METHOD FOR SIGNALLING NOISE SUBSTITUTION DURING AUDIO SIGNAL CODING

摘要

PROBLEM TO BE SOLVED: To signal a noise substitution during coding of an audio signal. SOLUTION: The time-domain audio signal is first transformed into the frequency domain to obtain spectral values. The spectral values are subsequently grouped together to form groups of spectral values. On the basis of a detection establishing whether a group of spectral values is a noisy group or not, a codebook is allocated to a non-noisy or tonal group by means of a codebook number for redundancy coding of the same. If a group is noisy, an additional codebook number which does not refer to a codebook is allocated to it in order to signal that this group is noisy and therefore does not have to be redundancy coded. An opportunity is provided to indicate the presence of a noise substitution in a scale factor band in the bit stream syntax of the MPEG-2 AAC Standard without having to interfere with the basic coding structure. COPYRIGHT: (C)2005,JPO&NCIPI