US5764698A
Expired / Lapsed
US
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Method and apparatus for efficient compression of high quality digital audio
Assignee: MediaTek Inc
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Filing: 1993-12-30
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Granted: 1998-06-09
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Expires: 2013-12-30
Abstract
Abstract A method and system for efficiently compressing a digital audio signal, wherein the digital audio signal includes a plurality of samples. Each of the samples are separated into a plurality of subbands. A signal to mask ratio (SMR) for each the subbands is predicted utilizing a model of relationships between energy values within each of the subbands and SMR values based on a predetermined psychoacoustic model. A number of are allocated bits in response to the predicted SMR and a preselected bit-rate. Then, each of the subbands are quantized based on the number of bits allocated, wherein the digital audio signal may be efficiently compressed.
Inventors
- 👤 Subramania Sudharsanan
- 👤 Selvarathinam Suthakaran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:09
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/66; H04B1/665
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
121 words
A method in a data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said method comprising: separating each of said plurality of samples into a plurality of subbands; predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 2
Independent Claim
121 words
A method in a data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said method comprising: separating each of said plurality of samples into a plurality of subbands; predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 3
Dependent Claim
72 words
The method of claim 1, wherein said step of predicting a signal to mask ratio includes predicting said signal to mask ratio as follows: ##EQU7## wherein y i is a signal to mask ratio for subband i,j is the sample frame, N is a number of sample frames, β i ,j is a prediction coefficient, β i ,33 is a bias coefficient, and x j is an energy value for subband i.
Claim 4
Dependent Claim
59 words
The method of claim 2 further comprising ascertaining prediction coefficients as follows: ##EQU8## wherein Y k (j) is a signal to mask ratio for a subband k at same frame j,k is a subband number, j is a frame number, N is a number of frames, ε k (j) is a modeling error for subband k at frame j.
Claim 5
Dependent Claim
16 words
The method of claim 3 further comprising acquiring signal to mask ratios from a psychoacoustic model.
Claim 6
Dependent Claim
132 words
A data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said data processing system comprising: separation means for separating each of said plurality of samples into a plurality of subbands; prediction means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; allocation means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and quantization means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 7
Dependent Claim
132 words
A data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said data processing system comprising: separation means for separating each of said plurality of samples into a plurality of subbands; prediction means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; allocation means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and quantization means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 8
Dependent Claim
70 words
The data processing system of claim 5, wherein said prediction means includes means for predicting said signal to mask ratio as follows: ##EQU9## wherein y i is a signal to mask ratio for subband i,j is the sample frame, N is a number of sample frames, β i ,j is a prediction coefficient, β i ,33 is a bias coefficient, and x j is an energy value for subband i.
Claim 9
Dependent Claim
63 words
The data processing system of claim 6 further comprising means for ascertaining prediction coefficients as follows: ##EQU10## wherein Y k (j) is a signal to mask ratio for a subband k at same frame j,k is a subband number, j is a frame number, N is a number of frames, ε k (j) is a modeling error for subband k at frame j.
Claim 10
Dependent Claim
20 words
The data processing system of claim 7 further comprising means for acquiring signal to mask ratios from a psychoacoustic model.
Claim 11
Dependent Claim
18 words
The data processing system of claim 8, wherein said psychoacoustic model is a psychoacoustic model specified by MPEG.
Claim 12
Dependent Claim
15 words
The data processing system of claim 9, wherein said psychoacoustic model is Psychoacoustic Model 2.
Claim 13
Dependent Claim
17 words
The data processing system of claim 6, wherein x j is a pseudo-energy value for subband j.
Claim 14
Dependent Claim
17 words
The data processing system of claim 6, wherein x j is a squared-energy value for subband j.
Claim 15
Dependent Claim
18 words
The data processing system of claim 6, wherein said data processing system is an IBM RISC SYSTEM/6000 computer.
Claim 16
Dependent Claim
16 words
The data processing system of claim 5, wherein said model is a plurality of prediction coefficients.
