Audio Stream Input/Output

Last updated

ASIO
Operating system Microsoft Windows
Type API

Audio Stream Input/Output (ASIO) is a computer audio interface driver protocol for digital audio specified by Steinberg, providing high data throughput, synchronization, and low latency between a software application and a computer's audio interface or sound card [1] .

Contents

ASIO was initially released in 1997 in order to enable streaming of one or more audio streams from an (multi-input/output) audio interface to a software and vice versa with minimal latency and sample accurate synchronization of the audio streams. It allows the audio streams to use any sample rate and supports bit resolutions of 16, 24, 32 bit integer and 32 or 64 bit floating point [2] .

The release of ASIO 2.0 in 1999 brought further enhancements such as ASIO Direct Monitoring, where an audio signal is monitored directly from the audio interface with basically zero latency, and ASIO Positioning Protocol, used to sample accurately synchronize a computer to other digital machines such as ADAT recorder or also other computers [3] .

The latest version ASIO 2.3 introduced monitoring for dropouts in the audio stream [4] .

ASIO bypasses the normal audio path from a user application through layers of intermediary operating system software so that an application connects directly to the sound card 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

Currently only Microsoft Windows is supported.

While originally supporting MacOS, the introduction of Core Audio with macOS X made ASIO support for this OS unnecessary.

There is also an experimental ASIO driver for Wine, WineASIO, [5] for a Windows compatibility layer for Linux. [6] WineASIO driver uses the JACK sound server as its audio back-end and allows many ASIO-aware applications to run with low latency under WINE. [6]

Licensing

The license to use the ASIO software development kit (SDK) and to distribute an ASIO driver is free of charge. Yet an SDK license agreement has to be signed [7] .

Distribution of the source code is not allowed. 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." [8]

See also

Related Research Articles

<span class="mw-page-title-main">Sound card</span> Expansion card that provides input and output of audio signals

A sound 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 audio interfaces used for professional audio applications.

<span class="mw-page-title-main">Advanced Linux Sound Architecture</span> Software framework

Advanced Linux Sound Architecture (ALSA) is a software framework and part of the Linux kernel that provides an application programming interface (API) for sound card device drivers.

<span class="mw-page-title-main">Ardour (software)</span> Open-source digital audio workstation

Ardour is a hard disk recorder and digital audio workstation application that runs on Linux, macOS, FreeBSD and Microsoft Windows. Its primary author is Paul Davis, who was also responsible for the JACK Audio Connection Kit. It is intended as a digital audio workstation suitable for professional use.

foobar2000 Freeware audio player

foobar2000 is a freeware audio player for Microsoft Windows, iOS, Android, macOS, and formerly Windows Phone, developed by Peter Pawłowski. It has a modular design, which provides user flexibility in configuration and customization. Standard "skin" elements can be individually augmented or replaced with different dials and buttons, as well as visualizers such as waveform, oscilloscope, spectrum, spectrogram (waterfall), peak and smoothed VU meters, which all of them are analysis-oriented, at least for built-in visualizations. foobar2000 offers third-party user interface modifications through a software development kit (SDK).

Steinberg Media Technologies GmbH is a German musical software and hardware company based in Hamburg. It develops software for writing, recording, arranging and editing music, most notably Cubase, Nuendo, and Dorico. It also designs audio and MIDI hardware interfaces, controllers, and iOS/Android music apps including Cubasis. Steinberg created several industry standard music technologies including the Virtual Studio Technology (VST) format for plug-ins and the ASIO protocol. Steinberg has been a wholly owned subsidiary of Yamaha since 2005.

<span class="mw-page-title-main">Virtual Studio Technology</span> Audio plug-in software interface

Virtual Studio Technology (VST) is an audio plug-in software interface that integrates software synthesizers and effects units into digital audio workstations. VST and similar technologies use digital signal processing to simulate traditional recording studio hardware in software. Thousands of plugins exist, both commercial and freeware, and many audio applications support VST under license from its creator, Steinberg.

<span class="mw-page-title-main">Pro Tools</span> Digital audio workstation

Pro Tools is a digital audio workstation (DAW) developed and released by Avid Technology for Microsoft Windows and macOS. It is used for music creation and production, sound for picture and, more generally, sound recording, editing, and mastering processes.

