OpenSL ES (Open Sound Library for Embedded Systems) is a royalty-free, cross-platform, hardware-accelerated, C-language audio

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

for 2D and 3D audio. It provides access to features such as 3D positional audio and

MIDI MIDI (; Musical Instrument Digital Interface) is a technical standard that describes a communications protocol, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, computers, and rel ...

playback. It is made for developers in the mobile and gaming industry and is working toward allowing for easy porting of applications across multiple platforms.

Overview

The OpenSL ES API has five major features: * Basic audio playback and recording * 3D audio effects including 3D positional audio * Music experience enhancing effects including bass boost and environmental reverb * Interactive music and ringtones using SP-MIDI, Mobile DLS, Mobile XMF * Buffer Queues The features of ''Audio Playback and Recording'' and ''Basic MIDI'' are common with OpenMAX AL.

Design

OpenSL ES utilizes an object oriented design to give application developers access to the audio functionality. The object model is shared with OpenMAX AL, and a device manufacturer can choose to implement one or both of the APIs. Together the two APIs give access to a wide range of functionality of the device's multimedia engine. The design goal of OpenSL ES is to give application developers access to advanced audio features such as 3D positional audio and

playback while striving for easy application porting between manufacturers and platforms. It is developed primarily for application developers in the mobile and gaming industry.

Profiles

To avoid fragmentation, OpenSL ES is divided up into three profiles: * Phone * Music * Game Each profile is designed for the respective device needs with a specific set of audio functionalities. A vendor can choose to be conformant with only one or with any combination of profiles. An application can query the OpenSL ES implementation to find out which profiles are supported. The application developer can then design their application to either work with only the common parts of the profiles, or adapt to the available functionality as given by the profiles in the device it is running on. An application developer can also specify both the minimum and the optimal profile requirements.

Development

OpenSL ES is managed by the

non-profit A nonprofit organization (NPO) or non-profit organisation, also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collective, public or social benefit, in co ...

technology

consortium A consortium (plural: consortia) is an association of two or more individuals, companies, organizations or governments (or any combination of these entities) with the objective of participating in a common activity or pooling their resources fo ...

Khronos Group The Khronos Group, Inc. is an open, non-profit, member-driven consortium of 170 organizations developing, publishing and maintaining royalty-free interoperability standards for 3D graphics, virtual reality, augmented reality, parallel computatio ...

. The current chair of the OpenSL ES working group is Erik Noreke.

Specification versions

OpenSL ES 1.0 Specification
was released 24 March 2009. * Minor release 1.0.1 followed 24 September 2009.
OpenSL ES 1.1 Specification
was released 18 January 2011.

Implementations

* Android 2.3 exposes OpenSL ES 1.0 as part of their NDK. The latency of the implementation has improved in later releases. * A full implementation of OpenSL ES 1.1 is available from

SRS Labs SRS Labs, Inc. was a Santa Ana, California-based audio technology engineering company that specialized in audio enhancement solutions for wide variety of consumer electronic devices. Originally a part of Hughes Aircraft Company, the audio division ...

References

External links

OpenSL ES website

Khronos Group website

Khronos OpenSL ES API Registry
containing specifications {{Khronos Group standards Application programming interfaces Audio libraries Video game engines