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Signed-off-by: Nlwx1059628 <liyifan37@huawei.com>
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zh-cn/application-dev/media/audio-capturer.md 0 → 100644
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# AudioCapturer音频采集开发指南
# **场景介绍**
AudioCapturer提供了用于获取原始音频文件的方法。开发者可以通过本指导了解应用如何通过AudioCapturer采集音频。
## 注意事项
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。
## 状态检查
应用程序开发人员应该记住，AudioCapturer 是基于状态的。<br/>也就是说，AudioCapturer 有一个内部状态，应用程序在调用录制器控制 API 时必须始终检查该状态，因为某些操作仅在录制器处于给定状态时才可接受。
如果应用程序在录制器处于不正确状态时执行操作，系统可能会抛出错误/异常或生成其他未定义的行为。
## 开发步骤
1. 使用createAudioCapturer()创建一个AudioCapturer实例。<br/>在audioCapturerOptions中设置音频采集器的相关参数。该实例可用于音频采集、控制和获取采集状态，以及注册通知回调。
```
var audioStreamInfo = {
samplingRate: audio.AudioSamplingRate.SAMPLE_RATE_44100,
channels: audio.AudioChannel.CHANNEL_1,
sampleFormat: audio.AudioSampleFormat.SAMPLE_FORMAT_S16LE,
encodingType: audio.AudioEncodingType.ENCODING_TYPE_RAW
}
var audioCapturerInfo = {
source: audio.SourceType.SOURCE_TYPE_MIC,
capturerFlags: 1
}
var audioCapturerOptions = {
streamInfo: audioStreamInfo,
capturerInfo: audioCapturerInfo
}
let audioCapturer = await audio.createAudioCapturer(audioCapturerOptions);
var state = audioRenderer.state;
```
2. 调用start()方法来启动/恢复采集任务。
启动完成后，采集器状态将变更为STATE_RUNNING，然后应用可以开始读取缓冲区。
```
await audioCapturer.start();
if (audioCapturer.state == audio.AudioState.STATE_RUNNING) {
console.info('AudioRecLog: Capturer started');
} else {
console.info('AudioRecLog: Capturer start failed');
}
```
3. 使用getBufferSize()方法获取要读取的最小缓冲区大小。
```
var bufferSize = await audioCapturer.getBufferSize();
console.info('AudioRecLog: buffer size: ' + bufferSize);
```
4. 读取采集器的音频数据并将其转换为字节流。重复调用read()方法读取数据，直到应用准备停止采集。
参考以下示例，将采集到的数据写入文件。
```
import fileio from '@ohos.fileio';
const path = '/data/data/.pulse_dir/capture_js.wav';
let fd = fileio.openSync(path, 0o102, 0o777);
if (fd !== null) {
console.info('AudioRecLog: file fd created');
}
else{
console.info('AudioRecLog: file fd create : FAILED');
return;
}
fd = fileio.openSync(path, 0o2002, 0o666);
if (fd !== null) {
console.info('AudioRecLog: file fd opened in append mode');
}
var numBuffersToCapture = 150;
while (numBuffersToCapture) {
var buffer = await audioCapturer.read(bufferSize, true);
if (typeof(buffer) == undefined) {
console.info('read buffer failed');
} else {
var number = fileio.writeSync(fd, buffer);
console.info('AudioRecLog: data written: ' + number);
}
numBuffersToCapture--;
}
```
5. 采集完成后，调用stop方法，停止录制。
```
await audioCapturer.stop();
if (audioCapturer.state == audio.AudioState.STATE_STOPPED) {
console.info('AudioRecLog: Capturer stopped');
} else {
console.info('AudioRecLog: Capturer stop failed');
}
```
6. 任务结束，调用release()方法释放相关资源。
```
await audioCapturer.release();
if (audioCapturer.state == audio.AudioState.STATE_RELEASED) {
console.info('AudioRecLog: Capturer released');
} else {
console.info('AudioRecLog: Capturer release failed');
}
```
