Digital audio watermarking for QoS assessment of MP3 music signals

Digital watermarking of multimedia contents has become a very active research area over the last several years. In this work, we propose an audio watermarking signal processing technique to provide a quality assessment of the received audio signal after a coding/transmission process. Specifically, a fragile watermark is hidden in MP3-like host data audio transport stream (MPEG-1 layer III) using a spread-spectrum approach. At the receiving side, the watermark is extracted and compared to its original counterpart. Since the alterations endured by the watermark are likely to be suffered by the MP3-file, as they follow the same communication link (including coder and transport connection), the watermark´s degradation can be used to estimate the overall alterations endured by the entire MP3-data. The Quality of Service assessment is based on the evaluation of the mean-square-error between the estimated and the actual watermark. The proposed technique has been designed for application to mobile multimedia communication systems. The results obtained through our simulation trials confirm the validity of such approach.