Summary

Recommendation ITU-T H.264 | International Standard ISO/IEC 14496-10 represents an evolution of the existing video coding standards (ITU-T H.261, ITU-T H.262, and ITU-T H.263) and it was developed in response to the growing need for higher compression of moving pictures for various applications such as videoconferencing, digital storage media, television broadcasting, Internet streaming, and communication. It is also designed to enable the use of the coded video representation in a flexible manner for a wide variety of network environments. The use of this Recommendation | International Standard allows motion video to be manipulated as a form of computer data and to be stored on various storage media, transmitted and received over existing and future networks and distributed on existing and future broadcasting channels.

The revision approved 2005-03 contained modifications of the video coding standard to add four new profiles, referred to as the High, High 10, High 4:2:2, and High 4:4:4 profiles, to improve video quality capability and to extend the range of applications addressed by the standard (for example, by including support for a greater range of picture sample precision and higher-resolution chroma formats). Additionally, a definition of new types of supplemental data was specified to further broaden the applicability of the video coding standard. Finally, a number of corrections to errors in the published text were included.

Corrigendum 1 to Rec. ITU-T H.264 corrected and updated various minor aspects to bring the ITU-T version of the text up to date relative to the April 2005 output status approved as a new edition of the corresponding jointly-developed and technically-aligned text ISO/IEC 14496-10. It additionally fixed a number of minor errors and needs for clarification and defined three previously-reserved sample aspect ratio indicators.

Amendment 1 "Support of additional colour spaces and removal of the High 4:4:4 Profile" contained alterations to Rec. ITU‑T H.264 | ISO/IEC 14496‑10 Advanced Video Coding to specify the support of additional colour spaces and to remove the definition of the High 4:4:4 profile.

NOTE – Rec. ITU-T H.264 is a twin text with ISO/IEC 14496‑10 and this amendment was published in two different documents in the ISO/IEC series:

–                The removal of the High 4:4:4 profile was found in ISO/IEC 14496-10:2005/Cor.2.

–                The specification for support of additional colour spaces was found in ISO/IEC 14496-10:2005/Amd.1.

Amendment 2 "New profiles for professional applications" contained extensions to Rec. ITU-T H.264 | ISO/IEC 14496‑10 Advanced Video Coding to specify the support of five additional profiles intended primarily for professional applications (the High 10 Intra, High 4:2:2 Intra, High 4:4:4 Intra, CAVLC 4:4:4 Intra, and High 4:4:4 Predictive profiles) and two new types of supplemental enhancement information (SEI) messages (the post-filter hint SEI message and the tone mapping information SEI message).

Amendment 3 "Scalable video coding" contained extensions to Rec. ITU-T H.264 | ISO/IEC 14496-10 Advanced Video Coding to specify a scalable video coding extension in three profiles (the Scalable Baseline, Scalable High, and Scalable High Intra profiles).

The ITU‑T H.264 edition published in 2005-11 included the text approved 2005-03 and its Corrigendum 1 approved 2005-09. ITU‑T H.264 (2005) Amd.2 (2007) was available only as pre-published text since it was superseded by ITU‑T H.264 Amd.3 (2007-11) before its publication; further, ITU-T H.264 Amd.3 was not published separately. This third edition integrated into the ITU-T H.264 edition published in 2005-11 all changes approved in Amendments 1 (2006-06), 2 (2007-04) and 3 (2007-11).

Corrigendum 1 (2009) provides a significant number of minor corrections, clarifications, consistency improvements and formatting improvements drafted in response to accumulated errata reports collected since publication of the 2nd edition (dated 2005-03, which included a Cor.1 approved 2005-09).

The ITU-T H.264 edition published in 2009-05 contained enhancement extensions to support multiview video coding (MVC), specification of a "Constrained Baseline Profile", and some miscellaneous corrections and clarifications.

The ITU-T H.264 edition published in 2010-03 contained the specification of a new profile (the Stereo High profile) for two‑view video coding with support of interlaced coding tools, the specification a new SEI message (the frame packing arrangement SEI message), and some miscellaneous corrections and clarifications.

The ITU-T H.264 edition approved in 2011-06 contained the specification of a new level (Level 5.2) supporting higher processing rates in terms of maximum macroblocks per second, a new profile (the Progressive High profile) to enable implementation of decoders supporting only the frame coding tools of the previously specified High profile, and included miscellaneous corrections and clarifications.

The edition of Rec. ITU-T H.264 approved in 2012-01 contained the specification of three additional profiles intended primarily for communication applications (the Constrained High, Scalable Constrained Baseline, and Scalable Constrained High profiles).

The edition of Rec. ITU-T H.264 approved in 2013-04 contained an additional profile for multiview video coding with depth information (the Multiview Depth High profile), and contained additional SEI message enhancements, additional colorimetry identifiers, and corrections and clarifications.

The edition of Rec. ITU-T H.264 approved in 2014-02 specified multi-resolution frame-compatible (MFC) enhancement for stereoscopic video coding, including the specification of an additional profile, the MFC High profile, an enhanced profile for combined multiview video coding with depth information (the Enhanced Multiview Depth High profile), and includes miscellaneous minor corrections and clarifications.

The edition of Rec. ITU T H.264 approved in 2016-02 specified MFC stereoscopic video with depth maps, including the specification of an additional profile, the MFC Depth High profile, and the mastering display colour volume SEI message, additional colour-related video usability information codepoint identifiers, and miscellaneous minor corrections and clarifications.

This edition of Rec. ITU T H.264, approved in 2016-10, specifies additional levels of decoder capability supporting larger picture sizes (Levels 6, 6.1, and 6.2), the green metadata SEI message, the alternative depth information SEI message, additional colour-related video usability information codepoint identifiers, and miscellaneous minor corrections and clarifications.