History MediaNotes / GamingAudio

With the move from [=CDs=] to [=DVDs=] (and later, digital downloads), game developers could no longer use Red Book audio for their games. Additionally, the one drawback of CD audio meant that transparently looping music as well as VariableMix is difficult if not impossible. So they turned to another technique - compressed audio files. Essentially, audio files used in modern games today are like standard [=MP3s=], except with a different compression algorithm and metadata regarding loop points. Such files have all the advantages of Red Book audio with several more, such as better looping. Initially, early processors were not powerful enough to handle this without choking (though this is technically only true for the PC largely due to the inefficient [=APIs=] while Macs had no such issues. Nevertheless developers often overlook the method due to writing games to be multi-platform). Today, most triple-A games tend to use proprietary audio formats like AD-X and Bink Audio, while indie games tending to use consumer formats such as [=MP3=] and [=OGG=]. Also, processors have not only gotten leaps and bounds faster, but had also went multi-core, making it trivial to decode compressed music while still having enough grunt to handle the general graphics and gameplay logic without choking up. Coupled with the fact that games are now often better optimized than before, the earlier issues that plagued software-driven wavetable synthesis no longer applies. As a matter of fact, compressed audio files tend to use less CPU power than software-driven wavetable since the CPU only has to decode two channels of audio as opposed to wavetable where the CPU has to interpret and generate ''16'' channels of audio and then downmix them to two. The only thing holding the technology back was Windows' inefficient API- it wasn't until the conception of UsefulNotes/DirectX, specifically [=DirectSound=], and the new WDM audio model which has multiple audio stream mixing capabilities that premiered with Windows 98, that the issue was resolved. On earlier versions of Windows, unless the software itself does the mixing (something that most developers don't do), it wouldn't be able to play the BGM and sound effects at the same time [[note]]some software synthesizers like the Yamaha SYXG series of softsynths offer a passthrough virtual driver to allow programs that expect a hybrid card to work. However, this method consumes ''even more'' CPU power and thus introduces a trivial amount of audio lag on lower end [=PCs=], and certain games still managed to create conflicts with the driver.[[/note]]

Many of the proprietary formats are driven by the API or licensed UsefulNotes/GameEngine. For example, a game using the [=CRI=] middleware will tend to use ADX or CRI Audio.

On early machines, there either wasn't any sound hardware, or the sound hardware was extremely simple, being able to click a speaker or play simple tones. This was also the default sound system on IBM PC compatibles for many years, as well as on early Apple computers like the [[UsefulNotes/AppleII Apple II, IIe and IIc]] (The Apple IIGS had PCM sample playback capabilities courtesy of an Esoniq PCM codec).

One step up from simple beeps and clicks was the ''programmable sound generator'' (PSG), a set of oscillators on a chip that could be programmed in real time. The simplest ones, like the Texas Instruments 76496 and GI/Microchip 8910, had 3 square-wave channels and 1 white noise channel, all with independent volume controls. At the other end of the spectrum was the UsefulNotes/{{Commodore 64}}'s SID, a full 3-channel hybrid analog synthesizer with sine, square and triangle wave oscillators, filters and white noise. The UsefulNotes/{{Atari ST}} and UsefulNotes/{{MSX}} also used a PSG audio chip, though later versions of the Atari ST also included a PCM audio codec for rudimentary speech and sound effects support. The UsefulNotes/Atari8BitComputers used a POKEY chip, which is also a PSG. Also, most sound cards released for the Apple II were PSG-based. Many [=PSGs=] could be fooled into playing back sampled audio by feeding PCM values into the volume control registers thousands of times a second, as heard on some Game Gear games by "Say-Gah!", and have even been used to do CPU-driven speech synthesis on several accounts. It's safe to say that from the late 70s to the early 80s, PSG chips were technically the backbone of gaming audio. Still not convinced? Creative Lab's first sound card for the PC before the widely-successful [=SoundBlaster=] was the CMS (''Creative Music System'', later rebranded as the ''Game Blaster''), which was PSG-based as well.

Additionally, the Yamaha OPL chips were also found on the [=MoonSound=], [=MSX Music=] and [=MSX Sound=] expansion cards for the MSX, and the popular [=AdLib=] sound card for [=PCs=] (and became the defacto standard until usurped by the [=SoundBlaster=] in the early 90s), as well as in most [=SoundBlaster=] PC sound cards and clones to provide [=AdLib=] compatibility. They were also used alongside PSG audio on UsefulNotes/PC98 computers. There was even an OPL-1 based FM Synthesis module (allegedly upgradable to OPL-2) for the UsefulNotes/{{Commodore 64}} in case the user needs even better quality music than the SID can provide.

When FM synthesis was popular, Yamaha owned the patents, so pretty much all arcade and console games that used FM used a Yamaha FM synthesizer chip to do the work. The UsefulNotes/SegaGenesis had a Yamaha FM+ TI PSG chip inside.

The first popular gaming platforms to use a PCM synthesis chipset were the Platform/AcornArchimedes, UsefulNotes/{{Amiga}}, UsefulNotes/{{SNES}}, and believe it or not, {{Pinball}} systems, mainly those that used [[Creator/{{Midway}} Midway's]] DCS PCM Synthesis board (which also saw use in Franchise/MortalKombat and VideoGame/RevolutionX cabinets, since it not only reproduces instruments more faithfully, but one of the many tricks PCM synthesis could do was transparently loop fully-voiced music tracks, which is an important feature of the latter game). The UsefulNotes/{{NES}} and UsefulNotes/SegaGenesis both had rudimentary PCM support, but this was mainly used for pre-recorded voices, sound effects, and drums. The modified [=OPL2=] chip (called an [=OPN2=]) used by the Genesis has a PCM codec mode, but the Genesis can also resort to manipulating the PSG to play back PCM sounds if needed- notable as it's how the Sonic 3 Launch Base zone BGM managed to have a percussion track and still have the "Go!" voice samples). Pretty much every system introduced since uses PCM.

