Java Language - 230 - Java TTS Libraries

Text-to-Speech (TTS) – Java TTS Libraries

Text-to-speech (TTS) technology allows computers to convert written text into spoken language, enabling applications to provide auditory output. In this article, we’ll explore the world of Java TTS libraries, which empower developers to integrate TTS functionality into their Java applications effectively.

1. Role of TTS in Java Applications

Text-to-speech has become a crucial component in various Java applications, enhancing accessibility and usability. Here are some common use cases for TTS in Java:

a. Accessibility: TTS technology ensures that visually impaired users can access and interact with applications by providing spoken content.

b. Navigation: Navigation apps and location-based services use TTS to deliver turn-by-turn directions and information.

c. Multilingual Support: TTS allows applications to support multiple languages and dialects, making them more versatile and user-friendly.

2. Java TTS Libraries

Let’s explore some of the Java TTS libraries that simplify the implementation of text-to-speech functionality in your applications:

2.1 FreeTTS

FreeTTS is a popular open-source TTS engine that provides a Java Speech API (JSAPI) implementation. Here’s an example of using FreeTTS to synthesize speech:


import com.sun.speech.freetts.Voice;
import com.sun.speech.freetts.VoiceManager;

public class FreeTTSExample {
    public static void main(String[] args) {
        // Initialize the VoiceManager
        VoiceManager voiceManager = VoiceManager.getInstance();

        // Get a list of available voices
        Voice[] voices = voiceManager.getVoices();
        for (Voice voice : voices) {
            System.out.println(voice.getName());
        }

        // Choose a voice
        Voice voice = voiceManager.getVoice("kevin16");
        if (voice != null) {
            voice.allocate();
            voice.speak("Hello, I'm FreeTTS, a text-to-speech engine for Java.");
        }
    }
}

This example demonstrates the use of FreeTTS to list available voices and synthesize speech using the “kevin16” voice.

2.2 MaryTTS

MaryTTS is a multilingual and open-source TTS system. It supports various voices and languages, making it a versatile choice for TTS applications. Here’s a MaryTTS example:


import marytts.modules.synthesis.Voice;
import marytts.modules.synthesis.VoiceList;
import marytts.client.MaryClient;
import marytts.util.data.audio.AudioPlayer;

public class MaryTTSExample {
    public static void main(String[] args) throws Exception {
        MaryClient maryClient = MaryClient.getMaryClient();

        // List available voices
        VoiceList voiceList = VoiceList.getVoiceList();
        System.out.println("Available voices:");
        voiceList.stream().map(Voice::getName).forEach(System.out::println);

        // Set the desired voice
        String selectedVoice = "cmu-slt-hsmm";
        maryClient.processAndPlayText("Hello, I am MaryTTS, your text-to-speech companion!", selectedVoice);
    }
}

In this code, MaryTTS is used to list available voices and synthesize text into speech using the “cmu-slt-hsmm” voice.

2.3 Google Cloud Text-to-Speech

Google Cloud Text-to-Speech is a cloud-based TTS service that offers natural and high-quality speech synthesis. Here’s an example of using Google Cloud Text-to-Speech in a Java application:


import com.google.cloud.texttospeech.TextToSpeech;
import com.google.cloud.texttospeech.TextToSpeechOptions;
import com.google.cloud.texttospeech.VoiceSelectionParams;
import com.google.cloud.texttospeech.AudioConfig;
import com.google.cloud.texttospeech.SynthesisInput;
import com.google.cloud.texttospeech.SynthesizeSpeechResponse;

import java.io.FileOutputStream;
import java.io.OutputStream;
import java.io.IOException;

public class GoogleTTSExample {
    public static void main(String[] args) throws IOException {
        TextToSpeech textToSpeech = TextToSpeechOptions.getDefaultInstance().getService();
        SynthesisInput input = SynthesisInput
            .newBuilder()
            .setText("Hello from Google Text-to-Speech in Java.")
            .build();
        VoiceSelectionParams voice = VoiceSelectionParams
            .newBuilder()
            .setName("en-US-Wavenet-D")
            .setLanguageCode("en-US")
            .build();
        AudioConfig audioConfig = AudioConfig
            .newBuilder()
            .setAudioEncoding(AudioConfig.AudioEncoding.LINEAR16)
            .build();

        SynthesizeSpeechResponse response = textToSpeech.synthesizeSpeech(input, voice, audioConfig);

        byte[] audioData = response.getAudioContent().toByteArray();
        try (OutputStream out = new FileOutputStream("output.wav")) {
            out.write(audioData);
        }
    }
}

This code demonstrates the usage of the Google Cloud Text-to-Speech API to synthesize speech and save it as an audio file.

3. Choosing the Right TTS Library

When selecting a Java TTS library for your project, consider factors like licensing, multilingual support, voice quality, and platform compatibility. FreeTTS, MaryTTS, and Google Cloud Text-to-Speech each have their strengths and may be better suited to different use cases.

4. Conclusion

Text-to-speech technology is invaluable for improving the accessibility and usability of Java applications. Java TTS libraries like FreeTTS, MaryTTS, and cloud-based solutions such as Google Cloud Text-to-Speech provide versatile options for incorporating speech synthesis capabilities into your applications. The choice of library depends on your specific requirements, so explore the available options and find the one that best fits your project’s needs.

Java Language – 230 – Java TTS Libraries