文章旨在帮助大家开发录音及语音识别时少踩一点坑。
效果
左侧为简易UI布局及识别成果,右侧为网易云播放的测试音频。
开发步骤
IDE安装、项目创建等在此略过。App采用SDK版本为API 6,使用JS UI。
1.权限申请
AI语音识别不需要任何权限,但此处使用到麦克风录制音频,就需要申请麦克风权限。
在config.json配置文件中添加权限:
- "reqPermissions": [
- {
- "name": "ohos.permission.MICROPHONE"
- }
- ]
在MainAbility中显示申明麦克风权限:
- @Override
- public void onStart(Intent intent) {
- super.onStart(intent);
- requestPermission();
- }
- //获取权限
- private void requestPermission() {
- String[] permission = {
- "ohos.permission.MICROPHONE",
- };
- List<String> applyPermissions = new ArrayList<>();
- for (String element : permission) {
- if (verifySelfPermission(element) != 0) {
- if (canRequestPermission(element)) {
- applyPermissions.add(element);
- }
- }
- }
- requestPermissionsFromUser(applyPermissions.toArray(new String[0]), 0);
- }
2.创建音频录制的工具类
首先创建音频录制的工具类AudioCaptureUtils。
而音频录制需要用到AudioCapturer类,而在创建AudioCapture类时又会用到AudioStreamInfo类及AudioCapturerInfo类,所以我们分别申明以上3个类的变量。
- private AudioStreamInfo audioStreamInfo;
- private AudioCapturer audioCapturer;
- private AudioCapturerInfo audioCapturerInfo;
在语音识别时对音频的录制是由限制的,限制如下:
所以我们在录制音频时需要注意:
1.采样率16000HZ
2.声道为单声道
3.仅支持普通话
作为工具类,为了使AudioCaptureUtils能多处使用,我们在创建构造函数时,提供声道与频率的参数重载,并在构造函数中初始化AudioStreamInfo类及AudioCapturerInfo类。
- //channelMask 声道
- //SampleRate 频率
- public AudioCaptureUtils(AudioStreamInfo.ChannelMask channelMask, int SampleRate) {
- this.audioStreamInfo = new AudioStreamInfo.Builder()
- .encodingFormat(AudioStreamInfo.EncodingFormat.ENCODING_PCM_16BIT)
- .channelMask(channelMask)
- .sampleRate(SampleRate)
- .build();
- this.audioCapturerInfo = new AudioCapturerInfo.Builder().audioStreamInfo(audioStreamInfo).build();
- }
在init函数中进行audioCapturer的初始化,在初始化时对音效进行设置,默认为降噪模式。
- //packageName 包名
- public void init(String packageName) {
- this.init(SoundEffect.SOUND_EFFECT_TYPE_NS,packageName );
- }
- //soundEffect 音效uuid
- //packageName 包名
- public void init(UUID soundEffect, String packageName) {
- if (audioCapturer == null || audioCapturer.getState() == AudioCapturer.State.STATE_UNINITIALIZED)
- audioCapturer = new AudioCapturer(this.audioCapturerInfo);
- audioCapturer.addSoundEffect(soundEffect, packageName);
- }
初始化后提供start、stop和destory方法,分别开启音频录制、停止音频录制和销毁,此处都是调用AudioCapturer类中对应函数。
- public void stop(){
- this.audioCapturer.stop();
- }
- public void destory(){
- this.audioCapturer.stop();
- this.audioCapturer.release();
- }
- public Boolean start() {
- if (audioCapturer == null)
- return false;
- return audioCapturer.start();
- }
提供一个读取音频流的方法及获取AudioCapturer实例的方法。
- //buffers 需要写入的数据流
- //offset 数据流的偏移量
- //byteslength 数据流的长度
- public int read(byte[] buffers, int offset, int bytesLength){
- return audioCapturer.read(buffers,offset,bytesLength);
- }
- //获取AudioCapturer的实例audioCapturer
- public AudioCapturer get(){
- return this.audioCapturer;
- }
3.创建语音识别的工具类
在上面我们已经创建好一个音频录制的工具类,接下来在创建一个语音识别的工具类 AsrUtils。
我们再回顾一下语音识别的约束与限制:
在此补充一个隐藏限制,PCM流的长度只允许640与1280两种长度,也就是我们音频读取流时只能使用640与1280两种长度。
接下来我们定义一些基本常量:
- //采样率限定16000HZ
- private static final int VIDEO_SAMPLE_RATE = 16000;
- //VAD结束时间 默认2000ms
- private static final int VAD_END_WAIT_MS = 2000;
- //VAD起始时间 默认4800ms
