现有的以MP3音频为载体的隐藏算法大都针对恒定码率编码(CBR)的MP3,而把动态码率编码(VBR)的MP3作为掩蔽载体的研究还比较少.与CBR相比,VBR编码技术能够使MP3音频体积更小、音质更高,这一优点使得VBR MP3在MP3音频市场中的份额越来越大.基于最低有效位方法,提出了一种针对编码参数比特率索引的VBR MP3音频隐写方法.该算法可实现盲提取,而且仅仅通过解析边信息即可提取秘密信息,而不需要对载体音频进行完全解码.实验结果表明,所提算法不仅感知性良好,同时隐藏容量不受音频风格的影响.
Most steganographic algorithms have been proposed for the MP3 audio which is encoded by CBR (Constants Bitrate) mode while few algorithms for VBR (Variable Bitrate) MP3.With a smaller file size and higher sound-quality, VBR-encoded MP3 audios receive a growing proportion in digital audio market. In this paper, a novel information hiding method is proposed by the least significant bit to modify the encoding parameter -bitrate_index during the compression process of VBR MP3.Tbe embedded data can be extracted by partly decoding the MP3 file instead of decompressing the file fully.The experimental results show that the proposed scheme has no perceived sound quality degradation introduced by data embedding as well as stable hidden capacity for the MP3 files with different styles.