Content deleted Content added
replace old info |
Rescuing 4 sources and tagging 0 as dead.) #IABot (v2.0.9.5 |
||
| (11 intermediate revisions by 11 users not shown) | |||
Line 12:
| version = 15.0
| version_date = {{Start date|2024|08|13|df=y}}
| organization = [[ITU-T]], [[ISO]], [[
| committee = [[ITU-T Study Group 16|SG16]] ([[VCEG]]), [[MPEG]]
| base_standards = [[H.261]], [[H.262]] (aka [[MPEG-2 Video]]), [[H.263]], [[ISO/IEC 14496-2]] (aka MPEG-4 Part 2)
| related_standards = [[H.265]] (aka HEVC), [[H.266]] (aka VVC)
| predecessor = [[H.263]]
| successor = [[H.265]]
| abbreviation =
| ___domain = [[Video compression]]
Line 24 ⟶ 26:
[[File:H.264 block diagram with quality score.jpg|thumb|Block diagram of video coding layer of H.264 encoder with perceptual quality score]]
'''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 compensation|motion-compensated]] coding.<ref>{{Cite web|url=https://www.itu.int/rec/T-REC-H.264|title=H.264 : Advanced video coding for generic audiovisual services|website=www.itu.int|url-status=live|archive-url=https://web.archive.org/web/20191031100750/https://www.itu.int/rec/T-REC-H.264|archive-date=2019-10-31|access-date=2019-11-22}}</ref> It is by far the most commonly used format for the recording, compression, and distribution of video content, used by
The intent of the H.264/AVC project was to create a standard capable of providing good video quality at substantially lower [[bit rate]]s than previous standards (i.e., half or less the bit rate of [[H.262/MPEG-2 Part 2|MPEG-2]], [[H.263]], or [[MPEG-4 Part 2]]), without increasing the complexity of design so much that it would be impractical or excessively expensive to implement. This was achieved with features such as a reduced-complexity integer [[discrete cosine transform]] (integer DCT),<ref name="apple"/> variable block-size segmentation, and multi-picture [[inter frame|inter-picture prediction]]. An additional goal was to provide enough flexibility to allow the standard to be applied to a wide variety of applications on a wide variety of networks and systems, including low and high bit rates, low and high resolution video, [[
H.264 was standardized by the [[ITU-T]] [[Video Coding Experts Group]] (VCEG) of [[ITU-T Study Group 16|Study Group 16]] together with the [[ISO/IEC JTC 1]] [[Moving Picture Experts Group]] (MPEG). The project partnership effort is known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC [[MPEG-4]] AVC standard (formally, ISO/IEC 14496-10 – MPEG-4 Part 10, Advanced Video Coding) are jointly maintained so that they have identical technical content. The final drafting work on the first version of the standard was completed in May 2003, and various extensions of its capabilities have been added in subsequent editions. [[High Efficiency Video Coding]] (HEVC), a.k.a. H.265 and MPEG-H Part 2 is a successor to H.264/MPEG-4 AVC developed by the same organizations, while earlier standards are still in common use.
H.264 is perhaps best known as being the most commonly used video encoding format on [[Blu-ray Disc]]s. It is also widely used by streaming Internet sources, such as videos from [[Netflix]], [[Hulu]], [[Amazon Prime Video]], [[Vimeo]], [[YouTube]], and the [[iTunes Store]], Web software such as the [[Adobe Flash Player]] and [[Microsoft Silverlight]], and also various [[HDTV]] broadcasts over terrestrial ([[
H.264 is restricted by [[patent]]s owned by various parties. A license covering most (but not all{{cn|date=February 2024}}) patents essential to H.264 is administered by a [[patent pool]] formerly administered by [[MPEG LA]]. Via Licensing Corp acquired MPEG LA in April 2023 and formed a new patent pool administration company called [[Via-LA|Via Licensing Alliance]].<ref>{{citation |url=https://www.streamingmedia.com/Articles/ReadArticle.aspx?ArticleID=158547 |title=Via LA's Heath Hoglund Talks MPEG LA/Via Licensing Patent Pool Merger |first=Jan |last=Ozer |date=2023-05-08 |publisher=StreamingMedia.com}}</ref> The commercial use of patented H.264 technologies requires the payment of royalties to Via and other patent owners. MPEG LA has allowed the free use of H.264 technologies for streaming Internet video that is free to end users, and [[Cisco]] paid royalties to MPEG LA on behalf of the users of binaries for its [[Open-source software|open source]] H.264 encoder [[openH264]].
