Hardware Reference
In-Depth Information
the ascension of the PCI bus for sound cards and large amounts of RAM in computers,
most soundcards and integrated audio devices adopted a so-called “soft wavetable” ap-
proach, loading 2MB-8MB of sampled musical instruments into the computer's RAM.
Whereas early games supported only digitized audio samples (because most early sound
cardshadpoorMIDIsupport),lateDOSgamessuchas DOOM begantoexploitthewide-
spread wavetable-based MIDI support found on most mid-1990s and more recent sound
cards.WithallcurrentsoundhardwaresupportingwavetableMIDIandtheimprovements
in DirectX 8.x and above for MIDI support, MIDI sound has become far more prevalent
for game soundtracks. Many websites also offer instructions for patching existing games
to allow MIDI support. Whether you play the latest games or like music, good MIDI per-
formance is likely to be important to you.
The most important factor for high-performance MIDI is the number of hardware voices.
Even the best sound cards normally support only 128 voices in hardware; the remainder
ofthevoicesrequiredbyaMIDIsoundtrackmustcomefromsoftware.Ifyoursoundcard
supportsonly32MIDIvoicesinhardwareorusessoftwaresynthesisonly,considerrepla-
cing it with a newer model.
On Windows-based systems with integrated audio, Microsoft GS Wavetable SW Synth, a
part of DirectMusic, is used for MIDI support.
Although most ISA and older PCI sound cards had provision for MIDI outputs via the
game port or dedicated MIDI ports, systems with modern integrated audio do not have
MIDI ports. However, a variety of MIDI input/output devices can be connected via USB
ports, or you can choose a sound card that incorporates MIDI ports (refer to Figure 13.2 )
or has a MIDI port daughtercard.
Tip
With Windows XP and older editions, you could select the MIDI output device you wanted
to use (such as a USB MIDI device or a third-party MIDI program) via the Control Panel's
Soundsapplet.However,thisoptionisnotincludedinWindowsVistaandWindows7.Ifyou
wanttoswitchtoadifferentMIDIoutputprogramordevicewiththeseversionsofWindows,
downloadandinstalltheMIDIOutSetterutilityavailablefrom http://www.codeproject.com/
KB/audio-video/MIDIOutSetter.aspx .
Data Compression
All audio adapters on the market today can easily produce CD-quality audio, which is
sampled at 44.1KHz. At this rate, recorded files (even of your own voice) can consume
more than 10MB for every minute of recording when stored as uncompressed WAV files.
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