Killer Game Programming in Java

MIDI

The previous section looked at the basic support in the Java Sound API for playing sampled audio. Now, I'll consider the other major part of the API, which is its support for playing MIDI sequences.

A key benefit of the MIDI is that it represents musical data in an efficient way, leading to drastic reductions in file sizes compared to sampled audio. For instance, files containing high-quality stereo sampled audio require about 10 MB per minute of sound, while a typical MIDI sequence may need less than 10 KB.

The secret to this phenomenal size reduction is that a MIDI sequence stores "instructions" for playing the music rather than the music itself. A simple analogy is that a sequence is the written score for a piece of music rather than a recording of it.

The drawback is that the sequence must be converted to audio output at runtime. This is achieved using a sequencer and synthesizer. Their configuration is shown in greatly simplified form in Figure 7-8.

Figure 7-8. A MIDI sequencer and synthesizer

A MIDI sequencer allows MIDI data sequences to be captured, stored, edited, combined, and performed, while the MIDI data's transformation into audio is being carried out by the synthesizer.

Continuing my analogy, the sequencer is the orchestral conductor who receives the score to play, perhaps making changes to it in the process. The synthesizer is the orchestra, made up of musicians playing ...