Title:
VOICE CODING AND DECODING SYSTEM
Document Type and Number:
Japanese Patent JP3849210
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To enable controlling dynamically quantity of coding information in accordance with the situation, to enable securing a transmission real time characteristic independently of variation of a circuit condition, and to enable varying flexibly quantity of storage information.
SOLUTION: A coder 1 vector-quantizes a residual difference signal to which an input voice signal is linear-prediction-analyzed using a code book. A transmitter 2 supplies a compressed coding bit stream outputted from the coder 1 to a communication circuit. A bit rate control section 3 decides a bit rate mode in accordance with a circuit condition, and controls a bit stream generation section 21. The bit stream generation section 21 controls dynamically a bit rate of a compressed coding bit rate stream by eliminating indexes of one part affecting less to reproduction of a voice signal out of indexes obtained by vector-quantized based on a bit rate mode, while adds information of a bit rate mode to a bit stream. In a decoding side, decoding processing is performed based on a bit rat e mode.
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Inventors:
Shigeki Fujii
Application Number:
JP6421797A
Publication Date:
November 22, 2006
Filing Date:
March 18, 1997
Export Citation:
Assignee:
Yamaha Corporation
International Classes:
G10L19/08; G10L19/083; G10L19/12; G10L19/16; G10L19/22; G10L19/24; H03M7/30; H04B14/04; (IPC1-7): G10L9/14; H03M7/30; H04B14/04
Domestic Patent References:
| JP6268606A | ||||
| JP7093892A |
Foreign References:
| WO1994007239A1 |
Other References:
神明夫,他,日本音響学会平成7年秋季研究発表会講演論文集,スケーラブルな階層構造を持つ楽音・音声の符号化,1997年 9月27日,3-1-5,p.277-278
片岡章俊,他,共役構造CELPによる8kbit/s音声符号化,日本音響学会平成4年秋季研究発表会講演論文集,1992年10月 5日,2-5-19,p.273-274
片岡章俊,他,共役構造CELPによる8kbit/s音声符号化,日本音響学会平成4年秋季研究発表会講演論文集,1992年10月 5日,2-5-19,p.273-274
Attorney, Agent or Firm:
Masaru Itami