摘要:
Fluctuation in decoded signal localization is suppressed to maintain the feel of stereo. A selection unit (220) selects balance parameters when the balance parameters are input from a gain coefficient decoding unit (210), or selects balance parameters input from a gain coefficient calculation unit (223) when there is no balance parameter input from the gain coefficient decoding unit (210), and outputs the selected balance parameters to a multiplication unit (221). The multiplication unit (221) multiplies a gain coefficient input from the selection unit (220) with a decoded monaural signal input from a monaural decoding unit (202) to perform balance adjustment processing.
摘要:
Provided is an audio decoding device capable of suppressing an information amount for a lost frame compensation process and encoding efficiency. In this device, a decoded sound source generation unit (203) generates a lost frame decoded sound source signal; a pitch pulse information decoding unit (204) decodes the pitch pulse position information and the pitch pulse amplitude information; a pitch pulse waveform learning unit (205) learns a pitch pulse learning waveform in the past frame in advance from the lost frame; a convolution unit (206) amplitude-adjusts the pitch pulse learning waveform according to the pitch pulse amplitude information, and convolutes the pitch pulse waveform into a time axis which has been amplitude-adjusted according to the pitch pulse position information; a sound source signal correction unit (207) adds or replaces the pitch pulse waveform convoluted into the time axis to the lost frame decoded sound source signal.
摘要:
Disclosed are an audio encoding device and an audio decoding device which reduce degradation of subjective quality of a decoding signal caused by power mismatch of a decoding signal which is generated by a concealing process upon disappearance of a frame. When a frame is lost, a past encoding parameter is used to obtain a concealed LPC of the current frame and a concealed sound source parameter. A normal CELP decoding is performed from the obtained concealed sound source parameter. Correction is performed by using a conceal parameter on the obtained concealed LPC and the concealed sound source signal. The power of the corrected concealed sound source signal is adjusted to match a reference sound source power. A filter gain of the synthesis filter is adjusted so as to adjust the power of a decoded sound signal to the power of a decoded sound signal during an error-free state. Moreover, a synthesis filter gain adjusting coefficient is calculated by using an estimated normalized residual power so that a filter gain of a synthesis filter formed by using a concealed LPC is a filter gain during an error-free state.
摘要:
Disclosed are an audio encoding device and an audio decoding device which reduce degradation of subjective quality of a decoding signal caused by power mismatch of a decoding signal which is generated by a concealing process upon disappearance of a frame. When a frame is lost, a past encoding parameter is used to obtain a concealed LPC of the current frame and a concealed sound source parameter. A normal CELP decoding is performed from the obtained concealed sound source parameter. Correction is performed by using a conceal parameter on the obtained concealed LPC and the concealed sound source signal. The power of the corrected concealed sound source signal is adjusted to match a reference sound source power. A filter gain of the synthesis filter is adjusted so as to adjust the power of a decoded sound signal to the power of a decoded sound signal during an error-free state. Moreover, a synthesis filter gain adjusting coefficient is calculated by using an estimated normalized residual power so that a filter gain of a synthesis filter formed by using a concealed LPC is a filter gain during an error-free state.
摘要:
An audio decoding device capable of suppressing an information amount for a lost flame compensation process and encoding efficiency is provided. A decoded sound source generator generates a lost frame's CELP decoded sound source signal. A pitch pulse information decoder CELP decodes a pitch pulse position information and a pitch pulse amplitude information. A pitch pulse waveform learner learns a pitch pulse learning waveform in a past frame in advance from the lost frame. A convolution adjuster amplitude-adjusts the pitch pulse learning waveform according to the pitch pulse amplitude information by considering a predetermined number of waveforms peripheral to a peak position of the lost frame's CELP decoded excitation signal, and convolutes a pitch pulse waveform into a time axis which has been amplitude-adjusted according to the pitch pulse position information. A sound source signal corrector adds or replaces the pitch pulse waveform convoluted into the time axis to the lost flame decoded sound source signal.
摘要:
Fluctuation in decoded signal localization is suppressed to maintain the feel of stereo. A selection unit selects balance parameters when the balance parameters are input from a gain coefficient decoding unit, or selects balance parameters input from a gain coefficient calculation unit when there is no balance parameter input from the gain coefficient decoding unit, and outputs the selected balance parameters to a multiplication unit. The multiplication unit multiplies a gain coefficient input from the selection unit with a decoded monaural signal input from a monaural decoding unit to perform balance adjustment processing.
摘要:
A scalable encoding device is capable of improving quality of a decoded signal without increasing an encoding amount and compensating data with a sufficient quality upon data loss. An extension layer bit distribution calculator calculates a bit distribution of a quality improving encoding data and compensation encoding data in the extension layer according to an audio mode of the input signal. An extension layer encoder generates quality improving encoding data according to the specified number of bits. A compensation information encoder extracts a part of core layer encoding data and makes it as compensation encoding data for the core layer. An extension layer encoded data generator multiplexes the extension layer bit distribution information, the compensation encoding data, and the quality improving encoding data so as to obtain extension layer encoding data.
摘要:
Provided is a scalable encoding device capable of improving quality of a decoded signal without increasing an encoding amount and compensating data with a sufficient quality upon data loss. In the scalable encoding device, an extension layer bit distribution calculation unit (103) calculates a bit distribution of a quality improving encoding data and compensation encoding data in the extension layer according to an audio mode of the input signal. An extension layer encoding unit (105) generates quality improving encoding data according to the specified number of bits. A compensation information encoding unit (104) extracts a part of core layer encoding data and makes it as compensation encoding data for the core layer. An extension layer encoded data generation unit (106) multiplexes the extension layer bit distribution information, the compensation encoding data, and the quality improving encoding data so as to obtain extension layer encoding data.
摘要:
An audio decoding device performs frame loss compensation capable of obtaining a decoded audio which is natural for ears with little noise. The audio decoding device includes a non-cyclic pulse waveform detection unit for detecting a non-cyclic pulse waveform section in a n−1-th frame, which is repeatedly used with a pitch cycle in the n-th frame upon compensation of loss of the n-th frame. The audio coding device also includes a non-cyclic pulse waveform suppression unit for suppressing a non-cyclic pulse waveform by replacing an audio source signal existing in the non-cyclic pulse waveform section in the n−1-th frame by a noise signal. The audio coding device further includes a synthesis filter for using a linear prediction coefficient decoded by an LPC decoding unit to perform synthesis by a synthesis filter by using the audio source signal of the n−1-th frame from the non-cyclic pulse waveform suppression unit as a drive audio source, thereby obtaining the decoded audio signal of the n-th frame.
摘要:
A scalable decoder capable of avoiding deterioration in subjective quality of a listener. The scalable decoder for decoding core layer encoding data and extension layer encoding data including an extension layer gain coefficient, wherein a voice analysis section detects variation in power of a core layer decoding voice signal being obtained from the core layer encoding data, a gain attenuation rate calculating section (140) sets the attenuation intensity variable depending on variation in power, and a gain attenuation section (143) attenuates the extension layer gain coefficient in a second period preceding a first period according to a set attenuation intensity when extension layer encoding data in the first period is missing, thus interpolating the extension layer gain coefficient in the first period.