== Naming ==
The H.264 name follows the [[ITU-T]] [[ITU-T#Recommendation categorization|naming convention]], where Recommendations are given a letter corresponding to their series and a recommendation number within the series. H.264 is part of "H-Series Recommendations: Audiovisual and multimedia systems". H.264 is further categorized into "H.200-H.499: Infrastructure of audiovisual services" and "H.260-H.279: [[Video encoding|Coding]] of moving video".<ref>{{Cite web |title=ITU-T Recommendations |url=https://www.itu.int:443/en/ITU-T/publications/Pages/recs.aspx |access-date=2022-11-01 |website=ITU |language=en-US}}</ref> The MPEG-4 AVC name relates to the naming convention in [[
== History ==
=== Overall history ===
In early 1998, the [[Video Coding Experts Group]] (VCEG – ITU-T SG16 Q.6) issued a call for proposals on a project called H.26L, with the target to double the coding efficiency (which means halving the bit rate necessary for a given level of fidelity) in comparison to any other existing video coding standards for a broad variety of applications. [[VCEG]] was chaired by [[Gary Sullivan (engineer)|Gary Sullivan]] ([[Microsoft]], formerly [[PictureTel]], U.S.). The first draft design for that new standard was adopted in August 1999. In 2000, [[Thomas Wiegand]] ([[
In December 2001, VCEG and the Moving Picture Experts Group ([[MPEG]] – [[ISO/IEC JTC 1/SC 29]]/WG 11) formed a Joint Video Team (JVT), with the charter to finalize the video coding standard.<ref name=JVTsite>[http://www.itu.int/en/ITU-T/studygroups/com16/video/Pages/jvt.aspx Joint Video Team], [[ITU-T]] Web site.</ref> Formal approval of the specification came in March 2003. The JVT was (is) chaired by [[Gary Sullivan (engineer)|Gary Sullivan]], [[Thomas Wiegand]], and Ajay Luthra ([[Motorola]], U.S.: later [[Arris Group|Arris]], U.S.). In July 2004, the Fidelity Range Extensions (FRExt) project was finalized. From January 2005 to November 2007, the JVT was working on an extension of H.264/AVC towards scalability by an Annex (G) called [[Scalable Video Coding]] (SVC). The JVT management team was extended by [[Jens-Rainer Ohm]] ([[RWTH Aachen University]], Germany). From July 2006 to November 2009, the JVT worked on [[Multiview Video Coding]] (MVC), an extension of H.264/AVC towards [[3D television]] and limited-range [[free-viewpoint television]]. That work included the development of two new profiles of the standard: the Multiview High Profile and the Stereo High Profile.
