A Steganography Method for G.729a Speech Coding

摘要

By analyzing and comparing the G.729a speech coding specifications, this paper proposes an effective information hiding method. The proposed method hides the transmitted confidential information bits according to the need of the hiding information to adjust the last bit value of the excitation pulse position coding in G.729a speech coding, thereby realizing the embedding of secret information. We discussed and introduced in detail the information embedding and extraction algorithm of the proposed information hiding method. In order to test the feasibility and efficiency of the method studied, we conducted simulation experiments. The experiment used six kinds of audio material clips that we recorded, cut and edited by ourselves, namely children's male voice, children's female voice, male singing voice, female singing voice, Chinese classical music, and western music. Experiments show that when the secret information transmission rate is 200 bit/s and the hiding rate is 2.5%, the percentage of PESQ value reduction of the voice carrier proposed by the information hiding method proposed in this paper is 5.31%. While the secret information transmission rate is 300 bit/s and the hiding rate is 3.75%, the percentage of PESQ value reduction is 7.95%. The experimental results showed that the algorithm discussed in this paper has a sound covert communication capacity and strong concealment, indicating that the proposed algorithm demonstrates good information hiding performance.