Editing OpenMAX

{{Infobox software
| name = OpenMAX
| developer = [[Khronos Group]]
| website = {{URL |www.khronos.org/openmax/}}
| logo = [[File:OpenMAX logo.svg|220px|OpenMAX logo]]
}}

'''OpenMAX''' (Open Media Acceleration), often shortened as "'''OMX'''", is a non-proprietary and royalty-free cross-platform set of [[C (programming language)|C-language]] programming interfaces. It provides abstractions for routines that are especially useful for processing of audio, video, and still images.<ref>http://www.cnx-software.com/2011/11/11/openmax-open-media-acceleration/ OpenMAX (Open Media Acceleration)</ref><ref>https://events.linuxfoundation.org/images/stories/pdf/lceu2012_debski.pdf {{Webarchive|url=https://web.archive.org/web/20140106032317/https://events.linuxfoundation.org/images/stories/pdf/lceu2012_debski.pdf |date=2014-01-06 }} Video4Linux2 - Path to a Standardized Video Codec API</ref> It is intended for low power and embedded system devices (including [[smartphone]]s, [[game console]]s, [[digital media player]]s, and [[set-top box]]es) that need to efficiently process large amounts of multimedia data in predictable ways, such as video codecs, graphics libraries, and other functions for video, image, audio, voice and speech.<ref>http://jan.newmarch.name/LinuxSound/Sampled/OpenMAX/ {{Webarchive|url=https://web.archive.org/web/20160312092757/https://jan.newmarch.name/LinuxSound/Sampled/OpenMAX/ |date=2016-03-12 }} Contents of full book "Linux Sound" - Chapter 13: OpenMAX/OpenSL</ref>

OpenMAX provides three layers of interfaces: application layer (AL), integration layer (IL) and development layer (DL). OpenMAX  is managed by the [[Non-profit organization|non-profit]] technology [[consortium]] [[Khronos Group]].<ref>http://www.khronos.org/openmax/ OpenMAX - The Standard for Media Library Portability (by Khronos Group)</ref>

==History==
Initially announced in July 2004.<ref>{{Cite web|url=https://www.khronos.org/news/press/khronos-group-announces-new-openmax-open-standard-for-enabling-effective-me|title = Khronos Group Announces New OpenMAX Open Standard for Enabling Effective Media Acceleration|date = 6 July 2004}}</ref>  The OpenMAX Working Group was initially founded by members [[ARM Holdings|ARM]], [[Motorola]], [[Samsung]], [[STMicroelectronics]], and [[Texas Instruments]].  Version 1.0 of the specification was published in December 2005.<ref>{{Cite book |last=The Khronos Group |title=OpenMAX™ Integration Layer Application Programming Interface Specification: Version 1.0 |date=2005-12-16 |publisher=The Khronos Group Inc. |edition=1.10 |language=en}}</ref> The last draft produced by the OpenMAX Working Group (1.2.0) dates from 2011<ref>{{Cite web|url=https://www.khronos.org/registry/OpenMAX-IL/|title = Khronos OpenMAX IL Registry - the Khronos Group Inc}}</ref> and no product has been declared as conformant since 2012.<ref>{{Cite web|url=https://www.khronos.org/conformance/adopters/conformant-products#openmaxil|title = The Khronos Group|date = 21 November 2021}}</ref> The OpenMAX specification were never updated to support recent codecs like HEVC or VP9, making Android the de facto source of updates to the OpenMAX IL standard.<ref>{{Cite web|url=https://android.googlesource.com/platform/frameworks/native/+/nougat-mr2.1-release/include/media/openmax/OMX_VideoExt.h|title = Include/Media/Openmax/OMX_VideoExt.h - platform/Frameworks/Native - Git at Google}}</ref>

