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 instancemTts = new TextToSpeech(this, this);} else {// missing data, install itIntent 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;@Deprecatedpublic TTS(Activity activity){Intent checkIntent = new Intent(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA);activity.startActivityForResult(checkIntent, 0x774);}@Deprecatedpublic 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 instancemTts = new TextToSpeech(activity, this);} else {// missing data, install itIntent 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();}@Overridepublic 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
附:
文字转语音(TTS) 应用 (APK)
