Design of a multifunction video decoder based on a motion-compensated predictive-interpolative coder

ABSTRACTIt is now possible to encode VCR quality video and stereo audio at only 1 .5 Mbit/s. In addition, standards have been defined for compressing full color still images and teleconferencing video at bit ratesof 64 to 1920 kbit/s. Finally there is great interest in the next generation of PCs which will incorporate multimedia displays and have capabilities to edit, store and transmit video and images over communication networks. Although the standards defined for video teleconferencing and those beingdefined for storage of video and images are different, they still have substantial parts that are common. Inthis paper, we describe the design of a multi-function decoder that is capable of decoding bit streams fromthe different encoders. By sharing functional modules that are common to the different algorithms, thedecoder can cope with the different standards with only a minimal increase in complexity required overthat needed for any one standard. In addition, it allows transparent display of video information coded atdifferent frame rates and using different aspect ratios, thus facilitating exchange of information betweenNTSC and PAL-based systems as well as film material.