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 decoding device reduces abrupt changes in the number of channels in a decoded signal when transmission errors occur as a result of lost frames in an encoding/decoding system for multichannel signals. In the device, a demultiplexer receives an encoded monaural signal and an encoded differential signal and detects change over time in the received encoded differential signal. An M signal decoder decodes the encoded monaural signal and obtains a decoded monaural signal. An S signal decoder decodes the encoded differential signal and obtains a decoded differential signal. A smoothing unit performs smoothing on the decoded differential signal by means of a computation involving the decoded differential signal and coefficients corresponding to the change over time detected by the demultiplexer. An L/R signal computation unit computes a decoded stereo signal from the decoded monaural signal and the smoothed decoded differential signal.
摘要翻译:由于多通道信号的编码/解码系统中的丢失帧的结果,当传输错误发生时,解码装置减少解码信号中的信道数量的突然变化。 在该装置中,解复用器接收经编码的单声道信号和经编码的差分信号,并检测接收到的编码差分信号中随时间的变化。 M信号解码器解码编码的单声道信号并获得解码的单声道信号。 S信号解码器对编码的差分信号进行解码并获得解码的差分信号。 平滑单元通过涉及解码的差分信号的计算和对应于由解复用器检测到的随时间变化的系数对解码的差分信号进行平滑处理。 L / R信号计算单元从解码的单声道信号和平滑的解码的差分信号计算解码的立体声信号。
摘要:
Provided is a decoding device that can reduce abrupt changes in the number of channels in a decoded signal when transmission errors occur as a result of lost frames in an encoding/decoding system for multichannel signals. Said decoding device is also capable of per-sample smoothing and can reduce degradation of audio quality. In the provided device, a demultiplexer (301) receives an encoded monaural signal and an encoded differential signal and detects change over time in the received encoded differential signal. An M signal decoder (302) decodes the encoded monaural signal and obtains a decoded monaural signal. An S signal decoder (303) decodes the encoded differential signal and obtains a decoded differential signal. A smoothing unit (304) performs smoothing on the decoded differential signal by means of a computation involving the decoded differential signal and coefficients corresponding to the change over time detected by the demultiplexer (301). An L/R signal computation unit (305) computes a decoded stereo signal from the decoded monaural signal and the smoothed decoded differential signal.
摘要翻译:提供了一种解码装置,当由于多信道信号的编码/解码系统中的丢失帧而导致发送错误时,可以减少解码信号中的信道数量的突然变化。 所述解码装置还能够进行逐采样平滑,并且可以降低音频质量的劣化。 在提供的装置中,解复用器(301)接收经编码的单声道信号和经编码的差分信号,并检测接收到的编码差分信号中随时间的变化。 M信号解码器(302)解码编码的单声道信号并获得解码的单声道信号。 S信号解码器(303)解码编码的差分信号并获得解码的差分信号。 平滑单元(304)通过涉及解码的差分信号的计算和对应于由解复用器(301)检测的随时间变化的系数对解码的差分信号进行平滑处理。 L / R信号计算单元(305)根据解码的单声道信号和经平滑解码的差分信号计算解码的立体声信号。
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:
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:
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:
There is disclosed an encoder apparatus whereby, when a band expanding technique for encoding, based on the spectral data of a lower frequency portion, the spectral data of a higher frequency portion is applied to a lower layer in a hierarchical encoding/decoding system, an efficient encoding can be performed in an upper layer as well, thereby improving the decoded-signal quality. In an encoder apparatus (101), a second layer decoder unit (207) calculates a spectrum (differential spectrum), which is to be encoded in a third layer encoder unit (210) that is an upper layer of the second layer decoder unit (207), by applying such an ideal gain (first gain parameter a1) that minimizes the energy of the differential spectrum.
摘要:
There is disclosed an encoder apparatus whereby, when a band expanding technique for encoding, based on the spectral data of a lower frequency portion, the spectral data of a higher frequency portion is applied to a lower layer in a hierarchical encoding/decoding system, an efficient encoding can be performed in an upper layer as well, thereby improving the decoded-signal quality. In an encoder apparatus (101), a second layer decoder unit (207) calculates a spectrum (differential spectrum), which is to be encoded in a third layer encoder unit (210) that is an upper layer of the second layer decoder unit (207), by applying such an ideal gain (first gain parameter a1) that minimizes the energy of the differential spectrum.
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.