Recently, many studies have been done for video semantic indexing from a huge amount of consumer video on the Internet. In this paper, we introduce the research activities in TRECVID workshop, which is an international workshop where many participants compete each other on video search performance. We focus on two TRECVID tasks, video semantic indexing and multimedia event detection, and explain the technologies used in these tasks. Finally, we discuss the future direction of the video search researches.