1. A method of decoding coded digital signals representative of audiovisual data and available in the form of a continuous bitstream in view of the binary description of a scene to be rendered on a displaying device, said method comprising a processing operation based on an evolutive syntactic language and including the steps of: extracting, by a processing device, from said bitstream, distinct elements called objects according to the structure of said scene; defining, by the processing device, an individual animation of said elements of the scene; defining, by the processing device, particular interactions between a user and said elements; and organizing, by the processing device, specific relations between said scene elements and corresponding individual animations and/or user interactions according to various classes of applications, characterized in that said processing operation further comprises an additional step: describing, by the processing device, a complex scene, built directly from any kind of bidimensional and tridimensional objects, according to a framework integrating both bidimensional and tridimensional features and unifying the composition and representation mechanisms of the scene structure.