Method and apparatus for encoding a picture sequence using predicted and non-predicted pictures which each include multiple macroblocks

Abstract

In MPEG, most video frames are encoded in inter mode. Every now and than a video frame is encoded in intra mode in order to limit error propagation and to enable access points for starting decoding of the video sequence. According to the invention, however, it is sufficient to encode in an intra frame only those pixel blocks in intra mode of which at least one pixel is used for predicting some future picture content information, whereas the other blocks can be encoded in inter mode. In order to check which blocks in the intra frame can be encoded in inter mode, a motion compensation pre-analysis of the following P-frame is performed, in order to find those blocks that need not be encoded in intra mode because no pixel in such blocks is used for the prediction of that following P-picture.