The Video Coding Experts Group or Visual Coding Experts Group (VCEG, also known as Question 6) is a working group of the

ITU Telecommunication Standardization Sector The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Commu ...

(ITU-T) concerned with standards for compression coding of video, images, audio, and other signals. It is responsible for standardization of the "H.26x" line of video coding standards, the "T.8xx" line of image coding standards, and related technologies. Administratively, VCEG is the informal name of Question 6 (Visual, audio and signal coding) of Working Party 3 (Audiovisual technologies and intelligent immersive applications) of

ITU-T Study Group 16 The ITU-T Study Group 16 (SG16) is a statutory group of the ITU Telecommunication Standardization Sector (ITU-T) concerned with multimedia coding, systems and applications, such as video coding standards. It is responsible for standardization of ...

(Multimedia and related digital technologies). Its abbreviated title is ITU-T Q.6/SG16, or more simply, ITU-T Q6/16. The goal of VCEG is to produce ITU-T Recommendations (

international standard international standard is a technical standard developed by one or more international standards organization, standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization ...

s) for video coding and image coding methods appropriate for conversational (e.g.

videoconferencing Videotelephony, also known as videoconferencing and video teleconferencing, is the two-way or multipoint reception and transmission of audio signal, audio and video signals by people in different locations for Real-time, real time communication. ...

and video telephony) and non-conversational (e.g., streaming, broadcast, file download, media storage/playback, or digital cinema) audio/visual services. This mandate concerns the maintenance and extension of existing video coding recommendations, and laying the ground for new recommendations using advanced techniques to significantly improve the trade-offs between bit rate, quality, delay, and algorithm complexity. Video coding standards are desired with sufficient flexibility to accommodate a diverse number of transport types (Internet,

LAN Lan or LAN may also refer to: Science and technology * Local asymptotic normality, a fundamental property of regular models in statistics * Longitude of the ascending node, one of the orbital elements used to specify the orbit of an object in spa ...

, Mobile, ISDN, GSTN, H.222.0, NGN, etc.). Question 6 is part of Study Group 16, which is responsible for standards relating to multimedia service capabilities, and application capabilities (including those supported for NGN). This encompasses multimedia terminals, systems (e.g., network signal processing equipment, multipoint conference units, gateways, gatekeepers, modems, and facsimile), protocols and signal processing (media coding).

History

VCEG was preceded in the

ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Co ...

(which was called the

CCITT The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Comm ...

at the time) by the "Specialists Group on Coding for Visual Telephony" chaired by Sakae Okubo ( NTT) which developed H.261. The first meeting of this group was held December 11–14, 1984, in

Tokyo, Japan Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...

. Okubo was also the ITU-T coordinator for developing the H.262/MPEG-2 Part 2 video coding standard and the requirements chairman in MPEG for the

MPEG-2 MPEG-2 (a.k.a. H.222/H.262 as was defined by the ITU) is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods, ...

set of standards. The first digital video coding standard was

H.120 H.120 was the first digital video compression standard. It was developed by COST 211 and published by the CCITT (now the ITU-T) in 1984, with a revision in 1988 that included contributions proposed by other organizations. The video turned out not ...

, created by the

(now ITU-T) in 1984. H.120 was not usable in practice, as its performance was too poor. H.120 was based on differential pulse-code modulation (DPCM), which had relatively inefficient compression. During the late 1980s, a number of companies began experimenting with the much more efficient motion-compensated block transform hybrid compression model for video coding. In 1994, Richard Shaphorst (Delta Information Systems) took over new video coding development in ITU-T with the launch of the project for developing

H.324 H.324 is an ITU-T recommendation for voice, video and data transmission over regular analog phone lines. It uses a regular 33,600 bit/s modem for transmission, the H.263 codec for video encoding and G.723.1 for audio. H.324 standard is formal ...

. Schaphorst appointed Karel Rijkse (KPN Research) to chair the development of the

H.263 H.263 is a video compression standard originally designed as a low-bit-rate compressed format for videotelephony. It was standardized by the ITU-T Video Coding Experts Group (VCEG) in a project ending in 1995/1996. It is a member of the H.26x fam ...

video coding standard as part of that project. In 1996, Schaphorst then appointed Gary Sullivan (PictureTel, since 1999

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washi ...

