Abstract: The present invention relates to a process for distributing audiovisual documents transmitted from a broadcasting office. The office broadcasts the documents to fixed distribution facilities. The users approach the facility and with the aid of a portable terminal request the downloading by radio of the documents that they have selected. Once downloaded, the users can connect the portable terminal to their home so as to reproduce the documents recorded in the terminal. The present invention also relates to the distribution facility and the portable terminal making it possible to store the document.

Abstract: The method of the present invention is directed to information compression which allows for compatible decoding of a group of television signals with increasing resolutions. According to the present invention, a first step, at the transmitter, involves strobing the space frequency band of the signal to be transmitted which has the highest resolution into adjacent subbands. Then, the signal with the highest resolution to be transmitted is independently coded in each subband. The subbands are then multiplexed by separating the coded signals in each subband by means of non-imitable synchronizing patterns. At the receiving decoder, the signals received relative to each subband are decoded only taking into consideration those which are necessary in order to reconstitute at least one member of a resolution group. The present invention finds particular application in the transmission system for high-definition TV images.