Identifying Compression History of Wave Audio and Its Applications
Audio signal is sometimes stored and/or processed in WAV (waveform) format without any knowledge of its previous compression operations. To perform some subsequent processing, such as digital audio forensics, audio enhancement and blind audio quality assessment, it is necessary to identify its compression history. In this article, we will investigate how to identify a decompressed wave audio that went through one of three popular compression schemes, including MP3, WMA (windows media audio) and AAC (advanced audio coding). By analyzing the corresponding frequency coefficients, including modified discrete cosine transform (MDCT) and Mel-frequency cepstral coefficients (MFCCs), of those original audio clips and their decompressed versions with different compression schemes and bit rates, we propose several statistics to identify the compression scheme as well as the corresponding bit rate previously used for a given WAV signal. The experimental results evaluated on 8,800 audio clips with various contents have shown the effectiveness of the proposed method. In addition, some potential applications of the proposed method are discussed.