Additive data insertion into MP3 bitstream using linbits characteristics

As the use of MP3 audio compression increases, the demand for the insertion of additive data, such as copyright information or information on music content itself, continues to grow, and related research has also progressed actively. When additive data is inserted into the MP3 bitstream, it should not cause any distortion in music quality or change the file size due to the modification of the MP3 bitstream structure. To satisfy these conditions, some additive data are inserted into the bitstream by modifying some linbits among the quantized integer coefficients having big values. The characteristics of linbits and their distribution are also considered. As a result of subjective sound quality evaluation through the mean opinion score (MOS) test, the quality value of MOS 4.6 is confirmed to be achievable at a data insertion rate of 60 bytes/sec. Using the proposed method, it is possible to insert additive data effectively into the encoded bitstream and to retrieve it easily; thus realizing various applications, such as audio database management.