8-Bit Sampled Voice (8SVX) is an

audio file format An audio file format is a file format for storing digital audio data on a computer system. The bit layout of the audio data (excluding metadata) is called the audio coding format and can be uncompressed, or compressed to reduce the file size, ofte ...

standard developed by

Electronic Arts Electronic Arts Inc. (EA) is an American video game company headquartered in Redwood City, California. Founded in May 1982 by Apple employee Trip Hawkins, the company was a pioneer of the early home computer game industry and promoted the ...

for the

Commodore Commodore may refer to: Ranks * Commodore (rank), a naval rank ** Commodore (Royal Navy), in the United Kingdom ** Commodore (United States) ** Commodore (Canada) ** Commodore (Finland) ** Commodore (Germany) or ''Kommodore'' * Air commodore ...

- Amiga computer series. It is a data subtype of the IFF file container format. It typically contains

linear pulse-code modulation Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the am ...

(LPCM) digital audio.

Description

The 8SVX subtype stores 8-bit audio data within chunks contained within an IFF file container. 8SVX subtypes can exist alone within IFF file containers (audio only), or can be

multiplexed In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource - a ...

together with other IFF subtypes, such as video animation streams. Metadata about the 8SVX data stream is contained in separate descriptor chunks that come prior to the main data body chunk.

Sample rate In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples". A sample is a value of the signal at a point in time and/or spa ...

, volume and compression type are described in a ''VHDR'' chunk. Various other chunks are available to describe the name, author and copyright. 8SVX supports features such as attack, release and section repeat, which are useful for storage of musical instrument samples. An example layout of an audio-only 8SVX IFF audio file:

Encoding

The majority of 8SVX data streams are encoded using uncompressed linear PCM streams. Optionally,

Fibonacci Fibonacci (; also , ; – ), also known as Leonardo Bonacci, Leonardo of Pisa, or Leonardo Bigollo Pisano ('Leonardo the Traveller from Pisa'), was an Italian mathematician from the Republic of Pisa, considered to be "the most talented Wester ...

-delta

lossy data compression In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data siz ...

is also available, resulting in a 50% compression ratio at the cost of decreased fidelity. Multi-byte values are stored in big-endian format, the native byte order for the

Motorola 68000 family The Motorola 68000 series (also known as 680x0, m68000, m68k, or 68k) is a family of 32-bit complex instruction set computer (CISC) microprocessors. During the 1980s and early 1990s, they were popular in personal computers and workstations and ...

Support

IFF-8SVX encoded audio was the default audio format for the Commodore Amiga. Most audio programs for the Amiga supported the format.

AmigaOS AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versions ...

3.0 introduced a

multimedia framework A multimedia framework is a software framework that handles media on a computer and through a network. A good multimedia framework offers an intuitive API and a modular architecture to easily add support for new audio, video and container formats ...

using the datatype subsystem that included an 8SVX decoder (8SVX.datatype). Many sound editing programs and

music tracker A music tracker (sometimes referred to as just tracker for short) is a type of music sequencer software for creating music. The music is represented as discrete musical notes positioned in several channels at discrete chronological positions on ...

programs of the late 1980s and early 1990s supported the format. It is still a common format for cross-platform audio editing programs (such as Sound eXchange). 8SVX support is also available to modern programs via libavcodec (and the related ffdshow codec package) as well as via

libsndfile libsndfile is a widely used C library written by Erik de Castro Lopo for reading and writing audio files. It supports a wide variety of audio file formats and will convert automatically from one to another. It allows the programmer to ignore m ...

Legacy

The Commodore Amiga computer series never received native hardware support for 16-bit digital audio before the decline of the platform. As such, the related 16SVX and MAUD subtypes never saw wide adoption. Shan Apple Computer developed a separate subtype known as AIFF which included support for 16-bit samples and additional compression types. It superseded 8SVX as the dominant audio subtype for IFF files.

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washin ...

and IBM co-developed the

RIFF A riff is a repeated chord progression or refrain in music (also known as an ostinato figure in classical music); it is a pattern, or melody, often played by the rhythm section instruments or solo instrument, that forms the basis or acc ...

file container and the related

WAVE In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (re ...

audio subtype for

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ser ...

. Both formats are heavily influenced by the IFF/8SVX container format, but like AIFF, were extended to support higher bit-depths and additional compression types.

References

External links