Improving the precision of shot boundary detection is very important.This paper presents an algorithm for shot boundary detection based on SVM(support vector machine)in compressed domain.It uses the features

such as the type of macroblock

the difference between DC coefficients of two co-located blocks in successive frames and the type of frame

to segment a video into the shots by classifying the frames into three classes

namely

the frames of cut change

gradual change and non-change.No thresholds

which are often hard to select in most shot detection methods

are involved in our algorithm.Experiments have shown that our algorithm is robust for motion of camera and large objects in video

and the experimental result of our algorithm on TREC-2001 video data set is 8% higher than the best result of 2001 TREC evaluation in F1 comparison when cut and gradual changes are both considered.