This paper describes a method for applying a watermark directly to an entropy coded H.264/AVC stream. This method can be applied when the stream, or at least the I-frames, is entropy coded with CAVLC. Most of the hard work goes into building an embedding table during an analysis stage. This table identifies small segments of data in the encoded stream that will be replaced. The table also provides alternative values for each segment. The embedding process involves replacing each identified segment with one of the alternative values from the table. The choice of alternative is informed by the payload to be embedded. The resulting bitstream is guaranteed to be compliant with the H.264/AVC standard.