==Layers==
'''OpenMAX AL''' is the interface between multimedia applications, such as a media player, and the platform [[media framework]]. It allows companies that develop applications to easily migrate their applications to different platforms (customers) that support the OpenMAX AL [[application programming interface]] (API).<ref>http://elinux.org/images/e/e0/The_OpenMAX_Integration_Layer_standard.pdf The OpenMAX Integration Layer standard</ref>

'''OpenMAX IL''' is the interface between media framework, (such as [[StageFright]] or MediaCodec API on Android, [[DirectShow]] on Windows, [[FFmpeg]] or [[GStreamer]] on Linux), and a set of multimedia components (such as an audio or video [[codec]]s). It allows companies that build platforms (e.g. allowing an implementation of an MP3 player) to easily change components like MP3 decoders and Equalizer effects and buy components for their platform from different vendors.<ref>http://elinux.org/images/5/52/Elc2011_garcia.pdf Integrating a Hardware Video Codec into Android Stagefright using OpenMAX IL</ref>

'''OpenMAX DL''' is the interface between physical hardware, such as [[digital signal processor]] (DSP) chips, [[Central processing unit|CPUs]], [[Graphics processing unit|GPUs]], and software, like video [[codec]]s and 3D engines. It allows companies to easily integrate new hardware that supports OpenMAX DL without reoptimizing their low level software.

==Application layer==
{{Infobox software
| name                   = OpenMAX AL
| logo                   = [[File:OpenMAX AL Logo.svg|OpenMAX AL Logo|220px]]
| developer              =  Khronos Group
| 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                = Various
}}
OpenMAX AL accommodates common multimedia application use cases by standardizing a set of representative [[Object (computer science)|objects]], as well as [[Interface (computer science)|interfaces]] on those objects, to control and configure them. The OpenMAX AL API is divided into two profiles: Media Player and Media Player/Recorder. A platform can be compliant to one or both of these profiles by providing all features included in a profile.

It is an application-level, [[C (programming language)|C-language]], multimedia API designed for resource-constrained devices. The OpenMAX AL API design puts particular emphasis on ensuring the API is suitable for [[Embedded system|mobile embedded devices]] - including basic mobile phones, smart “feature” phones, PDAs and mobile digital music players. Nevertheless, this does not preclude its applicability to other sophisticated media playback and recording devices.

The OpenMAX AL API design devotes particular attention to application-developer friendliness. Its status as an open cross-platform API enables developers to port the same source across multiple devices with minimal effort. Thus OpenMAX AL provides a stable base for application development.

===Features===
OpenMAX AL features include:
*Video playback and recording
*Audio playback and recording
*Image capture (camera) and display
*Camera controls
*Radio and [[Radio Data System|RDS]]
*Basic [[MIDI]] playback
*Metadata extraction and insertion

====Digital TV extension====
A digital television (DTV) extension specification of OpenMAX AL adds standards-agnostic mobile TV tuning, playback, recording and electronic program guide functionality to OpenMAX AL Multimedia API, as a modular royalty-free, cross-platform C-language API for high-performance digital TV-related applications on mobile and embedded devices. DTV Extension is compatible with all major mobile TV standards (e.g. DVB-H, ISDB-T, T-DMB, etc.), and supports broadcast, unicast and multicast delivery methods for Digital TV.<ref>http://www.khronos.org/openmax/al/dtv/ OpenMAX AL - Digital Television (DTV) Extension</ref><ref>https://www.khronos.org/news/press/khronos-group-releases-provisional-openmax-al-digital-tv-extension-specific Khronos Group Releases Provisional OpenMAX AL Digital TV Extension Specification</ref>

