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基于DirectShow的视频解码器的研究 摘要 本系统的设计能够完成的功能包括对本地音视频文件（主要是针对MPG格式的文件），以及网络实时音视频文件的传输与播放。其基本构成包括过滤器、缓冲区、编解码器。理论上，可以形成对这些音视频文件同时进行多路接收与编解码，但由于音视频文件数据量一般较大，且这种文件的运行占用较大的计算资源。故此次系统设计只考虑了最多两路文件的运行。对于网络的文件，则进行了流化处理，而不是传统的先下载完毕再播放。因此提高了计算机存储系统的利用率。对于音视频文件的运行，该软件设置了多种启动模式，各有优缺点，用户可以根据具体情况灵活选择启动模式。系统包含两个多媒体数据处理通道，对应两个声音处理通道，还拥有一些其它一些常用功能按钮。系统涉及的关键技术包括Filter原理的理解与实现、实时编解码过程的实现。 关键词：DirectShow 视频 解码器 Abstract What this system can do include transforming the audio and video data and performing them. These data comes from local disks or network. The system is composed of filter、buffer and coder/decoder. In theory, the system can simultaneity receive and encode and decode the data from two or more ways. However ,the capacity of video/audio data in itself is large. So when the application operating these data is running, large quantities of cpu resources will be utilized. Just for this reason, the system I have designed can only simultaneity deal with two ways of data at the most. When the system deals with network files, it streams these files. This way is different from the tradition way dealing with the audio/video files. In the tradition way ,we must download all the files from network to our local disk in advance, then we can play these files. To operate our audio/video files the system possesses of many starting modes. User can choose any one starting mode according to the actual cases. The system includes two ways dealing with multimedia data, and two ways dealing with sound corresponding to them. In addition, the system has many buttons perform different functions. The key technology of this system is as follows: The understanding and realizing towards theory of the system; The realizing of the codec in real-time way. Key Words：DirectShow Video Decoder 一 选题背景 1.1 课题来源 流媒体的定义很广泛，大多数时候指的是把连续的影像和声音信息经过压缩处理后放上网站服务器，让用户一边下载一边观看、收听，而不需要等整个压缩文件下载到自己机器就可以观看的视频/音频传输、压缩技术。流媒体也指代由这种技术支持的某种特定文件格式：压缩流式文件，它通过网络传输，并通过个人电脑软件进行解码。　　MCI是微软为Windows最初提出的多媒体编程接口，随着多媒体技术的迅速发展，各种压缩算法在