Low complexity video watermarking algorithm by exploiting CAVLC in H.264/AVC

As H.264/AVC digital video becomes more prevalent, issues of copyright protection and authentication that appropriate for this standard become very important. In this paper, an authentication watermarking algorithm for H.264/AVC compressed video by modulating CAVLC code words of 4×4 luminance blocks is proposed. During the embedding process, the eligible code words are first identified, and then the modulating rules between these code words and the watermark bits are established. The watermark information can be extracted directly from the encoded stream without resorting to the original video, and merely requires decoding the CAVLC code from bit stream rather than decoding the whole video. Experimental results show that the proposed watermarking scheme can effectively embed watermark information with little bit rate increase and almost no quality degradation.