Swing Hacks

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Chapter 10, Audio

#75 Build an Audio Waveform Display

HACK

Even better, if you have a custom install program, make it run the JMF and

MP3 installers first. If you don’t have an installer or don’t know which plat-

form the program will be installed on, use the cross-platform versions (also

available from the URLs mentioned in this hack). They are slower but are

completely written in Java so they can run on anything.

H A C K

#75

Build an Audio Waveform Display Hack #75

With a little understanding of audio data formats, you can easily build a basic

graphical audio display.

Representing audio visually is extremely useful. You can use waveform dis-

plays to quickly tell audio files apart, like a file thumbnail, or for non-linear

editing, such as deleting parts of the file and processing.

Figure 10-4 shows a waveform displayed in Audacity, a free, open source

audio editing application. This hack shows you how to build a basic wave-

form display from raw audio data.

The end result of this hack is displayed in Figure 10-5. You’ll start by read-

ing in the entire audio file using an

AudioInputStream. Then you’ll convert

the raw data from the stream into useful audio samples, organized by chan-

nel. With the converted channel audio data, you’ll create a single waveform

Figure 10-4. Audacity with an audio waveform displayed