingType: audio.AudioEncodingType.ENCODING_TYPE_RAW // 编码格式。
};
let audioRendererInfo: audio.AudioRendererInfo = {
usage: audio.StreamUsage.STREAM_USAGE_MUSIC, // 音频流使用类型：音乐。根据业务场景配置，参考StreamUsage。
rendererFlags: 0 // 音频渲染器标志。
};
let audioRendererOptions: audio.AudioRendererOptions = {
streamInfo: audioStreamInfo,
rendererInfo: audioRendererInfo
};
let audioManager = audio.getAudioManager();
let audioSessionManager: audio.AudioSessionManager = audioManager.getSessionManager();
let strategy: audio.AudioSessionStrategy = {
concurrencyMode: audio.AudioConcurrencyMode.CONCURRENCY_DEFAULT
};
@Entry
@Component
export struct AudioSessionDemo {
context = this.getUIContext().getHostContext() as common.UIAbilityContext;
audioData: Uint8Array = generateTestPCM(); // 测试PCM数据，按需替换为其他音频数据源
writeOffset = 0;
async aboutToAppear(): Promise<void> {
audioRenderer = await audio.createAudioRenderer(audioRendererOptions);
await this.init(); //初始化
}
async aboutToDisappear(): Promise<void> {
try {
await audioSessionManager.deactivateAudioSession();
} catch (error) {
console.error(`deactivateAudioSession ${JSON.stringify(error)}`);
}
await audioRenderer.release();
}
build() {
Column({ space: 10 }) {
Select([{ value: '默认模式（CONCURRENCY_DEFAULT）' },
{ value: '并发模式（CONCURRENCY_MIX_WITH_OTHERS）' },
{ value: '降低音量模式（CONCURRENCY_DUCK_OTHERS）' },
{ value: '暂停模式（CONCURRENCY_PAUSE_OTHERS）' }])
.value('默认模式（CONCURRENCY_DEFAULT）')
.optionFont({ size: 12 })
.onSelect((index: number, text: string) => {
console.info('Select:' + index + text);
strategy = {
concurrencyMode: text === '并发模式（CONCURRENCY_MIX_WITH_OTHERS）' ?
audio.AudioConcurrencyMode.CONCURRENCY_MIX_WITH_OTHERS :
text === '降低音量模式（CONCURRENCY_DUCK_OTHERS）' ? audio.AudioConcurrencyMode.CONCURRENCY_DUCK_OTHERS :
text === '暂停模式（CONCURRENCY_PAUSE_OTHERS）' ? audio.AudioConcurrencyMode.CONCURRENCY_PAUSE_OTHERS :
audio.AudioConcurrencyMode.CONCURRENCY_DEFAULT
};
});
Button('激活AudioSession并播放')
.onClick(async () => {
console.info(`strategy: ${JSON.stringify(strategy)}}`);
try {
await audioSessionManager.activateAudioSession(strategy);
await this.stopAndFlush();
await audioRenderer.start();
} catch (error) {
console.error(`activateAudioSession ${JSON.stringify(error)}`);
}
});
Button('取消激活AudioSession并停止播放').onClick(async () => {
try {
await audioSessionManager.deactivateAudioSession();
await this.stopAndFlush();
} catch (error) {
console.error(`deactivateAudioSession ${JSON.stringify(error)}`);
}
});
}
.padding(20)
.justifyContent(FlexAlign.Center)
.width('100%')
.height('100%');
}
async init() {
audioRenderer.on('writeData', (buffer: ArrayBuffer) => {
if (!this.audioData) {
return audio.AudioDataCallbackResult.INVALID;
}
let bufferView = new Uint8Array(buffer);
let writeLen = Math.min(buffer.byteLength, this.audioData.byteLength - this.writeOffset);
if (writeLen <= 0) {
this.writeOffset = 0; //归零循环播放，测试用
console.info('Play Done');
return audio.AudioDataCallbackResult.INVALID;
}
bufferView.set(this.audioData.slice(this.writeOffset, this.writeOffset + writeLen));
this.writeOffset += writeLen;
return audio.AudioDataCallbackResult.VALID;
});
}
async stopAndFlush() {
console.info('renderer status' + audioRenderer.state);
audioRenderer.stop().then(() => {
console.error('Renderer stop ok.');
}).catch((err: BusinessError) => {
console.error('Renderer stop failed. ', err);
});
audioRenderer.flush().then(() => {
console.error('Renderer flush ok.');
}).catch((err: BusinessError) => {
console.error('renderer flush err. ' + err);
});
this.writeOffset = 0;
}
}
function generateTestPCM(): Uint8Array {
const sampleRate = 8000;
const noteDuration = 0.5;
const amplitude = 0.35;
const freqMap: Record<number, number> = {
1: 523.25, // C5
2: 587.33, // D5
3: 659.25, // E5
4: 698.46, // F5
5: 783.99, // G5
6: 880.00, // A5
};
const melody = [
1, 1, 5, 5, 6, 6, 5, 0,
4, 4, 3, 3, 2, 2, 1, 0,
5, 5, 4, 4, 3, 3, 2, 0
];
const samplesPerNote = Math.floor(sampleRate * noteDuration); // 4000
const totalSamples = samplesPerNote * melody.length; // 96,000
const buffer = new ArrayBuffer(totalSamples * 2); // 192,000 bytes
const view = new DataView(buffer);
let idx = 0;
for (const note of melody) {
const freq = note ? freqMap[note] : 0;
for (let i = 0; i < samplesPerNote; i++) {
const t = i / sampleRate;
const wave = freq ? amplitude * Math.sin(2 * Math.PI * freq * t) : 0;
const sample = Math.round(wave * 32767);
const clamped = Math.max(-32768, Math.min(32767, sample));
view.setInt16(idx * 2, clamped, true);
idx++;
}
}
return new Uint8Array(buffer);
}