Audio decoding apparatus, audio coding apparatus, and system comprising the apparatuses
First Claim
Patent Images
1. An audio coding apparatus comprising:
- coding units;
a signal classifying unit configured to determine a classification of a property of an input signal as a classification of the input signal, according to the property; and
a selecting unit configured to select a coding unit based on the classification determined by said signal classifying unit and an index specified for said selecting unit, irrespective of the property of the input signal, from among said coding units and cause said selected coding unit to code the input signal, wherein;
said coding units are ranked from first to Nth, N being greater than 1 and a lower number indicating a higher rank,the index indicates a bit rate of a coded signal to be generated from the input signal by said coding unit,the classification includes a value S which increases as a degree of speech signal components in the input signal increases,a lowest coding unit that is ranked first is configured to code a frequency spectrum signal of the input signal,a highest coding unit that is ranked Nth is configured to separate the input signal into a linear prediction coefficient and an excitation signal, and code each of the linear prediction coefficient and the excitation signal, andsaid selecting unit is configured to;
select, from the coding units, a coding unit that is ranked higher than a predetermined rank, when (i) the bit rate indicated by the index is a first bit rate and (ii) the value S is smaller than or equal to a predetermined value A; and
select, from the coding units, a coding unit that is ranked higher than the predetermined rank, when (i) the bit rate indicated by the index is a second bit rate higher than the first bit rate and (ii) the value S is smaller than or equal to a predetermined value B, the predetermined value B being larger than the predetermined value A.
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Abstract
An audio decoding apparatus comprises: a plurality of decoding units; a band replicating unit which processes a decoded signal obtained when a corresponding decoding unit decodes a coded signal, according to a scheme specified by transmitted information; and an information transmitting unit which transmits, to a signal processing unit, information identifying the corresponding decoding unit from among the plurality of decoding units.
17 Citations
12 Claims
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1. An audio coding apparatus comprising:
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coding units; a signal classifying unit configured to determine a classification of a property of an input signal as a classification of the input signal, according to the property; and a selecting unit configured to select a coding unit based on the classification determined by said signal classifying unit and an index specified for said selecting unit, irrespective of the property of the input signal, from among said coding units and cause said selected coding unit to code the input signal, wherein; said coding units are ranked from first to Nth, N being greater than 1 and a lower number indicating a higher rank, the index indicates a bit rate of a coded signal to be generated from the input signal by said coding unit, the classification includes a value S which increases as a degree of speech signal components in the input signal increases, a lowest coding unit that is ranked first is configured to code a frequency spectrum signal of the input signal, a highest coding unit that is ranked Nth is configured to separate the input signal into a linear prediction coefficient and an excitation signal, and code each of the linear prediction coefficient and the excitation signal, and said selecting unit is configured to; select, from the coding units, a coding unit that is ranked higher than a predetermined rank, when (i) the bit rate indicated by the index is a first bit rate and (ii) the value S is smaller than or equal to a predetermined value A; and select, from the coding units, a coding unit that is ranked higher than the predetermined rank, when (i) the bit rate indicated by the index is a second bit rate higher than the first bit rate and (ii) the value S is smaller than or equal to a predetermined value B, the predetermined value B being larger than the predetermined value A. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An audio signal processing system conforming to the Unified Speech and Audio Codec (SAC) standard, said system comprising:
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an audio decoding apparatus; and an audio coding apparatus including; coding units; a signal classifying unit configured to determine a classification of a property of an input signal as a classification of the input signal according to the property; and a selecting unit configured to select a coding unit based on the classification determined by said signal classifying unit and an index specified for said selecting unit irrespective of the property of the input signal from said coding units, and causes said selected coding unit to code the input signal, wherein; said respective coding units are ranked from first to Nth, N being greater than 1 and a lower number indicating a higher rank, the index indicates a bit rate of a coded signal to be generated from the input signal by said coding unit, the classification includes a value S which increases as a degree of speech signal components in the input signal increases, a lowest coding unit that is ranked first is configured to code a frequency spectrum signal of the input signal, a highest coding unit that is ranked Nth is configured to separate the input signal into a linear prediction coefficient and an excitation signal, and code each of the linear prediction coefficient and the excitation signal, and said selecting unit is configured to; select, from the coding units, a coding unit that is ranked higher than a predetermined rank, when (i) the bit rate indicated by the index is a first bit rate and (ii) the value S is smaller than or equal to a predetermined value A; and select, from the coding units, a coding unit that is ranked higher than the predetermined rank, when (i) the bit rate indicated by the index is a second bit rate higher than the first bit rate and (ii) the value S is smaller than or equal to a predetermined value B, the predetermined values B being larger than the predetermined value A. - View Dependent Claims (10)
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11. An audio coding apparatus comprising:
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coding units; a signal classifying unit configured to determine a classification of a property of an input signal as a classification of the input signal, according to the property; and a selecting unit configured to select a coding unit based on the classification determined by said signal classifying unit and an index specified for said selecting unit, irrespective of the property of the input signal, from among said coding units, and cause said selected coding unit to code the input signal, wherein; said respective coding units are ranked from first to Nth, N being greater than 1 and a lower number indicating a higher rank, the index indicates an application of a coded signal to be generated from the input signal by said coding unit, the classification includes a value S which increases as a degree of speech signal components in the input signal increases, a lowest coding unit ranked first is configured to code a frequency spectrum signal of the input signal, a highest coding unit ranked Nth is configured to separate the input signal into a linear prediction coefficient and an excitation signal, and code each of the linear prediction coefficient and the excitation signal, and said selecting unit is configured to; select, from the coding units, a coding unit that is ranked higher than a predetermined rank, when (i) the application indicated by the index involves voice conversation and (ii) the value S is smaller than or equal to a predetermined value A; and select, from the coding units, a coding unit that is ranked higher than the predetermined rank, when (i) the application indicated by the index does not involve voice conversation and (ii) the value S is smaller than or equal to a predetermined value B, the predetermined value B being larger than the predetermined value A.
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12. An audio signal processing system conforming to the Unified Speech and Audio Codec (SAC) standard, said system comprising:
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an audio decoding apparatus; and an audio coding apparatus including; coding units; a signal classifying unit configured to determine a classification of a property of an input signal as a classification of the input signal, according to the property; and a selecting unit configured to select a coding unit based on the classification determined by said signal classifying unit and an index specified for said selecting unit, irrespective of the property of the input signal, from among said coding units, and cause said selected coding unit to code the input signal, wherein; said respective coding units are ranked from first to Nth, N being greater than 1 and a lower number indicating a higher rank, the index indicates an application of a coded signal to be generated from the input signal by said coding unit, the classification includes a value S which increases as a degree of speech signal components in the input signal increases, a lowest coding unit ranked first is configured to code a frequency spectrum signal of the input signal, a highest coding unit ranked Nth is configured to separate the input signal into a linear prediction coefficient and an excitation signal, and code each of the linear prediction coefficient and the excitation signal, and said selecting unit is configured to; select, from the coding units, a coding unit that is ranked higher than a predetermined rank, when (i) the application indicated by the index involves voice conversation and (ii) the value S is smaller than or equal to a predetermined value A; and select, from the coding units, a coding unit that is ranked higher than the predetermined rank, irrespective of the value S when the application indicated by the index does not involve voice conversation.
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Specification