基于分级汉明编码的G.723.1码流调制信息隐藏方法

对VoIP语音系统的信息隐藏算法进行了深入研究.通过码元组合排序及PESQ评价指标确定了G.723.1编码后码流的待嵌入载体比特位.使用汉明编码降低了嵌入过程中需要改变的载体数量,减小了嵌入过程导致的失真,并用混沌序列作为共享密钥,使发送方和接收方之间可以通过伪随机发生器生成单帧嵌入比特序列.引入分级编码优化了单帧嵌入...

Information hiding method of G.723.1 code stream modulation based on hierarchical Hamming coding

The information hiding algorithm for VoIP voice system is deeply studied.The carrier bits to be embedded in G.723.1 coded stream are determined by code element combination sorting and PESQ evaluation index.Hamming coding is used to reduce the number of carriers that need to be changed in the embedding process and reduce the distortion caused by the embedding process.Chaotic sequence is used as the shared key,so that the sender and receiver can generate a single frame embedded bit sequence through the pseudo-random generator.Hierarchical coding is introduced to optimize the embedding order of single frame embedded bit sequence,which further reduces the distortion caused by bit stream modulation.The experimental results show that hierarchical coding makes the optimization rate of PESQ rating reach 94.07%,which further enhances the embedding concealment.