View source for OpenSL ES

{{Use dmy dates|date=January 2020}}
{{for|the graphics API|OpenGL ES}}
{{Infobox software
| name = OpenSL ES
| logo = [[File:OpenSL ES logo.svg|220px|OpenSL ES Logo]]
| caption = The Standard for Enhanced Audio
| developer = [[Khronos Group|Khronos Group, Inc.]]
| latest_release_version = 1.1
| latest_release_date = {{Start date and age|2011|01|18}}
| operating_system = [[Cross-platform]]
| genre = [[Application programming interface|API]]
| license = Royalty free
| website = {{URL|http://www.khronos.org/opensles/}}
}}
'''OpenSL ES''' ('''Open Sound Library for Embedded Systems''') is a royalty-free, [[cross-platform]], [[hardware-accelerated]],  [[C (programming language)|C-language]] audio [[Application programming interface|API]] for 2D and 3D audio. It provides access to features such as [[3D audio|3D positional audio]] and [[MIDI]] 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<ref>{{Cite web|url=https://software.intel.com/en-us/articles/android-low-latency-audio-on-x86-based-mobile-devices|title = Intel Developer Zone}}</ref>

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 audio|3D positional audio]]
and [[MIDI]] 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 organization|non-profit]] technology [[consortium]] [[Khronos Group]]. The current chair of the OpenSL ES working group is Erik Noreke.

==Specification versions==
* [http://www.khronos.org/opensles/ OpenSL ES 1.0 Specification] was released 24 March 2009.<ref>[http://www.khronos.org/news/press/releases/khronos-group-releases-opensl-es-1.0-specification-for-portable-mobile/ Khronos Group Releases OpenSL ES 1.0 Specification for Portable Mobile and Embedded Audio Processing] {{webarchive|url=https://web.archive.org/web/20090407143033/http://www.khronos.org/news/press/releases/khronos-group-releases-opensl-es-1.0-specification-for-portable-mobile/ |date=7 April 2009 }}, Khronos press release</ref>
* Minor release 1.0.1 followed 24 September 2009.
* [http://www.khronos.org/opensles/ OpenSL ES 1.1 Specification] was released 18 January 2011.<ref>[http://www.khronos.org/news/press/releases/khronos-opensl-es-1-1-specification-for-stereo-3d-audio-mobile-os/ Khronos Group Releases OpenSL ES 1.1 Specification For Stereo and 3D Audio on Any Mobile Platform and OS] {{webarchive|url=https://web.archive.org/web/20110317193143/http://www.khronos.org/news/press/releases/khronos-opensl-es-1-1-specification-for-stereo-3d-audio-mobile-os |date=17 March 2011 }}, Khronos press release</ref>

== Implementations ==
* [[Android (operating system)|Android]] 2.3 exposes OpenSL ES 1.0 as part of their [[Android NDK]].<ref>{{cite web|url=http://news.softpedia.com/news/Android-2-3-Brings-Changes-for-Developers-too-New-SDK-Available-170952.shtml|title=Android 2.3 Brings Changes for Developers too, New SDK Available|author=Ionut Arghire|date=7 December 2010|work=softpedia}}</ref><ref>{{cite web|url=http://developer.android.com/ndk/guides/audio/opensl-for-android.html|title=Native Audio: OpenSL ES™ for Android|publisher=}}{{Dead link|date=August 2025 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The [[Latency (audio)|latency]] of the implementation has improved in later releases.<ref>{{cite web|url=https://source.android.com/devices/audio/latency_measurements.html|title=Audio Latency Measurements|publisher=}}</ref><ref>{{cite web|url=https://www.ntnu.edu/documents/1001201110/1266017954/DAFx-15_submission_29.pdf/c20ccc4f-1262-42ae-af5f-4a0b1305d142|title=APPROACHES FOR CONSTANT AUDIO LATENCY ON ANDROID|work=Proc. of the 18th Int. Conference on Digital Audio Effects|date=3 December 2015|author1=Rudi Villing}}</ref><ref>{{cite web|url=http://superpowered.com/android-marshmallow-latency|title=Rebooting Android's 10 Millisecond Problem: Audio Latency Improvements in Android 6.0 Marshmallow|work=Superpowered Audio for iOS, OSX and Android|date=25 August 2016}}</ref>
* A full implementation of OpenSL ES 1.1 is available from [[SRS Labs]].<ref>{{cite web|url=http://technews.tmcnet.com/news/2011/02/14/5310150.htm|title=SRS Labs Launches Industry's First Khronos OpenSL ES 1.1 Audio Solution for Android Mobile Devices at Mobile World Congress|publisher=}}</ref>

==See also==
*[[OpenMAX AL]] - Application level multimedia API
*[[OpenAL]] - advanced audio API for desktop and mobile
*[[Advanced Multimedia Supplements]] (JSR 234) - Java API for mobile devices

==References==
{{Reflist}}

==External links==
* [http://www.khronos.org/opensles OpenSL ES website]
* [http://www.khronos.org/ Khronos Group website]
* [http://www.khronos.org/registry/sles/ Khronos OpenSL ES API Registry] containing specifications

{{Khronos Group standards}}

[[Category:Application programming interfaces]]
[[Category:Audio libraries]]
[[Category:Video game engines]]