ADAPTIVE AND PROGRESSIVE AUDIO STREAM SCRAMBLING

摘要

The invention relates to a method of distributing digital audio sequences according to a nominal stream format, said sequences consisting of a succession of frames each comprising at least one block containing numerous coefficients corresponding to simple digitally-encoded auditory elements. According to the invention, the method comprises a step involving the modification of at least one block of the original stream. The invention is characterised in that the aforementioned modification step acts in an adaptive manner in relation to the original stream according to at least one part of the characteristics representative of the structure, contents and parameters of the original audio stream and the profile of the recipient as well as external events. In one particular embodiment, the modification step consists in replacing part of the coefficients in order to produce (i) a main audio stream with the nominal format and (ii) complementary modification information which enables the original stream to be reconstructed by a decoder belonging to the destination equipment, the range of the modifications being variable and determined by the above-mentioned representative characteristics. The invention also relates to a system for implementing said method.