) to launch the subsequent "H.263+" enhancement project, which was completed in 1998. In 1998, Sullivan was made rapporteur (chairman) of the question (group) for video coding in the ITU-T that is now called VCEG. After the H.263+ project, the group then completed an "H.263++" effort, produced H.263 Appendix III and H.263 Annex X, and launched the "H.26L" project with a call for proposals issued in January 1998 and a first draft design adopted in August 1999. In 2000, Thomas Wiegand ( Fraunhofer HHI) was appointed as an associated rapporteur (vice-chairman) of VCEG. Sullivan and Wiegand led the H.26L project as it progressed to eventually become the H.264 standard after formation of a Joint Video Team (JVT) with MPEG in 2001, completing the first version of the standard in 2003. (In MPEG, the H.264 standard is known as

MPEG-4 MPEG-4 is a group of international standards for the compression of digital audio and visual data, multimedia systems, and file storage formats. It was originally introduced in late 1998 as a group of audio and video coding formats and related t ...

part 10.) After 2003, VCEG and the JVT developed several substantial extensions of H.264, produced H.271, and conducted exploration work toward the creation of a future new standard with better compression capability. Wiegand has remained an associated rapporteur of VCEG since that time. In July 2006, the video coding work of the

led by VCEG was voted as the most influential area of the standardization work of the

and ITU-T in their 50-year history. The image coding work that is now in the domain of VCEG was also highly ranked in the voting, placing third overall. In January 2010, the Joint Collaborative Team on Video Coding (JCT-VC) was created as a group of video coding experts from ITU-T Study Group 16 (VCEG) and ISO/

IEC The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and r ...

JTC 1/ SC 29/WG 11 ( MPEG) to develop a new generation video coding standard now known as

High Efficiency Video Coding High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In comp ...

(HEVC, H.265, ISO/IEC 23008-2 and MPEG-H Part 2). In July 2014, Jill Boyce (then of Vidyo, later

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 ser ...

) was appointed as an additional associated rapporteur for VCEG. Boyce remained in that role for seven years, stepping down as associated rapporteur in June 2021. In May 2015 the ITU celebrated its 150-year anniversary, and the work of VCEG was one of the five areas of standardization to be recognized by an "ITU 150 Award" as one of the most influential topics of ITU work. VCEG and MPEG created another partnership called the Joint Video Exploration Team (JVET) in October 2015, later renaming it as the Joint Video Experts Team, which developed the

Versatile Video Coding Versatile Video Coding (VVC), also known as H.266, ISO/IEC 23090-3, and MPEG-I Part 3, is a video compression standard finalized on 6 July 2020, by the Joint Video Experts Team (JVET), a joint video expert team of the VCEG working group of ITU ...

(VVC, H.266, ISO/IEC 23090-3 and MPEG-I Part 3) standard, completing the first version of the standard in July 2020. In January 2022, Yan Ye (of Alibaba) was appointed as an associate rapporteur for VCEG.

Video coding standards

The organization now known as VCEG has standardized (and is responsible for the maintenance of) the following video compression formats: *

: the first digital video coding standard. v1 (1984) featured conditional replenishment, scalar quantization, differential

PCM Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the am ...

(

DPCM Differential pulse-code modulation (DPCM) is a signal encoder that uses the baseline of pulse-code modulation (PCM) but adds some functionalities based on the prediction of the samples of the signal. The input can be an analog signal or a digital ...

), variable-length coding and a switch for quincunx sampling. v2 (1988) added

motion compensation Motion compensation in computing, is an algorithmic technique used to predict a frame in a video, given the previous and/or future frames by accounting for motion of the camera and/or objects in the video. It is employed in the encoding of video d ...

and background prediction. This standard was little-used and no operational codecs exist that use it. * H.261: was the first practical digital video coding standard (late 1990). This design was a pioneering effort, based on motion-compensated discrete cosine transform (DCT) coding. All subsequent international video coding standards have been based closely on its design. MPEG-1 Part 2 was heavily influenced by this. * H.262: it is identical in content to the video part of the ISO/

MPEG-2 Part 2 standard (ISO/IEC 13818-2). This standard was developed in a joint partnership between VCEG and MPEG, and thus it became published as a standard of both organizations. ITU-T Recommendation H.262 and ISO/IEC 13818-2 were developed and published as "common text" international standards. As a result, the two documents are completely identical in all aspects. *

: was developed as an evolutionary improvement based on experience from H.261, and the MPEG-1 and MPEG-2 standards. Its first version was completed in 1995 and provided a suitable replacement for H.261 at all bitrates.

