Low Bitrate Audio Encoding/Decoding Scheme Having Cascaded Switches
First Claim
1. Audio encoder for encoding an audio input signal, the audio input signal being in a first domain, comprising:
- a first coding branch for encoding an audio signal using a first coding algorithm to acquire a first encoded signal;
a second coding branch for encoding an audio signal using a second coding algorithm to acquire a second encoded signal, wherein the first coding algorithm is different from the second coding algorithm; and
a first switch for switching between the first coding branch and the second coding branch so that, for a portion of the audio input signal, either the first encoded signal or the second encoded signal is in an encoder output signal,wherein the second coding branch comprises;
a converter for converting the audio signal into a second domain different from the first domain,a first processing branch for processing an audio signal in the second domain to acquire a first processed signal;
a second processing branch for converting a signal into a third domain different from the first domain and the second domain and for processing the signal in the third domain to acquire a second processed signal; and
a second switch for switching between the first processing branch and the second processing branch so that, for a portion of the audio signal input into the second coding branch, either the first processed signal or the second processed signal is in the second encoded signal.
1 Assignment
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Accused Products
Abstract
An audio encoder has a first information sink oriented encoding branch such as a spectral domain encoding branch, a second information source or SNR oriented encoding branch such as an LPC-domain encoding branch, and a switch for switching between the first encoding branch and the second encoding branch, wherein the second encoding branch has a converter into a specific domain different from the spectral domain such as an LPC analysis stage generating an excitation signal, and wherein the second encoding branch furthermore has a specific domain coding branch such as LPC domain processing branch, and a specific spectral domain coding branch such as LPC spectral domain processing branch, and an additional switch for switching between the specific domain coding branch and the specific spectral domain coding branch. An audio decoder has a first domain decoder such as a spectral domain decoding branch, a second domain decoder such as an LPC domain decoding branch for decoding a signal such as an excitation signal in the second domain, and a third domain decoder such as an LPC-spectral decoder branch and two cascaded switches for switching between the decoders.
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Citations
26 Claims
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1. Audio encoder for encoding an audio input signal, the audio input signal being in a first domain, comprising:
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a first coding branch for encoding an audio signal using a first coding algorithm to acquire a first encoded signal; a second coding branch for encoding an audio signal using a second coding algorithm to acquire a second encoded signal, wherein the first coding algorithm is different from the second coding algorithm; and a first switch for switching between the first coding branch and the second coding branch so that, for a portion of the audio input signal, either the first encoded signal or the second encoded signal is in an encoder output signal, wherein the second coding branch comprises; a converter for converting the audio signal into a second domain different from the first domain, a first processing branch for processing an audio signal in the second domain to acquire a first processed signal; a second processing branch for converting a signal into a third domain different from the first domain and the second domain and for processing the signal in the third domain to acquire a second processed signal; and a second switch for switching between the first processing branch and the second processing branch so that, for a portion of the audio signal input into the second coding branch, either the first processed signal or the second processed signal is in the second encoded signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. Method of encoding an audio input signal, the audio input signal being in a first domain, comprising:
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encoding an audio signal using a first coding algorithm to acquire a first encoded signal; encoding an audio signal using a second coding algorithm to acquire a second encoded signal, wherein the first coding algorithm is different from the second coding algorithm; and switching between encoding using the first coding algorithm and encoding using the second coding algorithm so that, for a portion of the audio input signal, either the first encoded signal or the second encoded signal is in an encoded output signal, wherein encoding using the second coding algorithm comprises; converting the audio signal into a second domain different from the first domain, processing an audio signal in the second domain to acquire a first processed signal; converting a signal into a third domain different from the first domain and the second domain and processing the signal in the third domain to acquire a second processed signal; and switching between processing the audio signal and converting and processing so that, for a portion of the audio signal encoded using the second coding algorithm, either the first processed signal or the second processed signal is in the second encoded signal.
