Leopard Speech-to-Text
Android Quick Start

Platforms

• Android (5.0+, API 21+)

Requirements

• Picovoice Account and AccessKey
• Android Studio
• Android device with USB debugging enabled or Android simulator

Picovoice Account & AccessKey

Signup or Login to Picovoice Console to get your AccessKey. Make sure to keep your AccessKey secret.

Quick Start

Setup

1. Install Android Studio.

2. Include mavenCentral() repository in the top-level build.gradle. Then add the following to the app's build.gradle:

dependencies {
    // ...
    implementation 'ai.picovoice:leopard-android:${LATEST_VERSION}' // replace with latest version
}

3. Add the following to the app's AndroidManifest.xml file to enable recording with an Android device's microphone:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />

Model File

Add the Leopard Speech-to-Text model file to your Android application:

1. Create a custom model using the Picovoice Console or use a default language model.
2. Add the model as a bundled resource by placing it under the ${ANDROID_APP}/src/main/assets directory of your Android project.

Usage

Create an instance of the engine with the Leopard Speech-to-Text Builder by passing in your AccessKey, model file and the Android app context:

import ai.picovoice.leopard.*;

final String accessKey = "${ACCESS_KEY}"; // AccessKey provided by Picovoice Console (https://console.picovoice.ai/)
final String modelPath = "${MODEL_PATH}"; // path relative to the assets folder or absolute path to file on device

try {
    Leopard leopard = new Leopard.Builder()
      .setAccessKey(accessKey)
      .setModelPath(modelPath)
      .build(appContext);
} catch (LeopardException ex) { }

Transcribe an audio file by providing the absolute path to the file on device:

File audioFile = new File("${AUDIO_FILE_PATH}");
LeopardTranscript transcript = leopard.processFile(audioFile.getAbsolutePath());

Transcribe raw audio data (sample rate of 16 kHz, 16-bit linearly encoded and 1 channel):

short[] getAudioData() {
    // ...
}
LeopardTranscript transcript = leopard.process(getAudioData());

When done, release resources explicitly:

leopard.delete();

Word Metadata

Along with the transcript, Leopard Speech-to-Text returns metadata for each transcribed word. Available metadata items are:

• Start Time: Indicates when the word started in the transcribed audio. Value is in seconds.
• End Time: Indicates when the word ended in the transcribed audio. Value is in seconds.
• Confidence: Leopard Speech-to-Text's confidence that the transcribed word is accurate. It is a number within [0, 1].
• Speaker Tag: If speaker diarization is enabled on initialization, the speaker tag is a non-negative integer identifying unique speakers, with 0 reserved for unknown speakers. If speaker diarization is not enabled, the value will always be -1.

Demo

For the Leopard Speech-to-Text Android SDK, we offer demo applications that demonstrate how to use the Speech-to-Text engine on audio recordings.

Setup

Clone the Leopard Speech-to-Text repository from GitHub using HTTPS:

git clone --recurse-submodules https://github.com/Picovoice/leopard.git

Usage

1. Open the Android demo using Android Studio.
2. Copy your AccessKey from Picovoice Console into the ACCESS_KEY variable in MainActivity.java.
3. Go to Build > Select Build Variant... and select the language you would like to run the demo in (e.g. enDebug -> English, itRelease -> Italian)
4. Run the application using a connected Android device or using an Android simulator.

Resources