Line 54 ⟶ 56:
=== Multiview video coding ===
The next major feature added to the standard was [[Multiview Video Coding]] (MVC). Specified in Annex H of H.264/AVC, MVC enables the construction of bitstreams that represent more than one view of a video scene. An important example of this functionality is [[
=== 3D-AVC and MFC stereoscopic coding ===
Line 81 ⟶ 83:
* Version 18 (Edition 8): (April 13, 2013) Amendment to specify the coding of depth map data for 3D stereoscopic video, including a Multiview Depth High profile.<ref name=AVC8June2013ITURecommendations/>
* Version 19 (Edition 8): (April 13, 2013) Corrigendum to correct an error in the sub-bitstream extraction process for multiview video.<ref name=AVC8June2013ITURecommendations/>
* Version 20 (Edition 8): (April 13, 2013) Amendment to specify additional [[color space]] identifiers (including support of [[
* Version 21 (Edition 9): (February 13, 2014) Amendment to specify the Enhanced Multiview Depth High profile.<ref name=AVC9February2014ITURecommendations>{{cite news |title=ITU-T Recommendation H.264 (02/2014) |publisher=ITU |url=http://www.itu.int/ITU-T/recommendations/rec.aspx?rec=12063 |date=2014-11-28 |access-date=2016-02-28}}</ref>
* Version 22 (Edition 9): (February 13, 2014) Amendment to specify the multi-resolution frame compatible (MFC) enhancement for 3D stereoscopic video, the MFC High profile, and minor corrections.<ref name=AVC9February2014ITURecommendations/>
Line 93 ⟶ 95:
== Applications ==
{{Further|List of video services using H.264/MPEG-4 AVC}}
The H.264 video format has a very broad application range that covers all forms of digital compressed video from low bit-rate Internet streaming applications to HDTV broadcast and Digital Cinema applications with nearly lossless coding. With the use of H.264, bit rate savings of 50% or more compared to [[MPEG-2 Part 2]] are reported. For example, H.264 has been reported to give the same Digital Satellite TV quality as current MPEG-2 implementations with less than half the bitrate, with current MPEG-2 implementations working at around 3.5 Mbit/s and H.264 at only 1.5 Mbit/s.<ref>{{cite journal |author=Wenger|title=RFC 3984 : RTP Payload Format for H.264 Video |newspaper=Ietf Datatracker |date=February 2005 |url=http://tools.ietf.org/html/rfc3984#page-2 |page=2|doi=10.17487/RFC3984 |display-authors=etal|url-access=subscription }}</ref> Sony claims that 9 Mbit/s AVC recording mode is equivalent to the image quality of the [[HDV]] format, which uses approximately 18–25 Mbit/s.<ref>{{cite web|title=Which recording mode is equivalent to the image quality of the High Definition Video (HDV) format?|website=Sony eSupport|url=https://ca.en.kb.sony.com/app/answers/detail/a_id/41994|access-date=December 8, 2018|archive-url=https://web.archive.org/web/20171109054553/https://ca.en.kb.sony.com/app/answers/detail/a_id/41994|archive-date=November 9, 2017|url-status=dead|df=mdy-all}}</ref>
To ensure compatibility and problem-free adoption of H.264/AVC, many standards bodies have amended or added to their video-related standards so that users of these standards can employ H.264/AVC. Both the [[Blu-ray Disc]] format and the now-discontinued [[HD DVD]] format include the H.264/AVC High Profile as one of three mandatory video compression formats. The Digital Video Broadcast project ([[
The [[Advanced Television Systems Committee]] (ATSC) standards body in the United States approved the use of H.264/AVC for broadcast television in July 2008, although the standard is not yet used for fixed ATSC broadcasts within the United States.<ref>{{cite web |url=http://www.atsc.org/cms/standards/a_72_part_1.pdf |title=ATSC Standard A/72 Part 1: Video System Characteristics of AVC in the ATSC Digital Television System |access-date=2011-07-30 |url-status=dead |archive-url=https://web.archive.org/web/20110807103348/http://www.atsc.org/cms/standards/a_72_part_1.pdf |archive-date=August 7, 2011 |df=mdy-all }}</ref><ref>{{cite web |url=http://www.atsc.org/cms/standards/a_72_part_2.pdf |title=ATSC Standard A/72 Part 2: AVC Video Transport Subsystem Characteristics |access-date=2011-07-30 |archive-url=https://web.archive.org/web/20110807103411/http://www.atsc.org/cms/standards/a_72_part_2.pdf |archive-date=August 7, 2011 |url-status=dead |df=mdy-all }}</ref> It has also been approved for use with the more recent [[ATSC-M/H]] (Mobile/Handheld) standard, using the AVC and SVC portions of H.264.<ref>{{cite web |url=http://atsc.org/cms/standards/a153/a_153-Part-7-2009.pdf |title=ATSC Standard A/153 Part 7: AVC and SVC Video System Characteristics |access-date=2011-07-30 |url-status=dead |archive-url=https://web.archive.org/web/20110726151422/http://atsc.org/cms/standards/a153/a_153-Part-7-2009.pdf |archive-date=July 26, 2011 |df=mdy-all }}</ref>
Line 139 ⟶ 141:
** Logarithmic step size control for easier bit rate management by encoders and simplified inverse-quantization scaling
** Frequency-customized quantization scaling matrices selected by the encoder for perceptual-based quantization optimization
* An in-loop [[
* An [[
** [[Context-adaptive binary arithmetic coding]] (CABAC), an algorithm to losslessly compress syntax elements in the video stream knowing the probabilities of syntax elements in a given context. CABAC compresses data more efficiently than CAVLC but requires considerably more processing to decode.
