| Digital compression is a key technology in the multimedia applications. It reduces requirement of the storage and the bandwidth transmitted by compressing the multimedia data effectively, and can encode and transmit in real time. Multimedia applications based on video compression also emerge gradually because of its promising future. Digital video has been becoming an indispensable part in the daily life gradually.However, video encoding is a very complex computation process. It demands a very high ability of process and a high performance processor to computer. Since the computing work of the digital video process is extremely large, it is impossible to achieve real time by using traditional sequential program design method in the single processor system environment. Nevertheless, most of the multimedia applications covered by H.264 (MPEG-4 Part 10) require real time process. Parallelism makes use of higher performance than a single computer. What's more, the structure of the H.264 encoder is fit for distributed parallel computing perfectly.The parallel computing environment based on message passing is a widely used program paradigm on the parallel computers. Message passing can be realized efficiently and portable in various applications. Express, P4, PVM, and MPI are the environments of message passing used generally at present. Among them, MPI (Message Passing Interface) is the most important program paradigm. It has many advantages such as portable, powerful and high efficient. Based on the characteristics of MPI, we implement the video encoding parallel algorithm using MPI.Based on the macroblock, aiming at the characteristics of group of pictures and slice, utilizing the spatial and temporal local relativity of digital video and employing the parallel program design method on the message passing parallel computing environment as MPI, it is brought forward that H.264 video encoding algorithm shall be used to realize the real time process of digital video.
|
PDF Full Text Request