Flite TTS Engine for Android

Author

Alok Parlikar

Introduction

Flite (festival-lite) is a small, fast runtime speech synthesis engine developed at Carnegie Mellon University and primarily designed for small embedded devices. Flite is an opensource synthesis engine that can be used to provide text-to-speech functionality on smartphones and similar devices. For more information about Flite, visit www.cmuflite.org

This application wraps the Flite engine so that it can be installed as an application on Android devices. This app gets installed as a TTS library, thereby allowing other applications to make use of Flite for synthesis.

Installing this Application

This app is not yet available on the Google Play Store, but you can generate an apk file by building this source code, or download an APK file from the Github page and install it on your device. Devices running Android versions 2.3 (Gingerbread) or later are supported.

After installing this application, you will have to:

1. Enable Flite from "Text to Speech Settings" on your phone
2. Install voice data
3. Go to "Language" settings and select the voice that you want.

By clicking on "Listen to a sample" you can verify that Flite is working.

Using Flite for TTS in Your Application

If you are developing an application and would like to use Flite for speech synthesis, you can specify "edu.cmu.cs.speech.tts.flite" as the package name of the engine to use.

Building this App from Source using the Build script

Instructions here are for development on Linux.

Requirements

In order to build this application, you need the following:

• Android NDK Release 10e or newer
• Android SDK with the SDK Platform package for Android 5.1.1 (API 22)

Application Build Steps

Export necessary environment variables :

export ANDROID_NDK=/path/to/android/ndk
export ANDROID_SDK=/path/to/android/sdk
bash ./build.sh

Wait for the build script do download, verify, extract, patch and build the Flite Engine and App.

The final apk will be placed in bin/FliteEngine-debug.apk.

Building this App from Source manually

Instructions here are for development on Linux.

Requirements

In order to build this application, you need the following:

• Flite 2.0.0 or later. A version can be downloaded from http://www.festvox.org/flite/packed/flite-2.0/flite-2.0.0-release.tar.bz2
• Android NDK Release 10d
• Android SDK Release 24.0.2

Application Build Steps

Export necessary environment variables :

export FLITEDIR=/path/to/flite-2.0.0
export FLITE_APP_DIR=/path/to/this/application
export ANDROID_NDK=/path/to/android/ndk
export ANDROID_SDK=/path/to/android/sdk

Build Flite Engine for multiple architectures :

cd $FLITEDIR
./configure --with-langvox=android --target=armeabi-android
make
./configure --with-langvox=android --target=armeabiv7a-android
make
./configure --with-langvox=android --target=x86-android
make
./configure --with-langvox=android --target=mips-android
make

Build installable application package (debug mode) :

cd $FLITE_APP_DIR
ant debug