** [[Context-adaptive variable-length coding]] (CAVLC), which is a lower-complexity alternative to CABAC for the coding of quantized transform coefficient values. Although lower complexity than CABAC, CAVLC is more elaborate and more efficient than the methods typically used to code coefficients in other prior designs.
** A common simple and highly structured [[
* Loss resilience features including:
** A [[Network Abstraction Layer]] (NAL) definition allowing the same video syntax to be used in many network environments. One very fundamental design concept of H.264 is to generate self-contained packets, to remove the header duplication as in MPEG-4's Header Extension Code (HEC).<ref name="rfc3984_3"/> This was achieved by decoupling information relevant to more than one slice from the media stream. The combination of the higher-level parameters is called a parameter set.<ref name="rfc3984_3"/> The H.264 specification includes two types of parameter sets: Sequence Parameter Set (SPS) and Picture Parameter Set (PPS). An active sequence parameter set remains unchanged throughout a coded video sequence, and an active picture parameter set remains unchanged within a coded picture. The sequence and picture parameter set structures contain information such as picture size, optional coding modes employed, and macroblock to slice group map.<ref name="rfc3984_3">RFC 3984, p.3</ref>
Line 173 ⟶ 175:
;Extended Profile (XP, 88): Intended as the streaming video profile, this profile has relatively high compression capability and some extra tricks for robustness to data losses and server stream switching.
;Main Profile (MP, 77): This profile is used for standard-definition digital TV broadcasts that use the MPEG-4 format as defined in the DVB standard.<ref>{{cite web|url=http://www.etsi.org/deliver/etsi_ts/101100_101199/101154/01.09.01_60/ts_101154v010901p.pdf |title=TS 101 154 – V1.9.1 – Digital Video Broadcasting (DVB); Specification for the use of Video and Audio Coding in Broadcasting Applications based on the MPEG-2 Transport Stream |access-date=2010-05-17}}</ref> It is not, however, used for high-definition television broadcasts, as the importance of this profile faded when the High Profile was developed in 2004 for that application.
;High Profile (HiP, 100): The primary profile for broadcast and disc storage applications, particularly for high-definition television applications (for example, this is the profile adopted by the [[Blu-ray Disc]] storage format and the [[
;Progressive High Profile (PHiP, 100 with constraint set 4): Similar to the High profile, but without support of field coding features.
;Constrained High Profile (100 with constraint set 4 and 5): Similar to the Progressive High profile, but without support of B (bi-predictive) slices.
