Apparatus for,and method of,encoding a signal

摘要

There is provided an apparatus and method for encoding a code signal particularly into an audio signal. Previously as a result of data compression protocol codes hidden into "sync periods" have been degraded or lost as a result of, for example, low pass filtering. Sometimes, during quiet intervals codes were audible. The invention overcomes the problem of encoding a code into an audio signal by sampling the audio signal in order to determine its energy content and embedding the code into a suitable portion of the audio signal so that the code is hidden within a sufficiently energetic portion of audio signal. The advantage is that code is never audible.