DOLBY INTERNATIONAL AB (20240257790). EFFICIENT COMBINED HARMONIC TRANSPOSITION

EFFICIENT COMBINED HARMONIC TRANSPOSITION

Organization Name

DOLBY INTERNATIONAL AB

Inventor(s)

Per Ekstrand of Saltsjobaden SE

Lars Villemoes of Järfälla SE

Per Hedelin of Göteborg SE

EFFICIENT COMBINED HARMONIC TRANSPOSITION

This abstract first appeared for US patent application 20240257790 titled 'EFFICIENT COMBINED HARMONIC TRANSPOSITION

Original Abstract Submitted

the present document relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (hfr), and to digital effect processors, e.g. so-called exciters, where generation of harmonic distortion adds brightness to the processed signal. in particular, a system configured to generate a high frequency component of a signal from a low frequency component of the signal is described. the system may comprise an analysis filter bank () configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank () has a frequency resolution of �f. the system further comprises a nonlinear processing unit () configured to determine a set of synthesis subband signals from the set of analysis subband signals using a transposition order p; wherein the set of synthesis subband signals comprises a portion of the set of analysis subband signals phase shifted by an amount derived from the transposition order p; and a synthesis filter bank () configured to generate the high frequency component of the signal from the set of synthesis subband signals; wherein the synthesis filter bank () has a frequency resolution of f�f; with f being a resolution factor, with f≥1; wherein the transposition order p is different from the resolution factor f.