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Press Release

Khronos Group Releases OpenSL ES 1.1 Specification For Stereo and 3D Audio on Any Mobile Platform an

Support from Creative, Google, Nokia, NVIDIA, Qualcomm & SRS Labs, Inc. + Others

January 18, 2011 – San Jose, CA – The Khronos™ Group (Beaverton, OR) today publicly released the OpenSL ES™ 1.1 specification for high-performance, low-latency audio across any mobile and embedded device platform or operating system.  OpenSL ES 1.1 enables psychoacoustically enhanced 3D audio across a wide range of applications, such as gaming, videoconferencing, music and ringtones as well as advanced stereo and MIDI functionality. 

OpenSL ES works not only on smartphones and leading-edge mobile devices but also portable designs utilizing older hardware.  Regardless of its deployment platform, OpenSL ES provides a common reference API (Application Programming Interface) that enables any device to achieve the maximum audio performance available to its hardware.  OpenSL ES is the latest addition to the line of Khronos APIs creating a common platform of hardware-accelerated, cross platform functionality for mobile devices, including OpenGL ES™ (2D/3D graphics) and OpenMAX™ IL (system-level multimedia) and OpenMAX™ AL (application-level multimedia).  The OpenSL ES 1.1 specification is immediately available for download at and may be used royalty-free by implementers and developers.

OpenSL ES Details

OpenSL ES 1.1 is a fully featured audio API that enables application developers to control and utilize advanced audio functionality in a device while being isolated from platform specifics.  This allows audio-enhanced applications to run on a multitude of hardware-accelerated and software-based platforms.  OpenSL ES was designed by many of the leading industry audio experts to provide access to a broad range of audio functionality, including:

  • Playback of PCM and encoded content, MIDI ringtones and UI sounds, as well as extraction of content metadata;
  • General audio controls such as volume, rate and pitch; music player effects such as equalizer, bass boost, preset reverberation and stereo widening, as well as advanced 3D effects such as Doppler, environmental reverberation and virtualization;
  • Advanced MIDI including SP-MIDI, mobile DLS, mobile XMF, MIDI messages and the ability to use the output of the MIDI engine as a 3D sound source;
  • Full 3D positional audio including grouping of 3D sound sources;
  • Audio recording in PCM as well as non-PCM formats;
  • Optional support for LED and vibrator control, 3D macroscopic control and audio recording;
  • Provides a portable foundation for implementing the audio portions of higher-level APIs such as JSR 135 and JSR 234;
  • Technical details unique to OpenSL ES 1.1 include support for:
    • Buffer queues
    • Content pipes
    • Better application control of 3D performance
    • Explicit object ordering
    • Dynamic sources and sinks
    • Multiple version support
    • Metadata support for streaming playback
    • Extension configuration support

Due to the broad range of audio functionality it offers, OpenSL ES defines three overlapping profiles allowing implementers to select the features required by a particular device while preserving application portability (one or more profiles may be used on a device):

  • The Phone profile provides playback controls and volume controls, sound prioritization and MIDI as well as the ability to direct sound to multiple simultaneous outputs;
  • The Music profile provides balance and pan controls, sound prioritization and audio effects such as virtualization, preset reverberation and equalizer controls;
  • The Game profile provides buffer queues, pitch and playback rate control, environmental reverberation and extensive positional 3D audio controls that complement the use of OpenGL ES for 3D graphics in sophisticated mobile applications.

An Adopters Program for OpenSL ES, including extensive conformance tests to ensure cross-implementation consistency and trademark usage by conformant implementations, will be released by Khronos during the first quarter of 2011.  SRS Labs, Inc. also has a complete OpenSL ES v1.1 Phone – Music – Game solution, including all of the optional features and relevant IP blocks required, available for license to interested companies.


OpenSL ES seamlessly integrates with the latest version of OpenMAX™ AL for a complete multimedia-enhanced mobile solution, with OpenMAX AL providing multimedia playback and recording capabilities while OpenSL ES provides advanced stereo and 3D audio functionality.  (EDITORS NOTE: OpenMAX AL 1.1 was announced simultaneously at the Khronos press conference on January 18, 2011 – see press release for further details).

"The enhancements released in OpenSL ES 1.1 and OpenMAX AL 1.1 enable handset manufactures to provide application developers with a truly portable advanced audio and streaming multimedia solution.  The combined power of OpenSL ES and OpenMAX AL, linked by their common architecture, has never before been available in a standard developed specifically for mobile solutions," said Neil Trevett, President of the Khronos Group.

3rd-Party Support

A number of leading companies have worked on the OpenSL ES 1.1 specification, including: AMD®, Creative®, Ericsson®, Google®, Nokia®, NVIDIA®, Qualcomm® and SRS Labs, Inc.  A full list of the OpenSL ES Working Group members may be found at

“Today’s smartphones and other advanced mobile devices either carry or have access to massive libraries of songs, movies and TV shows but, unfortunately, almost all of these mobile devices suffer the drawback of collapsed audio due to their small and closely spaced speaker configurations,” said Bob Lyle, Managing Director of Global Business Development for SRS Labs, Inc.  “To address this inherent shortcoming, SRS has developed several new audio enhancement solutions and we are very excited to be contributing to the OpenSL ES specification and bringing our unique psychoacoustic know-how and world class technologies to a wide range of mobile applications, effectively delivering a compelling and dynamic audio experience to any mobile device.”

"OpenSL ES brings powerful, advanced 3D audio to mobile devices in a simple and standardized way.  It empowers applications to harness hardware acceleration and third party audio enhancements in a simple to use, object-oriented design," said Erik Noreke, Chair of the OpenSL ES Working Group and an Independent Standardization Specialist.  "The adopters program provides access to the Khronos royalty-free IP license, one of the most implementer-friendly IP policies in the industry."

About The Khronos Group
The Khronos Group is an industry consortium creating open standards to enable the authoring and acceleration of parallel computing, graphics and dynamic media on a wide variety of platforms and devices.  Khronos standards include OpenGL®, OpenGL® ES, OpenCL™, OpenMAX™, OpenVG™, OpenSL ES™, OpenKODE™, and COLLADA™.  All Khronos members are able to contribute to the development of Khronos specifications, are empowered to vote at various stages before public deployment and are able to accelerate the delivery of their cutting-edge media platforms and applications through early access to specification drafts and conformance tests.  More information is available at


Khronos, OpenKODE, OpenVG, OpenSL ES and OpenMAX are trademarks of the Khronos Group Inc. OpenCL is a trademark of Apple Inc., COLLADA is a trademark of Sony Computer Entertainment Inc. and OpenGL is a registered trademark and the OpenGL ES and OpenGL SC logos are trademarks of Silicon Graphics Inc. used under license by Khronos. All other product names, trademarks, and/or company names are used solely for identification and belong to their respective owners.