US5642423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital surround sound processor
Assignee: Sony Corp
•
Filing: 1995-11-22
•
Granted: 1997-06-24
•
Expires: 2015-11-22
Abstract
Abstract A digital surround sound decoder. The decoder uses an architecture including two signal processing chips to achieve a program that can decode audio data at sufficiently high resolution. The decoder performs in real time and is compatible with standard surround sound formats. The decoder includes software that utilizes table lookups for critical functions in the decoding process. The processing flow of the decoder's program takes advantage of the multi-function capability within the specific processors used in the design while using a minimum number of program instructions. The program implements band pass filtering, sum-difference calculations, fast-attack slow-decay integration, summation and reciprocal processing, determination of fast and slow modes, look-up table indexing, adaptive matrix processing and various other functions to generate decoded surround sound signals from encoded left and right signal inputs.
Inventors
- 👤 Paul Embree
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:54
CPC Classifications
H; H04; H04S; H04S3/00; H04S3/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
128 words
A method for performing digital surround sound decoding in a system including a processor coupled to a memory, wherein the memory includes a plurality of lookup tables having parameter values, wherein the system is provided with digitized left and right audio signal data, wherein the audio signal data includes encoded center and surround signal data, the method comprising the steps of deriving left, right, center and surround values from the digitized left and right audio signal data; forming indexes from the left, right, center and surround values for indexing the lookup tables; retrieving parameter values from the lookup tables according to the derived indexes; and combining the retrieved parameter values with the left, right, center and surround values to generate decoded left, right center and surround channel signals.
Claim 2
Independent Claim
128 words
A method for performing digital surround sound decoding in a system including a processor coupled to a memory, wherein the memory includes a plurality of lookup tables having parameter values, wherein the system is provided with digitized left and right audio signal data, wherein the audio signal data includes encoded center and surround signal data, the method comprising the steps of deriving left, right, center and surround values from the digitized left and right audio signal data; forming indexes from the left, right, center and surround values for indexing the lookup tables; retrieving parameter values from the lookup tables according to the derived indexes; and combining the retrieved parameter values with the left, right, center and surround values to generate decoded left, right center and surround channel signals.
Claim 3
Dependent Claim
109 words
A digital surround sound decoder comprising: a processor coupled to a memory; first processing means for deriving left, right, center and surround values from digitized left and right audio signal data; a plurality of lookup tables stored in the memory, wherein each lookup table includes parameter values; second processing means for indexing the lookup tables with indexes derived from the left, right, center and surround values, and for retrieving the parameter values from the lookup tables according to the derived indexes; and third processing means for combining the retrieved parameter values with the left, right, center and surround values to generate decoded left, right, center and surround channel signals.
Claim 4
Dependent Claim
109 words
A digital surround sound decoder comprising: a processor coupled to a memory; first processing means for deriving left, right, center and surround values from digitized left and right audio signal data; a plurality of lookup tables stored in the memory, wherein each lookup table includes parameter values; second processing means for indexing the lookup tables with indexes derived from the left, right, center and surround values, and for retrieving the parameter values from the lookup tables according to the derived indexes; and third processing means for combining the retrieved parameter values with the left, right, center and surround values to generate decoded left, right, center and surround channel signals.
References Cited (Backward Citations)
US3970788A
Cited
US3864516A
Cited
US3944735A
Cited
US5046098A
Cited
US4862502A
Cited
US5216718A
Cited
US5524054A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-23 | 2000-12-23 | 2001-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-23 | 2004-12-23 | 2005-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-23 | 2008-12-23 | 2009-06-24 | $7700.00 | Window Closed / Lapsed |