Method and apparatus for encoding/decoding speech signal
First Claim
1. An apparatus for encoding a speech signal, the apparatus comprising:
- a linear predictive (LP) analysis unit/quantization unit to determine an immittance spectral frequencies (ISF) index;
a closed loop pitch search unit to determine a pitch index;
a fixed codebook search unit to determine a code index;
a gain vector quantization (VQ) unit to determine a gain VQ index of each of an adaptive codebook and a fixed codebook; and
a bit rate control unit to control at least two indexes of the ISF index, the pitch index, the code index, and the gain VQ index to be encoded to be variable bit rates based on a source feature of a speech signal and reserved bits.
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Abstract
An apparatus and method for encoding/decoding a speech signal which determines a variable bit rate based on reserved bits obtained from a target bit rate, is provided. The variable bit rate is determined based on a source feature of the speech signal and the reserved bits is obtained based on the target bit rate. The apparatus for encoding the speech signal may include a linear predictive (LP) analysis unit/quantization unit to determine an immittance spectral frequencies (ISF) index, a closed loop pitch search unit, a fixed codebook search unit, a gain vector quantization (VQ) unit to determine a gain vector quantization (VQ) index, and a bit rate control unit to control at least two indexes of the ISF index, the pitch index, the code index, and the gain VQ index to be encoded to be variable bit rates based on a source feature of a speech signal and the reserved bits.
12 Citations
28 Claims
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1. An apparatus for encoding a speech signal, the apparatus comprising:
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a linear predictive (LP) analysis unit/quantization unit to determine an immittance spectral frequencies (ISF) index; a closed loop pitch search unit to determine a pitch index; a fixed codebook search unit to determine a code index; a gain vector quantization (VQ) unit to determine a gain VQ index of each of an adaptive codebook and a fixed codebook; and a bit rate control unit to control at least two indexes of the ISF index, the pitch index, the code index, and the gain VQ index to be encoded to be variable bit rates based on a source feature of a speech signal and reserved bits. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An apparatus for decoding a speech signal, the apparatus comprising:
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a demultiplexing unit to receive and to demultiplex a variable bit rate bitstream, and to extract an ISF index, a gain VQ index, a code index, and a pitch index from the variable rate bitstream; a linear predictive coefficient decoding unit to decode a linear predictive coefficient using quantizer information included in the ISF index; a gain decoding unit to decode an adaptive codebook gain and a fixed codebook gain using the quantizer information included in the gain VQ index; a fixed codebook decoding unit to decode a fixed codebook vector using fixed codebook information used in the code index; an adaptive codebook decoding unit to decode an adaptive codebook vector using pitch allocation bit information included in the pitch index; an excitation signal configuration unit to configure an excitation signal by multiplying each decoded gain from the gain decoding unit by the fixed codebook vector and the adaptive codebook vector and by summing results of the multiplying; a synthesis filter unit to synthesize the excitation signal with the ISF index; and a post-processing unit to post-process the speech signal.
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18. A method for encoding a speech signal, the method comprising:
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determining an ISF index using a variable bit rate based on at least one of a source feature and a reserved bits; determining a pitch index; determining a code index based on the reserved bits and a fluctuation feature of the reserved bits; determining a gain VQ index based on the reserved bits; and generating a variable bitstream including the determined ISF index, the pitch index, the code index, and the gain VQ index. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification