Verfahren zum Signalisieren einer Rauschsubstitution beim Codieren eines Audiosignals

摘要

The invention relates to a method for signalling a noise substitution during audio signal coding. According to said method, the audio signal is first transformed in the frequency range to obtain spectral values. The spectral values are subsequently grouped to form spectral value groups. On the basis of a detection whether a group of spectral values is a noise group or not, a coding table is allocated to a non-noise group or a tonal group by means of a coding table number for redundancy coding of the same. If a group is a noise group it is allocated an additional coding table number which does not refer to a coding table in order to signal that this group is a noise group and that it must not be redundancy coded. By signalling noise substitution by means of a Huffman-code table number for noise groups of spectral values which are for instance scale factor band sections and which must not be redundancy coded, an opportunity is provided for implementing availability of a noise substitution in a scale factor band in the bit flow syntax of the MPEG-2 Advanced Audio coding Standard, without intervening in the basic coding structure and without having to touch the structure of the existing bit flow syntax.