Research Of Video Streaming Watermarking Techniques Based On H.264/AVC

With the rapid development of multimedia technology and computer networks, the creation and spread of digital media are becoming more conveniently, meanwhile the problem of piracy is also serious. The security of multimedia information is an important issue to be resolved. Digital Watermarking technique can embed copyright information into the original data without harm to its usage. Moreover, the watermark is hard to be removed, and can only be detected by specially-designed extraction algorithm. As an effective solution to the copyright protection of digital products, digital watermarking is a hot research topic in the field of multimedia security. Video watermarking is an important branch.This thesis briefly reviews the currently available video watermarking algorithms, and utilizes the features and tools of H.264/AVC video coding standards. The fragile watermark based integrity authentication scheme and watermark embedding scheme for Copyright tracing in P2P network are proposed respectively. The main work is summarized as follows.First, the state-of-the-art video watermarking is briefly reviewed, and the start-point of research on watermarking techniques for video streaming is analyzed.Second, a fragile watermark based video authentication scheme is proposed for the integrity authentication of low bit-rate video. According public-key and secret-key, the authentication code is created from the character information of the inter frame. The authentication information is embedded into motion vector of the P frame and B frame as watermark. The integrity authentication can be carried out by partial decoding the video stream, and does not need the original video stream for watermark detection. Experimental results show that the proposed approach can maintain a slight bit-rate increase and visual distortion, and can authenticate I frame, P frame and B frame effectively.Third, a novel watermark tracing and audition scheme is proposed for non-central P2P network. The characteristics of non-centre P2P network will lead to repeated embedding when audition watermark is dynamically embedded. A real time information hiding algorithm based on Intra prediction modes is proposed for H.264/AVC video stream. It utilizes the block types and modes of intra prediction to embed watermark. I4-blocks are divided into groups, and two watermark bits are mapped to every three I4-blocks by matrix coding between watermark bit and intra prediction modes. Since only the mode of an I4-block is changed for every two watermark bits, it can guarantee a high PSNR and slight bitrate increase after watermark embedding. Moreover, embedding position templates is utilized to select candidate I4-blocks for watermark embedding, which further enhances the security of watermark. Experimental results on several test sequences demonstrate the proposed scheme can realized blind extraction.