===Specification versions===
* OpenMAX AL 1.0 Provisional Specification -  a provisional version, dated 2007-09-02, to facilitate feedback from the community before the final 1.0 release.
* [http://www.khronos.org/registry/omxal/specs/OpenMAX_AL_1_0_Specification.pdf OpenMAX AL 1.0 Specification] - dated 2009-06-23
* [http://www.khronos.org/registry/omxal/specs/OpenMAX_AL_1_0_1_Specification.pdf OpenMAX AL 1.0.1 Specification] - dated 2010-03-12
* [http://www.khronos.org/openmax/al/ OpenMAX AL 1.1 Specification] - dated 2011-01-18<ref>[http://www.khronos.org/news/press/releases/khronos-openmax-al-specification-application-level-video-audio-processing/ Khronos Group Releases OpenMAX AL Specification for Application-level Video, Audio and Image Processing on Mobile and Handheld Devices] {{webarchive|url=https://web.archive.org/web/20110317195852/http://www.khronos.org/news/press/releases/khronos-openmax-al-specification-application-level-video-audio-processing |date=2011-03-17 }}, Khronos press release</ref>

=== Implementations===
* [[Android (operating system)|Android]] 4.0 and later exposes OpenMAX AL as part of its [[Android software development#Android NDK|NDK (Native Development Kit)]].<ref>{{Cite web|url=https://developer.android.com/about/versions/android-4.0-highlights.html|title=Ice Cream Sandwich}}</ref>
* [http://limoa.sourceforge.net/ LIM OpenMAX] is an open source implementation of OpenMAX AL and OpenMAX IL for Linux.

===Comparison with OpenSL ES===
[[OpenSL ES]] (Open Sound Library for Embedded Systems) is another Khronos Group API that also provides an audio library for the same target market as OpenMAX AL, while OpenMAX target the complete multimedia services. OpenSL ES and OpenMAX AL audio subset share the same common architecture and have a few common features:
* Audio playback and recording
* Basic MIDI playback
* Metadata extraction

==Integration layer==
{{Infobox software
| name                   = OpenMAX IL
| logo                   = [[File:OpenMAX IL Logo.svg|OpenMAX IL Logo|220px]]
| developer              = Khronos Group
| latest_release_version = 1.1.2
| latest_release_date    = {{Start date and age|2008|09|15}}
| latest preview version = 1.2.0
| latest_preview_date    = {{Start date and age|2011|11|07}}
| operating_system       = [[Cross-platform]]
| genre                  = [[Application programming interface|API]]
| license                = Various
}}
The OpenMAX IL API strives to give media components portability across an array of platforms using the [[C (programming language)|C-language]]. In the OpenMAX IL, components represent individual blocks of functionality. Components can be sources, sinks, codecs, filters, splitters, mixers, or any other data operator. Depending on the implementation, a component could possibly represent a piece of hardware, a software codec, another processor, or a combination thereof.

The interface abstracts the hardware and software architecture in the system. The OpenMAX IL API allows the user to load, control, connect, and unload the individual components. This flexible core architecture allows the Integration Layer to easily implement almost any media use case and mesh with existing graph-based media frameworks. The key focus of the OpenMAX IL API is portability of media components.

The OpenMAX IL API design devotes particular attention to use case flexibility and optimized data transfers between components.

The OpenMAX IL API was chosen as the base for the API to integrate Audio and Video codecs on Android, which has resulted in most SoC vendors shipping a minimal implementation that only supports the subset required by Android. Applications do not use those OpenMAX IL components directly, but only through the Android MediaCodec API. Android's subset of OpenMAX IL with its extensions is now the de facto standard.

In 2011 the provisional version 1.2.0 was released.<ref>{{Cite book |last=The Khronos Group |title=OpenMAX™ Integration Layer Application Programming Interface Specification: Version 1.2.0 Provisional |date=2011-11-07 |publisher=The Khronos Group Inc. |edition=1.2.0.0 |language=en}}</ref>

