/java-lame

Native Java port of the LAME library.

Primary LanguageJavaGNU Lesser General Public License v3.0LGPL-3.0

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 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 use Java LAME in a project?

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

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

A sample of its use:

public byte[] encodePcmToMp3(byte[] pcm) {
  LameEncoder encoder = new LameEncoder(inputFormat, 256, MPEGMode.STEREO, Lame.QUALITY_HIGHEST, false);

  ByteArrayOutputStream mp3 = new ByteArrayOutputStream();
  byte[] buffer = new byte[encoder.getPCMBufferSize()];

  int bytesToTransfer = Math.min(buffer.length, pcm.length);
  int bytesWritten;
  int currentPcmPosition = 0;
  while (0 < (bytesWritten = encoder.encodeBuffer(pcm, currentPcmPosition, bytesToTransfer, buffer))) {
    currentPcmPosition += bytesToTransfer;
    bytesToTransfer = Math.min(buffer.length, pcm.length - currentPcmPosition);

    mp3.write(buffer, 0, bytesWritten);
  }

  encoder.close();
  return mp3.toByteArray();
}