  H.264/Advanced Video Coding (AVC) is one of the most commonly used video
compression standard currently. In this paper, we propose a Reversible Data
Hiding (RDH) method based on H.264/AVC videos. In the proposed method, the
macroblocks with intra-frame $4\times 4$ prediction modes in intra frames are
first selected as embeddable blocks. Then, the last zero Quantized Discrete
Cosine Transform (QDCT) coefficients in all $4\times 4$ blocks of the
embeddable macroblocks are paired. In the following, a modification mapping
rule based on making full use of modification directions are given. Finally,
each zero coefficient-pair is changed by combining the given mapping rule with
the to-be-embedded information bits. Since most of last QDCT coefficients in
all $4\times 4$ blocks are zero and they are located in high frequency area.
Therefore, the proposed method can obtain high embedding capacity and low
distortion.
