In digital television broadcasting, video and audio are divided into packet units and multiplexed to be transmitted. As a classification of a packet, there is a fixed length packet and a variable length packet. An example of the variable length packet is a type length value (TLV) packet of advanced broadband digital broadcasting (advanced BS). Hereinafter, the variable length packet is simply referred to as a packet.
In multiplexed transmission, error correction coding is performed on a transmitting side, and decoding is performed on a signal sent as a multiplexed stream on a receiving side. In general, a unit of error correction coding/decoding (referred to as a block, slot and the like) and a unit of a packet does not coincide with each other, and the packet steps over a plurality blocks or a plurality of packets are present in one block.
In general, the packet includes a header and a data part. A length (packet length) of the packet may be known from a parameter indicating a data length stored in the header. On the receiving side, there is a case where information formatted to the packet unit is output from the data length and information indicating a boundary of the packet such as system information.
If a receiver fails in error correction decoding of a certain block in a transmission stream, all packets using even a little bit of a decoding result of the block are invalidated. In the packet to be invalidated, since the data length stored in the header of the packet might be erroneous, a series of packets are invalidated (refer to Patent Document 1).