Due to the nature of B frames, an MPEG player (or in this case analyzer) needs to decode frames in an order that doesn't necessarily correspond to their presentation order. In this error message you are given two values: the frame number and the decode frame number. In this case the frame number given is the frame that is being prepared for presentation to the screen but because it is dependent on frames after itself, other frames may need to be decoded before it can be fully decoded. In this case the decoded frame number given is the frame that was in the process of being decoded as a prerequisite for the frame that is dependent on it and is also the source of the error. In summary, whenever one of these errors pops up on a stream that contains B frames, the error corresponds to the decode frame number (the decode frame is the B frame) and the frame number is merely given as reference information. This is explained in more detail on pages 6-181 through 6-183 of the MTS4EA user manual.