SoundFont
Encyclopedia
SoundFont is a brand name that collectively refers to a file format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

 and associated technology designed to bridge the gap between recorded
Digital recording
In digital recording, digital audio and digital video is directly recorded to a storage device as a stream of discrete numbers, representing the changes in air pressure for audio and chroma and luminance values for video through time, thus making an abstract template for the original sound or...

 and synthesized audio, especially for the purposes of computer music composition. SoundFont is also a registered trademark
Trademark
A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...

 of E-mu Systems, Inc.
E-mu Systems
E-mu Systems, Inc. is a synthesizer maker and pioneer in samplers and low-cost digital sampling music workstations.-History:Founded in 1971 by Scott Wedge and Dave Rossum, E-mu began making modular synthesizers...

, and the exclusive license for re-formatting and managing historical SoundFont content has been acquired by Digital Sound Factory
Digital Sound Factory
Digital Sound Factory is a sound design company that creates sound libraries, known as SoundFont libraries, for playback on synthesizers and computers compatible with Steinberg Cubase, Cakewalk Sonar, Propellerheads Reason, Steinberg Halion, Native Instruments Kontakt, Apple Garageband, Apple...

.

SoundFont technology is an implementation of Sample-based synthesis
Sample-based synthesis
Sample-based synthesis is a form of audio synthesis that can be contrasted to either subtractive synthesis or additive synthesis. The principal difference with sample-based synthesis is that the seed waveforms are sampled sounds or instruments instead of fundamental waveforms such as the saw waves...

, first used on the Sound Blaster AWE32
Sound Blaster AWE32
Sound Blaster AWE32 is an ISA sound card from Creative Technology. It is an expansion board for PCs. The Sound Blaster AWE32, introduced in March 1994, was a near full-length ISA sound card, measuring 14 inches in length, due to the number of features included.-MIDI capability:The Sound Blaster...

 sound card for its General Midi
General MIDI
General MIDI or GM is a standardized specification for music synthesizers that respond to MIDI messages. GM was developed by the MIDI Manufacturers Association and the Japan MIDI Standards Committee and first published in 1991...

 support, and is still supported on current Sound Blaster
Sound Blaster
The Sound Blaster family of sound cards was the de facto standard for consumer audio on the IBM PC compatible system platform, until the widespread transition to Microsoft Windows 95, which standardized the programming interface at application level , and the evolution in PC design led to onboard...

 products.

History

The original SoundFont 1.0 version of the file format was developed in the early 1990s by E-mu Systems
E-mu Systems
E-mu Systems, Inc. is a synthesizer maker and pioneer in samplers and low-cost digital sampling music workstations.-History:Founded in 1971 by Scott Wedge and Dave Rossum, E-mu began making modular synthesizers...

 and Creative Labs. A specification for this version was never released to the public. The first and only major device to utilize this version was Creative's Sound Blaster AWE32
Sound Blaster AWE32
Sound Blaster AWE32 is an ISA sound card from Creative Technology. It is an expansion board for PCs. The Sound Blaster AWE32, introduced in March 1994, was a near full-length ISA sound card, measuring 14 inches in length, due to the number of features included.-MIDI capability:The Sound Blaster...

 in 1994. Files in this format conventionally have the file extension of .SBK.

The SoundFont 2.0 version of the file format was developed in 1996. The 2.0 format generalized the data representation using perceptually additive real world units, redefined some of the instrument layering features within the format, added true stereo sample support and removed some obscure features of the 1.0 version whose behavior was difficult to specify. This version was fully disclosed as a public specification, with the goal of making the SoundFont format an industry standard. All SoundFont 1.0 compatible devices were updated to support the SoundFont 2.0 format shortly after the format was released to the public, and consequently the 1.0 version became obsolete. Files in this format (and all other 2.x formats, see below) conventionally have the file extension of SF2.

The SoundFont 2.1 version of the file format was introduced in 1998 with an E-mu sound card product called the Audio Production Studio. The 2.1 version added features allowing sound designers to configure the way MIDI controllers influence synthesizer parameters. The 2.1 format is bidirectionally compatible with the 2.0 format, which means that synthesizers capable of rendering 2.1 format will also by definition render 2.0 format, and synthesizers that are only capable of rendering 2.0 format will also read and render 2.1 format, but just not apply the new features.

The SoundFont 2.4 version of the file format was introduced in 2005 with the Sound Blaster X-Fi
Sound Blaster X-Fi
Sound Blaster X-Fi is a lineup of sound cards in Creative Labs' Sound Blaster series.-History:The series was launched in August 2005 as a lineup of PCI sound cards, served as the introduction for their X-Fi audio processing chip, with models ranging from XtremeMusic , to Platinum, Fatal1ty FPS, and...

 product. (There never was a 2.2 or a 2.3 version.) The 2.4 format added support for 24-bit samples. The 2.4 format is bidirectionally compatible with the 2.1 format, which makes it so synthesizers that are only capable of rendering 2.0 or 2.1 format would automatically render instruments using 24-bit samples at 16-bit precision.

Functionality

Sample playback based MIDI synthesizers use wavetables to define the base samples that are used to render their MIDI files. MIDI files in themselves don't contain any sounds, rather they contain only instructions to render them, and consequently rely on the wavetables to render such sounds correctly. SoundFont-compatible synthesizers allow users to use SoundFont banks to augment these wavetables with custom samples to render their music.

A SoundFont bank contains base samples in PCM format (similar to .wav files
WAV
Waveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...

) that are mapped to sections on a musical keyboard. A SoundFont bank also contains other music synthesis parameters such as loops, vibrato
Vibrato
Vibrato is a musical effect consisting of a regular, pulsating change of pitch. It is used to add expression to vocal and instrumental music. Vibrato is typically characterised in terms of two factors: the amount of pitch variation and the speed with which the pitch is varied .-Vibrato and...

 effect, and velocity sensitive volume changing.
SoundFont banks can conform to standard sound sets such as General MIDI
General MIDI
General MIDI or GM is a standardized specification for music synthesizers that respond to MIDI messages. GM was developed by the MIDI Manufacturers Association and the Japan MIDI Standards Committee and first published in 1991...

, or use other wholly custom sound-set definitions.

External links

  • Creative's SoundFont pages, the official SoundFont page with downloads of Vienna, a SoundFont editor.
  • SFPack, a utility to compress and decompress SoundFont Pack files (.sfpack)
  • SfArk, a utility to compress and decompress SoundFont Ark files (.sfark)
  • BassMidi, free SoundFont based software synthesizer that works with Windows 7 (even 64 bit).
  • FluidSynth, free SoundFont based software synthesizer.
  • TiMidity++, another free SoundFont software synthesizer.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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