Audio coding device, audio coding method, and computer-readable recording medium storing audio coding computer program

摘要

An audio coding device includes a time frequency transform unit that, with respect to each of a plurality of channels included in an audio signal, generates a time frequency signal indicating frequency components at each time by performing a time frequency transform on a signal of the channel; a transient detection unit that detects a transient with respect to each of the plurality of channels so as to obtain a transient detection time; a transient time correction unit that, when a difference in transient detection times between an early detection channel in which the transient detection time is earliest and a late detection channel that is a channel other than the early detection channel among the plurality of channels is within a range in which the transient; a grid determination unit that, with respect to each of the plurality of channels, and a coding unit that codes.

主权项

1. An audio coding device comprising:
a time frequency transform unit that, with respect to each of a plurality of channels included in an audio signal, generates a time frequency signal indicating frequency components at each time by performing a time frequency transform on a signal of the channel; a transient detection unit that detects a transient with respect to each of the plurality of channels so as to obtain a transient detection time; a transient time correction unit that, when a difference in transient detection times between an early detection channel in which the transient detection time is earliest and a late detection channel that is a channel other than the early detection channel among the plurality of channels is within a range in which the transient being regarded as a transient caused by the same sound, makes a correction so that the transient detection time of the late detection channel coincides with the transient detection time of the early detection channel; a grid determination unit that, with respect to each of the plurality of channels, sets a grid for a non-transient sound in a section in which the transient has not been detected, and sets a grid for a transient sound having a length of time shorter than that of the grid for a non-transient sound in a section in which the transient has been detected; and a coding unit that codes the audio signal for each grid for a transient sound or for each grid for a non-transient sound.