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zh-cn/application-dev/media/audio-renderer.md 0 → 100644
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# AudioRenderer音频渲染开发指导
## 场景介绍
AudioRenderer提供了渲染音频文件和控制播放的接口，开发者可以通过本指导，了解如何在输出设备中播放音频文件并管理播放任务。<br/>
同时，AudioRenderer支持音频中断的功能。<br/>
**音频中断：** 当优先级较高的音频流需要播放时，AudioRenderer会中断优先级较低的流。例如，当用户在收听音乐时有来电，则优先级较低音乐播放将被暂停，具体可参考[开发步骤](#开发步骤）。
## 状态检查：
您还应该记住，AudioRenderer 是基于状态的。
也就是说，AudioRenderer 有一个内部状态，在调用播放控制 API 时必须始终检查它，因为某些操作仅在音频播放器处于给定状态时才可接受。
如果您在不正确的状态下执行操作，系统可能会抛出错误/异常或生成其他未定义的行为。
## **异步操作：**
大多数AudioRenderer调用都是异步的。因此，UI线程不会被阻塞。<br/>对于每个API，框架都提供callback函数和promise函数。
在本例中，为了简单起见，使用了promise函数。[**js api audio.md**](../reference/apis/js-apis-audio.md)为callback和promise提供参考。
## 使用步骤
1. 使用createAudioRenderer()创建一个AudioRenderer实例。
在audioCapturerOptions中设置相关参数。该实例可用于音频渲染、控制和获取采集状态，以及注册通知回调。
```
var audioStreamInfo = {
samplingRate: audio.AudioSamplingRate.SAMPLE_RATE_44100,
channels: audio.AudioChannel.CHANNEL_1,
sampleFormat: audio.AudioSampleFormat.SAMPLE_FORMAT_S16LE,
encodingType: audio.AudioEncodingType.ENCODING_TYPE_RAW
}
var audioRendererInfo = {
content: audio.ContentType.CONTENT_TYPE_SPEECH,
usage: audio.StreamUsage.STREAM_USAGE_VOICE_COMMUNICATION,
rendererFlags: 1
}
var audioRendererOptions = {
streamInfo: audioStreamInfo,
rendererInfo: audioRendererInfo
}
let audioRenderer = await audio.createAudioRenderer(audioRendererOptions);
```
2. 使用on('interrupt')方法订阅音频中断事件。<br/>当优先级更高或相等的Stream-B请求激活并使用输出设备时，Stream-A被中断。
在某些情况下，框架会采取暂停播放、降低音量等强制操作，并通过InterruptEvent通知应用。在其他情况下，应用可以自行对InterruptEvent做出响应。<br/>
在音频中断的情况下，应用可能会碰到音频数据写入失败的问题。所以建议不感知、不处理中断的应用在写入音频数据前，使用audioRenderer.state检查播放器状态。而订阅音频中断事件，可以获取到更多详细信息，具体可参考[InterruptEvent](../reference/apis/js-apis-audio.md#interruptevent8)。
```
audioRenderer.on('interrupt', (interruptEvent) => {
console.info('InterruptEvent Received');
console.info('InterruptType: ' + interruptEvent.eventType);
console.info('InterruptForceType: ' + interruptEvent.forceType);
console.info('AInterruptHint: ' + interruptEvent.hintType);
if (interruptEvent.forceType == audio.InterruptForceType.INTERRUPT_FORCE) {
switch (interruptEvent.hintType) {
// Force Pause: Action was taken by framework.
// Halt the write calls to avoid data loss.
case audio.InterruptHint.INTERRUPT_HINT_PAUSE:
isPlay = false;
break;
// Force Stop: Action was taken by framework.
// Halt the write calls to avoid data loss.
case audio.InterruptHint.INTERRUPT_HINT_STOP:
isPlay = false;
break;
// Force Duck: Action was taken by framework,
// just notifying the app that volume has been reduced.
case audio.InterruptHint.INTERRUPT_HINT_DUCK:
break;
// Force Unduck: Action was taken by framework,
// just notifying the app that volume has been restored.
case audio.InterruptHint.INTERRUPT_HINT_UNDUCK:
break;
}
} else if (interruptEvent.forceType == audio.InterruptForceType.INTERRUPT_SHARE) {
switch (interruptEvent.hintType) {
// Share Resume: Action is to be taken by App.
