摘要:
To provide an acoustic signal processing apparatus which can reduce the amount of calculation in matrix arithmetic. An acoustic signal processing apparatus converts down-mixed acoustic signals of NI channels to acoustic signals of NO channels, where NO>NI. The acoustic signal processing apparatus includes: a first matrix arithmetic unit for performing arithmetic on a matrix with K rows and NI columns, where NO>K≧NI, for the down-mixed acoustic signals of the NI channels, and outputting K signals obtained after the matrix arithmetic; K decorrelation units for generating signals incoherent, in terms of time characteristics, with the signals obtained after the matrix arithmetic, while maintaining frequency characteristics of the signals obtained after the matrix arithmetic; and a second matrix arithmetic unit for performing arithmetic on a matrix with NO rows and (NI+K) columns for the down-mixed acoustic signals of the NI channels and for the K incoherent signals, and outputting the acoustic signals of the NO channels.
摘要:
A combination device (305) according to the present invention includes: a detection unit (501) that detects active coded bitstreams that are effective coded bitstreams from a plurality of coded bitstreams (116) within a predetermined time period; a first combining unit (504) that combines, from a plurality of downmix sub-streams (115) included in the coded bitstreams (116), only downmix sub-streams (115) included in the active coded bitstreams so as to generate a combined downmix sub-stream (121); and a second combining unit (506) that combines, from a plurality of parameter sub-streams (113) included in the coded bitstreams (116), only parameter sub-streams (113) included In the active coded bitstreams so as to generate a combined parameter sub-stream (122).
摘要:
An encoder of the present invention includes: G storage sections for storing G groups of data; a selection section for selecting one of H Huffman codebooks having codebook numbers for each of the groups of data; G encoding sections Huffman-encoding the G groups of data by using the selected Huffman codebook; and an encoding section for encoding the codebook number of each Huffman codebook selected. The selection section includes a calculation section for calculating a code length and a control section for selecting one of the Huffman codebooks. When the Huffman codebook selected is an unsigned codebook, a number of bits required for sign information has previously been added to the calculated code length.
摘要:
With respect to audio signal coding and decoding apparatuses, there is provided a coding apparatus that enables a decoding apparatus to reproduce an audio signal even through it does not use all of data from the coding apparatus, and a decoding apparatus corresponding to the coding apparatus. A quantization unit constituting a coding apparatus includes a first sub-quantization unit comprising sub-quantization units for low-band, intermediate-band, and high-band; a second sub-quantization unit for quantizing quantization errors from the first sub-quantization unit; and a third sub-quantization unit for quantizing quantization errors which have been processed by the first sub-quantization unit and the second sub-quantization unit.
摘要:
A coding unit codes an audio signal by using a vector quantization method to reduce the quantity of data. An audio code having a minimum distance among auditive distances between sub-vectors produced by dividing an input vector and audio codes in a transmission-side code book is selected. A portion corresponding to an element of a sub-vector having a high auditive importance is handled in an audio code selecting unit while neglecting the codes indicating phase information and subjected to comparative retrieval with respect to audio codes in a transmission-side code book. Extracted phase information corresponding to an element portion of the sub-vector is added to the result obtained and output as a code index. Thereby, the calculation amount in the code retrieval of vector quantization and the number of codes in the code book are decreased without lowering the quality of an audio signal.
摘要:
An audio signal is converted from time domain into frequency conversion signal, and is coded at high speed. In order that the frequency information decoded by using the quantizing data may not be zero when the frequency conversion signal is quantized, the guarantee value K(B) of the quantizing precision is calculated. The relative quantizing precision SF(B) in each band and the quantizing precision information Com common to all bands are determined, and final quantizing precision information ASF(B) are calculated by these values, and the frequency conversion signal is quantized in the quantizing unit. Thus, it is possible to quantize by a single quantizing loop, only on the restricting condition of assuring the minimum quantizing information.
摘要:
The present invention is a signal processing device which performs parallel processes A and B efficiently. There is a deviation in the throughputs of the process A and B in processing an audio signal. First to Nth sub signal processing sections have capabilities to complete the process A within a period (N×T). A main signal processing sections has a capability to complete the process B within a period T. Efficient signal processing can be achieved by processing an input digital signal by means of distinct sub signal processing devices one after another and then processing the signal by the main signal processing section. (N×T).
摘要:
An encoding apparatus includes a quantized spectral sequence generation section for generating a quantized spectral sequence by quantizing an audio signal with a predetermined quantization precision, and a circulating code vector quantization section for outputting a spectral sequence code containing circulating position identification information indicating how much a reference spectral sequence is circulated to obtain a circulant quantized spectral sequence which is most similar to the quantized spectral sequence.
摘要:
An encoding apparatus includes a band gain encoding section for calculating an average amplitude of a frequency spectrum stream corresponding to each of a plurality of frequency bands so as to generate a first code representing the average amplitude of the frequency spectrum stream; an encoding band determination section for determining at least one frequency band, for which the corresponding frequency spectrum stream is to be quantized and encoded from among the plurality of frequency bands; a spectrum encoding section for quantizing and encoding the frequency spectrum stream of each of the at least one frequency band determined by the encoding band determination section so as to generate a second code; and an encoded stream generation section for generating an encoded stream based on the first code and the second code.
摘要:
An exponent part extraction section extracts a bit series from the exponent part of an inputted floating point data. A mantissa part extraction section extracts the uppermost K bits from the mantissa part of the floating point data. A first conversion section inputs the output e from the exponent part extraction section and outputs the value of a function X(e) thereof. A second conversion section inputs the output f from the mantissa part extraction section and outputs the value of a function Y(f) thereof. A multiplier section multiplies together these values. By setting suitable tables in advance in the first and the second conversion sections, the calculation of the v^p for an item v of floating point data can be performed.