An information hiding method based on context-based adaptive variable length coding

Abstract

Current video information hiding algorithms based on H.264 cannot meet the requirement of real-time transmission and get compromise between embedding strength and the changing amplitude of bits stream. To solve these problems, a real-time video information hiding method in CAVLC for H.264/AVC is proposed, which combines information hiding with CAVLC process, and embeds the secret information in the number of trailing coefficients of 4 × 4 macroblocks. Aiming at alleviating video degradation and the embedded secret in real-time transmission, the method is time-efficient and robust. Experimental results show that the embedding process cannot bring detectable video degradation, and only cause a small change in the length of the video stream. Moreover, the embedded secret information can be recovered correctly when being transferred under different RTP lost channels. And the secret information can be extracted directly from the encoded stream without resorting to the original video.