// Resume the force paused stream if required.
case audio.InterruptHint.INTERRUPT_HINT_RESUME:
startRenderer();
break;
// Share Pause: Stream has been interrupted,
// It can choose to pause or play concurrently.
case audio.InterruptHint.INTERRUPT_HINT_PAUSE:
isPlay = false;
pauseRenderer();
break;
}
}
});
```
3. 调用start()方法来启动/恢复播放任务。
启动完成后，渲染器状态将变更为STATE_RUNNING，然后应用可以开始读取缓冲区。
```
async function startRenderer() {
var state = audioRenderer.state;
// state should be prepared, paused or stopped.
if (state != audio.AudioState.STATE_PREPARED || state != audio.AudioState.STATE_PAUSED ||
state != audio.AudioState.STATE_STOPPED) {
console.info('Renderer is not in a correct state to start');
return;
}
await audioRenderer.start();
state = audioRenderer.state;
if (state == audio.AudioState.STATE_RUNNING) {
console.info('Renderer started');
} else {
console.error('Renderer start failed');
}
}
```
4. 调用write()方法向缓冲区写入数据。
将需要播放的音频数据读入缓冲区，重复调用write()方法写入。
```
async function writeBuffer(buf) {
var state = audioRenderer.state;
if (state != audio.AudioState.STATE_RUNNING) {
console.error('Renderer is not running, do not write');
isPlay = false;
return;
}
let writtenbytes = await audioRenderer.write(buf);
console.info('Actual written bytes: ' + writtenbytes);
if (writtenbytes < 0) {
console.error('Write buffer failed. check the state of renderer');
}
}
// Reasonable minimum buffer size for renderer. However, the renderer can accept other read sizes as well.
const bufferSize = await audioRenderer.getBufferSize();
const path = '/data/file_example_WAV_2MG.wav';
let ss = fileio.createStreamSync(path, 'r');
const totalSize = 2146166; // file_example_WAV_2MG.wav
let rlen = 0;
let discardHeader = new ArrayBuffer(44);
ss.readSync(discardHeader);
rlen += 44;
var id = setInterval(() => {
if (isPlay || isRelease) {
if (rlen >= totalSize || isRelease) {
ss.closeSync();
stopRenderer();
clearInterval(id);
}
let buf = new ArrayBuffer(bufferSize);
rlen += ss.readSync(buf);
console.info('Total bytes read from file: ' + rlen);
writeBuffer(buf);
} else {
console.info('check after next interval');
}
} , 30); // interval to be set based on audio file format
```
5. （可选）调用pause()方法或stop()方法暂停/停止渲染音频数据。
```
async function pauseRenderer() {
var state = audioRenderer.state;
if (state != audio.AudioState.STATE_RUNNING) {
console.info('Renderer is not running');
return;
}
await audioRenderer.pause();
state = audioRenderer.state;
if (state == audio.AudioState.STATE_PAUSED) {
console.info('Renderer paused');
} else {
console.error('Renderer pause failed');
}
}
async function stopRenderer() {
var state = audioRenderer.state;
if (state != audio.AudioState.STATE_RUNNING || state != audio.AudioState.STATE_PAUSED) {
console.info('Renderer is not running or paused');
return;
}
await audioRenderer.stop();
state = audioRenderer.state;
if (state == audio.AudioState.STATE_STOPPED) {
console.info('Renderer stopped');
} else {
console.error('Renderer stop failed');
}
}
```
6. 任务完成，调用release()方法释放相关资源。
AudioRenderer会使用大量的系统资源，所以请确保完成相关任务后，进行资源释放。
```
async function releaseRenderer() {
if (state_ == RELEASED || state_ == NEW) {
console.info('Resourced already released');
return;
}
await audioRenderer.release();
state = audioRenderer.state;
if (state == STATE_RELEASED) {
console.info('Renderer released');
} else {
console.info('Renderer release failed');
}
}
```
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