In simple terms, the problems faced by a media processing system are twofold: how to build a machine with the required performance, and how to efficiently program it once built.
It is tempting to liken the problems associated with digital video
today to those faced by early forays into digital audio. Early
attempts at processing digital audio required the use of specialized
architectures and processors; most audio processing algorithms can be
implemented today using a single chip programmable digital signal
processor, with many algorithms implementable on today's general
purpose microprocessors. Until now, video processing systems have
used specialized architectures and processors. In the past few years
several implementations of programmable digital video signal
processors have appeared, especially targeted at implementing low
resolution motion compensated transform based coding. The data
intensive nature of the image processing task, however, differentiates
it from audio processing.
While the input/output data rates in a typical digital audio system are
determined by the sensitivity of the human auditory system, the video data
rates will be technology limited for many years to come.
Six channels of uncompressed audio data require only 4.2 Mbits/sec of data
, but an uncompressed video channel today requires between 66 and 26,000
Mbits/sec of data, making parallel processing necessary for most applications.