Coder/decoder for digital signals to be transmitted and/or stored.

摘要

System for coding digital signals comprising a source coder followed by a transmission channel coder, and notable in that, in the case where the source coder is a variable-length coding chain (10), the channel coder comprises in series a coding sub-unit with selective protection and a coding sub-unit without selective protection. The signals being arranged in data blocks, this system itself comprises: (A) a stage (100) for coding block lengths, provided in order to determine along a block a cumulated length of codewords output by the said source coder and ensure the coding of the block lengths thus determined, a stage (200) for selective protection of the said blocks and a stage for multiplexing the signals output by the said stages for coding lengths and for selective protection. The corresponding decoding system comprises a transmission channel decoder followed by a source decoder, the channel decoder itself comprising in series a decoding sub-unit with non-selective protection and a decoding sub-unit with n levels of selective protection. <IMAGE>