Audio: Then & Now
anufacturing sound cards was a popular business venture at one point: The Sound Card Drivers Web site (www.soundcarddrivers.com) lists drivers from around 300 different sound card brands, both active and defunct (but mostly defunct). Audio standards and products for the computer have changed tremendously in the past 20-plus years. This timeline doesnt mention every sound board or digital audio milestone you might have encountered over the years, but it does highlight a few you might have forgotten and a few youre still using today (marked with red).
C64 SID. Music files made on the Commodore 64 (C64) computer are called SID tunes, short for the Sound Interface Device chip found on the C64. The SID chip, introduced in 1982, was extremely advanced for its time. You can use a SID emulator to re-create the sounds of the C64 on your current computer. AY. The AY sound chip provided some similar music to the C64 SID and was part of ZX Spectrum computers.
Roland MT-32 and LAPC-1. Introduced in 1987, the Roland MT-32 was a consumer-level MIDI synthesizer that provided tons of features. The Roland LAPC-1 appeared later, essentially featuring the MT-32 on a sound card. AdLib. AdLib Multimedia created one of the first sound cards for the PC in 1987. Gamers especially embraced the AdLib card, which provided an alternative to the beeps and buzzes that dominated games previously.
Sound Blaster. Creative released its first Sound Blaster sound card in 1990. The first Sound Blaster offered an 11voice FM synthesizer and a joystick/MIDI port, and it was advanced for its time. One of its biggest selling points was its AdLib compatibility, but The Sound Blaster Audigy 2 is a powerful 24-bit internal sound card from Creative Technology. this didnt last because Sound Blaster quickly became the best-selling sound card. Software developers and game developers began touting their products as Sound Blaster-compatible, giving the PC audio industry its first semblance of a sound card standard.

1990 1992

Windows Media Player. This software, included in the Windows OS since the mid-1990s, provides tons of features for handing audio playback and ripping audio files.
Macintosh. In contrast to the early incarnations of the PC, which was considered a business computer that didnt need audio, Apples Macintosh computer embraced audio from its 1984 introduction. Apple received a technical Grammy award in 2002 for its contributions to the music and recording industries over the years. Apple is now enjoying success with its iPod MP3 player. MIDI. The MIDI standard initially appeared 20 years ago, designed to allow musicians to control one keyboard from another. MIDI grew quickly as a PC audio specification, though, and now appears in several different types of products, including synthesizers, recording equipment, cell phones, and computer sound cards. A MIDI file doesnt require much storage space. Most of todays PC audio products support MIDI. CD. The compact disc first appeared in 1982, offering a digital audio storage medium and greatly improving the sound quality of recordings. CDs remain the top audio storage medium in use today. Because they both contain digital audio, CDs and computers are a natural pair, and nearly any CD drive or DVD drive on a computer can play an audio CD.

C/MS. Creative Labs first major product in the U.S. was the 1988 release of the C/MS (Creative Music System), which was a 12voice stereo music synthesizer card. Creative followed later that year with the Game Blaster, a full stereo sound board for the PC.
MP3. MP3, short for MPEG Audio Layer 3, is a compressed audio format introduced in 1992. MP3 files make it easy to share audio recordings across the Internet. The popularity of MP3 files exploded in the late 1990s, thanks to file-sharing Web sites and MP3 players.

Practical Game Programming

Audio Make some noise

Copyright 2010 Jari Komppa - http://iki.fi/sol/

Audio is important.

Tomlinson Holman's eXperiment.
Audio is not my favorite segment.
Simple on the surface, complex issues.
Still, audio adds a lot to the experience.
Even a beep is better than silence.

History (on the pc)

Piezoelectric beepers / pc speakers
Beep! -> some arpeggios, even (noisy) d/a Somewhat metallic sound LPT DACs, soundblaster, Pro Audio Spectrum. Gravis Ultrasound, Roland LAPC-1, SB AWE32
FM synthesis (adlib, soundblaster)
Wavetable (sample playback)
Now: DAC again (MP3, software wavetable.)

Typical i/o

Possibly transitioning depending on the situation in the game. Several sound effects at the same time.

Sound effects

Data formats
Bits per sample (1/4/8/16/24, 8/16 typical) Signed / unsigned data Looping / not looping Sample rate (8khz 48khz typical) Channels (mono, stereo, surround) Compression (none, adpcm, mp3/ogg)

Positional audio

"3d audio" Most useful for first person games For 2d games, stereo panning is in most cases good enough
Playing audio: ring buffer

Ring buffer

Write head
Pros: low latency, better control Cons: tricky

Play head

Playing audio: buffered

buffer

When a buffer is finished, callback triggers Application mixes new buffer, adds it into queue Pros: simple Cons: potentially higher latency

Practical use

Game populated with audio events. Audio events trigger change in audio. In simplest form, trigger a sound effect. In more complex form, audio designer can do all sorts of weird things with a separate audio designing software Audio may go through environmental filters (echoes etc).

homework

Take a game, preferably a commercial title. Listen.
How does the background audio work? Does it fade in and out different songs? Does the game use positional audio? Does the game's audio do something interesting?
Write a short report of your findings.