Research On Technologies Of AMR Steganography And Steganalysis Based On Pitch Delay

In recent years,with the development of mobile communication,AMR as the voice of mobile Internet voice communication compression encoding standard is widely used for voice communication encoding quality and network bandwidth usage requirements.The research of steganography algorithm based on AMR speech has been developed gradually,the detection is difficult,and the steganalysis algorithm is less.Therefore,it is of great significance and application value to carry out the research of steganalysis method and to design better steganography algorithms based on AMR speech.This paper focuses on the steganography and steganalysis algorithms of pitch delay in AMR adaptive codebook search.The main innovations and works of this paper are as follows:1)After the research and analysis of AMR adaptive codebook search,we found that there is a certain relationship between pitch delay and pitch period.The experimental results show that,in the AMR coding,the pitch delay in voiced segments has short-term relative stability,and the jitter amplitude of pitch delay in unvoiced segments is lager and randomness is obvious.The above theoretical and experimental analysis promote the two algorithms in the paper.2)In order to detect the existing steganography algorithms in AMR adaptive codebook search,this paper designs and realizes the steganalysis algorithm based on the correlation of pitch delay since the existing steganography algorithms destroy the short-term relative stability of pitch delay in voiced segments.The algorithm combines the AMR coding principle to calculate the multi-order Markov transition probability of the difference between subframes,and construct the steganalysis feature by using the feature optimization and uniting with C-MSDPD feature.The experimental results show that the correct rate is better than existing steganography algorithms when the EBR is low.3)In order to ensure the safe transmission of secret information,since the pitch delay in unvoiced segments do not have short-term relative stability,the adaptive steganography algorithm based on the jitter characteristic of pitch delay in unvoiced segments is designed and realized in this paper.After the analysis of AMR coding principle,we use the pitch delay difference distribution of continuous odd subframes to select the suitable embedded subframes adaptively and avoid to destory the short-term relative stability of pitch delay in voiced segments.We also design the steganography rules to ensure the embedded capacity.The experimental results show that the designed adaptive steganography algorithm has good performance and good hearing concealment.This paper focuses on the pitch dalay of AMR adaptive codebook search,based on the existing steganography algorithms proposes effective steganalysis algorithm.And designs steganography algorithm with good performance and good hearing concealment.The research results can be widely used in the field of 3G mobile voice communications and provide technical support for the security of voice data.