<span class="mw-page-title-main">Digital audio workstation</span> Electronic device or application software used for recording, editing and producing audio files

A digital audio workstation is an electronic device or application software used for recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software program on a laptop, to an integrated stand-alone unit, all the way to a highly complex configuration of numerous components controlled by a central computer. Regardless of configuration, modern DAWs have a central interface that allows the user to alter and mix multiple recordings and tracks into a final produced piece.

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 can handle the mixing and recording of multiple audio streams. DirectSound was originally written for Microsoft by John Miles.

Final Scratch is a DJ tool created by the Dutch company N2IT with input from Richie Hawtin and John Acquaviva that allows manipulation and playback of digital audio sources using traditional vinyl and turntables. It seeks to cross the divide between the versatility of digital audio and the tactile control of vinyl turntablism.

<span class="mw-page-title-main">Sound Blaster X-Fi</span> Computer sound card

Sound Blaster X-Fi is a lineup of sound cards in Creative Technology's Sound Blaster series.

<span class="mw-page-title-main">PulseAudio</span> Sound server for Unix-like operating systems

PulseAudio is a network-capable sound server program distributed via the freedesktop.org project. It runs mainly on Linux, including Windows Subsystem for Linux on Microsoft Windows and Termux on Android; various BSD distributions such as FreeBSD, OpenBSD, and macOS; as well as Illumos distributions and the Solaris operating system. It serves as a middleware in between applications and hardware and handles raw PCM audio streams.

This article describes audio APIs and components in Microsoft Windows which are now obsolete or deprecated.

<span class="mw-page-title-main">LinuxSampler</span> Music sampler

LinuxSampler is music sampler software aiming to provide a pure software audio sampler with professional grade features comparable to both hardware and commercial software samplers, as well as to introduce new features not yet available by other samplers. Much of LinuxSampler is free software, but commercial reuse of some, such as the back-end, is restricted.

The Helix Board 12 FireWire is a mixer developed by Phonic Corporation that features a FireWire Interface, able to connect the mixer to Windows and Mac computers. The product was released in 2005 and has since become a signature product for the company

Latency refers to a short period of delay between when an audio signal enters a system, and when it emerges. Potential contributors to latency in an audio system include analog-to-digital conversion, buffering, digital signal processing, transmission time, digital-to-analog conversion, and the speed of sound in the transmission medium.

<span class="mw-page-title-main">Software effect processor</span>

A software effect processor is a computer program that alters the sound from a digital source through audio signal processing in real time. It is a digital analog of hardware effects processors. It is an integral part of audio editing software, such as in Adobe Audition

RTP-MIDI is a protocol to transport MIDI messages within Real-time Transport Protocol (RTP) packets over Ethernet and WiFi networks. It is completely open and free, and is compatible both with LAN and WAN application fields. Compared to MIDI 1.0, RTP-MIDI includes new features like session management, device synchronization and detection of lost packets, with automatic regeneration of lost data. RTP-MIDI is compatible with real-time applications, and supports sample-accurate synchronization for each MIDI message.

SoundGrid is a networking and processing platform audio application made by Waves Audio and developed in cooperation with DiGiCo.

References

  1. "ASIO ? What is it?". Steinberg Forums. 20 June 2016. Retrieved 11 September 2024.
  2. "ASIO ? What is it?". Steinberg Forums. 20 June 2016. Retrieved 11 September 2024.
  3. "Steinberg Cubase VST 3.7". www.soundonsound.com. Retrieved 11 September 2024.
  4. ASIO SDK 2.3.pdf, as part of the ASIO SDK.
  5. "WineASIO website". Archived from the original on 1 March 2020. Retrieved 1 March 2020.
  6. 1 2 Mielewczik, Michael (2008). "Renoise für Linux. Musikproduktion im Retro-Stil". LinuxLife (in German). 5/2008: 69–72.
  7. Steinberg ASIO SDK Licensing Agreement Version 2.0.3, PDF available as part of the ASIO SDK.
  8. "ASIO Audio Interface". 2008. Retrieved 2 December 2019.