摘要:
Disclosed is an adaptive excitation vector quantization device capable of improving quantization accuracy of adaptive excitation vector quantization while suppressing increase of the calculation amount in CELP encoding which performs encoding in sub-frame units. An adaptive excitation vector generator cuts out an adaptive excitation vector of a frame length (n) from an adaptive excitation codebook. An impulse response matrix former forms a n×n impulse response matrix using impulse response matrixes of sub-frames inputted from a synthesis filter. A target vector generator adds a linear prediction residual vector of each sub-frame to form a target vector of frame length (n). An evaluation measure calculator calculates an evaluation measure of the adaptive excitation vector quantization by using the adaptive excitation vector, the impulse response matrix, and the target vector.
摘要:
Disclosed is an LPC vector quantization device capable of quantizing an LSP vector by using correlation between divided vectors. The device includes: a vector dividing unit (101) for dividing an inputted LSP vector into a first divided vector and a second divided vector; a first quantization unit (102) for quantizing the first divided vector by using a first codebook formed by a plurality of first code vectors to generate a first code; a prediction vector selection unit (103) for predicting a second divided vector from the first code by using a prediction codebook formed by a plurality of prediction code vectors to create a prediction vector; a prediction residual generation unit (104) for obtaining a residual between the prediction vector and the second divided vector to create a prediction residual vector; a second quantization unit (105) for quantizing the prediction residual vector by using a second codebook formed by a plurality of second code vectors to create a second code; and a multiplexing unit (106) for generating a quantization vector code by multiplexing the first code and the second code.
摘要:
An audio/music decoding device capable of improving quality of a decoded signal generated by conceal processing of a frame erase using a scalable encoding method. The audio/music decoding device includes a frame loss detector that determines whether encoded information is normally received and generates frame loss information indicating the result of the determination. According to the frame loss information, a first decoder performs decoding by using at least one of the following encoded information: the first encoded information on the frame immediately before, the first encoded information on the current frame, and the second encoded information on the current frame. According to the frame loss information, a second decoder performs decoding by using at least one of the following encoded information: the first encoded information on the frame immediately before, the first encoded information on the current frame, the second encoded information on the frame immediately before, and the second encoded information on the current frame. An adder adds the decoded signal outputted from the first decoder and the decoded signal outputted from the second decoder.
摘要:
An adaptive sound source vector quantization device includes a first pitch cycle instructor, a search range calculator, and a second pitch cycle instructor. The first pitch cycle instructor successively instructs pitch cycle search candidates in a predetermined search range having a search resolution which transits over a predetermined pitch cycle candidate for the first sub-frame. The search range calculator calculates a predetermined range before and after the pitch cycle of the first sub-frame as the pitch cycle search range for the second sub-frame, if the predetermined range includes the predetermined pitch cycle search candidate. In the predetermined range, the search resolution transits over a boundary defined by the predetermined pitch cycle. The second pitch cycle instructor successively instructs the pitch cycle search candidates in the search range for the second sub-frame.
摘要:
A coding device is provided with features in which optimum coding in a higher layer is flexibly carried out based on a coding result of a lower layer and a quality audio signal in limited circumstances is served to users. In this coding device, a basic layer coding unit codes an input signal to generate a basic layer information source code and outputs a linear prediction coefficient (LPC) and a quantum LPC, which are parameters calculated at coding, to an expanded layer control unit. A basic layer decoding unit decodes the basic layer information source code. An adding unit reverses a polarity of a basic layer decoded signal, adds the same to the input signal, and calculates a difference signal. The expanded layer control unit generates expanded layer mode information indicative of a coding mode in an expanded layer based on the LPC and the quantum LPC. An expanded layer coding unit codes the difference signal obtained from the adding unit under control of the expanded layer control unit.
摘要:
There is disclosed an audio encoding device capable of realizing effective encoding while using audio encoding of the CELP method in an extended layer when hierarchically encoding an audio signal. In this device, a first encoding section (115) subjects an input signal (S11) to audio encoding processing of the CELP method and outputs the obtained first encoded information (S12) to a parameter decoding section (120). The parameter decoding section (120) acquires a first quantization LSP code (L1), a first adaptive excitation lag code (A1), and the like from the first encoded information (S12), obtains a first parameter group (S13) from these codes, and outputs it to a second encoding section (130). The second encoding section (130) subjects the input signal (S11) to a second encoding processing by using the first parameter group (S13) and obtains second encoded information (S14). A multiplexing section (154) multiplexes the first encoded information (S12) with the second encoded information (S14) and outputs them via a transmission path N to a decoding apparatus (150).
摘要:
Disclosed is a vector quantizer in which, in multistage vector quantization, the vector quantization of the following stage can be performed adaptively to the result of the vector quantization of the preceding stage to improve the accuracy of the quantization at less calculation amount and bit rate. The quantizer comprises a product set circle calculating section (108) for calculating a product set circle indicating a product set of a cluster circle of a first code vector selected as the result of the quantization of a first stage from a first codebook (101) and a cluster circle of a second code vector selected as the result of the quantization of a second stage from a second codebook (105), and an adjusting section (109) for adjusting an quantization error of the second stage or a third codebook so that a cluster circle of the third codebook indicating a set of all vectors represented by all vectors of the third codebook is consistent with the product set circle calculated by the product set circle calculating section (108).
摘要:
Disclosed is an adaptive sound source vector quantization device capable of improving quantization accuracy of adaptive sound source vector quantization while suppressing increase of the calculation amount in CELP sound encoding which performs encoding in sub-frame unit. In the device, a search adaptive sound source vector generation unit (103) cuts out an adaptive sound source vector of a frame length (n) from an adaptive sound source codebook (102), a search impulse response matrix generation unit (105) generates a search impulse response matrix of n n by using an impulse response matrix for each of sub-frames inputted from a synthesis filter (104), a search target vector generation unit (106) adds the target vector of each sub-frame so as to generate a search target vector of frame length (n), an evaluation scale calculation unit (107); calculates the evaluation scale of the adaptive sound source vector quantization by using the search adaptive sound source vector, the search impulse response matrix, and the search target vector.
摘要:
A signal decoding apparatus preventing substantial noise from being produced when transmission error occurs during decoding of scalable-coded information. In this signal decoding apparatus, a coded information operation section (601) performs error detection for base layer coded information, first enhancement layer coded information and second enhancement layer coded information using transmission error detection bits. A decoding operation control section (602) performs ON/OFF control of control switches (606, 607) in accordance with pattern information indicating error detection results and bit rate patterns, and controls the sampling frequencies of sampling frequency adjustment sections (608, 609). A base layer decoding section (603), first enhancement layer decoding section (604) and second enhancement layer decoding section (605) perform decoding of coded information or frame loss compensation processing, depending on error detection results and bit rates. Sampling frequency adjustment sections (608, 609) adjust the sampling frequency of the decoded signal.
摘要:
A coding device is provided with features in which optimum coding in a higher layer is flexibly carried out based on a coding result of a lower layer and a quality audio signal in limited circumstances is served to users. In this coding device, a basic layer coding unit codes an input signal to generate a basic layer information source code and outputs a linear prediction coefficient (LPC) and a quantum LPC, which are parameters calculated at coding, to an expanded layer control unit. A basic layer decoding unit decodes the basic layer information source code. An adding unit reverses a polarity of a basic layer decoded signal, adds the same to the input signal, and calculates a difference signal. The expanded layer control unit generates expanded layer mode information indicative of a coding mode in an expanded layer based on the LPC and the quantum LPC. An expanded layer coding unit codes the difference signal obtained from the adding unit under control of the expanded layer control unit.