音声符号化装置

Sound coding device

Abstract

(57)【要約】 【目的】 本発明は、CELP方式に基づく符号化装置 におけるROM容量削減を目的とする。 【構成】 上記目的を達成するために本発明は、確率的 符号帳探索の際に確率的符号帳に格納されているコード ベクトルの正順だけでなく逆順のベクトルもコードベク トルとして用いる。
PURPOSE: To halve the code book size without degrading a tone quality and without increasing a calculation quantity by using not only normal order of a code vector stored in a probabilistic code book but also a vector in reverse order as a code vector when a code book is searched. CONSTITUTION: A basic function of a CELP system is composed of an input sound 21, an LPC analyzing part 22, an adaptive code book 23, a probabilistic code book 24, an adding part 25, an LPC synthesizing part 26, a comparing part 27, a parameter coding part 28 and a transmitting passage 20. When a probabilistic code book is searched, two code vectors in normal order and reverse order are generated from a single code vector, and the respective ones are used as a candidate for search. An index of an optimal code vector and a code single bit in normal order and reverse order are transmitted as codes. Since the search using this reverse order vector is processing by only reversely using a sample pointer of the code vectors, it can be performed in the same calculation quantity with a conventional calculation quantity.

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Cited By (6)

    Publication numberPublication dateAssigneeTitle
    JP-2007226253-ASeptember 06, 2007Matsushita Electric Ind Co Ltd, 松下電器産業株式会社Voice coding device and voice decoding device
    JP-2009501944-AJanuary 22, 2009マイクロソフト コーポレーションディジタル・メディア・スペクトル・データの効率的コーディングに使用される辞書内のコードワードの変更
    JP-4525693-B2August 18, 2010パナソニック株式会社音声符号化装置および音声復号化装置
    US-9349376-B2May 24, 2016Microsoft Technology Licensing, LlcBitstream syntax for multi-process audio decoding
    US-9443525-B2September 13, 2016Microsoft Technology Licensing, LlcQuality improvement techniques in an audio encoder
    US-9741354-B2August 22, 2017Microsoft Technology Licensing, LlcBitstream syntax for multi-process audio decoding