Software Optimization of Video Codecs on Pentium Processor with MMX Technology
- PDF / 690,144 Bytes
- 10 Pages / 600 x 792 pts Page_size
- 95 Downloads / 154 Views
oftware Optimization of Video Codecs on Pentium Processor with MMX Technology Pohsiang Hsu Microsoft Corporation, One Microsoft Way, 25/2481, Redmond, WA 98052-6399, USA Email: [email protected]
K. J. Ray Liu Department of Electrical and Computer Engineering, University of Maryland, College Park, USA Email: [email protected] Received 14 March 2001 and in revised form 3 May 2001 A key enabling technology for the proliferation of multimedia PC’s is the availability of fast video codecs, which are the basic building blocks of many new multimedia applications. Since most industrial video coding standards (e.g., MPEG1, MPEG2, H.261, H.263) only specify the decoder syntax, there are a lot of rooms for optimization in a practical implementation. When considering a specific hardware platform like the PC, the algorithmic optimization must be considered in tandem with the architecture of the PC. Specifically, an algorithm that is optimal in the sense of number of operations needed may not be the fastest implementation on the PC. This is because special instructions are available which can perform several operations at once under special circumstances. In this work, we describe a fast implementation of H.263 video encoder for the Pentium processor with MMX technology. The described codec is adopted for video mail and video phone softwares used in IBM ThinkPad. Keywords and phrases: video coding, MMX, software optimization.
1. INTRODUCTION Recent advances in the personal computer (PC) industry have provided the necessary computation power and storage required by many multimedia applications. These tremendous technological advances have enabled the PCs to perform image/video compression and decompression efficiently in software only. Some examples include the popular software implementations of JPEG standard used to exchange images over the Internet, MPEG1 and MPEG2 decoders for music videos and movies stored in CD-ROM and DVD-ROM, respectively, and the H.263 standard for video conferencing and video telephony. These software tools facilitate the introduction of desktop video, video based interactive multimedia services, and desktop video conferencing to the general publics with a PC. Some advantages of implementing the video codec (COder/DECoder) in software for the PC are the elimination of expensive hardware, the ease of upgrade through replacement of software modules, and the wide availability of PCs. Due to the fact that a great deal of parallelism exists in many DSP algorithms including video encoding and decoding, many microprocessors have been designed to support dedicated hardware to exploit the parallelism. These special hardware extensions give microprocessors the ability to pro-
cess multiple data with the same operation efficiently through the addition of an SIMD (single instruction multiple data) instruction set. This feature is often referred to as subword parallelism, pack-arithmetic, or multimedia extension [1]. Indeed, many widely used general-purpose microprocessor platforms are adopting various forms of thi
Data Loading...