- //这两参数与识别准确率有关,相关信息可百度查看,在此使用系统默认
- private static final int VAD_FRONT_WAIT_MS = 4800;
- //输入时常 20000ms
- private static final int TIMEOUT_DURATION = 20000;
- //PCM流长度仅限640或1280
- private static final int BYTES_LENGTH = 1280;
- //线程池相关参数
- private static final int CAPACITY = 6;
- private static final int ALIVE_TIME = 3;
- private static final int POOL_SIZE = 3;
因为要在后台持续录制音频,所以需要开辟一个新的线程。此处用到java的ThreadPoolExecutor类进行线程操作。
定义一个线程池实例以及其它相关属性如下:
- //录音线程
- private ThreadPoolExecutor poolExecutor;
- /* 自定义状态信息
- ** 错误:-1
- ** 初始:0
- ** init:1
- ** 开始输入:2
- ** 结束输入:3
- ** 识别结束:5
- ** 中途出识别结果:9
- ** 最终识别结果:10
- */
- public int state = 0;
- //识别结果
- public String result;
- //是否开启语音识别
- //当开启时才写入PCM流
- boolean isStarted = false;
- //ASR客户端
- private AsrClient asrClient;
- //ASR监听对象
- private AsrListener listener;
- AsrIntent asrIntent;
- //音频录制工具类
- private AudioCaptureUtils audioCaptureUtils;
在构造函数中初始化相关属性:
- public AsrUtils(Context context) {
- //实例化一个单声道,采集频率16000HZ的音频录制工具类实例
- this.audioCaptureUtils = new AudioCaptureUtils(AudioStreamInfo.ChannelMask.CHANNEL_IN_MONO, VIDEO_SAMPLE_RATE);
- //初始化降噪音效
- this.audioCaptureUtils.init("com.panda_coder.liedetector");
- //结果值设为空
- this.result = "";
- //给录音控件初始化一个新的线程池
- poolExecutor = new ThreadPoolExecutor(
- POOL_SIZE,
- POOL_SIZE,
- ALIVE_TIME,
- TimeUnit.SECONDS,
- new LinkedBlockingQueue<>(CAPACITY),
- new ThreadPoolExecutor.DiscardOldestPolicy());
- if (asrIntent == null) {
- asrIntent = new AsrIntent();
- //设置音频来源为PCM流
- //此处也可设置为文件
- asrIntent.setAudioSourceType(AsrIntent.AsrAudioSrcType.ASR_SRC_TYPE_PCM);
- asrIntent.setVadEndWaitMs(VAD_END_WAIT_MS);
- asrIntent.setVadFrontWaitMs(VAD_FRONT_WAIT_MS);
- asrIntent.setTimeoutThresholdMs(TIMEOUT_DURATION);
- }
- if (asrClient == null) {
- //实例化AsrClient
- asrClient = AsrClient.createAsrClient(context).orElse(null);
- }
- if (listener == null) {
- //实例化MyAsrListener
- listener = new MyAsrListener();
- //初始化AsrClient
- this.asrClient.init(asrIntent, listener);
- }
- }
- //够建一个实现AsrListener接口的类MyAsrListener
- class MyAsrListener implements AsrListener {
- @Override
- public void onInit(PacMap pacMap) {
- HiLog.info(TAG, "====== init");
- state = 1;
- }
- @Override
- public void onBeginningOfSpeech() {
- state = 2;
- }
- @Override
- public void onRmsChanged(float v) {
- }
- @Override
- public void onBufferReceived(byte[] bytes) {
- }
- @Override
- public void onEndOfSpeech() {
- state = 3;
- }
- @Override
- public void onError(int i) {
- state = -1;
- if (i == AsrError.ERROR_SPEECH_TIMEOUT) {
- //当超时时重新监听
- asrClient.startListening(asrIntent);
- } else {
- HiLog.info(TAG, "======error code:" + i);
- asrClient.stopListening();
- }
- }
- //注意与onIntermediateResults获取结果值的区别
- //pacMap.getString(AsrResultKey.RESULTS_RECOGNITION);
- @Override
- public void onResults(PacMap pacMap) {
- state = 10;
- //获取最终结果
- //{"result":[{"confidence":0,"ori_word":"你 好 ","pinyin":"NI3 HAO3 ","word":"你好。"}]}
- String results = pacMap.getString(AsrResultKey.RESULTS_RECOGNITION);
- ZSONObject zsonObject = ZSONObject.stringToZSON(results);
- ZSONObject infoObject;
