method for obtaining a frequency-shifted and envelope-adjusted signal, method for obtaining a frequency-shifted and envelope-adjusted signal, apparatus for obtaining a frequency-shifted and envelope-adjusted signal, apparatus for obtaining a frequency-envelope-folded signal set, decoder to decode encoded signals and method to decode encoded signals

摘要

"subband domain spectral conversion / splitting". The present invention relates to a novel method and apparatus for improving high frequency reconstruction (hfr) techniques using frequency conversion or unfolding or a combination thereof. The present invention can be applied to audio source coding systems, and allows a substantial reduction in their computational complexity. This is accomplished by frequency conversion or deployment in the subband domain, preferably together with a spectral envelope setting in the same domain. The concept of dissonance bandwidth filtering is additionally presented. The present invention provides a low complexity intermediate quality hfr method useful in natural audio and voice coding applications.