This letter presents a new fast search algorithm for the multitap adaptive codebook used in the G.723.1 standard speech coder. In contrast with the standard method that a closed-loop pitch lag and gains for a fifth-order pitch predictor are searched simultaneously, the proposed algorithm adopts a sequential and restricted approach to determine the parameters. In other words, the proposed scheme first determines a couple of pitch lag candidates using a first-order pitch predictor and then computes the pitch gains of the fifth-order predictor within a restricted search area. Experimental results confirm that the proposed algorithm reduces the total complexity by 30.69% in the encoding process and provides speech quality equivalent to the standard method.
Bibliographical noteFunding Information:
Manuscript received January 11, 2004; revised April 7, 2004. This work was supported in part by the Biometric Engineering Research Center (KOSEF). The associate editor coordinating the review of this paper and approving it for publication was Prof. Mark Hasegawa-Johnson.
All Science Journal Classification (ASJC) codes
- Signal Processing
- Electrical and Electronic Engineering
- Applied Mathematics