EP0559348A2
Expired / Lapsed
EP
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Rate control loop processor for perceptual encoder/decoder
Assignee: AT&T Inc
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Filing: 1993-02-17
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Granted: —
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Expires: 2013-02-17
Abstract
Abstract In a perceptual audio coder, a method and apparatus for quantizing audio signals is disclosed which advantageously produces a quantized audio signal which can be encoded within an acceptable range. Advantageously, the quantizer uses a scale factor which is interpolated between a threshold based on the calculated threshold of hearing at a given frequency and the absolute threshold of hearing at the same frequency.
Inventors
- 👤 James David Johnston
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 20:21
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; H; H04; H04B; H04B1/00; H04B1/66; H04B1/665
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
133 words
An apparatus for quantizing a signal, said apparatus CHARACTERIZED IN THAT: (a) means 1303 for forming a threshold scale factor, 6 0 , based on a calculated threshold of hearing at a frequency; (b) means 1303 for forming an absolute scale factor, 6A, based on an absolute threshold of hearing at said frequency; (c) means 1305 for establishing a utilized scale factor based on said threshold scale factor and said absolute scale factor; and (d) means 1307, 1311, 1315 for iteratively performing the following steps, (1) quantizing said signal with said utilized scale factor to form a quantized signal, (2) evaluating a cost associated with said quantized signal, and (3) adjusting said utilized scale factor between said threshold scale factor and said absolute scale factor, until said cost is within a permissible range.
Claim 2
Independent Claim
133 words
An apparatus for quantizing a signal, said apparatus CHARACTERIZED IN THAT: (a) means 1303 for forming a threshold scale factor, 6 0 , based on a calculated threshold of hearing at a frequency; (b) means 1303 for forming an absolute scale factor, 6A, based on an absolute threshold of hearing at said frequency; (c) means 1305 for establishing a utilized scale factor based on said threshold scale factor and said absolute scale factor; and (d) means 1307, 1311, 1315 for iteratively performing the following steps, (1) quantizing said signal with said utilized scale factor to form a quantized signal, (2) evaluating a cost associated with said quantized signal, and (3) adjusting said utilized scale factor between said threshold scale factor and said absolute scale factor, until said cost is within a permissible range.
Claim 3
Dependent Claim
28 words
The apparatus of claim 1 wherein said means for establishing a utilized scale factor comprises means for interpolating between said threshold scale factor and said absolute scale factor.
Claim 4
Dependent Claim
28 words
The apparatus of claim 1 wherein said means for adjusting said utilized scale factor comprises means for interpolating between said threshold scale factor and said absolute scale factor.
Claim 5
Dependent Claim
28 words
The apparatus of claim 1 wherein said means for evaluating a cost comprises means for evaluating a cost associated with said quantized signal and said utilized scale factor.
Claim 6
Dependent Claim
24 words
The apparatus of claim 1 wherein said apparatus further comprises means for quantizing said utilized scale factor to form a quantized utilized scale factor.
Claim 7
Independent Claim
117 words
A method for quantizing a signal CHARACTERIZED IN THAT: (a) forming a threshold scale factor, 0 0 , based on a calculated threshold of hearing at a frequency; (b) forming an absolute scale factor, 6A, based on an absolute threshold of hearing at said frequency; (c) establishing a utilized scale factor based on said threshold scale factor and said absolute scale factor; and (d) iteratively performing the following steps, (1) quantizing said signal with said utilized scale factor to form a quantized signal, (2) evaluating a cost associated with said quantized signal, and (3) adjusting said utilized scale factor between said threshold scale factor and said absolute scale factor, until said cost is within a permissible range.
Claim 8
Independent Claim
117 words
A method for quantizing a signal CHARACTERIZED IN THAT: (a) forming a threshold scale factor, 0 0 , based on a calculated threshold of hearing at a frequency; (b) forming an absolute scale factor, 6A, based on an absolute threshold of hearing at said frequency; (c) establishing a utilized scale factor based on said threshold scale factor and said absolute scale factor; and (d) iteratively performing the following steps, (1) quantizing said signal with said utilized scale factor to form a quantized signal, (2) evaluating a cost associated with said quantized signal, and (3) adjusting said utilized scale factor between said threshold scale factor and said absolute scale factor, until said cost is within a permissible range.
Claim 9
Dependent Claim
29 words
The method of claim 6 wherein said step of establishing a utilized scale factor comprises the step of interpolating between said threshold scale factor and said absolute scale factor.
Claim 10
Dependent Claim
29 words
The method of claim 6 wherein said step of adjusting said utilized scale factor comprises the step of interpolating between said threshold scale factor and said absolute scale factor.
Claim 11
Dependent Claim
29 words
The method of claim 6 wherein said step of evaluating a cost comprises the step of evaluating a cost associated with said quantized signal and said utilized scale factor.
Claim 12
Dependent Claim
22 words
The method of claim 6 further comprising the step of quantizing said utilized scale factor to form a quantized utilized scale factor.
References Cited (Backward Citations)
No citation records indexed.
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