Quick Algorithm for BCH Error-correcting Decoding of H.261 Video Coder Recommendation

As BCH is a kind of linear error-correcting code with good performance up to now,it has been used widely.But for the relatively longer codes,it cost large computation,so special hardware is alwayes employed in real-time communication.But in low-cost communication system or desktop communication system with no hardware support,the most urgent problem is how to complete the computation of BCH code efficiently,namely the algorithm efficiency of BCH code.In this paper,firstly,coding method and error-correction theory of BCH(511,493) error-correcting in video coding recommendation H.261 are introduced,then the low efficiency in classical division algorithm with software completion is analyzed.Subsequently,a kind of quick algorithm on correcting 2-bit random errors is offered.With practical evidence,this algorithm can increase the whole running speed at least 20 times than the classical division algorithm and meet the requirement in real-time video communication.It has been successfully used in PSTN and ISDN videophone.