Method and apparatus for selective signal coding based on core encoder performance
First Claim
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1. A method for coding an input audio signal, the method comprising:
- encoding the input signal using a core layer encoder to produce a core layer encoded signal;
decoding the core layer encoded signal to produce a reconstructed signal;
comparing the reconstructed signal to the input signal, wherein the comparing comprises estimating an energy E_err of the reconstructed signal that contain errors, determining a ratio S(k)/Sc(k) of component S(k) of the input signal to the component Sc(k) of the reconstructed signal exceeds a threshold value and summing the energies of those components Sc(k) of the reconstructed signal when the ratio S(k)/Sc(k) does not exceed the threshold value;
selecting an enhancement layer encoder from a plurality of enhancement layer encoders dependent upon the comparison between the reconstructed signal and the input signal; and
generating an enhancement layer encoded signal using the selected enhancement layer encoder, the enhancement layer encoded signal being dependent upon the input signal.
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Abstract
In a selective signal encoder, an input signal is first encoded using a core layer encoder to produce a core layer encoded signal. The core layer encoded signal is decoded to produce a reconstructed signal and an error signal is generated as the difference between the reconstructed signal and the input signal. The reconstructed signal is compared to the input signal. One of two or more enhancement layer encoders selected dependent upon the comparison and used to encode the error signal. The core layer encoded signal, the enhancement layer encoded signal and the selection indicator are output to the channel (for transmission or storage, for example).
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Citations
15 Claims
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1. A method for coding an input audio signal, the method comprising:
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encoding the input signal using a core layer encoder to produce a core layer encoded signal; decoding the core layer encoded signal to produce a reconstructed signal; comparing the reconstructed signal to the input signal, wherein the comparing comprises estimating an energy E_err of the reconstructed signal that contain errors, determining a ratio S(k)/Sc(k) of component S(k) of the input signal to the component Sc(k) of the reconstructed signal exceeds a threshold value and summing the energies of those components Sc(k) of the reconstructed signal when the ratio S(k)/Sc(k) does not exceed the threshold value; selecting an enhancement layer encoder from a plurality of enhancement layer encoders dependent upon the comparison between the reconstructed signal and the input signal; and generating an enhancement layer encoded signal using the selected enhancement layer encoder, the enhancement layer encoded signal being dependent upon the input signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A selective signal encoder comprising a processor that includes instructions for executing functions of the encoder, the encoder comprising:
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a core layer encoder that receives an input audio signal to be encoded and produces a core layer encoded signal; a core layer decoder that receives the core layer encoded signal as input and produces a reconstructed signal; a plurality of enhancement layer encoders each selectable to encode an error signal to produce an enhanced layer encoded signal, the error signal comprising a difference between the input signal and the reconstructed signal; and a comparator/selector module that selects an enhancement layer encoder of the plurality of enhancement layer encoders dependent upon a comparison of the input signal and core layer encoded signal, wherein the comparator/selector module estimates an energy E_err of the reconstructed signal that contains errors, determines a ratio S(k)/Sc(k) of component S(k) of the input signal to the component Sc(k) of the reconstructed signal exceeds a threshold value and sum the energies in components Sc(k) of the reconstructed signal when the ratio S(k)/Sc(k) does not exceed the threshold value, and further, wherein the input signal is encoded as the core layer encoded signal, the enhanced layer encoded signal and an indicator of the selected enhanced layer encoder. - View Dependent Claims (12, 13, 14, 15)
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Specification