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题名	基于XScale的嵌入式Real播放器设计和实现
作者	陈志辉
学位类别	博士
答辩日期	2007-05-26
授予单位	中国科学院声学研究所
授予地点	声学研究所
关键词	Real 媒体播放器 无线MMX 丢帧 字幕
其他题名	Design and implementation of embedded Real player based on XScale
学位专业	信号与信息处理
中文摘要	随着网络和多媒体技术的发展，特别是新一代视频编解码技术的进步，数字视频业务得到迅速普及，各种视频播放终端和设备得到越来越广泛的应用。媒体播放器是实现音视频多媒体回放的软件或硬件，对视频业务的开展起到关键性支撑作用。 作为新一代视频编解码技术的典型代表，RealVideo已成为视频内容的重要发布格式。为此，本文在深入研究媒体播放器核心技术的基础上，结合Real媒体格式和视频技术的特点，设计了具有模块化、流水线、可移植、易扩展等特点的嵌入式Real播放器框架结构，并基于XScale平台实现了嵌入式Real媒体播放器。 针对Real视频复杂度高、容易造成系统视频处理能力不足的情况，播放器实现了提高系统性能的优化方法，并设计和实现了多种提高视频播放效果的策略和方法： (1) 利用XScale芯片提供的无线MMX单元，依赖其单指令多数据特性，采用软件流水线和多采样方法，对Real视频解码器进行了优化，使得解码性能有近30％的提升，保证了Real媒体播放功能的实现； (2) 针对大尺寸视频序列解码复杂度整体偏高的情况，设计和实现了帧滤波机制。该机制通过测试平台处理能力和估计视频序列解码复杂度，设定目标播放帧频，并实施滤波，能够整体降低视频播放复杂度； (3) 设计和实现了基于丢帧的自适应分级处理方法。该方法充分考虑不同类型的视频帧的解码特点，在保证解码的正确性和处理的独立性的前提下动态平衡视频播放负担； (4) 设计和实现了解码质量控制策略。该策略利用人眼视觉特性，通过牺牲较小的图像质量，大幅度降低视频解码复杂度，有效改善和提高视频节目的播放效果。 为满足人们在学习和娱乐时对于字幕的需求，本文还实现了基于颜色分量和基于视频Overlay的两种字幕显示方法，并给出了两种方法的分析比较结果。 测试及试用表明，本文实现的基于XScale的嵌入式Real播放器基本功能完善、媒体播放性能稳定可靠。
英文摘要	With the development of network and multimedia technology, especially the progress of the new generation video compression techniques, digital video services have gained fast popularity, and various video playing terminals and platforms have achieved wider and wider application. Media player is the software or hardware that performs audio and video playback, and plays a key role in video applications. As the representative of new generation video compression techniques, RealVideo has become an important distribution format of digital video contents. After deeply researching on the key technologies of media player, considering about Real media format and RealVideo characteristics, a modular, pipelining, portable, and extendable Real player framework is designed in this paper. And an embedded Real media player is implemented based on XScale platform. Several methods and strategies are designed and implemented in the embedded player to improve system performance and avoid the situation of short of capability in processing high complexity RealVideo sequences. (1) By using the wireless MMX unit on the platform, taking full advantage of SIMD (Single Instruction Multiple Data) characteristic, and adopting software pipelining and multi-sample method, the RealVideo decoder is optimized with 30% performance increase, which ensures the working of Real media playback; (2) Targeting the situation of big dimension video frames, a frame filtering scheme is designed and implemented which is based on platform performance and video sequence complexity. The filter will largely decrease video playing overload; (3) A scalable adaptive processing method which is based on frame skipping is designed and implemented. The method has fully considered the characteristic of different frame types, and will dynamically balance video playing overload providing the video decoding correctness and processing independence; (4) A video decoding quality control strategy is designed and implemented which is based on people’s visual characteristic. By sacrificing little picture quality, it will largely decrease video decoding complexity and is effective in improving visual effect. At the same time, two subtitle display methods which based on separate color and video overlay theories are implemented to meet people’s demand for subtitle display. Tests show the embedded Real player based on XScale has possessed of complete video playing capability and reliable performance.
语种	中文
公开日期	2011-05-07
页码	110
内容类型	学位论文
源URL	[http://159.226.59.140/handle/311008/236]
专题	声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文
推荐引用方式 GB/T 7714	陈志辉. 基于XScale的嵌入式Real播放器设计和实现[D]. 声学研究所. 中国科学院声学研究所. 2007.

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