Music information encoding/decoding device and method
AssigneeSony Corporation
InventorsShiro Suzuki, Minoru Tsuji, Keisuke Toyama
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Abstract
In an audio-information encoding apparatus, in order to encode an audio signal containing a white-noise component, an index iL indicating the energy level of the white-noise component and an index iR designating the start index of a random-number table are introduced into a code train. In an audio-information decoding apparatus (20), a white-noise generating unit (25) uses the indices iL and iR contained in the code train, thereby generating a white-noise signal Sw(t) on the time axis, which has the same level as the white noise, and an adder (26) adds the white-noise signal to an audio signal Sf(t) decoded on the time axis, outputting as an output audio signal So(t).
Claims12
An audio-information encoding apparatus for dividing an audio signal on a time axis into blocks for every predetermined time period, frequency transforming and encoding each block, said apparatus comprising:
- a white-noise level determining unit for:
- (i) determining, for each block, a white-noise level of an extracted white-noise component of a frequency transformed audio signal and generating a first index by quantizing the white-noise level contained in the audio signal;
- and, (ii) generating a second index designating a start location of a random-number table adapted to generate a white-noise component in a decoding side;
- and
- an encoding unit that encodes, for each block, (i) a quantized value resulting from normalization and quantization of the frequency transformed audio signal, (ii) the first index, and (iii) the second index.
An audio-information encoding method for dividing an audio signal on a time axis into blocks for every predetermined time period, frequency transforming and encoding each block, the method comprising:
- determining, for each block, a white-noise level of an extracted white-noise component of a frequency transformed audio signal;
- generating a first index by quantizing the white-noise level contained in the audio signal, and a second index designating a start location of a random-number table adapted to generate a white-noise component in a decoding side;
- and
- encoding, for each block, (i) a quantized value resulting from normalization and quantization of the frequency transformed audio signal, (ii) the first index, and (iii) the second index, wherein
- said determining and generating steps are performed by a white-noise level determining unit and said encoding step is performed by an encoding unit.
A computer program product, comprising a computer usable recording medium having a computer readable program code embodied therein, said computer readable program code adapted to perform an audio-information encoding process of dividing an audio signal on a time axis into blocks for every predetermined time period, frequency transforming and encoding each block, the process comprising:
- determining, for each block, a white-noise level of an extracted white-noise component of a frequency transformed audio signal;
- generating a first index by quantizing the white-noise level contained in the audio signal, and a second index designating a start location of a random-number table adapted to generate a white-noise component in a decoding side;
- and
- encoding, for each block, (i) a quantized value resulting from normalization and quantization of the frequency transformed audio signal, (ii) the first index, and (iii) the second index.
An audio-information decoding apparatus for decoding an encoded frequency signal, inverse frequency transforming the decoded frequency signal, thereby generating an audio signal on a time axis, said apparatus comprising:
- a white-noise generating unit that generates a white-noise component on the time axis, based on (i) a first encoded index indicating the energy level of the white-noise component and (ii) a second encoded index designating a start location of a random-number table;
- and
- an adder that adds the audio signal and the white-noise component on the time axis.
An audio-information decoding method for decoding an encoded frequency signal, inverse frequency transforming the decoded frequency signal, thereby generating an audio signal on a time axis, said method comprising:
- generating a white-noise component on the time axis, based on (i) a first encoded index indicating the energy level of the white-noise component and (ii) a second encoded index designating a start location of a random-number table;
- and
- adding the audio signal and the white-noise component on the time axis, wherein
- said generating step is performed by a white-noise generating unit, and said adding step is performed by an adder.
A computer program product, comprising a computer usable recording medium having a computer readable program code embodied therein, said computer readable program code adapted to perform an audio-information decoding process of decoding an encoded frequency signal, inverse frequency transforming the decoded frequency signal, thereby generating an audio signal on a time axis, said process comprising:
- generating a white-noise component on the time axis, based on (i) a first encoded index indicating the energy level of the white-noise component and (ii) a second encoded index designating a start location of a random-number table;
- and
- adding the audio signal and the white-noise component on the time axis.
Dependencies are inferred from the claim text.