VOICE CODING DEVICE, VOICE DECODING DEVICE, VOICE CODING METHOD AND VOICE DECODING METHOD
First Claim
1. A speech encoding apparatus configured to encode a wide band signal in a first layer and to encode an extended band signal, whose frequency band is located in higher frequency than the wide band signal, in an extended band layer, the apparatus comprising:
- a band-selecting unit that selects a frequency band to which limiting is applied when encoding is performed in the extended band layer; and
a band-limiting unit that applies the limiting to the selected frequency band of an input signal.
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Accused Products
Abstract
A voice coding device capable of preventing overall quality degradation even when the bit rate for coding is lowered. The voice coding device codes a wide band signal in a first layer, and codes an extended band signal whose frequency band is located in higher frequency than the wide band signal in an extended band layer. An adaptive band selection unit (301) selects a frequency band to be excluded from a coding object in the extended band layer or a frequency band whose energy is to be attenuated in the extended band layer. A band-limited signal generation unit (302) excludes, within the frequency band of an input signal, the frequency band selected by the adaptive band selection unit (301) from the coding object, or attenuates the energy of the frequency band selected by the adaptive band selection unit (301).
31 Citations
20 Claims
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1. A speech encoding apparatus configured to encode a wide band signal in a first layer and to encode an extended band signal, whose frequency band is located in higher frequency than the wide band signal, in an extended band layer, the apparatus comprising:
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a band-selecting unit that selects a frequency band to which limiting is applied when encoding is performed in the extended band layer; and a band-limiting unit that applies the limiting to the selected frequency band of an input signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A speech decoding apparatus configured to decode, in a first layer, first layer encoded information obtained by encoding a wide band signal in an encoding apparatus and to decode, in an extended band layer, extended band layer encoded information obtained by encoding an extended band signal whose frequency band is located in higher frequency than the wide band signal in the encoding apparatus, the decoding apparatus comprising:
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a band-selecting unit that selects a frequency band to which limiting is applied when outputting is performed in the extended band layer; and a band-limiting unit that applies the limiting to the selected frequency band of a decoded signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A speech encoding method for encoding a wide band signal in a first layer and for encoding an extended band signal whose frequency band is located in higher frequency than the wide band signal in an extended band layer, the method comprising:
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selecting a frequency band to which limiting is applied when encoding is performed in the extended band layer; and applying the limiting to the selected frequency band of an input signal.
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20. A speech decoding method for decoding a wide band signal in a first layer and for decoding an extended band signal whose frequency band is located in higher frequency than the wide band signal in an extended band layer, the method comprising:
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selecting a frequency band to which limiting is applied when outputting is performed in the extended band layer; and applying the limiting to the selected frequency band of a decoded signal.
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Specification