Title:
ADPCM COMPRESSOR, ADPCM EXPANSION DEVICE AND ADPCM COMPANDER
Document Type and Number:
Japanese Patent JP3462066
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To ensure the permissible quality and to reduce the circuit scale.
SOLUTION: A subtractor 21 takes a difference between an input signal and a predicted signal from a prediction device 25, and a quantizer 22 quantizes the difference and provides an output. The quantized output obtained this time is given to an inverse quantizer 24, where the output is inversely quantized and recovered. Based on a value of a recovered signal at one preceding time (equal to a compression signal at one preceding time), the prediction device 25 selects whether receive data at one preceding time are outputted as a predicted value or data resulting from linearly extrapolating data at one preceding time and two-preceding time are outputted as predicted data and outputs the predicted data to the subtractor 2.
Inventors:
Hiroyuki Eguchi
Application Number:
JP1749898A
Publication Date:
November 05, 2003
Filing Date:
January 29, 1998
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
H03M3/04; H03M7/38; H04B14/04; H04B14/06; (IPC1-7): H03M7/38; H03M3/04; H04B14/06
Domestic Patent References:
| JP3265309A | ||||
| JP487422A | ||||
| JP3265308A | ||||
| JP63211987A | ||||
| JP623535A | ||||
| JP62222726A | ||||
| JP3179921A |
Attorney, Agent or Firm:
Hidekazu Miyoshi (3 outside)