A scalable off-line MPEG-2 video encoding scheme using a multiprocessor system

Abstract Video compression plays a central role in a vast number of multimedia applications but its computational requirements overwhelm the capabilities of any present single processor system. In this paper, we explore the use of parallel machines like the Intel Paragon to compress MPEG-2 video sequences. The motivation is to build a production-based compression facility by exploiting the potential power of the available machine. Given a video sequence or a set of sequences, the aim of the parallel encoder is to achieve the maximum possible encoding rate. A collective scheduling scheme for the processors, I/O nodes, and disks is proposed that provides fast I/O, minimizes the idle times of processors, and enables the system to work in a highly balanced fashion. An efficient data layout scheme for storing video frames is also proposed in order for the I/O to sustain the desired data transfer rates. Using a small percentage of processors as the I/O nodes results in an efficient utilization of the system resources. As shown by experimental and analytical results, the encoding scheme is scalable and higher performance can be achieved with larger machines. The performance of the proposed scheme can be many times the real-time encoding rates with Standard Interface Format (SIF) and CCIR-601 video sequences. The experimental results indicate about two-fold gain in performance compared to the previous studies. Such a system is useful for the conversion of analog videos to compressed digital form in large studios, digital libraries, and other multimedia database environments. The proposed scheme partitions the system into groups of compute nodes, and I/O nodes, and can be easily extended to other MIMD machines or a set of networked workstations.