摘要:
Provided are a coding device, a decoding device, and methods thereof, with which it is possible to implement high sound quality coding and decoding in layered coding (scalable coding or embedded coding) wherein each layer comprises a plurality of bit rates (multi-rate). In the coding device (100), a feature analysis unit (101) extracts feature values of an input signal. Then a bit rate determination unit (102) determines, on the basis of the feature values of the input signal, a combination of a coding rate (low region coding rate) of a low region signal coding unit (104) which carries out coding of a low region part of the input signal and a coding rate (high region coding rate) of a high region signal coding unit (105) which carries out coding of a high region part of the input signal.
摘要:
Provided are a coding device, a decoding device, and methods thereof, with which it is possible to implement high sound quality coding and decoding in layered coding (scalable coding or embedded coding) wherein each layer comprises a plurality of bit rates (multi-rate). In the coding device (100), a feature analysis unit (101) extracts feature values of an input signal. Then a bit rate determination unit (102) determines, on the basis of the feature values of the input signal, a combination of a coding rate (low region coding rate) of a low region signal coding unit (104) which carries out coding of a low region part of the input signal and a coding rate (high region coding rate) of a high region signal coding unit (105) which carries out coding of a high region part of the input signal.
摘要:
Provided is an encoder which can effectively encode/decode spectrum data of a broad frequency signal in a high frequency range, can dramatically reduce the number of the arithmetic operations to be performed, and can improve the quality of the decoded signal. The encoder comprises a first layer coding unit (202) which encodes an input signal in a low frequency range below a predetermined frequency to generate first coded information, a first layer decoding unit (203) which decodes the first coded information to generate a decoded signal, and a second layer coding unit (206) which splits the input signal in a high frequency range above a predetermined frequency, into a plurality of sub-bands, presumes the respective sub-hands from the input signal or decoded signal, partially selects a spectrum component within each sub-band, and calculates an amplitude adjustment parameter used to adjust the amplitude of the selected spectrum component to thereby generate second coding information.
摘要:
A scalable decoding apparatus capable of providing decoded audio signals of high quality having less degradation of a high frequency spectrum even when decoding audio signals by generating the high frequency spectrum by use of a low frequency spectrum. In the apparatus, an amplitude adjusting part uses different adjustment coefficients in accordance with the characteristic of first layer spectrum information to adjust the amplitude of a first layer decoded signal spectrum, and then outputs the amplitude-adjusted first layer decoded signal spectrum to a pseudo-spectrum generating part. Using amplitude-adjusted first layer decoded signal spectrum received from the amplitude adjusting part, the pseudo-spectrum generating part generates and outputs a pseudo-spectrum of high frequencies to a scaling part. The scaling part scales the spectrum received from the pseudo-spectrum generating part and then outputs it to an adder.
摘要:
A scalable encoding device for realizing scalable encoding by CELP encoding of a stereo sound signal and improving the encoding efficiency. In this device, an adder and a multiplier obtain an average of a first channel signal CH1 and a second channel signal CH2 as a monaural signal M. A CELP encoder for a monaural signal subjects the monaural signal M to CELP encoding, outputs the obtained encoded parameter to outside, and outputs a synthesized monaural signal M′ synthesized by using the encoded parameter to a first channel signal encoder. By using the synthesized monaural signal M′ and the second channel signal CH2, the first channel signal encoder subjects the first channel signal CH1 to CELP encoding to minimize the sum of the encoding distortion of the first channel signal CH1 and the encoding distortion of the second channel signal CH2.
摘要:
A scalable encoding device for realizing scalable encoding by CELP encoding of a stereo sound signal and improving the encoding efficiency. In this device, an adder and a multiplier obtain an average of a first channel signal CH1 and a second channel signal CH2 as a monaural signal M. A CELP encoder for a monaural signal subjects the monaural signal M to CELP encoding, outputs the obtained encoded parameter to outside, and outputs a synthesized monaural signal M′ synthesized by using the encoded parameter to a first channel signal encoder. By using the synthesized monaural signal M′ and the second channel signal CH2, the first channel signal encoder subjects the first channel signal CH1 to CELP encoding to minimize the sum of the encoding distortion of the first channel signal CH1 and the encoding distortion of the second channel signal CH2.
摘要:
A scalable decoding apparatus capable of providing decoded audio signals of high quality having less degradation of a high frequency spectrum even when decoding audio signals by generating the high frequency spectrum by use of a low frequency spectrum. In the apparatus, an amplitude adjusting part (1211) uses different adjustment coefficients in accordance with the characteristic of first layer spectrum information to adjust the amplitude of a first layer decoded signal spectrum, and then outputs the amplitude-adjusted first layer decoded signal spectrum to a pseudo-spectrum generating part (1012). Using amplitude-adjusted first layer decoded signal spectrum received from the amplitude adjusting part (1211), the pseudo-spectrum generating part (1012) generates and outputs a pseudo-spectrum of high frequencies to a scaling part (1013). The scaling part (1013) scales the spectrum received from the pseudo-spectrum generating part (1012) and then outputs it to an adder (B).
摘要:
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).
摘要:
Disclosed is a spectral smoothing device with a structure whereby smoothing is performed after a nonlinear conversion has been performed for a spectrum calculated from an audio signal, and with which the amount of processing calculation is significantly reduced while maintaining excellent audio quality. With this spectral smoothing device, a sub band division unit (102) divides an input spectrum into multiple sub bands; a representative value calculation unit (103) calculates a representative value for each sub band using an arithmetic mean and a geometric mean; with respect to each representative value, a nonlinear conversion unit (104) performs a nonlinear conversion the characteristic of which is further emphasized as the value increases; and a smoothing unit (105) that smoothes the representative value which has undergone the nonlinear conversion for each sub band, at the frequency domain.
摘要:
A stereo signal encoding device is provided that enables a lower bitrate without decreasing quality when applying an intermittent transmission technique to a stereo signal. A stereo encoding unit generates first stereo encoded data by encoding the stereo signal when the stereo signal of the current frame is an audio section. A stereo DTX encoding unit is a means for encoding the stereo signal when the stereo signal of the current frame is a non-audio section. The stereo DTX encoding unit generates second stereo encoded data by encoding each of a monaural signal spectral parameter that is a spectral parameter of a monaural signal generated using the first channel signal and the second channel signal, first channel signal information relating to the first channel signal, and second channel signal information relating to the second channel signal.