Abstract: In an MPEG audio and video signal transmission system in which audio and video signals are encoded in packets which are multiplexed to form a stream for transmission, a receiver system includes a demultiplexer to separate audio and video packets. The header for each packet is parsed, and an error propagation header is inserted with each packet to identify byte count of the packet and an error flag. In a preferred embodiment the error propagation header includes a first byte representing the total byte count and a single bit in a second byte as the error flag. The error propagation header allows errors to be accurately located even in the presence of variable delay introduced by buffers.