MPEG-4 Part 2 MPEG-4 Part 2, MPEG-4 Visual (formally ISO/IEC 14496-2) is a video compression format developed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC standards. It uses block-wise motion compensation and a discrete cosi ...

is substantially similar to this. * H.263v2: also known as H.263+ or as the 1998 version of H.263, is the informal name of the second edition of the H.263 international video coding standard. It retains the entire technical content of the original version of the standard, but enhances H.263 capabilities by adding several annexes which substantially improve encoding efficiency and provide other capabilities (such as enhanced robustness against data loss in the transmission channel). The H.263+ project was completed in late 1997 or early 1998, and was then followed by an "H.263++" project that added a few more enhancements in late 2000. * H.264: Advanced Video Coding ( AVC) is the most widely used standard in the series of international video coding standards. It was developed by a Joint Video Team (JVT) consisting of experts from ITU-T's Video Coding Experts Group (VCEG) and ISO/IEC's Moving Picture Experts Group ( MPEG) created in 2001. The ITU-T H.264 standard and the ISO/IEC MPEG-4 Part 10 standard (formally, ISO/IEC 14496-10) are technically identical. The final drafting work on the first version of the standard was completed in May 2003. As has been the case with past standards, its design provides a balance between the coding efficiency, implementation complexity, and cost based on state of VLSI design technology (

CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, a ...

s, DSPs,

ASIC An application-specific integrated circuit (ASIC ) is an integrated circuit (IC) chip customized for a particular use, rather than intended for general-purpose use, such as a chip designed to run in a digital voice recorder or a high-efficie ...

FPGA A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturinghence the term '' field-programmable''. The FPGA configuration is generally specified using a hardware d ...

s, etc.). **H.264.1: Conformance testing for H.264 **H.264.2: Reference software for H.264 * H.265: High Efficiency Video Coding (HEVC), also known as ISO/IEC 23008-2 and MPEG-H Part 2, was completed in January 2013 for its first edition. HEVC has approximately twice the compression capability of its H.264/MPEG-4 AVC predecessor and was similarly developed with MPEG in a joint team known as the Joint Collaborative Team on Video Coding (JCT-VC). **H.265.1: Conformance testing for H.265 **H.265.2: Reference software for H.265 *

H.266 Versatile Video Coding (VVC), also known as H.266, ISO/IEC 23090-3, and MPEG-I Part 3, is a video compression standard finalized on 6 July 2020, by the Joint Video Experts Team (JVET), a joint video expert team of the VCEG working group of ITU-T ...

: Versatile Video Coding (VVC), also known as ISO/IEC 23090-3 and MPEG-I Part 3, is a video compression standard finalized on 6 July 2020, by the Joint Video Experts Team (JVET), a joint video expert team of the VCEG working group of ITU-T Study Group 16 and the MPEG working group of ISO/IEC JTC 1. It is the successor to High Efficiency Video Coding (HEVC, also known as ITU-T H.265 and MPEG-H Part 2). **H.266.1: Conformance testing for H.266 **H.266.2: Reference software for H.266

Image coding standards

Starting in late 2006, VCEG has also been responsible for the ITU-T work on still image coding standards including the following: *

JPEG JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...

(ITU-T T.80, T.81, T.83, T.84, T.86, T.871, T.872 and T.873) and the JPEG-like ITU-T T.851 * JBIG-1 (ITU-T T.80, T.82 and T.85) * JBIG-2 (ITU-T T.88 and T.89) * JPEG-LS (ITU-T T.87 and T.870) * JPEG 2000 (ITU-T T.800 through T.815) * JPEG XR (ITU-T T.832, T.833, T.834, T.835, and T.Sup2) *

MRC MRC may refer to Government * Medical Research Council (United Kingdom) * Medical Reserve Corps, a US network of volunteer organizations * Municipalité régionale de comté (regional county municipality), Quebec, Canada * Military Revolutionar ...

(ITU-T T.44) VCEG works on most of these image coding standards jointly with ISO/IEC JTC 1/SC 29/WG 1 (the Joint Photographic Experts Group/

Joint Bi-level Image experts Group The Joint Bi-level Image Experts Group (JBIG) is a group of experts nominated by national standards bodies and major companies to work to produce standards for bi-level image coding. The "joint" refers to its status as a committee working on both I ...

Other related standards

* H.271: Video back channel messages for conveyance of status information and requests from a video receiver to a video sender * H.272: Procedures and values for video gamma compensation in multimedia system * H.273: Coding-independent code points (CICP) for video signal type identification, also ISO/IEC 23091-2 * H.274: Versatile supplemental enhancement information (VSEI) messages for coded video bitstreams, also ISO/IEC 23002-7

References

External links