- if (zsonObject.getZSONArray("result").getZSONObject(0) instanceof ZSONObject) {
- infoObject = zsonObject.getZSONArray("result").getZSONObject(0);
- String resultWord = infoObject.getString("ori_word").replace(" ", "");
- result += resultWord;
- }
- }
- //中途识别结果
- //pacMap.getString(AsrResultKey.RESULTS_INTERMEDIATE)
- @Override
- public void onIntermediateResults(PacMap pacMap) {
- state = 9;
- // String result = pacMap.getString(AsrResultKey.RESULTS_INTERMEDIATE);
- // if (result == null)
- // return;
- // ZSONObject zsonObject = ZSONObject.stringToZSON(result);
- // ZSONObject infoObject;
- // if (zsonObject.getZSONArray("result").getZSONObject(0) instanceof ZSONObject) {
- // infoObject = zsonObject.getZSONArray("result").getZSONObject(0);
- // String resultWord = infoObject.getString("ori_word").replace(" ", "");
- // HiLog.info(TAG, "=========== 9 " + resultWord);
- // }
- }
- @Override
- public void onEnd() {
- state = 5;
- //当还在录音时,重新监听
- if (isStarted)
- asrClient.startListening(asrIntent);
- }
- @Override
- public void onEvent(int i, PacMap pacMap) {
- }
- @Override
- public void onAudioStart() {
- state = 2;
- }
- @Override
- public void onAudioEnd() {
- state = 3;
- }
- }
开启识别与停止识别的函数:
- public void start() {
- if (!this.isStarted) {
- this.isStarted = true;
- asrClient.startListening(asrIntent);
- poolExecutor.submit(new AudioCaptureRunnable());
- }
- }
- public void stop() {
- this.isStarted = false;
- asrClient.stopListening();
- audioCaptureUtils.stop();
- }
- //音频录制的线程
- private class AudioCaptureRunnable implements Runnable {
- @Override
- public void run() {
- byte[] buffers = new byte[BYTES_LENGTH];
- //开启录音
- audioCaptureUtils.start();
- while (isStarted) {
- //读取录音的PCM流
- int ret = audioCaptureUtils.read(buffers, 0, BYTES_LENGTH);
- if (ret <= 0) {
- HiLog.error(TAG, "======Error read data");
- } else {
- //将录音的PCM流写入到语音识别服务中
- //若buffer的长度不为1280或640时,则需要手动处理成1280或640
- asrClient.writePcm(buffers, BYTES_LENGTH);
- }
- }
- }
- }
识别结果是通过listener的回调获取的结果,所以我们在处理时是将结果赋值给result,通过getresult或getResultAndClear函数获取结果。
- public String getResult() {
- return result;
- }
- public String getResultAndClear() {
- if (this.result == "")
- return "";
- String results = getResult();
- this.result = "";
- return results;
- }
4.创建一个简易的JS UI,并通过JS调ServerAbility的能力调用Java
hml代码:
- <div class="container">
- <div>
- <button class="btn" @touchend="start">开启</button>
- <button class="btn" @touchend="sub">订阅结果</button>
- <button class="btn" @touchend="stop">关闭</button>
- </div>
- <text class="title">
- 语音识别内容: {{ text }}
- </text>
- </div>
样式代码:
- .container {
- flex-direction: column;
- justify-content: flex-start;
- align-items: center;
- width: 100%;
- height: 100%;
- padding: 10%;
- }
- .title {
- font-size: 20px;
- color: #000000;
- opacity: 0.9;
- text-align: left;
- width: 100%;
- margin: 3% 0;
- }
- .btn{
- padding: 10px 20px;
- margin:3px;
- border-radius: 6px;
- }
js逻辑控制代码:
- //js调Java ServiceAbility的工具类
- import { jsCallJavaAbility } from '../../common/JsCallJavaAbilityUtils.js';
- export default {
- data: {
- text: ""
- },
- //开启事件
- start() {
