Topic summary
Video coding
Extracted from the Wikipedia article Video coding format.
Video coding standards
The first digital video coding standard was H.120, developed by the CCITT (now ITU-T) in 1984. H.120 was not usable in practice, as its performance was too poor. H.120 used motion-compensated DPCM coding, a lossless compression algorithm that was inefficient for video coding. 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. H.261 was the first practical video coding standard, and uses patents licensed from a number of companies, including Hitachi, PictureTel, NTT, BT, and Toshiba, among others. Since H.261, motion-compensated DCT compression has been adopted by all the major video coding standards (including the H.26x and MPEG formats) that followed.