Coding generic audio signals at low bitrates and low delay

摘要

A mixed time-domain/frequency-domain coding device and method for coding an input sound signal, wherein a time-domain excitation contribution is calculated in response to the input sound signal. A cut-off frequency for the time-domain excitation contribution is also calculated in response to the input sound signal, and a frequency extent of the time-domain excitation contribution is adjusted in relation to this cut-off frequency. Following calculation of a frequency-domain excitation contribution in response to the input sound signal, the adjusted time-domain excitation contribution and the frequency-domain excitation contribution are added to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal. In the calculation of the time-domain excitation contribution, the input sound signal may be processed in successive frames of the input sound signal and a number of sub-frames to be used in a current frame may be calculated.

主权项

1. A mixed time-domain/frequency-domain coding device for coding an input sound signal, comprising:
a calculator of a time-domain excitation contribution in response to the input sound signal; a calculator of a cut-off frequency for the time-domain excitation contribution in response to the input sound signal; a filter responsive to the cut-off frequency for adjusting a frequency extent of the time-domain excitation contribution; a calculator of a frequency-domain excitation contribution in response to the input sound signal; and an adder of the filtered time-domain excitation contribution and the frequency-domain excitation contribution to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal.