MPEG-4 Part 2, MPEG-4 Visual (formally 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 ...

14496-2) is a

video compression format A video coding format (or sometimes video compression format) is a content representation format for storage or transmission of digital video content (such as in a data file or bitstream). It typically uses a standardized video compression algo ...

developed by the

Moving Picture Experts Group The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by ISO and IEC that sets standards for media coding, including compression coding of audio, video, graphics, and genomic data; and transmission and f ...

(MPEG). It belongs to the

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 ...

ISO/IEC standards. It uses block-wise

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 a discrete cosine transform (DCT), similar to previous standards such as MPEG-1 Part 2 and H.262/MPEG-2 Part 2. Several popular

codec A codec is a device or computer program that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or ...

s including DivX,

Xvid Xvid (formerly "XviD") is a video codec library following the MPEG-4 video coding standard, specifically MPEG-4 Part 2 Advanced Simple Profile (ASP). It uses ASP features such as b-frames, global and quarter pixel motion compensation, lumi m ...

, and

Nero Digital Nero Digital is a brand name applied to a suite of MPEG-4-compatible video and audio compression codecs developed by Nero AG of Germany and Ateme of France. The audio codecs are integrated into the ''Nero Digital Audio+'' audio encoding tool for ...

implement this standard. Note that

MPEG-4 Part 10 Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, is a video compression standard based on block-oriented, motion-compensated coding. It is by far the most commonly used format for the recording, compression, and distr ...

defines a different format from MPEG-4 Part 2 and should not be confused with it. MPEG-4 Part 10 is commonly referred to as H.264 or AVC, and was jointly developed by

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 ...

and MPEG. MPEG-4 Part 2 is

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 ...

compatible in the sense that a basic H.263 bitstream is correctly decoded by an MPEG-4 Video decoder. (MPEG-4 Video decoder is natively capable of decoding a basic form of H.263.) In MPEG-4 Visual, there are two types of video object layers: the video object layer that provides full MPEG-4 functionality, and a reduced functionality video object layer, the video object layer with short headers (which provides bitstream compatibility with base-line H.263). MPEG-4 Part 2 is partially based on ITU-T H.263. The first MPEG-4 Video Verification Model (simulation and test model) used ITU-T H.263 coding tools together with shape coding.

History

The MPEG-4 Visual format was developed by the

(MPEG) committee. The specification was authored by Swiss-Iranian engineer Touradj Ebrahimi (later the president of

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 ...

) and Dutch engineer Caspar Horne. The standard was developed using patents from over a dozen organizations, listed by MPEG LA in a

patent pool In patent law, a patent pool is a consortium of at least two companies agreeing to cross-license patents relating to a particular technology. The creation of a patent pool can save patentees and licensees time and money, and, in case of blocking ...

. The majority of patents used for the MPEG-4 Visual format were from three Japanese companies:

Mitsubishi Electric , established on 15 January 1921, is a Japanese multinational electronics and electrical equipment manufacturing company headquartered in Tokyo, Japan. It is one of the core companies of Mitsubishi. The products from MELCO include elevators an ...

(255 patents),

Hitachi () is a Japanese multinational conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Nissan ''zaibatsu'' and later DKB Group and Fuyo G ...

(206 patents), and

Panasonic formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb ...

(200 patents). See '' Patent holders'' below for a full list of patent holders.

Editions

Profiles

To address various applications ranging from low-quality, low-resolution surveillance cameras to high definition TV broadcasting and DVDs, many video standards group features into profiles and levels. MPEG-4 Part 2 has approximately 21 profiles, including profiles called Simple, Advanced Simple, Main, Core, Advanced Coding Efficiency, Advanced Real Time Simple, etc. The most commonly deployed profiles are Advanced Simple and Simple, which is a subset of Advanced Simple. Most of the video compression schemes standardize the

bitstream A bitstream (or bit stream), also known as binary sequence, is a sequence of bits. A bytestream is a sequence of bytes. Typically, each byte is an 8-bit quantity, and so the term octet stream is sometimes used interchangeably. An octet may ...

(and thus the decoder) leaving the encoder design to the individual implementations. Therefore, implementations for a particular profile (such as DivX or Nero Digital which are implementations of Advanced Simple Profile and Xvid that implements both profiles) are all technically identical on the decoder side. A point of comparison would be that an MP3 file can be played in any MP3 player, whether it was created through iTunes, Windows Media Player,

LAME Lame or LAME may refer to: Music * "Lame" (song) by Unwritten Law * ''Lame'' (album) by Iame People * Ibrahim Lame (born 1953), Nigerian educator and politician * Jennifer Lame (), American film editor * Quintín Lame (1880–1967), Colombian ...

, or the common Fraunhofer encoder.

Simple Profile (SP)

Simple Profile is mostly aimed for use in situations where low bit rate and low resolution are mandated by other conditions of the applications, like network bandwidth, device size etc. Examples are

mobile phone A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whi ...

s, some low end

video conferencing 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. ...

systems,

electronic surveillance Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing or directing. This can include observation from a distance by means of electronic equipment, such as ...

systems etc.

Advanced Simple Profile (ASP)

The Advanced Simple Profile was not included in the original standard. Its notable technical features relative to the Simple Profile, which is roughly similar to

, include: * Support for "MPEG"-style quantization * Support for interlaced video * Support for

B pictures A B movie or B film is a low-budget commercial motion picture. In its original usage, during the Golden Age of Hollywood, the term more precisely identified films intended for distribution as the less-publicized bottom half of a double feature ...

(a.k.a. ''

B-frame In the field of video compression a video frame is compressed using different algorithms with different advantages and disadvantages, centered mainly around amount of data compression. These different algorithms for video frames are called pi ...

s'') * Quarter Pixel

( Qpel) *

Global motion compensation {{refimprove, date=September 2008 ''Global motion compensation'' ''(GMC)'' is a motion compensation technique used in video compression to reduce the bitrate required to encode video. It is most commonly used in MPEG-4 ASP, such as with the Div ...

(GMC) The MPEG quantization and interlace support are designed in basically similar ways to the way it is found in

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, ...

Part 2. The B picture support is designed in a basically similar way to the way it is found in MPEG-2 Part 2 and H.263v2. The quarter-pixel motion compensation feature of ASP was innovative, and was later also included (in somewhat different forms) in later designs such as

, HEVC,

VC-1 SMPTE 421, informally known as VC-1, is a video coding format. Most of it was initially developed as Microsoft's proprietary video format Windows Media Video 9 in 2003. With some enhancements including the development of a new Advanced Profile ...

and VVC. Some implementations of MPEG-4 Part 2 omit support for this feature, because it has a significantly harmful effect on the speed of software decoders and it is not always beneficial for quality. The global motion compensation feature is not actually supported in most implementations although the standard officially requires decoders to support it. Most encoders do not support it either, and some experts say that it does not ordinarily provide any benefit in compression. When used, ASP's global motion compensation has a large unfavorable impact on speed and adds considerable complexity to the implementation.

Simple Studio Profile (SStP)

The MPEG-4 Simple Studio Profile (SStP), or ISO/IEC 14496-2, has six levels going from

SDTV Standard-definition television (SDTV, SD, often shortened to standard definition) is a television system which uses a resolution that is not considered to be either high or enhanced definition. "Standard" refers to it being the prevailing sp ...

4K resolution 4K resolution refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 38402160 (4K UHD) is the domi ...

. MPEG-4 SStP allows for up to 12-bit bit depth and up to 4:4:4

chroma subsampling Chroma subsampling is the practice of encoding images by implementing less resolution for chroma information than for luma information, taking advantage of the human visual system's lower acuity for color differences than for luminance. It is u ...

, using Intra-frame coding only. MPEG-4 SStP is used by

HDCAM SR HDCAM is a high-definition video digital recording videocassette version of Digital Betacam introduced in 1997 that uses an 8-bit discrete cosine transform (DCT) compressed 3:1:1 recording, in 1080i-compatible down-sampled resolution of 14 ...

Patent holders

The following organizations hold patents for MPEG-4 Visual technology, as listed in the

administered by MPEG LA.

Criticisms

MPEG-4 Part 2 has drawn some industry criticism.

FFmpeg FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing of vid ...

's maintainer Michael Niedermayer has criticised MPEG-4 for lacking an in-loop

deblocking filter A deblocking filter is a video filter applied to decoded compressed video to improve visual quality and prediction performance by smoothing the sharp edges which can form between macroblocks when block coding techniques are used. The filter ai ...

, GMC being too computationally intensive, and OBMC being defined but not allowed in any profiles among other things.

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 ...

's Ben Waggoner states "Microsoft (well before my time) went down the codec standard route before with MPEG-4 part 2, which turns out to be a profound disappointment across the industry - it didn't offer that much of a compression advantage over MPEG-2, and the protracted license agreement discussions scared off a lot of adoption. I was involved in many digital media projects that wouldn't even touch MPEG-4 in the late 1990s to early 2000s because there was going to be a 'content fee' that hadn't been fully defined yet."VC-1 and H264 - Page 2 - Doom9's Forum
/ref>

Popular software implementations

3ivx 3ivx ( ) was an MPEG-4 compliant video codec suite, created by 3ivx Technologies, based in Sydney, Australia. 3ivx video codecs were released from 2001 to 2012, with releases of related technologies continuing until 2015. 3ivx provided plugins to a ...

* DivX * HDX4 *

libavcodec libavcodec is a free and open-source library of codecs for encoding and decoding video and audio data. libavcodec is an integral part of many open-source multimedia applications and frameworks. The popular MPV, xine and VLC media players u ...

QuickTime QuickTime is an extensible multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. Created in 1991, the latest Mac version, QuickTime X, is a ...

Notes

External links

MPEG-4 Part 2: Visual
*
Official MPEG web site

MPEG-4 Visual Patent List (MPEG LA)
{{MPEG MPEG-4 Open standards covered by patents Videotelephony 1999 software 20th-century inventions