Line 266 ⟶ 268:
| {{no}} || {{no}} || {{no}} || {{yes}} || {{yes}} || {{yes}} || {{yes}} || {{yes}} || {{yes}}
|-
! 4:0:0 ([[
| {{no}} || {{no}} || {{no}} || {{no}} || {{yes}} || {{yes}} || {{yes}} || {{yes}} || {{yes}}
|-
Line 548 ⟶ 550:
The 2nd generation [[Intel]] "[[Sandy Bridge]]" [[Intel Core|Core i3/i5/i7]] processors introduced at the January 2011 CES ([[Consumer Electronics Show]]) offer an on-chip hardware full HD H.264 encoder, known as [[Intel Quick Sync Video]].<ref>{{cite web |url=http://software.intel.com/en-us/articles/quick-reference-guide-to-intel-integrated-graphics/ |title=Quick Reference Guide to generation Intel Core Processor Built-in Visuals |publisher=Intel Software Network |date=2010-10-01 |access-date=2011-01-19}}</ref><ref>{{cite web |url=http://www.intel.com/content/www/us/en/architecture-and-technology/quick-sync-video/quick-sync-video-general.html |title=Intel Quick Sync Video|publisher=www.intel.com |date=2010-10-01 |access-date=2011-01-19}}</ref>
A hardware H.264 encoder can be an [[
ASIC encoders with H.264 encoder functionality are available from many different semiconductor companies, but the core design used in the ASIC is typically licensed from one of a few companies such as [[Chips&Media]], Allegro DVT, [[On2]] (formerly Hantro, acquired by Google), [[Imagination Technologies]], NGCodec. Some companies have both FPGA and ASIC product offerings.<ref>{{cite web |url=http://www.design-reuse.com/sip/?q=H.264+encoder |title=Design-reuse.com |publisher=Design-reuse.com |date=1990-01-01 |access-date=2010-05-17}}</ref>
Line 556 ⟶ 558:
== Licensing ==
{{see also|Microsoft Corp. v. Motorola Inc.|Qualcomm Inc. v. Broadcom Corp.}}
In countries where [[software patent|patents on software algorithms]] are upheld, vendors and commercial users of products that use H.264/AVC are expected to pay patent licensing royalties for the patented technology that their products use.<ref>{{cite web |url=http://www.mpegla.com/main/programs/AVC/Documents/avcweb.pdf |title=Briefing portfolio |website=www.mpegla.com |access-date=December 1, 2016 |archive-date=November 28, 2016 |archive-url=https://web.archive.org/web/20161128050907/http://www.mpegla.com/main/programs/AVC/Documents/avcweb.pdf |url-status=dead }}</ref> This applies to the Baseline Profile as well.<ref>{{cite web|url=http://blogs.sun.com/openmediacommons/entry/oms_video_a_project_of|title=OMS Video, A Project of Sun's Open Media Commons Initiative|access-date=2008-08-26|archive-url=https://web.archive.org/web/20100511060302/http://blogs.sun.com/openmediacommons/entry/oms_video_a_project_of|archive-date=May 11, 2010|url-status=dead|df=mdy-all}}</ref>
A private organization known as [[MPEG LA]], which is not affiliated in any way with the MPEG standardization organization, administers the licenses for patents applying to this standard, as well as other [[patent pool]]s, such as for MPEG-4 Part 2 Video, HEVC and MPEG-DASH. The patent holders include [[Fujitsu]], [[Panasonic]], [[Sony]], [[Mitsubishi]], [[Apple Inc.|Apple]], [[Columbia University]], [[KAIST]], [[
