Acoustic signal processing system, acoustic signal decoding apparatus, processing method in the system and apparatus, and program

摘要

The amount of computation in an acoustic signal decoding apparatus for a signal transform process from a frequency domain to a time domain is reduced while realizing the generation of appropriate output acoustic signals.;An output control unit 340 receives, from a code string separating unit 310, pieces of window information including a window shape showing the type window function related to a windowing process of input channels, and, if all the pieces of window information are the same, switches the connections of output switching units 351 to 355 to a frequency domain mixing unit 510. The frequency domain mixing unit 510 mixes frequency domain signals of five channels supplied from a decoding/dequantizing unit 320 on the basis of downmix information that causes the number of output channels to be smaller than the number of input channels. IMDC/windowing processing units 521 and 522 transform frequency domain signals of two channels output from the frequency domain mixing unit 510 into time domain signals, thereby outputting the signals as acoustic signals of two channels.

主权项

1. An acoustic signal decoding apparatus comprising:
an output control unit configured to perform control to simultaneously output frequency domain signals having identical pieces of window information on the basis of the window information including a window shape showing the type of window function related to the frequency domain signals that are obtained by performing a windowing process on acoustic signals of a plurality of input channels; a frequency domain mixing unit configured to mix the frequency domain signals of the input channels having the identical pieces of window information on the basis of downmix information and output the signals as frequency domain signals corresponding to the number of output channels smaller than the number of the input channels; and an output sound generating unit configured to generate acoustic signals of the output channels by transforming the frequency domain signals of the output channels output from the frequency domain mixing unit into time domain signals and by performing the windowing process on the time domain signals obtained through the transforming.