'''Code-excited linear prediction''' ('''CELP''') is a [[speech coding]] algorithm originally proposed by M.R. Schroeder and B.S. Atal in 1985. At the time, it provided significantly better quality than existing low bit-rate algorithms, such as [[Residualresidual-excited linear prediction|RELP]] and [[Linearlinear predictive coding|LPC]] [[vocoders]] (e.g., [[FS-1015]]). Along with its variants, such as [[ACELPalgebraic CELP]], [[RCELPrelaxed CELP]], [[LDlow-delay CELP]] and [[VSELPvector sum excited linear prediction]], it is currently the most widely used speech coding algorithm. It is also used in [[MPEG-4 Audio]] speech coding. CELP is commonly used as a generic term for a class of algorithms and not for a particular codec.
