前言
在 Android 中，TTS全称叫做 Text to Speech，从字面就能理解它解决的问题是什么，把文本转为语音服务，意思就是你输入一段文本信息，然后Android 系统可以把这段文字播报出来。这种应用场景目前比较多是在各种语音助手APP上，很多手机系统集成商内部都有内置文本转语音服务，可以读当前页面上的文本信息。同样，在一些阅读类APP上我们也能看到相关服务，打开微信读书，里面就直接可以把当前页面直接用语音方式播放出来，特别适合哪种不方便拿着手机屏幕阅读的场景。
Android系统从1.6版本开始就支持TTS, 不过遗憾的是系统默认的TTS引擎:Pico TTS，并不支持中文。
在查找了许相关资料后, 发现很多的资源都已经失效, APK找不到, 对应的页面404. 更多的厂商则转成了开放平台甚至不再提供离线/免费服务.
目前找到的离线TTS
注:下面的链接可能需要科学上网才可以访问
| 应用名称 | 支持离线 | 备注 | 下载地址 |
|---|---|---|---|
| ITRI TTS | 是 | 无 | 下载 |
| 讯飞语记 | 是 | 需打开一次, 但不需要登陆 | 下载 |
| 科大讯飞语音引擎3.0 | 是 | 推荐 | 下载 |
| Speech Services by Google | 否 | 需要科学上网, 离线需要先下载语音包 | 下载 |
使用
首先, 安装对应的TTS应用, 再在设置中设置对应的语音输出服务
一般设置的步骤为: 设置>无障碍>文字转语音(TTS)输出
程序调用只需使用SDK标准的TTS接口即可.
在介绍TTS使用的文章中, 下面这一段的代码, 对于前面的科大讯飞或ITRI TTS并没什么效果, 只是多了一个弹窗, 当然, 也可以理解为, 这两个APP并没有按标准接口开发.
//显示应用选择窗.
Intent checkIntent = new Intent();
checkIntent.setAction(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA);
startActivityForResult(checkIntent, MY_DATA_CHECK_CODE);
private TextToSpeech mTts;
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
if (requestCode == MY_DATA_CHECK_CODE) {
if (resultCode == TextToSpeech.Engine.CHECK_VOICE_DATA_PASS) {
// success, create the TTS instance
mTts = new TextToSpeech(this, this);
} else {
// missing data, install it
Intent installIntent = new Intent();
installIntent.setAction(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);
startActivity(installIntent);
}
}
}
在程序中打印TTS所支持的语言及声音getAvailableLanguages和getVoices:
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
Set<Locale> ava = mTts.getAvailableLanguages();
if (ava != null) {
for (Locale l : ava) {
Logger.v(TAG, "supported " + l.toString());
}
} else {
Logger.d(TAG, "no supported language");
}
Set<Voice> voices = mTts.getVoices();
if(voices != null){
for(Voice v : voices){
Logger.d(TAG, "TTS Voice: " + v.toString());
}
}
}
String engine = mTts.getDefaultEngine();
Logger.d(TAG, "TTS Engine = " + engine);
2022-10-18 15:21:22.577 25266-25266 TextToSpeech com.tts.test I Connected to ComponentInfo{tw.pu.tts/tw.pu.tts.UttsService}
2022-10-18 15:21:22.582 25266-26006 TextToSpeech com.tts.test I Set up connection to ComponentInfo{tw.pu.tts/tw.pu.tts.UttsService}
2022-10-18 15:21:22.594 25266-25266 TTS com.tts.test D onInit 0
2022-10-18 15:21:22.650 25266-25266 TTS com.tts.test V supported zh
2022-10-18 15:21:22.650 25266-25266 TTS com.tts.test V supported en
2022-10-18 15:21:22.650 25266-25266 TTS com.tts.test V supported zh__#Hans
2022-10-18 15:21:22.650 25266-25266 TTS com.tts.test V supported zh__#Hant
2022-10-18 15:21:22.690 25266-25266 TTS com.tts.test D TTS Voice: Voice[Name: zh, locale: zh__#Hans, quality: 300, latency: 300, requiresNetwork: false, features: []]
2022-10-18 15:21:22.691 25266-25266 TTS com.tts.test D TTS Voice: Voice[Name: en, locale: en, quality: 300, latency: 300, requiresNetwork: false, features: []]
2022-10-18 15:21:22.691 25266-25266 TTS com.tts.test D TTS Voice: Voice[Name: zh, locale: zh, quality: 300, latency: 300, requiresNetwork: false, features: []]
2022-10-18 15:21:22.691 25266-25266 TTS com.tts.test D TTS Voice: Voice[Name: zh, locale: zh__#Hant, quality: 300, latency: 300, requiresNetwork: false, features: []]
