MIDI vs. Digitized Audio
Originally developed to allow musicians to connect synthesizers together, the
MIDI protocol is now finding widespread use as a delivery medium to replace or
supplement digitized audio in games and multimedia applications.
A D V E R T I S E M E N T
There are
several advantages to generating sound with a MIDI synthesizer rather than using
sampled audio from disk or CD-ROM. The first advantage is storage space. Data
files used to store digitally sampled audio in PCM format (such as .WAV files)
tend to be quite large. This is especially true for lengthy musical pieces
captured in stereo using high sampling rates.
MIDI data files, on the other hand, are extremely small when compared with
sampled audio files. For instance, files containing high quality stereo sampled
audio require about 10 Mbytes of data per minute of sound, while a typical MIDI
sequence might consume less than 10 Kbytes of data per minute of sound. This is
because the MIDI file does not contain the sampled audio data, it contains only
the instructions needed by a synthesizer to play the sounds. These instructions
are in the form of MIDI messages, which instruct the synthesizer which sounds to
use, which notes to play, and how loud to play each note. The actual sounds are
then generated by the synthesizer.
For computers, the smaller file size also means that less of the PCs
bandwidth is utilized in spooling this data out to the peripheral which is
generating sound. Other advantages of utilizing MIDI to generate sounds include
the ability to easily edit the music, and the ability to change the playback
speed and the pitch or key of the sounds independently. This last point is
particularly important in synthesis applications such as karaoke equipment,
where the musical key and tempo of a song may be selected by the user.
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