DCT is a

digital recording In digital recording, an audio signal, audio or video signal is converted into a stream of discrete numbers representing the changes over time in air pressure for audio, or Color, chroma and luminance values for video. This number stream is s ...

component video Component video is an analog video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video (CAV) information that is transmitted or stored as three separate signals. Compo ...

videocassette Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocasset ...

format developed and introduced by

Ampex Ampex Data Systems Corporation is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name ''AMPEX'' is an acronym, created by its founder, which stands for Alexander M. Poniatoff Excell ...

in 1992. It was based on the D1 format, and unlike the uncompressed recording scheme of D1, it was the first digital videotape format to use

data compression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compressi ...

. Like D1 (and D2), it uses a similar cassette loaded with 3/4" (19mm) width tape. One of the models of VCR released for the format was the Ampex DCT-1700D.

Overview

The type of data compression used by the format,

discrete cosine transform A discrete cosine transform (DCT) expresses a finite sequence of data points in terms of a sum of cosine functions oscillating at different frequency, frequencies. The DCT, first proposed by Nasir Ahmed (engineer), Nasir Ahmed in 1972, is a widely ...

(DCT), shares the same acronym as the format, but the meaning is different for the latter (the format's acronym meaning Data Component Technology).Mika Iisakkila

, ''Video recording formats'' DST ( Data Storage Technology), a data-only version of DCT, was also developed by Ampex at the same time for the backup and archiving of data from servers and other enterprise-oriented IT systems. However, it was used by television networks such as Fox and

The Discovery Channel Discovery Channel, known as The Discovery Channel from 1985 to 1995, and often referred to as simply Discovery, is an American cable channel that is best known for its ongoing reality television shows and promotion of pseudoscience. It initi ...

in the late 1990s to early 2000s for mass storage of

video file A video file format is a type of file format for storing digital video data on a computer system. Video is almost always stored using lossy compression to reduce the file size. A video file normally consists of a container (e.g. in the Matro ...

data for their aired programming originating from their

video server {{refimprove, date=September 2014 A video server is a computer-based device that is dedicated to delivering video. Video servers are used in a number of applications, and often have additional functions and capabilities that address the needs of p ...

s for on-air

playout In broadcasting, channel playout is the generation of the source signal of a radio or television channel produced by a broadcaster, coupled with the transmission of this signal for primary distribution or direct-to-audience distribution via any ...

, with the servers being networked to a robotic DST tape jukebox (such as an Ampex DST 800 Automated Cartridge Library) for video file access. DCT was also used by movie studios such as

Warner Brothers Warner Bros. Entertainment Inc. (WBEI), commonly known as Warner Bros. (WB), is an American filmed entertainment studio headquartered at the Warner Bros. Studios complex in Burbank, California and the main namesake subsidiary of Warner Bro ...

for mastering some of their first movie releases to

DVD The DVD (common abbreviation for digital video disc or digital versatile disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any ki ...

around the latter format's introduction in the US in 1997.

References

External links

Cutaway view of a DCT VCR

Encyclopedia Pro's entry on DCT

Ampex's History
{{Homevid Videocassette formats

Overview

References

See also

External links