Java Audio Tools

AudioTools.zip contains a collection of Java programs for manipulating sampled audio (e.g. WAV files and tones).

The examples use AudioTools.java which packages up a wide range of functions for sampled audio, falling into eight broad groups:

1. playing/looping audio;
2. loading/saving audio;
3. recording;
4. tone generation;
5. wave functions for generating tones;
6. audio drawing tools;
7. audio information;
8. audio array manipulation;

A lot of AudioTools.java is derived from StdAudio.java by Robert Sedgewick and Kevin Wayne, and AudioEffects.java at the Univ. of Montana. Over the years, I've also borrowed code from other sources, including JSresources.org and java2s.com.

Sedgewick and Wayne's clever idea is to manipulate sampled audio using only a 44,100 Hz (CD quality), 16-bit, monaural format, which means that a sample can be stored as an array of doubles. This makes it very easy to apply audio effects, such as volume adjustment, echoing, padding and cutting, and even reversal of the sample.

AudioTools.zip includes several examples:

• AudioRecorder.java: a command line tool for recording from the microphone;
   
• ClipPlayer.java: a simple GUI for loading and playing a sound clip, which includes a play/stop button, a progress bar, and a volume control slider;
   
• Mozart.java, which implements Mozart's musical dice game;
   
• PlayTones.java: plays simple tunes made up of tones (with durations) read from text files;
   
• TestSounds.java and TestEffects.java: potpourris of mini examples using different features of AudioTools.java

There's also a JFreeChart-based program called ChartAudio.java, which can be attached to a play() call, and dynamically draws a time-series chart of the audio. It produces output such as:

Incidentally, AudioTools.java doesn't support MIDI processing, although that is part of Java sound. There's a lot of MIDI examples at JSresources.org, or you could look at Chapter 5 of my book Killer Game Programming in Java.

Download

• Almost everything is in AudioTools.zip (6.5 MB). Last updated: 27th Feb. 2022.
  
• mozart.zip (35 MB), a large collection of audio sample for construction Mozart waltzes. Last updated: 27th Feb. 2022.