=== Implementations===
* [http://tizonia.org Tizonia] is an open source OpenMAX IL implementation for Linux that supports version 1.2.0.<ref>{{Cite web|url = http://www.juanrubio.me/2013/01/announcing-tizonia-openmax-il/|title = Announcing Tizonia OpenMAX IL|access-date = 2013-12-04|archive-date = 2014-11-12|archive-url = https://web.archive.org/web/20141112121026/http://www.juanrubio.me/2013/01/announcing-tizonia-openmax-il/|url-status = dead}}</ref>
* [http://omxil.sourceforge.net Bellagio] is an open source OpenMAX IL implementation for Linux maintained by [[STMicroelectronics]].<ref>{{Cite web|url = http://elinux.org/images/e/e0/The_OpenMAX_Integration_Layer_standard.pdf|title = The OpenMAX Integration Layer standard}}</ref>
* [http://limoa.sourceforge.net/ LIM OpenMAX] is an open source implementation of OpenMAX AL and OpenMAX IL for Linux.
* [[Mesa (computer graphics)|Mesa]] provides hardware accelerated drivers that can be used with Bellagio or Tizonia.<ref>{{cite mailing list |url=https://lists.freedesktop.org/archives/mesa-dev/2013-October/046943.html |title=OpenMAX state tracker |date=24 October 2013 |access-date=28 November 2015 |mailing-list=mesa-dev |last=König |first=Christian}}</ref><ref>{{Cite web|url = https://summerofcode.withgoogle.com/archive/2017/projects/6355967214092288|title = Add OpenMAX state tracker in Mesa/Gallium that uses Tizonia}}</ref>
* [https://android.googlesource.com/platform/frameworks/av/+/nougat-mr2.1-release/media/libstagefright/omx/ Android StageFright], a partial implementation of IL that is the de facto standard.

==Development layer==
{{Infobox software
| name                   = OpenMAX DL
| logo                   = [[File:OpenMAX-DL.svg|OpenMAX DL Logo|220px]]
| developer              = Khronos Group
| latest_release_version = 1.0.2
| latest_release_date    = {{Start date and age|2007|12|21}}
| operating_system       = [[Cross-platform]]
| genre                  = [[Application programming interface|API]]
| license                = Various
}}
The OpenMAX DL API defines a set of low-level multimedia kernels or media processing building blocks. The building blocks might be used to accelerate traditional computational hotspots within standardized media [[codec]]s and other integrated media processing engines. The functional scope of the OpenMAX DL interface spans several domains including [[signal processing]] and [[image processing]], [[Audio codec|audio coding]], [[Image compression|image coding]], and [[Video codec|video coding]].

OpenMAX DL is split into five application domains:
* AC - Audio Codecs (MP3 decoder and AAC decoder components)
* IC - Image Codecs (JPEG components)
* IP - Image Processing (Generic image processing functions)
* SP - Signal Processing (Generic audio processing functions)
* VC - Video Codecs (H.264 and MP4 components)

=== Implementations===
* Optimized implementations for [[ARM architecture#Advanced SIMD (NEON)|NEON]] (for [[ARM Cortex-A8|Cortex A8]] cores) and [[ARM architecture#SIMD extensions for multimedia|SIMD]] (for [[ARM11]] cores), as well as an [[C (programming language)|ANSI C]] reference implementation, were previously available from ARM for registered users.<ref>{{Cite web|url=http://www.arm.com:80/community/multimedia/standards-apis.php|title = Khronos Standards - ARM|date = 12 September 2022 | archive-url=https://web.archive.org/web/20131004052326/http://www.arm.com:80/community/multimedia/standards-apis.php | archive-date=2013-10-04}}</ref><ref>{{Cite web|url=https://developer.arm.com/documentation/dht0002/a/Introducing-NEON/Developing-for-NEON/Using-NEON-optimized-libraries|title = Using NEON optimized libraries|date = 12 September 2022}}</ref>
* The OpenMAX API is supported by the [[PlayStation 3]] console.{{Citation needed|date=September 2022}}

==Working group==
The OpenMAX working group was founded alongside sister project [[OpenVG]] on July 6, 2004. Promoting members in 2008 were [[AMD]], [[Apple Inc|Apple]], [[ARM Holdings|ARM]], [[Creative Technology|Creative]], [[Dell Inc]], [[Ericsson]], [[Freescale]], [[Imagination Technologies|Imagination Technologies Group plc]], [[Intel]], [[IBM]], [[Motorola]], [[Nokia]], [[Nvidia Corporation]], [[Samsung Electronics|Samsung Electronics Co. Ltd]], [[SK Telecom]], [[Sony Computer Entertainment|Sony Computer Entertainment Inc]] and [[Texas Instruments]].

