軟體MPEG-2解碼器之研究

Abstract

本論文基於軟體實作的優點，實作一個軟體MPEG-2解碼器(MPEG-2 Decoder)。實作此MPEG-2解碼器包含三個部分，分別為實作MPEG-2系統解 碼器(MPEG-2 System Decoder)、使用MMX技術加速MPEG Software SimulationGroup (MSSG) MPEG-2影像解碼器(MPEG-2 Video Decoder)以 及修改Maplay 1.2為MPEG-2音效解碼器(MPEG-2 Audio Decoder)。並且於 本論文中提供完整的MSSG影像解碼器程式構造報告、MMX改寫過程報告和 MMX對MPEG-2影像解碼器效能影響的分析。最後，於本解碼器中加入可變 性品質服務的功能(Adaptive Quality of Service)，使本解碼器可自動 偵測系統之負載，進而選用不同模式。使電腦於不同的負載下，影像輸出 的每秒訊框張數(Frame Rate)均可控制於一穩定的範圍中，讓影像不會出 現跳動或閃爍等各種不穩定的情形。同時以中央處理器(CPU)的machine cycle，精確測量可變性品質服務的各種模式，於執行時的表現。 According to advantages of the software implementation, this thesis develops a software MPEG-2 Decoder. The implementation of this software MPEG-2 Decoder contains three key parts: developing a MPEG-2 System Decoder, using MMX to enhance the MPEG Software Simulation Group's (MSSG) MPEG-2 Video Decoder, and modifying Maplay 1.2 to be a MPEG-2 Audio Decoder. We provide a trace report of MSSG Video Decoder, the details of MMX coding techniuqe and the influence of MMX technology to MPEG-2 Video Decoder. At last, with the Adaptive Quality of Services, this software MPEG-2 Decoder can detect the work load of system and choose one proper mode to play with a consistent Frame Rate. We also use the CPU machine cycle to analysis each mode of this Adaptive Quality of Services and provide some precise evaluations.