Study on adaptive job assignment for multiprocessor implementation of MPEG2 video encoding

The high demand on computation performance by multimedia information processing such as digital video compression and decompression has made multiprocessor computation more and more popular. In this paper, we present our study on adaptive job assignment for multiprocessor implementation of a Motion Picture Expert Group 2 (MPEG2) video encoding algorithm. Data partitioning technique is used for job assignment to the processors in the multiprocessor environment to exploit the data structure adopted by the MPEG standard that divides a frame of a picture into macro blocks (MBs) which are processed independently during encoding. An adaptive data partitioning scheme is developed to cope with the inherent nonuniform spatial distribution of motion activities, such that the computation load distribution over processors is as uniform as possible, which helps improve the speedup of the whole multiprocessor system. Simulations with several video sequences have shown that, in comparison to its nonadaptive counterpart, the adaptive scheme can effectively improve the speedup of the multiprocessor system. In addition, the speedup scales well with the increase of the number of processors used in the computation.