Methods and apparatus for decoding video images

摘要

A method and apparatus for decoding a compressed motion compensated video sequence is provided. The image data comprising a plurality of reference pictures (R) and motion vectors for deriving intermediate pictures (I,B) from preceding pictures in the sequence. The maximum vertical extent of the motion vector corresponds to a number of lines of image data. A reference picture is received along with a set of motion vectors to derive a next picture in the sequence from the reference picture. This next picture is decoded once the vertical extent of the reference picture received exceeds the maximum vertical extent of a motion vector from a starting position. A further next set of motion vectors for deriving a further next picture in the sequence is then received and for each further next picture the image data is decoded using the respective further next set of motion vectors when the area of a respective previous picture has been decoded to said maximum vertical extent of a motion vector from a starting position.