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1. US20110260893 - Adaptive differential pulse code modulation encoding apparatus and decoding apparatus

Office United States of America
Application Number 13142010
Application Date 25.12.2009
Publication Number 20110260893
Publication Date 27.10.2011
Grant Number 08482439
Grant Date 09.07.2013
Publication Kind B2
IPC
H ELECTRICITY
03
BASIC ELECTRONIC CIRCUITRY
M
CODING, DECODING OR CODE CONVERSION, IN GENERAL
7
Conversion of a code where information is represented by a given sequence or number of digits to a code where the same information is represented by a different sequence or number of digits
30
Compression; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
32
Conversion to or from delta modulation, i.e. one-bit differential modulation
H03M 7/32
CPC
G10L 19/04
H03M 7/3046
Applicants Sato Yasushi
Kyushu Institute of Technology
Ryu Atsuko
Inventors Sato Yasushi
Ryu Atsuko
Agents Buchanan Ingersoll & Rooney P.C.
Priority Data 2008-333060 26.12.2008 JP
Title
(EN) Adaptive differential pulse code modulation encoding apparatus and decoding apparatus
Abstract
(EN)

A signal corresponding to a short-period change and a signal corresponding to a long-period change of a sound signal are detected, and optimal quantization is performed based on the combination of the two signals. In an ADPCM encoding apparatus (100), a differential value dn between a 16-bit input signal Xn and a decoded signal Yn-1 of one sample ago is calculated by a subtractor (102). Thereafter, the 16-bit differential value dn is adaptively quantized by an adaptive quantizing section (103), so as to be converted to a (1 to 8)-bit length-variable ADPCM value Dn. Thereafter, the ADPCM value Dn is compression-encoded by a compression-encoding section (108) to generate a signal D′n, and the signal D′n is framed by a framing section (130) and outputted. Further, in an ADPCM decoding apparatus, a framed input signal is subjected to a reverse of the aforesaid process so as to be decoded.