Digital watermarking of MPEG-2 coded video in the bitstream domain

Embedding information into multimedia data, also called watermarking, is a topic that has gained increased attention. For video broadcast applications, watermarking schemes operating on compressed video are desirable. We present a scheme for robust watermarking of MPEG-2 encoded video. The watermark is embedded into the MPEG-2 bitstream without increasing the bit-rate, and can be retrieved even from the decoded video and without knowledge of the original, unwatermarked video. The scheme is robust and of much lower complexity than a complete decoding process followed by watermarking in the pixel domain and re-encoding. Although an existing MPEG-2 bitstream is partly altered, the scheme avoids visible artifacts by adding a drift compensation signal. The scheme has been implemented and the results confirm that a robust watermark can be embedded into MPEG encoded video which can be used to securely transmit arbitrary binary information at a data rate of several bytes/second. The scheme is also applicable to other hybrid coding schemes like MPEG-1, H.261, and H.263