==See also==
* [[vaAPI|Video Acceleration API (VA API)]]
* [[VDPAU|VDPAU (Video Decode and Presentation API for Unix)]]
* [[X-Video Bitstream Acceleration|X-Video Bitstream Acceleration (XvBA)]]
* [[X-Video Motion Compensation]] (XvMC)
* [[DirectX Video Acceleration|DirectX Video Acceleration (DxVA) API]] - [[Microsoft Windows]] analogue
* [[Distributed Codec Engine|Distributed Codec Engine (libdce)]] is a [[Texas Instruments]] API for the video codec engine in [[OMAP]] based embedded systems
* [[VideoToolbox]] is an API from [[Apple Inc.]] for hardware-accelerated decoding on [[Apple TV]] and [[Mac OS X]].<ref>{{cite web|access-date=2018-08-05|title=VideoToolbox - Apple Developer Documentation|url=https://developer.apple.com/documentation/videotoolbox|website=developer.apple.com}}</ref>
* [[OpenVideo Decode|OpenVideo Decode (OVD)]] – a new open cross-platform video acceleration API from [[AMD]].<ref>{{cite web |url=http://developer.amd.com/gpu/AMDAPPSDK/assets/OpenVideo_Decode_API.PDF |title=Archived copy |access-date=2012-01-16 |url-status=dead |archive-url=https://web.archive.org/web/20110409080000/http://developer.amd.com/gpu/AMDAPPSDK/assets/OpenVideo_Decode_API.PDF |archive-date=2011-04-09 }} OpenVideo Decode (OVD) API</ref>
* [[Nvidia PureVideo]] - the [[Stream processing|bit-stream technology]] from [[NVIDIA]] used in their graphics chips to accelerate video decoding on hardware [[Graphics processing unit|GPU]].
* [[Unified Video Decoder|UVD (Unified Video Decoder)]] - the [[Stream processing|bit-stream technology]] from [[ATI Technologies]] used in their graphics chips to accelerate video decoding on hardware [[Graphics processing unit|GPU]].

==References==
{{Reflist|30em}}

==External links==
*[http://www.khronos.org/openmax/ Khronos Group — OpenMAX Overview and API specifications]
*[http://www.khronos.org/openmax/ Khronos Group — Public API Registry]
*[http://www.khronos.org/registry/omxal/specs/OpenMAX_AL_1_1_Specification.pdf Khronos Group — OpenMAX AL 1.1 Specification]
*[http://www.khronos.org/registry/omxil/specs/OpenMAX_IL_1_1_2_Specification.pdf Khronos Group — OpenMAX IL 1.1.2 Specification]
*[http://www.khronos.org/files/openmax_dl_spec_1_0_2.pdf Khronos Group — OpenMAX DL 1.0.2 Specification]
*[https://silver.arm.com/browse/ ARM - Free OpenMAX Library]
*[http://www.mentor.com/products/embedded_software/nucleus_rtos/nucleus_mmf Mentor Graphics - Nucleus MMF Leverages OpenMAX IL]
*[http://www.mentor.com//products/embedded_software/news/mentorachievesindustryfirstopenmaxconformancenucleusosmultimediaframework Mentor Graphics - Press Release, Mentor Achieves Industry-First OpenMAX Conformance for Nuclues OS Multimedia Framework]

{{Khronos Group standards}}

[[Category:Application programming interfaces]]