Audio decoding device, audio encoding device, audio decoding method, audio encoding method, audio decoding program, and audio encoding program
First Claim
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1. An audio decoding device that decodes an encoded audio signal and outputs the audio signal, comprising a processor configured to:
- decode an encoded sequence containing the encoded audio signal and obtain a decoded signal; and
shape a temporal envelope of a decoded signal in a plurality of frequency bands based on decoding related information concerning decoding of the encoded sequence by;
the processor being configured to replace a part of the decoded signal corresponding to a part of the frequency bands where the temporal envelope is not to be shaped with another signal in a frequency domain, the processor further configured to shape a part of the decoded signal corresponding to another part of the frequency bands where the temporal envelope is to be shaped and the part of the frequency bands where the temporal envelope is not to be shaped into a desired temporal envelope by filtering with a filter the part of the decoded signal corresponding to the another part of the frequency bands where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the part of the frequency bands where the temporal envelope is not to be shaped, the filter comprising a linear prediction coefficient obtained by the processor by linear prediction analysis of the decoded signal in the frequency domain and, after the temporal envelope shaping, the processor further configured to set the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the part of the frequency bands where the temporal envelope is not to be shaped.
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Abstract
The purpose of the present invention is to reduce distortion a frequency band component encoded with a small number of bits in a time domain and improve quality. An audio decoding device decodes an encoded audio signal and outputs the audio signal. A decoding unit decodes an encoded sequence containing an encoded audio signal and obtains a decoded signal. A selective temporal envelope shaping unit shapes a temporal envelope of a decoded signal in the frequency band on the basis of decoding related information concerning decoding of the encoded sequence.
5 Citations
18 Claims
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1. An audio decoding device that decodes an encoded audio signal and outputs the audio signal, comprising a processor configured to:
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decode an encoded sequence containing the encoded audio signal and obtain a decoded signal; and shape a temporal envelope of a decoded signal in a plurality of frequency bands based on decoding related information concerning decoding of the encoded sequence by; the processor being configured to replace a part of the decoded signal corresponding to a part of the frequency bands where the temporal envelope is not to be shaped with another signal in a frequency domain, the processor further configured to shape a part of the decoded signal corresponding to another part of the frequency bands where the temporal envelope is to be shaped and the part of the frequency bands where the temporal envelope is not to be shaped into a desired temporal envelope by filtering with a filter the part of the decoded signal corresponding to the another part of the frequency bands where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the part of the frequency bands where the temporal envelope is not to be shaped, the filter comprising a linear prediction coefficient obtained by the processor by linear prediction analysis of the decoded signal in the frequency domain and, after the temporal envelope shaping, the processor further configured to set the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the part of the frequency bands where the temporal envelope is not to be shaped. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11)
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2. An audio decoding device that decodes an encoded audio signal and outputs the audio signal, comprising processor configured to:
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extract temporal envelope information concerning a temporal envelope of an audio signal from an input encoded sequence; decode an encoded sequence containing the encoded audio signal and obtain a decoded signal; and shape a temporal envelope of a decoded signal in a plurality of frequency bands based on decoding related information concerning decoding of the encoded sequence by; the processor being configured to replace a part of the decoded signal corresponding to a part of the frequency bands where the temporal envelope is not to be shaped with another signal in a frequency domain, the processor further configured to shape a part of the decoded signal corresponding to another part of the frequency bands where the temporal envelope is to be shaped and the part of the frequency bands where the temporal envelope is not to be shaped into a desired temporal envelope by filtering with a filter the part of the decoded signal corresponding to the another part of the frequency bands where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the part of the frequency bands where the temporal envelope is not to be shaped, the filter comprising a linear prediction coefficient obtained by the processor by linear prediction analysis of the decoded signal in the frequency domain and, after the temporal envelope shaping, the processor further configured to set the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the part of the frequency bands where the temporal envelope is not to be shaped.
