This java port of LAME 3.98.4 was created by Ken Händel for his jump3r - Java Unofficial MP3 EncodeR project:, then modified by daberkow to support in memory mp3 conversions. While this Java app/library maintains the code currently from the upstream project, I am mostly focused on maintaining the in memory conversion pipeline, and promise nothing about the rest of the codebase.

Original sources by the authors of LAME: http://www.sourceforge.net/projects/lame

The code is - as the original - licensed under the LGPL (see LICENSE).

• Reading MP3 Files and converting them to PCM audio
• Java 11+ compatible
• Tested, Built, Signed, and Published with GitHub actions
• No dependencies, 100% self contained and native code

Remove some of the, to me, extra code around the command line application and streamline.

First run the ./scripts/download_test_assets.sh script to download a test track.

To create a JAR file, you may start the gradle build process with the included gradle wrapper:

$ ./gradlew clean build test

After having created a JAR file, you certainly can run it as a command line application:

$ cd /build/libs
$ java -jar java-lame-1.0.0.jar

This library is available in Maven Central!

Gradle

implementation group: 'co.ntbl', name: 'lame', version: '1.0.0'

Maven

<dependency>
    <groupId>co.ntbl</groupId>
    <artifactId>lame</artifactId>
    <version>1.0.0</version>
</dependency>

File mp3TestFile = new File("./test_assets/house.mp3");

LameDecoder decoder = new LameDecoder(Files.readAllBytes(mp3TestFile.toPath()));

ByteBuffer buffer = ByteBuffer.allocate(decoder.getBufferSize());
ByteArrayOutputStream pcm = new ByteArrayOutputStream();

while (decoder.decode(buffer)) {
    pcm.write(buffer.array());
}

byte[] wavBytes = asWav(pcm.toByteArray(), decoder.getSampleRate(), decoder.getChannels());

Test sound 'Jingle004' (CC BY-NC 3.0) by 'cydon': https://freesound.org/people/cydon/sounds/133054/

Download script for house music from: https://mixkit.co/free-stock-music/