國立臺灣大學電子工程學研究所陳少傑2006-07-262018-07-102006-07-262018-07-102005-07-31http://ntur.lib.ntu.edu.tw//handle/246246/20039本研究計畫之目的，在整合應用以ARM 為基礎的嵌入式多媒體即時作業系統於 H.264/MPEG-4 多媒體上。由於H.264 是 一種因應即時系統(RTOS)所設計的可擴 展性串流傳輸(scalability stream media communication)的編碼技術。H.264 主要架 構於細粒度可擴展(Fine Granular Scalability, FGS)的壓縮編碼機制。細粒度 可擴展壓縮編碼技術是最新MPEG-4 串流 式傳輸標準，能依頻寛的差異來調整傳輸 的方式。細粒度擴展縮編碼技術以編入可 選擇性的增強層(enhanced layers) 於碼 中，來提高影像傳輸的品質。本計畫主要 在於設計一種簡單有效的即時階層可擴展 的影像傳輸系統。在增強層編碼及H.264 的基本層(base layer)編碼上使用漸進的細 粒度可擴展編碼(Progressive Fine Granularity Scalable, PFGS) 能直接使用 H.264 的格式特色來實現FGS。同時加入 了LB-LLF (Layer-Based Least- Laxity-First scheduling algorithm) 的排程演算法，來增 進網路傳輸影像的品質。由實驗結果顯示 本系統在串流影像品質PSNR 值上確有較 佳的效能。With the recent development in stream media, scalable H.264 video encoding is designed to be used in real-time video communications systems. The method is based on the Fine Granular Scalability (FGS) video coding method. It provides a framework to adapt to variations in the channel bandwidth and was recently standardized in the Streaming Video Profile of MPEG-4. In this project we proposed and implemented a simple and effective real-time layer-based scalable video communication system. In this system we use Progressive Fine Granularity Scalable (PFGS) scheme to encode the enhancement layer and H.264 to encode the base layer. This scheme is a direct implementation of FGS onto H.264 and does not employ any H.264-specific features for FGS. We also use the adaptive Layer-Based Least-Laxity- First (LB-LLF) scheduling algorithm to improve the output quality of video on network and to achieve synchronized playback effect. The experimental results show that subjective quality of the video stream is significantly improved using our methods.application/pdf1930883 bytesapplication/pdfzh-TW國立臺灣大學電子工程學研究所即時作業系統排程嵌入式系統多媒 體應用Real-Time Operating System (RTOS)SchedulingEmbedded SystemMultimedia Applicationreporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/20039/1/932215E002010.pdf