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===Video coding standards===
The first digital video coding standard was [[H.120]], developed by the [[ITU-T|CCITT]] (now ITU-T) in 1984.<ref name="history">{{cite web |title=The History of Video File Formats Infographic |url=http://www.real.com/resources/digital-video-file-formats/ |website=[[RealNetworks]] |access-date=August 5, 2019 |date=April 22, 2012}}</ref> H.120 was not usable in practice, as its performance was too poor.<ref name="history" /> H.120 used motion-compensated DPCM coding,<ref name="ITU"/> a lossless compression algorithm that was inefficient for video coding.<ref name="Ghanbari"/> During the late 1980s, a number of companies began experimenting with [[discrete cosine transform]] (DCT) coding, a much more efficient form of compression for video coding. The CCITT received 14 proposals for DCT-based video compression formats, in contrast to a single proposal based on [[vector quantization]] (VQ) compression. The [[H.261]] standard was developed based on motion-compensated DCT compression.<ref name="Ghanbari"/><ref name="Li"/> H.261 was the first practical video coding standard,<ref name="history" /> and uses [[patents]] licensed from a number of companies, including [[Hitachi]], [[PictureTel]], [[Nippon Telegraph and Telephone|NTT]], [[BT
[[MPEG-1]], developed by the [[Moving Picture Experts Group]] (MPEG), followed in 1991, and it was designed to compress [[VHS]]-quality video.<ref name="history"/> It was succeeded in 1994 by [[MPEG-2]]/[[H.262/MPEG-2 Part 2|H.262]],<ref name="history"/> which was developed with patents licensed from a number of companies, primarily [[Sony]], [[Technicolor SA|Thomson]] and [[Mitsubishi Electric]].<ref name="mp2-patents"/> MPEG-2 became the standard video format for [[DVD]] and [[SD digital television]].<ref name="history"/> Its motion-compensated DCT algorithm was able to achieve a [[compression ratio]] of up to 100:1, enabling the development of [[digital media]] technologies such as [[video on demand]] (VOD)<ref name="Lea"/> and [[high-definition television]] (HDTV).<ref name="Shishikui">{{cite journal |last1=Shishikui |first1=Yoshiaki |last2=Nakanishi |first2=Hiroshi |last3=Imaizumi |first3=Hiroyuki |title=An HDTV Coding Scheme using Adaptive-Dimension DCT |journal=Signal Processing of HDTV: Proceedings of the International Workshop on HDTV '93, Ottawa, Canada |date=October 26–28, 1993 |pages=611–618 |doi=10.1016/B978-0-444-81844-7.50072-3 |url=https://books.google.com/books?id=j9XSBQAAQBAJ&pg=PA611 |publisher=[[Elsevier]] |isbn=9781483298511}}</ref> In 1999, it was followed by [[MPEG-4 Visual|MPEG-4]]/[[H.263]], which was a major leap forward for video compression technology.<ref name="history"/> It uses patents licensed from a number of companies, primarily Mitsubishi, [[Hitachi]] and [[Panasonic]].<ref name="mp4-patents"/>
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