| 摘要 |
PURPOSE: An apparatus for overlapping/adding window in an AC-3 decoder is to eliminate an aliasing phenomenon generated by an overlapping between adjacent windows, thereby exactly restoring an audio signal. CONSTITUTION: An apparatus for overlapping/adding window in an AC-3 decoder comprises an address generating/controlling portion(10) for generating an address to access a memory and a buffer and controlling an overlapping and adding operation of a window with respect to a time-base signal, a window memory for storing a data table to overlap the window, a down mix buffer(30) for storing a signal converted from frequency domain into time domain, a delaying buffer(40) for storing a former block data delayed to overlap the window, a sample calculating portion(50) for overlapping and adding a windowing value of the former block data and a windowing value of a present block data according to a control of the address generating/controlling portion to eliminate an aliasing phenomenon, and a PCM calculating portion(60) for rounding a level of a data output from the sample calculating portion to generate a pulse code modulation data. |