- jsCallJavaAbility.callAbility("ControllerAbility",100,{}).then(result=>{
- console.log(result)
- })
- },
- //关闭事件
- stop() {
- jsCallJavaAbility.callAbility("ControllerAbility",101,{}).then(result=>{
- console.log(result)
- })
- jsCallJavaAbility.unSubAbility("ControllerAbility",201).then(result=>{
- if (result.code == 200) {
- console.log("取消订阅成功");
- }
- })
- },
- //订阅Java端结果事件
- sub() {
- jsCallJavaAbility.subAbility("ControllerAbility", 200, (data) => {
- let text = data.data.text
- text && (this.text += text)
- }).then(result => {
- if (result.code == 200) {
- console.log("订阅成功");
- }
- })
- }
- }
ServerAbility:
- public class ControllerAbility extends Ability {
- AnswerRemote remote = new AnswerRemote();
- AsrUtils asrUtils;
- //订阅事件的委托
- private static HashMap<Integer, IRemoteObject> remoteObjectHandlers = new HashMap<Integer, IRemoteObject>();
- @Override
- public void onStart(Intent intent) {
- HiLog.error(LABEL_LOG, "ControllerAbility::onStart");
- super.onStart(intent);
- //初始化语音识别工具类
- asrUtils = new AsrUtils(this);
- }
- @Override
- public void onCommand(Intent intent, boolean restart, int startId) {
- }
- @Override
- public IRemoteObject onConnect(Intent intent) {
- super.onConnect(intent);
- return remote.asObject();
- }
- class AnswerRemote extends RemoteObject implements IRemoteBroker {
- AnswerRemote() {
- super("");
- }
- @Override
- public boolean onRemoteRequest(int code, MessageParcel data, MessageParcel reply, MessageOption option) {
- Map<String, Object> zsonResult = new HashMap<String, Object>();
- String zsonStr = data.readString();
- ZSONObject zson = ZSONObject.stringToZSON(zsonStr);
- switch (code) {
- case 100: {
- //当js发送code为100时,开启语音识别
- asrUtils.start();
- break;
- }
- case 101: {
- //当js发送code为101时,关闭语音识别
- asrUtils.stop();
- break;
- }
- case 200: {
- //当js发送code为200时,订阅获取识别结果事件
- remoteObjectHandlers.put(200 ,data.readRemoteObject());
- //定时获取语音识别结果并返回JS UI
- getAsrText();
- break;
- }
- default: {
- reply.writeString("service not defined");
- return false;
- }
- }
- reply.writeString(ZSONObject.toZSONString(zsonResult));
- return true;
- }
- @Override
- public IRemoteObject asObject() {
- return this;
- }
- }
- public void getAsrText() {
- new Thread(() -> {
- while (true) {
- try {
- Thread.sleep(1 * 500);
- Map<String, Object> zsonResult = new HashMap<String, Object>();
- zsonResult.put("text",asrUtils.getResultAndClear());
- ReportEvent(200, zsonResult);
- } catch (RemoteException | InterruptedException e) {
- break;
- }
- }
- }).start();
- }
- private void ReportEvent(int remoteHandler, Object backData) throws RemoteException {
- MessageParcel data = MessageParcel.obtain();
- MessageParcel reply = MessageParcel.obtain();
- MessageOption option = new MessageOption();
- data.writeString(ZSONObject.toZSONString(backData));
- IRemoteObject remoteObject = remoteObjectHandlers.get(remoteHandler);
- remoteObject.sendRequest(100, data, reply, option);
- reply.reclaim();
- data.reclaim();
- }
- }
至此简易的语音识别功能完毕。
相关演示:https://www.bilibili.com/video/BV1E44y177hv/
完整代码开源:https://gitee.com/panda-coder/harmonyos-apps/tree/master/AsrDemo