摘要:
A coding apparatus capable of coding a spectrum at a low bit rate and with high quality without producing any disturbance in a harmonic structure of the spectrum. In this apparatus, internal state setting section sets an internal state of a filtering section using a first spectrum S1(k). A pitch coefficient setting section outputs a pitch coefficient T by gradually changing it. The filtering section calculates an estimated value S′2(k) of a second spectrum S2(k) based on a pitch coefficient T. A search section calculates the degree of similarity between S2(k) and S′2(k). At this time, pitch coefficient T′ corresponding to the maximum calculated degree of similarity is given to a filter coefficient calculation section. The filter coefficient calculation section determines a filter coefficient βi using this pitch coefficient T′.
摘要:
An encoder, decoder, encoding method, and decoding method enabling acquisition of high-quality decoded signal in scalable encoding of an original signal in first and second layers even if the second or upper layer section performs low bit-rate encoding. In the encoder, a spectrum residue shape codebook stores candidates of spectrum residue shape vectors, a spectrum residue gain codebook stores candidates of spectrum residue gains, and a spectrum residue shape vector and a spectrum residue gain are sequentially outputted from the candidates according to the instruction from a search section. A multiplier multiplies a candidate of the spectrum residue shape vector by a candidate of the spectrum residue gain and outputs the result to a filtering section. The filtering section performs filtering by using a pitch filter internal state set by a filter state setting section, a lag T outputted by a lag setting section, and a spectrum residue shape vector which has undergone gain adjustment.
摘要:
A coding apparatus reduces a circuit scale and the amount of coding processing calculation. A frequency domain conversion section performs a frequency analysis of the signal sampled at a sampling rate Fx with an analysis length of 2·Na and calculates first spectrum S1(k)(0≦k
摘要翻译:编码装置减少电路规模和编码处理计算量。 频域转换部对分析长度为2·Na的采样率Fx进行采样的信号的频率分析,计算出第一频谱S1(k)(0≦̸ k
摘要:
An encoding apparatus and method for generating low-frequency-band encoding information and high-frequency-band encoding information from an original signal. The encoding apparatus includes a first spectrum calculator that calculates a first spectrum of a low frequency band from a decoded signal of the low-frequency-band encoding information, a second spectrum calculator that calculates a second spectrum from the original signal, an estimator that divides a high frequency band of the second spectrum into a plurality of bands and estimates the second spectrum included in each band, using the first spectrum, and a first error component encoder that encodes a first error component between the high frequency band of the second spectrum and an estimated spectrum. A corresponding decoding apparatus and method provides decoding.
摘要:
A down-sampler 101 down-samples the sampling rate of an input signal from sampling rate FH to sampling rate FL. A base layer coder 102 encodes the sampling rate FL acoustic signal. A local decoder 103 decodes coding information output from base layer coder 102. An up-sampler 104 raises the sampling rate of the decoded signal to FH. A subtractor 106 subtracts the decoded signal from the sampling rate FH acoustic signal. An enhancement layer coder 107 encodes the signal output from subtractor 106 using a decoding result parameter output from local decoder 103.
摘要:
A transform coding apparatus includes an input scale factor calculating section that calculates an input scale factor having a predetermined number of scale factors associated with an input spectrum as an element, and a codebook that stores a plurality of scale factor candidates having a predetermined number of elements and outputs one scale factor candidate. The transform coding apparatus also includes an error calculating section that calculates an error on a per element basis, a weighted error calculating section that determines a weight on a per element basis and calculates a sum of products of the error and the weight to calculate a weighted error, and a searching section that searches for a scale factor candidate that minimizes the weighted error in the codebook.
摘要:
A coding apparatus reduces a circuit scale and the amount of coding processing calculation. A frequency domain conversion section performs a frequency analysis of the signal sampled at a sampling rate Fx with an analysis length of 2·Na and calculates first spectrum S1(k)(0≦k
摘要翻译:编码装置减少电路规模和编码处理计算量。 频域转换部对分析长度为2·Na的采样率Fx进行采样的信号的频率分析,计算出第一频谱S1(k)(0≦̸ k