On August 26, 2010, MPEG LA announced that royalties would not be charged for H.264 encoded Internet video that is free to end users.<ref>{{cite web|url=http://www.mpegla.com/Lists/MPEG%20LA%20News%20List/Attachments/74/n-10-08-26.pdf|title=MPEG LA's AVC License Will Not Charge Royalties for Internet Video that is Free to End Users through Life of License|publisher=MPEG LA|date=2010-08-26|access-date=2010-08-26|archive-date=November 7, 2013|archive-url=https://web.archive.org/web/20131107135621/http://www.mpegla.com/Lists/MPEG%20LA%20News%20List/Attachments/74/n-10-08-26.pdf|url-status=dead}}</ref> All other royalties remain in place, such as royalties for products that decode and encode H.264 video as well as to operators of free television and subscription channels.<ref>{{cite news|url=https://www.pcmag.com/article2/0,2817,2368359,00.asp |title=MPEG LA Cuts Royalties from Free Web Video, Forever |publisher=pcmag.com |date=2010-08-26 |access-date=2010-08-26 |first=Mark |last=Hachman}}</ref> The license terms are updated in 5-year blocks.<ref>{{cite web |url=http://www.mpegla.com/main/programs/AVC/Pages/FAQ.aspx |title=AVC FAQ |publisher=MPEG LA |date=2002-08-01 |access-date=2010-05-17 |archive-url=https://web.archive.org/web/20100507102710/http://www.mpegla.com/main/programs/AVC/Pages/FAQ.aspx |archive-date=May 7, 2010 |url-status=dead }}</ref>
Line 587 ⟶ 589:
== Further reading ==
{{Refbegin}}
* {{Cite journal |url = http://ip.hhi.de/imagecom_G1/assets/pdfs/csvt_overview_0305.pdf |first1 = Thomas |last1 = Wiegand |first2 = Gary J. |last2 = Sullivan |first3 = Gisle |last3 = Bjøntegaard |first4 = Ajay |last4 = Luthra |title = Overview of the H.264/AVC Video Coding Standard |journal = IEEE Transactions on Circuits and Systems for Video Technology |date = July 2003 |volume = 13 |issue = 7 |pages = 560–576 |doi = 10.1109/TCSVT.2003.815165 |access-date = January 31, 2011 |archive-date = April 29, 2011 |archive-url = https://web.archive.org/web/20110429013301/http://ip.hhi.de/imagecom_G1/assets/pdfs/csvt_overview_0305.pdf |url-status = dead }}
* {{Cite journal |url = http://www.fastvdo.com/spie04/spie04-h264OverviewPaper.pdf |first1 = Pankaj |last1 = Topiwala |first2 = Gary J. |last2 = Sullivan |first3 = Ajay |last3 = Luthra |editor1-first = Andrew G |editor1-last = Tescher |s2cid = 2308860 |title = The H.264/AVC Advanced Video Coding Standard: Overview and Introduction to the Fidelity Range Extensions |journal = SPIE Applications of Digital Image Processing XXVII |series = Applications of Digital Image Processing XXVII |date = August 2004 |volume = 5558 |page = 454 |doi = 10.1117/12.564457 |bibcode = 2004SPIE.5558..454S |access-date = January 31, 2011 }}
* {{Cite
* {{Cite journal |url = https://archive.org/download/video-coding-using-the-h.-264-mpeg-4-avc-compression-standard/Video%20coding%20using%20the%20H.264%3AMPEG-4%20AVC%20compression%20standard.pdf |first1 = Atul |last1 = Puri |first2 = Xuemin |last2 = Chen |first3 = Ajay |last3 = Luthra |title = Video coding using the H.264/MPEG-4 AVC compression standard |journal = Signal Processing: Image Communication |date = October 2004 |volume = 19 |issue = 9 |pages = 793–849 |access-date = March 30, 2011 |doi = 10.1016/j.image.2004.06.003 }}
* {{Cite journal |url = http://ip.hhi.de/imagecom_G1/assets/pdfs/pieee_sullivan_wiegand_2005.pdf |first1 = Gary J. |last1 = Sullivan |first2 = Thomas |last2 = Wiegand |s2cid = 1362034 |title = Video Compression—From Concepts to the H.264/AVC Standard |journal = Proceedings of the IEEE |date = January 2005 |volume = 93 |issue = 1 |pages = 18–31 |access-date = January 31, 2011 |doi = 10.1109/jproc.2004.839617 }}
* {{cite web |url=http://www.vcodex.com/h264.html |title=Learn about video compression and H.264 |work=VCODEX |publisher=Vcodex Limited |first1=Iain E. G. |last1=Richardson |access-date=January 31, 2011 |date=January 2011 |archive-date=January 28, 2011 |archive-url=https://web.archive.org/web/20110128164552/http://www.vcodex.com/h264.html |url-status=dead }}
{{Refend}}
| |||