Encoding method and apparatus for bit compressing digital audio signals and recording medium having encoded audio signals recorded thereon by the encoding method
First Claim
1. A method for encoding audio signals comprising dividing input audio signals into a two-dimensional block of time and frequency and quantizing the two-dimensional blocks based upon bit allocation as determined for each of the two-dimensional blocks,wherein the improvement comprises the steps ofcalculating scale factors indicating characteristics of signal components for each of the plural two-dimensional blocks, anddetermining bit allocation for a pre-set one of the two-dimensional blocks based upon the scale factor of the pre-set two-dimensional block and plural scale factors of plural ones of the two-dimensional blocks neighboring to said pre-set two-dimensional block on the frequency axis.
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Abstract
A method for encoding audio signals includes dividing input audio signals into a two-dimensional block of time and frequency and quantizing the two-dimensional blocks based upon bit allocation as determined for each of the two-dimensional blocks. Scale factors are calculated indicating characteristics of signal components for each of the plural two-dimensional blocks, and bit allocations are determined for a pre-set one of the two-dimensional blocks based upon the scale factor of the pre-set two-dimensional block and plural scale factors of plural ones of the two-dimensional blocks neighboring to said pre-set two-dimensional block on the frequency axis.
102 Citations
18 Claims
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1. A method for encoding audio signals comprising dividing input audio signals into a two-dimensional block of time and frequency and quantizing the two-dimensional blocks based upon bit allocation as determined for each of the two-dimensional blocks,
wherein the improvement comprises the steps of calculating scale factors indicating characteristics of signal components for each of the plural two-dimensional blocks, and determining bit allocation for a pre-set one of the two-dimensional blocks based upon the scale factor of the pre-set two-dimensional block and plural scale factors of plural ones of the two-dimensional blocks neighboring to said pre-set two-dimensional block on the frequency axis.
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9. An apparatus for encoding audio signals in which the input audio signals are divided into a two-dimensional block of time and frequency and the two-dimensional blocks are quantized based upon bit allocation as determined for each of the two-dimensional blocks,
wherein the improvement comprises means for calculating scale factors indicating characteristics of signal components for each of the plural two-dimensional blocks, and means for determining bit allocation for a pre-set one of the two-dimensional blocks based upon the scale factor of the pre-set two-dimensional block and plural scale factors of plural ones of the two-dimensional blocks neighboring to said pre-set two-dimensional block on the frequency axis.
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17. A method for decoding encoded audio signals comprising the steps of
dividing input audio signals into plural two-dimensional blocks of time and frequency, calculating a scale factor indicating characteristics of signal components for each of the plural two-dimensional blocks, receiving the information concerning bit allocation of said pre-set two-dimensional block as determined based upon the scale factor of the pre-set two-dimensional block and plural scale factors of plural ones of the two-dimensional blocks neighboring to said pre-set two-dimensional block on the frequency axis, and decoding the encoded audio signals, quantized based upon the information concerning the bit allocation, with the aid of the information concerning the bit allocation.
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18. An apparatus for decoding encoded audio signals comprising
means for dividing input audio signals into plural two-dimensional blocks of time and frequency, calculating a scale factor indicating characteristics of signal components for each of the plural two-dimensional blocks, receiving the information concerning bit allocation of said pre-set two-dimensional block as determined based upon the scale factor of the pre-set two-dimensional block and plural scale factors of plural ones of the two-dimensional blocks neighboring to said pre-set two-dimensional block on the frequency axis, and means for decoding the encoded audio signals, quantized based upon the information concerning the bit allocation, with the aid of the information concerning the bit allocation.
Specification