Patent ID: 8130811

Claim:
A method comprising: receiving a media signal transmitted over a communication channel from a transmitter, wherein the channel from the transmitter is susceptible to distortion that varies as a function of time, causing degradation in quality of service, and wherein the received media signal represents audio and/or video information; recreating a reference digital watermark from the received media signal; extracting a second digital watermark, using a processor, from the received media signal, wherein extraction comprises decoding plural message symbols steganographically encoded as the second digital watermark in the received media signal; and evaluating the second digital watermark relative to the reference digital watermark to measure time-based degradation in quality of service of the received media signal based on differences between the second and reference digital watermarks, wherein evaluating the second digital watermark comprises comparing the decoded symbols with a set of reference symbols to identify errors there between, and wherein the errors are indicative of the quality of service of the received media signal.