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12. An audio decoding device that decodes an encoded audio signal and outputs the audio signal, comprising a processor configured to:
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decode an encoded sequence containing the encoded audio signal and obtain a decoded signal; and shape the decoded signal into a desired temporal envelope by filtering the decoded signal in the frequency domain with a filter, the filter comprising a linear prediction coefficient obtained by linear prediction analysis of the decoded signal in the frequency domain, and by the processor being configured to replace a part of the decoded signal corresponding to a frequency band where the temporal envelope is not to be shaped with another signal in a frequency domain, the processor further configured to shape a part of the decoded signal corresponding to another frequency band where the temporal envelope is to be shaped and the frequency band where the temporal envelope is not to be shaped into a desired temporal envelope by filtering with the filter the decoded signal corresponding to the another frequency band where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to frequency band where the temporal envelope is not to be shaped and, after the temporal envelope shaping, the processor further configured to set the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the frequency band where the temporal envelope is not to be shaped.
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13. An audio decoding method of an audio decoding device that decodes an encoded audio signal and outputs the audio signal, comprising:
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a decoding step of decoding, with the audio decoding device, an encoded sequence containing the encoded audio signal and obtaining a decoded signal; and a selective temporal envelope shaping step of shaping, by the audio decoding device, a temporal envelope of a decoded signal in a frequency band based on decoding related information concerning decoding of the encoded sequence, wherein the selective temporal envelope shaping step comprises replacing, by the audio decoding device, a part of the decoded signal corresponding to a frequency band where the temporal envelope is not to be shaped with another signal in a frequency domain, then shaping, by the audio decoding device, a part of the decoded signal corresponding to another frequency band where the temporal envelope is to be shaped and the frequency band where the temporal envelope is not to be shaped into a desired temporal envelope by filtering, with the audio decoding device, the part of the decoded signal corresponding to the another frequency band where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the frequency band where the temporal envelope is not to be shaped with a filter using a linear prediction coefficient obtained by linear prediction analysis of the decoded signal in the frequency domain and, after the temporal envelope shaping, setting, by the audio decoding device, the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the frequency band where the temporal envelope is not to be shaped.
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14. An audio decoding method of an audio decoding device that decodes an encoded audio signal and outputs the audio signal, comprising:
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a extracting step of extracting, with the audio decoding device, temporal envelope information concerning a temporal envelope of an audio signal from an encoded sequence; a decoding step of decoding, by the audio decoding device, the encoded sequence and obtaining a decoded signal; and a selective temporal envelope shaping step of shaping, by the audio decoding device, a temporal envelope of a decoded signal in a frequency band based on at least one of the temporal envelope information and decoding related information concerning decoding of the encoded sequence, wherein the selective temporal envelope shaping step comprises replacing, by the audio decoding device, a part of the decoded signal corresponding to a frequency band where the temporal envelope is not to be shaped with another signal in a frequency domain, shaping, with the audio decoding device, a part of the decoded signal corresponding to another frequency band where the temporal envelope is to be shaped and the frequency band where the temporal envelope is not to be shaped into a desired temporal envelope by filtering, with the audio decoding device, the part of the decoded signal corresponding to the another frequency band where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the frequency band where the temporal envelope is not to be shaped with a filter using a linear prediction coefficient obtained by linear prediction analysis of the decoded signal in the frequency domain and, after the temporal envelope shaping, setting, by the audio decoding device, the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the frequency band where the temporal envelope is not to be shaped.
