Patent ID: 7191389

Claim:
A receiver, comprising a decoder for receiving encoded video signals, wherein the decoder is operative to decode said encoded video signals transmitted through air, and transmitted selectively in inter-frame prediction format wherein the signals represent differences between selected macroblocks in successive frames when a specific difference criterion between said successive macroblocks is not exceeded, the decoder also being operative to decode a transmitted through air mode indicator signal indicative of whether or not the last received macroblock was encoded in said inter-frame prediction format, frames comprising macroblocks; the receiver further comprising: a video signal error detection system comprising a first comparator for comparing macroblocks in successive frames output from said decoder and applying said specific difference criteria to provide an indication of whether inter-frame prediction should apply or not, and a second comparator for comparing the indication from the first comparator with said mode indicator signal, the second comparator being operative to generate an error signal when a divergence is detected.