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16. Decoder for decoding an encoded audio signal, the encoded audio signal comprising a first coded signal, a first processed signal in a second domain, and a second processed signal in a third domain, wherein the first coded signal, the first processed signal, and the second processed signal are related to different time portions of a decoded audio signal, and wherein a first domain, the second domain and the third domain are different from each other, comprising:
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a first decoding branch for decoding the first encoded signal based on the first coding algorithm; a second decoding branch for decoding the first processed signal or the second processed signal, wherein the second decoding branch comprises a first inverse processing branch for inverse processing the first processed signal to acquire a first inverse processed signal in the second domain; a second inverse processing branch for inverse processing the second processed signal to acquire a second inverse processed signal in the second domain; a first combiner for combining the first inverse processed signal and the second inverse processed signal to acquire a combined signal in the second domain; and a converter for converting the combined signal to the first domain; and a second combiner for combining the converted signal in the first domain and the first decoded signal output by the first decoding branch to acquire a decoded output signal in the first domain. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. Method of decoding an encoded audio signal, the encoded audio signal comprising a first coded signal, a first processed signal in a second domain, and a second processed signal in a third domain, wherein the first coded signal, the first processed signal, and the second processed signal are related to different time portions of a decoded audio signal, and wherein a first domain, the second domain and the third domain are different from each other, comprising:
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decoding the first encoded signal based on a first coding algorithm; decoding the first processed signal or the second processed signal, wherein the decoding the first processed signal or the second processed signal comprises; inverse processing the first processed signal to acquire a first inverse processed signal in the second domain; inverse processing the second processed signal to acquire a second inverse processed signal in the second domain; combining the first inverse processed signal and the second inverse processed signal to acquire a combined signal in the second domain; and converting the combined signal to the first domain; and combining the converted signal in the first domain and the decoded first signal to acquire a decoded output signal in the first domain.
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24. Encoded audio signal comprising:
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a first coded signal encoded or to be decoded using a first coding algorithm, a first processed signal in a second domain, and a second processed signal in a third domain, wherein the first processed signal and the second processed signal are encoded using a second coding algorithm, wherein the first coded signal, the first processed signal, and the second processed signal are related to different time portions of a decoded audio signal, wherein a first domain, the second domain and the third domain are different from each other, and side information indicating whether a portion of the encoded signal is the first coded signal, the first processed signal or the second processed signal.
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25. Computer program for performing, when running on the computer, the method of encoding an audio signal, the audio input signal being in a first domain, comprising:
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encoding an audio signal using a first coding algorithm to acquire a first encoded signal; encoding an audio signal using a second coding algorithm to acquire a second encoded signal, wherein the first coding algorithm is different from the second coding algorithm; and switching between encoding using the first coding algorithm and encoding using the second coding algorithm so that, for a portion of the audio input signal, either the first encoded signal or the second encoded signal is in an encoded output signal, wherein encoding using the second coding algorithm comprises; converting the audio signal into a second domain different from the first domain, processing an audio signal in the second domain to acquire a first processed signal; converting a signal into a third domain different from the first domain and the second domain and processing the signal in the third domain to acquire a second processed signal; and switching between processing the audio signal and converting and processing so that, for a portion of the audio signal encoded using the second coding algorithm, either the first processed signal or the second processed signal is in the second encoded signal.
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26. Computer program for performing, when running on the computer, the method of decoding an encoded audio signal, the encoded audio signal comprising a first coded signal, a first processed signal in a second domain, and a second processed signal in a third domain, wherein the first coded signal, the first processed signal, and the second processed signal are related to different time portions of a decoded audio signal, and wherein a first domain, the second domain and the third domain are different from each other, comprising:
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decoding the first encoded signal based on a first coding algorithm; decoding the first processed signal or the second processed signal, wherein the decoding the first processed signal or the second processed signal comprises; inverse processing the first processed signal to acquire a first inverse processed signal in the second domain; inverse processing the second processed signal to acquire a second inverse processed signal in the second domain; combining the first inverse processed signal and the second inverse processed signal to acquire a combined signal in the second domain; and converting the combined signal to the first domain; and combining the converted signal in the first domain and the decoded first signal to acquire a decoded output signal in the first domain.
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Specification