Encoding and decoding system using masking characteristics of channels for ...

Ill

United States Patent m

Kim

US005734657A [ii] Patent Number: [45] Date of Patent:

5,734,657 Mar. 31, 1998

[54] ENCODING AND DECODING SYSTEM

USING MASKING CHARACTERISTICS OF
CHANNELS FOR BIT ALLOCATION

[75] Inventor: Seoung-bong Kim. Suwon, Rep. of
Korea

[73] Assignee: Samsung Electronics Co., Ltd., Kyungki-Do, Rep. of Korea

[21] Appl. No.: 380,614

[22] Filed: Jan. 30, 1995

[30] Foreign Application Priority Data

Jan. 28, 1994 [KR] Rep. of Korea 94-1577

[51] Int. CI.6 G10L9/00

[52] U.S. CI 370/437; 395/2.38; 395/2.39

[58] Field of Search 395/2.09, 2.12,

395/2.14, 2.35, 2.36, 2.37. 2.38, 2.39. 239, 2.1, 2.2; 381/29. 34, 36. 40, 41; 370/431,

437

[56] References Cited

U.S. PATENT DOCUMENTS

4,896,362 1/1990 Vddhuis et al 395/2.38

4,972,484 11/1990 Theileetal 395/2.38

5,105,463 4/1992 Vddhuis et al 395/2.38

5,301,255 4/1994 Nagaietal 395/239

5,309,232 5/1994 Hartungetal 348/384

5,375,189 12/1994 Tsutsui et al 395/2.38

5,394,473 2/1995 Davidson 381/36

5,479,562 12/1995 Fielder et al 395/2.38

5,490,130 2/1996 Akagiri et al 369/124

5,491,773 2/1996 Veldhuis et al 395/2.38

5,495,552 2/1996 Sugiyama et al 395/2.1

Primary Examiner—Douglas W. Olms
Assistant Examiner—Ricky Q. Ngo

Attorney, Agent, or Firm—Sughrue, Mion. Zinn. Macpeak & Seas, PLLC

[57] ABSTRACT

An encoding apparatus which utilizes masking characteristics of channels for bit allocation in order to encode digitally sampled audio signals of at least two channels in units of an audio frame, allocates the bits to the divided bands of the first and second channels, detects a channel having a masking to noise ratio in which the respective divided bands exceed the masking threshold value based on the first masking threshold value with respect to the first channel and the second masking threshold value with respect to the second channel, and uses all the number of the bits which are not used for the channel among the total number of the bits of one audio frame for bit allocation of the other channel, thereby improving the quality of the sound even when an audio signal which includes many high frequency components is reproduced.

18 Claims, 4 Drawing Sheets