【作者】 李小霞；

【导师】 周端；

【作者基本信息】 西安电子科技大学 ， 计算机应用技术， 2006， 硕士

【摘要】 本论文介绍了视频编码技术的发展状况和视频编码的基本原理和方法。讨论了无专利要求的Ogg Theora数字视频编码的技术。基于Theora视频编码器规范,研究了Theora的帧布局、图像区域、块和超级块、宏块、编码模式和预测、从帧到宏块的分割等特点和技术。详细讨论了根据Theora的规范要求,如何利用libtheora函数库给出的数据结构及函数编程实现编码器。论文研究了将Theora视频编码器移植到基于ARM处理器的嵌入式系统上的技术。先一步进行的工作是用C语言先将Theora编码器在PC机上实现,在这个过程中研究了如何使用autoconf和automake将代码进行有效的编译。第2部分的工作是对嵌入式操作系统的学习研究,并将编码器移植到Xscale255处理器为核心的评估板上。嵌入式操作系统选用的是源代码开放的Linux。论文介绍了软件设计过程,包括开发环境的搭建、内核的编译与移植、bootloader开发、文件系统移植、系统启动过程等。最后针对XHPER255B评估板的特点,将Theora编码器移植其上,实现了嵌入式系统上的Theora编码器功能。更多还原

【Abstract】 In this paper, development of the video coding and basic principle and method of the coding technology of videos are introduced. A patent-free digital video coding algorithm called as Ogg Theora is described. Based on the theora_I_specification, the characteristic of the frame layout, picture region, blocks and super blocks, macro blocks, coding modes and prediction are deeply analyzed. According to specification of Theora, making use of data structure and function provided in function library called as libtheora, the realization of video encoder is discussed in detail.The technology on how to transplant Theora video encoder to the embedded system based on ARM processor is studied in thesis. At first, the job starts with realizing Theora encoder on the PC first in C language. In this course how to use autoconf and automake to carry on valid compiling of the code is studied. The second part work is the research of embedded operating system, and the transplant of the encoder to the evaluation board powered by Xscale255 processor.The Linux operating system which is open source code is selected for use as the the embedded operating system. The software development including setting up of the development environment, compiling and transplantation, bootloader development, file system transplanting, systematic start-up course of the kernel is introduced. Finally, aiming at characteristic of the board to XHPER255B, Theora encoder is transplanted and function on the embedded system.更多还原