Java LAME

This java port of LAME 3.98.4 was created by Ken Händel for his 'jump3r - Java Unofficial MP3 EncodeR' project: http://sourceforge.net/projects/jsidplay2/

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).

How to build

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

$ ./gradlew jar

The resulting library is then to be found in the following directory:

./build/libs/

You can find an already built JAR file in the releases: https://github.com/nwaldispuehl/java-lame/releases

How to publish artifact to local Maven repository for the use in Maven projects

To store the artifact in the local Maven repository (e.g. ~/.m2/repository/) use this task:

$ ./gradlew publishToMavenLocal

It is then present at the expected location, e.g.:

$ ls ~/.m2/repository/net/sourceforge/lame/lame/3.98.4    
lame-3.98.4.jar  lame-3.98.4.module  lame-3.98.4.pom

and can be used in local Maven projects with this signature:

<dependency>
    <groupId>net.sourceforge.lame</groupId>
    <artifactId>lame</artifactId>
    <version>3.98.4</version>
</dependency>

How to publish artifact to Maven Central

If you intend to publish the artifact to Maven Central (https://search.maven.org/) please first adapt the groupId in the build.gradle file to your own domain / projectname. Consult https://docs.gradle.org/current/userguide/publishing_maven.html for how to publish to a Maven repository.

How to run

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

$ cd /build/libs
$ java -jar net.sourceforge.lame-3.98.4.jar

How to run the test

To see the creation of a MP3 file in action one can run the test class LameEncoderTest.java:

$ ./gradlew check

It takes the src/test/resources/test.wav file as input and writes the converted data into build/test.mp3.

How to use Java LAME in a project?

WAV/PCM to MP3

To convert a WAV/PCM byte array to an MP3 byte array, you may use Ken Händels LameEncoder which offers the following convenience method for converting chunks of such byte buffer:

LameEncoder#encodeBuffer(final byte[] pcm, final int pcmOffset, final int pcmLength, final byte[] encoded)

A sample of its use can be found in the LameEncoderTest.java: https://github.com/nwaldispuehl/java-lame/blob/master/src/test/java/net/sourceforge/lame/lowlevel/LameEncoderTest.java

MP3 to WAV/PCM

Analog for decoding; the following method allows for easy conversion of a MP3 file into a PCM byte array:

LameDecoder#decode(final ByteBuffer sampleBuffer)

A sample of its use can be found in the LameDecoderTest.java: https://github.com/nwaldispuehl/java-lame/blob/master/src/test/java/net/sourceforge/lame/lowlevel/LameDecoderTest.java

Credits

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