Samsung Electronics Co., Ltd.

Sang-hyun Chi

Chang-yong Son

Kang-eun Lee

Sang-won Kang

Yong-Serk Kim

Seong-Kyu Hwang

Nam-il Lee

Sang-Won Kang

A coding apparatus including a base layer, a speech quality enhancement layer, and a multiplexer. The base layer filters an input speech signal using linear prediction coding and generates an excitation signal corresponding to the filtered speech signal through a fixed codebook search and an adaptive codebook search. The speech quality enhancement layer searches a fixed codebook using parameters obtained through the fixed codebook search in the base layer, or searches the fixed codebook using a target signal, which is obtained by removing a contribution of a fixed codebook of the base layer and a signal which is obtained by synthesizing and filtering a previous fixed codebook of the speech quality enhancement layer from a target signal for the fixed codebook search of the base layer. The multiplexer multiplexes signals generated by the base layer and the at least one speech quality enhancement layer.

Bitrate scalable speech coding and decoding apparatus and method

A fast search method for searching for an optimum codeword for nearest neighbor vector quantization. An upper boundary value and a lower boundary value between which an optimum codeword will exist in a codebook are calculated using a distortion of a designated element in an input vector and an experimentally determined threshold. Further, a start point and an end point for codebook search are determined using a binary search method from a codebook rearranged in descending order, and a full search scheme is applied only within a search range calculated by the determined start point and end point, thereby determining an optimum codeword for nearest neighbor vector quantization.

Fast search method for nearest neighbor vector quantization

Growing community of inventors

Gangwon-do, South Korea

Sang-hyun Chi