Patent ID: 7565296
Filing Date: 2009-07-21
Classification: G10L,G11B

Abstract:
1. A digital audio watermark inserting method that encodes a digital audio signal by using a scale factor table, the method comprising an encoder for: transforming the digital audio signal into a plurality of sub-band samples; extracting a scale factor for each of the plurality of sub-band samples, wherein each scale factor comprises an amplitude factor of the corresponding sub-band sample; transforming the extracted scale factor for each of the plurality of sub-band samples into a scale factor index using the scale factor table; inserting a watermark signal into the scale factor index for each of the plurality of sub-band samples, wherein one scale factor index is allocated for every bit of the watermark signal, wherein the watermark signal is inserted into the scale factor index for each of the plurality of sub-band samples during the process of transforming the extracted scale factor for each of the plurality of sub-band samples, and wherein a minimal bit number of a watermark signal per frame to be transmitted is predetermined; and forcibly allocating a bit to an arbitrary sub-band and inserting the watermark signal in a corresponding scale factor index if the scale factor is transmitted less than the predetermined bit number of the watermark signal per frame.