Patent ID: 7672373

Claim:
A method comprising: accepting in a processing apparatus a compressed video stream that is compressed by a compression method that uses macroblocks for each frame, and that encodes some frames using predictive encoding based on one or more reference frames for each predictively encoded frame, and further, that uses different macroblock types for predictively encoded frames; identifying by the processing apparatus a sequence of frames, at least a portion of which is substantially visually indistinguishable for each frame in the sequence, and that includes a predictively encoded frame and the at least one reference frame of the predictively encoded frame; creating by the processing apparatus an ordered set of macroblocks, with the macroblock types of different macroblocks in the ordered set used to encode digital watermark information; and replacing by the processing apparatus the at least a portion of the predictively encoded frame of the identified sequence with a newly-encoded predictively encoded replacement frame that contains the created ordered set of macroblocks in the position of the portion if only a portion is identified, including the encoded watermarking information, the encoding of the replacement frame in the replacing being such that the size of the newly-encoded replacement frame or portion of frame has the same size in bits as the predictively encoded frame or portion of frame being replaced, such that the method transforms the compressed video stream into a compressed video stream that includes the encoded watermarking information.