DCT is a lossy compression technique that was first proposed by Nasir Ahmed in 1972, and was later adapted into a motion-compensated DCT algorithm for video coding standards such as the H.26x formats from 1988 onwards and the MPEG formats from 1991 onwards. Streaming services were only made possible as a result of two major technological developments: discrete cosine transform (DCT) video compression and asymmetric digital subscriber line (ADSL) data transmission. Up until the 1990s, it was not thought possible that a television programme could be squeezed into the limited telecommunication bandwidth of a copper telephone cable to provide a streaming service of acceptable quality, as the required bandwidth of a digital television signal was around 200 Mbit/s, which was 2,000 times greater than the bandwidth of a speech signal over a copper telephone wire.
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