Apparatus for decoding digital video data with small memory requirement

Claim 1

In combination, a coding apparatus for coding digital video data in a block format allowing compression of the video data representing a two dimensional group of picture elements belonging to a plurality of frames, the coding apparatus comprising: sub-sampling means for sub-sampling picture elements in predetermined positions in each of a succession of frames, the phase being inverted between two continuous frames, to reduce the number of picture elements in each of the frames, thereby producing lines of thinned-out data with n picture element data in each line; block segmentation means for arranging the picture elements of the thinned out data in time-sequential blocks, the block segmentation means including a two-line memory means and means for alternately writing n picture element data from each one of continuous pairs of lines of the thinned out data into the two-line memory means in a memory address pattern such that two successive picture element data are written in two contiguous memory addresses which are then followed by two contiguous memory addresses into which are written two successive picture element data from the next succeeding line of thinned out data, and reading out the data from the two-line memory means as block segmented data; movement discriminating means for receiving the block segmented data and detecting movement in each block and generating a discriminating code indicative of detected movement; and encoding the block segmented data and transmitting the discriminating code and the encoded block segmented data; and further including a decoding apparatus comprising: decoding means for receiving the encoded block segmented data and the discriminating code and decoding the encoded data to generate decoded block segmented data; block desegmentation means connected to the decoding means for converting the decoded block segmented data into scanning picture element data; adaptive interpolation means connected to the block desegmentation means and supplied with the scanning picture element data, for performing spatial interpolation of the scanning picture element data, in accordance with the discriminating code, to reconstitute the original digital video data.