Apparatus and method for generating audio subband values and apparatus and method for generating time-domain audio samples

摘要

An embodiment of an apparatus for generating audio subband values in audio subband channels has an analysis windower for windowing a frame of time-domain audio input samples being in a time sequence extending from an early sample to a later sample using an analysis window function having a sequence of window coefficients to obtain windowed samples. The analysis window function has a first group of window coefficients and a second group of window coefficients. The first group of window coefficients is used for windowing later time-domain samples and the second group of window coefficients is used for windowing an earlier time-domain samples. The apparatus further has a calculator for calculating the audio subband values using the windowed samples.

主权项

1. Apparatus for generating complex-valued audio subband values in audio subband channels, comprising:
an analysis windower for windowing a frame of time-domain audio input samples being in a time sequence extending from an early sample to a later sample using an analysis window function comprising a sequence of window coefficients to acquire windowed samples, the analysis window function comprising a first group of window coefficients comprising a first portion of the sequence of window coefficients and a second group of window coefficients comprising a second portion of the sequence of window coefficients, the first portion comprising less window coefficients than the second portion, wherein an overall energy value of the window coefficients in the first portion is higher than an overall energy value of the window coefficients of the second portion, wherein the first group of window coefficients is used for windowing later time-domain samples and the second group of window coefficients is used for windowing earlier time-domain samples; and a calculator for calculating the audio subband values using the windowed samples, wherein the calculator comprises a time/frequency converter adapted to generating the audio subband values such that all subband values based on one frame of windowed samples represent a spectral representation of the windowed samples of the frame of windowed samples, and wherein the time/frequency converter is adapted to generating complex-valued audio subband values.