Audio Stream Input/Output (ASIO) is a computer sound card
driver protocol for
digital audio specified by
Steinberg
Steinberg Media Technologies GmbH (trading as Steinberg) is a German musical software and hardware company based in Hamburg. It develops music writing, recording, arranging, and editing software, most notably Cubase, Nuendo, and Dorico. It als ...
, providing a low-
latency and high fidelity interface between a software application and a computer's
sound card
A sound card (also known as an audio card) is an internal expansion card that provides input and output of audio signals to and from a computer under the control of computer programs. The term ''sound card'' is also applied to external au ...
. Whereas
Microsoft
Microsoft Corporation is an American multinational corporation, multinational technology company, technology corporation producing Software, computer software, consumer electronics, personal computers, and related services headquartered at th ...
's
DirectSound
DirectSound is a deprecated software component of the Microsoft DirectX library for the Windows operating system, superseded by XAudio2. It provides a low-latency interface to sound card drivers written for Windows 95 through Windows XP and c ...
is commonly used as an intermediary signal path for non-professional users, ASIO allows musicians and
sound engineer
An audio engineer (also known as a sound engineer or recording engineer) helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction, ...
s to access external hardware directly.
Overview
ASIO bypasses the normal audio path from a user application through layers of intermediary Windows operating system software so that an application connects directly to the
sound card
A sound card (also known as an audio card) is an internal expansion card that provides input and output of audio signals to and from a computer under the control of computer programs. The term ''sound card'' is also applied to external au ...
hardware. Each layer that is bypassed means a reduction in latency (the delay between an application sending audio information and it being reproduced by the sound card, or input signals from the sound card being available to the application). In this way, ASIO offers a relatively simple way of accessing multiple audio inputs and outputs independently.
Operating systems
Interface support is normally restricted to
Microsoft Windows. Starting with
Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
,
KMixer
This article describes audio APIs and components in Microsoft Windows which are now obsolete or deprecated.
Multimedia Extensions (MME)
The MME API or the Windows Multimedia API (also known as ''WinMM'') was the first universal and standardized ...
has been removed and replaced by
WASAPI
Windows Vista (formerly codenamed Windows "Longhorn") has many significant new features compared with previous Microsoft Windows versions, covering most aspects of the operating system.
In addition to the new user interface, security capabilities ...
and a new
WaveRT
Windows Vista (formerly codenamed Windows "Longhorn") has many significant new features compared with previous Microsoft Windows versions, covering most aspects of the operating system.
In addition to the new user interface, security capabilities ...
port driver.
There is also an experimental ASIO driver for
Wine
Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are ...
, WineASIO, for a Windows compatibility layer for Linux. WineASIO driver uses the
JACK
Jack may refer to:
Places
* Jack, Alabama, US, an unincorporated community
* Jack, Missouri, US, an unincorporated community
* Jack County, Texas, a county in Texas, USA
People and fictional characters
* Jack (given name), a male given name, ...
sound server as its audio back-end and allows many ASIO-aware applications to run with low latency under WINE.
Other free or open source alternatives are ASIO4All, FlexASIO, ASIO2KS, and ASIO2WASAPI.
Being a proprietary protocol, it does not have any universal compatibility with Windows-based
DAW and other recording software. For example, the user manual of the
Audacity audio editor states: "Licensing restrictions prevent us including ASIO support in released versions of Audacity, but Audacity can be compiled with ASIO support for private, non-distributable use."
See also
*
JUCE
JUCE is an open-source cross-platform C++ application framework, used for the development of desktop and mobile applications. JUCE is used in particular for its GUI and plug-ins libraries. It is dual licensed under the GPLv3 and a commercial ...
, an open-source C++ toolkit that includes support for ASIO audio devices.
*
JACK Audio Connection Kit, a similar system primarily for Linux.
References
External links
Steinberg website
{{DEFAULTSORT:Audio Stream Input Output
Application programming interfaces
Audio libraries
Digital audio