Once games started to ship on [=CDs=], Red Book audio for game soundtracks became common. The audio could be played from the CD just like music on a music CD, while the game data lived in memory. This technology was actually developed in tandem with PCM sample playback and competed with PCM synthesis, and is sometimes used together with the former (for example, in the PC port of VideoGame/WipeOut and VideoGame/QuakeII, where the music is played from the music CD partition of the disc while the sound effects are played through PCM sample playback). A nice side-effect of this would be that the game CD is its own soundtrack CD and the soundtrack can be enjoyed on any regular CD player, and it also adds an extra layer of complexity for [[CopyProtection copy protection]] in that multi-partition game discs are difficult to duplicate reliably. Additionally, the music often sounds better than PCM sampled music, since real instruments could be played and recorded. On the downside, however, looping music tends to be difficult if not impossible to implement- as evident in ''VideoGame/SonicCD'' on the UsefulNotes/SegaCD, where the music had a short fade-out and [[FadeIn fade-in]] section when repeating. It also makes VariableMix impossible to implement as well.

This was one of the main draws of the UsefulNotes/AppleMacintosh in the early 90s, when educational and adventure games alike started using these for music as an alternative to FM synthesis [[note]]Indeed, Macs ''don't'' have a FM synthesizer built in, their musical abilities are mostly down to [=QuickTime's=] software PCM synthesizer engine, red book CD audio, PCM music playback, or a MIDI keyboard attached to a SCSI-to-MIDI converter, the latter being only found in homes of music enthusiasts[[/note]].

The first popular gaming platforms to use a PCM synthesis chipset were the UsefulNotes/AcornArchimedes, UsefulNotes/{{Amiga}}, UsefulNotes/{{SNES}}, and believe it or not, {{Pinball}} systems, mainly those that used [[Creator/{{Midway}} Midway's]] DCS PCM Synthesis board (which also saw use in Franchise/MortalKombat and VideoGame/RevolutionX cabinets, since it not only reproduces instruments more faithfully, but one of the many tricks PCM synthesis could do was transparently loop fully-voiced music tracks, which is an important feature of the latter game). The UsefulNotes/{{NES}} and UsefulNotes/SegaGenesis both had rudimentary PCM support, but this was mainly used for pre-recorded voices, sound effects, and drums. The modified [=OPL2=] chip (called an [=OPN2=]) used by the Genesis has a PCM codec mode, but the Genesis can also resort to manipulating the PSG to play back PCM sounds if needed- notable as it's how the Sonic 3 Launch Base zone BGM managed to have a percussion track and still have the "Go!" voice samples). Pretty much every system introduced since uses PCM.

Additionally, the Yamaha OPL chips were also found on the [=MoonSound=], [=MSX Music=] and [=MSX Sound=] expansion cards for the MSX, and the popular [=AdLib=] sound card for [=PCs=] (and became the defacto standard until usurped by the [=SoundBlaster=] in the early 90s), as well as in most [=SoundBlaster=] PC sound cards and clones to provide [=AdLib=] compatibility. There was even an OPL-1 based FM Synthesis module (allegedly upgradable to OPL-2) for the UsefulNotes/{{Commodore 64}} in case the user needs even better quality music than the SID can provide.

Once games started to ship on [=CDs=], Red Book audio for game soundtracks became common. The audio could be played from the CD just like music on a music CD, while the game data lived in memory. This technology was actually developed in tandem with PCM sample playback and competed with PCM synthesis, and is sometimes used together with the former (for example, in the PC port of VideoGame/WipeOut and VideoGame/QuakeII, where the music is played from the music CD partition of the disc while the sound effects are played through PCM sample playback). A nice side-effect of this would be that the game CD is its own soundtrack CD and the soundtrack can be enjoyed on any regular CD player, and it also adds an extra layer of complexity for [[CopyProtection copy protection]] in that multi-partition game discs are difficult to duplicate reliably. Additionally, the music often sounds better than PCM sampled music, since real instruments could be played and recorded. On the downside, however, looping music tends to be difficult if not impossible to implement- as evident in ''VideoGame/SonicCD'' on the UsefulNotes/SegaCD, where the music had a short fade-out and fade-in section when repeating. It also makes VariableMix impossible to implement as well.

The first popular gaming platforms to use a PCM synthesis chipset were the UsefulNotes/AcornArchimedes, UsefulNotes/{{Amiga}}, UsefulNotes/{{SNES}}, and believe it or not, {{Pinball}} systems, mainly those that used [[Creator/{{Midway}} Midway's]] DCS PCM Synthesis board (which also saw use in VideoGame/MortalKombat and VideoGame/RevolutionX cabinets, since it not only reproduces instruments more faithfully, but one of the many tricks PCM synthesis could do was transparently loop fully-voiced music tracks, which is an important feature of the latter game). The UsefulNotes/{{NES}} and UsefulNotes/SegaGenesis both had rudimentary PCM support, but this was mainly used for pre-recorded voices, sound effects, and drums. The modified [=OPL2=] chip (called an [=OPN2=]) used by the Genesis has a PCM codec mode, but the Genesis can also resort to manipulating the PSG to play back PCM sounds if needed- notable as it's how the Sonic 3 Launch Base zone BGM managed to have a percussion track and still have the "Go!" voice samples). Pretty much every system introduced since uses PCM.