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US5764698A Expired / Lapsed US ⏱️ 0.0 years remaining

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
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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.

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

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