Audio encoder and decoder for encoding and decoding frames of a sampled audio signal

摘要

An audio encoder (10) adapted for encoding frames of a sampled audio signal to obtain encoded frames, wherein a frame comprises a number of time domain audio samples. The audio encoder (10) comprises a predictive coding analysis stage (12) for determining information on coefficients of a synthesis filter and an excitation frame based on a frame of audio samples, the excitation frame comprising samples of an excitation signal for the synthesis filter. The audio encoder (10) further comprises a time-aliasing introducing transformer (14) for transforming overlapping excitation frames to the frequency domain to obtain excitation frame spectra, wherein the time-aliasing introducing transformer (14) is adapted for transforming the overlapping excitation frames in a critically-sampled way. Moreover, the audio encoder (10) comprises a redundancy reducing encoder (16) for encoding the excitation frame spectra to obtain the encoded frames based on the coefficients and the encoded excitation frame spectra.