Title:
CODER DECODER
Document Type and Number:
Japanese Patent JP3146121
Kind Code:
B2
Abstract:
PURPOSE: To attain compression coding with a high compression efficiency by making a word length variable with respect to each selected quantizer.
CONSTITUTION: A masking calculation section 24 calculates a signal versus masking ratio. A border bit calculation section 25 obtains a minimum word length (border bit number) used by a mid-riser quantizer. A required bit number calculation section 26 obtains a minimum word length (required bit number) where a signal to quantization noise ratio is a signal to masking ratio or over as to a mid-tread/mid-riser quantizer and selects a word length and a quantizer. A bit distribution section 27 adjusts the word length in response to a bit number able to be distributed to one frame and decides the word length and a quantizer by referencing the border bit number. Thus, the deterioration in the compression accuracy and the compression rate is prevented and compression coding with a high compression efficiency is conducted by selecting a quantizer in use at a lower limit word length where a mid-riser quantizer is available.
Inventors:
Daiichi Sawabe
Application Number:
JP3665495A
Publication Date:
March 12, 2001
Filing Date:
February 24, 1995
Export Citation:
Assignee:
Sharp Corporation
International Classes:
G10L19/00; G10L19/02; G10L19/032; H03M7/30; (IPC1-7): H03M7/30; G10L19/00
Domestic Patent References:
| JP3263925A | ||||
| JP4104617A | ||||
| JP6244735A | ||||
| JP59178030A | ||||
| JP4504192A |
Attorney, Agent or Firm:
Aoyama Ryo (1 person outside)