2022-10-18 15:21:22.698 25266-25266 TTS com.tts.test D TTS Engine = tw.pu.tts
注: TTS的功能需要在TextToSpeech.OnInitListener回调, 并确认状态正常后才可以开始正常工作
完整代码TTS.java
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.media.AudioAttributes;
import android.media.AudioManager;
import android.speech.tts.TextToSpeech;
import android.speech.tts.Voice;
import java.util.Locale;
import java.util.Set;
public class TTS implements TextToSpeech.OnInitListener {
final String TAG = "TTS";
TextToSpeech mTts;
public TTS(Context context){
mTts = new TextToSpeech(context, this);
}
public TTS(Context context, TextToSpeech.OnInitListener lis){
mTts = new TextToSpeech(context, this);
setOnInitListener(lis);
}
final int DATA_CHECK_CODE = 0x774;
@Deprecated
public TTS(Activity activity){
Intent checkIntent = new Intent(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA);
activity.startActivityForResult(checkIntent, 0x774);
}
@Deprecated
public void onActivityResult(Activity activity, int requestCode, int resultCode, Intent data) {
if (requestCode == DATA_CHECK_CODE) {
if (resultCode == TextToSpeech.Engine.CHECK_VOICE_DATA_PASS) {
// success, create the TTS instance
mTts = new TextToSpeech(activity, this);
} else {
// missing data, install it
Intent installIntent = new Intent(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);
activity.startActivity(installIntent);
}
}
}
public TextToSpeech getTts(){
return mTts;}
private void dump(){
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
Set<Locale> ava = mTts.getAvailableLanguages();
if (ava != null) {
for (Locale l : ava) {
Logger.v(TAG, "supported " + l.toString());
}
//mTts.setLanguage(Locale.US);
} else {
Logger.d(TAG, "no supported language");
}
Set<Voice> voices = mTts.getVoices();
if(voices != null){
for(Voice v : voices){
Logger.d(TAG, "TTS Voice: " + v.toString());
}
}
}
String engine = mTts.getDefaultEngine();
Logger.d(TAG, "TTS Engine = " + engine);
}
public void setSpeechSpeed(float speed){
mTts.setSpeechRate(speed);
}
public void setVoiceFreq(float freq){
mTts.setPitch(freq);
}
public void speak(String s){
if(mTts == null){
Logger.e(TAG, "speak failed: TTS not ready");
return;
}
int res = mTts.speak(s, TextToSpeech.QUEUE_ADD, null);
if(res != 0){
Logger.w(TAG, "speak failed: " + res);
}else{
Logger.d(TAG, "speak " + s + " done");
}
}
public void stop(){
mTts.stop();
}
@Override
public void onInit(int status) {
Logger.d(TAG, "onInit " + status);
if(status == 0) {
dump();
mTts.setPitch(1f);
mTts.setSpeechRate(1f);
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
AudioAttributes attr = new AudioAttributes.Builder().setLegacyStreamType(AudioManager.STREAM_MUSIC).build();
mTts.setAudioAttributes(attr);
}
}
if(initLis != null)initLis.onInit(status);
}
TextToSpeech.OnInitListener initLis;
public void setOnInitListener(TextToSpeech.OnInitListener initLis){
this.initLis = initLis;
}
}
参考
Android 中文語音引擎資源
Android中使用自带TextToSpeech实现离线语音合成功能
The 7 Best Text-to-Speech Apps for Android
Android中提供的免费文字转语音功能TextToSpeech之快速入门用法（Android TTS 语音合成播报）
An introduction to Text-To-Speech in Android