Claim 17
Dependent Claim
132 words
A computer program product for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples comprising: first instruction means for separating each of said plurality of samples into a plurality of subbands; second instruction means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; third instruction means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and fourth instruction means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 18
Dependent Claim
132 words
A computer program product for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples comprising: first instruction means for separating each of said plurality of samples into a plurality of subbands; second instruction means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; third instruction means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and fourth instruction means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 19
Independent Claim
130 words
An apparatus for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said data processing system comprising: separation means for separating each of said plurality of samples into a plurality of subbands; prediction means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; allocation means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and quantization means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 20
Independent Claim
130 words
An apparatus for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said data processing system comprising: separation means for separating each of said plurality of samples into a plurality of subbands; prediction means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; allocation means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and quantization means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 21
Dependent Claim
68 words
The apparatus of claim 16, wherein said prediction means includes means for predicting said signal to mask ratio as follows: ##EQU11## wherein y i is a signal to mask ratio for subband i,j is the sample frame, N is a number of sample frames, β i ,j is a prediction coefficient, β i ,33 is a bias coefficient, and x j is an energy value for subband i.
Claim 22
Dependent Claim
133 words
A data processing system comprising: a processor; a digital audio source that provides a digital audio signal, wherein said digital audio signal includes a plurality of samples; separation means for separating each of said plurality of samples into a plurality of subbands; processor means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; processor means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and processor means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 23
Dependent Claim
133 words
A data processing system comprising: a processor; a digital audio source that provides a digital audio signal, wherein said digital audio signal includes a plurality of samples; separation means for separating each of said plurality of samples into a plurality of subbands; processor means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of relationships between energy values within each of said plurality of subbands and signal to mask ratios values based on a predetermined psychoacoustic model; processor means for allocating a number of bits in response to said predicted signal to mask ratio and a preselected bit-rate; and processor means for quantizing each of said plurality of subbands based on said number of bits allocated, wherein said digital audio signal may be efficiently compressed.
Claim 24
Dependent Claim
30 words
The data processing system of claim 18, wherein said separation means is a processor including instruction means for separating each of said plurality of samples into a plurality of subbands.
Claim 25
Dependent Claim
72 words
The data processing system of claim 18, wherein said processor means for predicting includes means for predicting said signal to mask ratio as follows: ##EQU12## wherein y i is a signal to mask ratio for subband i,j is the sample frame, N is a number of sample frames, β i ,j is a prediction coefficient, β i ,33 is a bias coefficient, and x j is an energy value for subband i.
Claim 26
Dependent Claim
63 words
The data processing system of claim 20 further comprising means for ascertaining prediction coefficients as follows: ##EQU13## wherein Y k (j) is a signal to mask ratio for a subband k at same frame j,k is a subband number, j is a frame number, N is a number of frames, ε k (j) is a modeling error for subband k at frame j.
Claim 27
Independent Claim
93 words
A method in a data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said method comprising: separating each of said plurality of samples into a plurality of subbands; and predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of the relationships between energy values within each of said plurality of subbands and signal to mask ratio values based on a predetermined psychoacoustic model, wherein said model includes a matrix of prediction coefficients indexed by subbands.
Claim 28
Independent Claim
93 words
A method in a data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said method comprising: separating each of said plurality of samples into a plurality of subbands; and predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of the relationships between energy values within each of said plurality of subbands and signal to mask ratio values based on a predetermined psychoacoustic model, wherein said model includes a matrix of prediction coefficients indexed by subbands.
Claim 29
Dependent Claim
98 words
A data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said data processing system comprising: separation means for separating each of said plurality of samples into a plurality of subbands; and predicting means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of the relationships between energy values within each of said plurality of subbands and signal to mask ratio values based on a predetermined psychoacoustic model, wherein said model includes a matrix of prediction coefficients indexed by subbands.
Claim 30
Dependent Claim
98 words
A data processing system for efficiently compressing a digital audio signal, wherein said digital audio signal includes a plurality of samples, said data processing system comprising: separation means for separating each of said plurality of samples into a plurality of subbands; and predicting means for predicting a signal to mask ratio for each of said plurality of subbands utilizing a model of the relationships between energy values within each of said plurality of subbands and signal to mask ratio values based on a predetermined psychoacoustic model, wherein said model includes a matrix of prediction coefficients indexed by subbands.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-06-08 | 2001-12-08 | 2002-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-08 | 2005-12-08 | 2006-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-08 | 2009-12-08 | 2010-06-09 | $7700.00 | Window Closed / Lapsed |