Method and system for reduction of quantization-induced block-discontinuities and general purpose audio codec
7 Assignments
0 Petitions
Accused Products
Abstract
Compressing the digitized time-domain continuous input signal typically includes formatting the input signal into a plurality of time-domain blocks having boundaries, forming an overlapping time-domain block by prepending a fraction of a previous time-domain block to a current time-domain block, transforming each overlapping time-domain block to a transform domain block including a plurality of coefficients, partitioning the coefficients of each transform domain block into signal coefficients and residue coefficients, quantizing the signal coefficients for each transformed domain block and generating signal quantization indices indicative of such quantization, modeling the residue coefficients for each transform domain block as stochastic noise and generating residue quantization indices indicative of such quantization, and formatting the signal quantization indices and the residue quantization indices for each transform domain block as an output bit-stream. The continuous data may include audio data.
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Citations
134 Claims
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1-15. -15. (canceled)
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16. A method for performing an adaptive cosine packet transform, including:
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calculating bell window functions;
calculating a cosine packet transform table for at least one time splitting level utilizing the bell window functions;
determining whether a pre-split at the time splitting level is needed for a current frame;
recalculating the cosine packet transform table at selected levels depending on the pre-split determination;
building a statistics tree for only the selected levels;
generating an extended statistics tree from the statistics tree;
performing a best basis analysis to determine an extended best basis tree from the extended statistics tree; and
determining optimal transform coefficients from the extended best basis tree. - View Dependent Claims (17)
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18. A method for performing an adaptive cosine packet transform, including:
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determining whether a pre-split is needed for a current cosine packet transform frame to form pre-split subframes;
applying a cosine packet transform to the pre-split subframes based on the determination;
performing a best basis analysis; and
determining optimal transform coefficients. - View Dependent Claims (19, 20, 21, 22)
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23-42. -42. (canceled)
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43. A method for performing an inverse adaptive cosine packet transform, including:
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calculating bell window functions;
joining an extended best basis tree into a combined best basis tree; and
synthesizing a time-domain signal from optimal cosine packet coefficients using the bell window functions. - View Dependent Claims (44)
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45-60. -60. (canceled)
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61. A computer program, residing on a computer-readable medium, for performing an adaptive cosine packet transform, the computer program comprising instructions for causing a computer to:
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calculate bell window functions;
calculate a cosine packet transform table for at least one time splitting level utilizing the bell window functions;
determine whether a pre-split at the time splitting level is needed for a current frame;
recalculate the cosine packet transform table at selected levels depending on the pre-split determination;
build a statistics tree for only the selected levels;
generate an extended statistics tree from the statistics tree;
perform a best basis analysis to determine an extended best basis tree from the extended statistics tree; and
determine optimal transform coefficients from the extended best basis tree. - View Dependent Claims (62)
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63. A computer program, residing on a computer-readable medium, for performing an adaptive cosine packet transform, the computer program comprising instructions for causing a computer to:
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determine whether a pre-split is needed for a current cosine packet transform frame to form pre-split subframes;
apply a cosine packet transform to the pre-split subframes based on the determination;
perform a best basis analysis; and
determine optimal transform coefficients. - View Dependent Claims (64, 65, 66, 67)
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68-87. -87. (canceled)
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88. A computer program, residing on a computer-readable medium, for performing an inverse adaptive cosine packet transform, the computer program comprising instructions for causing a computer to:
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calculate bell window functions;
join an extended best basis tree into a combined best basis tree; and
synthesize a time-domain signal from optimal cosine packet coefficients using the bell window functions. - View Dependent Claims (89)
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90-105. -105. (canceled)
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106. A system for performing an adaptive cosine packet transform, including:
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means for calculating bell window functions;
means for calculating a cosine packet transform table for at least one time splitting level utilizing the bell window functions;
means for determining whether a pre-split at the time splitting level is needed for a current frame;
means for recalculating the cosine packet transform table at selected levels depending on the pre-split determination;
means for building a statistics tree for only the selected levels;
means for generating an extended statistics tree from the statistics tree;
means for performing a best basis analysis to determine an extended best basis tree from the extended statistics tree; and
means for determining optimal transform coefficients from the extended best basis tree. - View Dependent Claims (107)
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108. A system for performing an adaptive cosine packet transform, including:
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means for determining whether a pre-split is needed for a current cosine packet transform frame to form pre-split subframes;
means for applying a cosine packet transform to the pre-split subframes based on the determination;
means for performing a best basis analysis; and
means for determining optimal transform coefficients. - View Dependent Claims (109, 110, 111, 112)
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113-132. -132. (canceled)
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133. A system for performing an inverse adaptive cosine packet transform, including:
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means for calculating bell window functions;
means for joining an extended best basis tree into a combined best basis tree; and
means for synthesizing a time-domain signal from optimal cosine packet coefficients using the bell window functions. - View Dependent Claims (134)
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Specification