Real-time parallel MPEG-2 decoding in software

The growing demand for high quality compressed video has led to an increasing need for real-time MPEG decoding at greater resolutions and picture sizes. With the widespread availability of small-scale multiprocessors, a parallel software implementation may provide an effective solution to the decoding problem. We present a parallel decoder for the MPEG standard, implemented on a shared memory multiprocessor. Goal of this work is to provide an all-software solution for real-time, high-quality video decoding and to investigate the important properties of this application as they pertain to multiprocessor systems. Both coarse and fine grained implementations are considered for parallelizing the decoder. The coarse-grained approach exploits parallelism at the group of pictures level, while the fine-grained approach parallelizes within pictures, at the slice level. A comparative evaluation of these methods is made, with results presented in terms of speedup, memory requirements, load balance, synchronization time, and temporal and spatial locality. Both methods demonstrate very good speedups and locality properties.