Video compression is the core technology for video conference, and its quality depends on the compression technology. The H.264 is a high-performance en/decoding algorithm, which has higher compression ratio and better network suitability. This paper introduces the key technology of the H.264 coding algorithm and the framework of Directshow technology. Besides, through embedding the FFmpeg, the open-source library of H.264, into the Directshow Filter Graph, researchers can encode and decode the video data of users.