Multi-channel Audio Information Hiding
We consider a method of hiding many audio channels in one host signal. The purpose of this is to provide a ‘mix’ that incorporates information on all the channels used to produce it, thereby allowing all, or, at least some channels to be stored in the mix for later use (e.g. for re-mixing and/or archiving). After providing an overview of some recently published audio water marking schemes in the time and transform domains, we present a method that is based on using a four least significant bits scheme to embed five MP3 files into a single 16-bit host WAV file without incurring any perceptual audio distortions in either the host data or embedded files. The host WAV file is taken to be the final mix associated with the original multi-channel data before applying minimal MP3 compression (WAV to MP3 conversion), or, alternatively, an arbitrary host WAV file into which other multi-channel data in an MP3 format is hidden. The embedded information can be encrypted and/or the embedding locations randomized on a channelby-channel basis depending on the security protocol desired by the user. The method is illustrated by providing example m-code for interested readers to reproduce the results obtained to date and as a basis for further development.