The Open Sound System (OSS) is an interface for making and capturing sound in
Unix
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...
and
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
operating systems. It is based on standard Unix
devices system call
In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, acc ...
s (i.e.
POSIX
The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming interf ...
read
Read
Read may refer to:
* Reading, human cognitive process of decoding symbols in order to construct or derive meaning
* Read (automobile), an American car manufactured from 1913 to 1915
* Read (biology), an inferred sequence of base pairs of ...
,
write
Writing is a medium of human communication which involves the representation of a language through a system of physically inscribed, mechanically transferred, or digitally represented symbols.
Writing systems do not themselves constitute h ...
,
ioctl
In computing, ioctl (an abbreviation of input/output control) is a system call for device-specific input/output operations and other operations which cannot be expressed by regular system calls. It takes a parameter specifying a request code; th ...
, etc.). The term also sometimes refers to the software in a Unix kernel that provides the OSS interface; it can be thought of as a
device driver
In computing, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabling operating systems and ot ...
(or a collection of device drivers) for
sound controller hardware. The goal of OSS is to allow the writing of sound-based applications that are agnostic of the underlying sound hardware.
OSS was created by
Hannu Savolainen
Hannu, Hennu or Henenu was an Egyptian noble, serving as ''m-r-pr'' "majordomo" to Mentuhotep III in the 20th century BC. He reportedly re-opened the trade routes to Land of Punt, Punt and Ancient Libya, Libya for the Middle Kingdom of Egypt. He ...
and is distributed under
four license options, three of which are
free software licences
A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and software distribution, redistribute that software. These actions are usually prohibited by copyright law, but the rights-holde ...
, thus making OSS
free software
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...
.
API
The API is designed to use the traditional Unix framework of open(), read(), write(), and ioctl(), via special devices. For instance, the default device for sound input and output is /dev/dsp. Examples using the shell:
cat
/dev/random > /dev/dsp # plays
white noise
In signal processing, white noise is a random signal having equal intensity at different frequencies, giving it a constant power spectral density. The term is used, with this or similar meanings, in many scientific and technical disciplines, ...
through the speaker
cat /dev/dsp > a.a # reads data from the microphone and copies it to file a.a
Free, proprietary, free
The project was initially
free software
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...
, but following the project's success, Savolainen was contracted by the company
4Front Technologies and made his support for newer sound devices and improvements