Audio Recording
Android Quick Start

Platforms

• Android (5.0+, API 21+)

Requirements

• Android Studio
• Android device with USB debugging enabled or Android simulator

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:android-voice-processor:${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.RECORD_AUDIO" />

Usage

Access the singleton instance of VoiceProcessor:

import ai.picovoice.android.voiceprocessor.*;

VoiceProcessor voiceProcessor = VoiceProcessor.getInstance();

Add listeners for audio frames and errors:

final VoiceProcessorFrameListener frameListener = frame -> {
    // use audio data
};
final VoiceProcessorErrorListener errorListener = e -> {
    // handle error
};

voiceProcessor.addFrameListener(frameListener);
voiceProcessor.addErrorListener(errorListener);

Start audio capture with the desired frame length and audio sample rate:

final int frameLength = 512;
final int sampleRate = 16000;

voiceProcessor.start(frameLength, sampleRate);

Stop audio capture:

voiceProcessor.stop();

Once audio capture has started successfully, any frame listeners assigned to the VoiceProcessor will start receiving audio frames with the given frameLength and sampleRate.

Capturing with Multiple Listeners

Any number of listeners can be added to and removed from the VoiceProcessor instance. However, the instance can only record audio with a single audio configuration (frameLength and sampleRate), which all listeners will receive once a call to start() has been made. To add multiple listeners:

VoiceProcessorFrameListener listener1 = frame -> { };
VoiceProcessorFrameListener listener2 = frame -> { };
VoiceProcessorFrameListener[] listeners = new VoiceProcessorFrameListener[] {
        listener1, listener2 
};

voiceProcessor.addFrameListeners(listeners);

voiceProcessor.removeFrameListeners(listeners);
// or
voiceProcessor.clearFrameListeners();

Demo

For the Voice Processor Android SDK we have an example app that demonstrates how to use VoiceProcessor in an Android app.

Setup

Clone the android-voice-processor repository from GitHub:

git clone https://github.com/Picovoice/android-voice-processor.git

Usage

1. Open the example app using Android Studio or build with Gradle:

./gradlew assembleDebug

2. Toggle recording on and off with the button in the center of the screen. While recording, the VU meter on the screen will respond to the volume of incoming audio.

For more information on our Voice Processor demo for Android, head over to our GitHub repository.

Resources