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15. An audio decoding method of an audio decoding device that decodes an encoded audio signal and outputs the audio signal, comprising:
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a decoding step of decoding, with the audio decoding device, an encoded sequence containing the encoded audio signal and obtaining a decoded signal; and a temporal envelope shaping step of shaping, with the audio decoding device, the decoded signal into a desired temporal envelope by filtering the decoded signal in the frequency domain with use of a filter using a linear prediction coefficient obtained by linear prediction analysis of the decoded signal in the frequency domain, wherein the selective temporal envelope shaping step comprises replacing, by the audio decoding device, a part of the decoded signal corresponding to a frequency band where the temporal envelope is not to be shaped with another signal in a frequency domain, wherein the filtering comprises shaping, by the audio decoding device, a part of the decoded signal corresponding to another frequency band where the temporal envelope is to be shaped and the frequency band where the temporal envelope is not to be shaped into a desired temporal envelope by filtering, with the audio decoding device, the part of the decoded signal corresponding to the another frequency band where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the frequency band where the temporal envelope is not to be shaped and, after the temporal envelope shaping, setting, by the audio decoding device, the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the frequency band where the temporal envelope is not to be shaped.
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16. A non-transitory computer readable storage medium storing an audio decoding program that causes a computer to execute:
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a decoding step of decoding an encoded sequence containing the encoded audio signal and obtaining a decoded signal; and a selective temporal envelope shaping step of shaping a temporal envelope of a decoded signal in a frequency band based on decoding related information concerning decoding of the encoded sequence, wherein the selective temporal envelope shaping step comprises replacing a part of the decoded signal corresponding to a frequency band where the temporal envelope is not to be shaped with another signal in a frequency domain, then shaping a part of the decoded signal corresponding to another frequency band where the temporal envelope is to be shaped and the frequency band where the temporal envelope is not to be shaped into a desired temporal envelope by filtering the part of the decoded signal corresponding to the another frequency band where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the frequency band where the temporal envelope is not to be shaped with a filter using a linear prediction coefficient obtained by linear prediction analysis of the decoded signal in the frequency domain and, after the temporal envelope shaping, setting the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the frequency band where the temporal envelope is not to be shaped.
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17. A non-transitory computer readable storage medium storing an audio decoding program that causes a computer to execute:
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a extracting step of extracting temporal envelope information concerning a temporal envelope of an audio signal from an encoded sequence; a decoding step of decoding the encoded sequence and obtaining a decoded signal; and a selective temporal envelope shaping step of shaping a temporal envelope of a decoded signal in a frequency band based on at least one of the temporal envelope information and decoding related information concerning decoding of the encoded sequence, wherein the selective temporal envelope shaping step comprises replacing a part of the decoded signal corresponding to a frequency band where the temporal envelope is not to be shaped with another signal in a frequency domain, shaping a part of the decoded signal corresponding to another frequency band where the temporal envelope is to be shaped and the frequency band where the temporal envelope is not to be shaped into a desired temporal envelope by filtering the part of the decoded signal corresponding to the another frequency band where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the frequency band where the temporal envelope is not to be shaped with a filter using a linear prediction coefficient obtained by linear prediction analysis of the decoded signal in the frequency domain and, after the temporal envelope shaping, setting the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the frequency band where the temporal envelope is not to be shaped.
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18. A non-transitory computer readable storage medium storing an audio decoding program that causes a computer to execute:
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a decoding step of decoding an encoded sequence containing the encoded audio signal and obtaining a decoded signal; and a temporal envelope shaping step of shaping the decoded signal into a desired temporal envelope by filtering the decoded signal in the frequency domain with use of a filter using a linear prediction coefficient obtained by linear prediction analysis of the decoded signal in the frequency domain, wherein the selective temporal envelope shaping step comprises replacing a part of the decoded signal corresponding to a frequency band where the temporal envelope is not to be shaped with another signal in a frequency domain, wherein the filtering comprises shaping a part of the decoded signal corresponding to another frequency band where the temporal envelope is to be shaped and the frequency band where the temporal envelope is not to be shaped into a desired temporal envelope by filtering the part of the decoded signal corresponding to the another frequency band where the temporal envelope is to be shaped and the another signal in the frequency domain corresponding to the frequency band where the temporal envelope is not to be shaped and, after the temporal envelope shaping, setting the part of the decoded signal replaced with the another signal in the frequency domain back to the part of the decoded signal corresponding to the frequency band where the temporal envelope is not to be shaped.
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Specification