Abstract: The video component(s) of a digital audio-visual first program are switched onto the video components of a second digital, audio-visual program by (1) switching onto the video component of the second program, subsequent to the switch command and to the end of a picture of the first program, and (2) replacing, as seen in the order of transmission, each non Intra picture of the component of a second program, with a picture having coding performed independently of (a) the picture data of the replaced picture and (b) of the contents of the pictures to which it refers until the beginning of the next Intra picture of the component of the second program.

Abstract: First digital audio-visual program video component(s) are switched on a second digital audio-visual program video component(s) by switching on the beginning of the first set of images including an Intra-coded picture of the second program video component encountered after the switching command. In the transmission order of images, each bidirectionally predictive-coded picture of the first set of images referring to the set of images pertaining to the set of images preceding it before switching, is substituted for a bidirectionally predictive-coded picture of the video coding which is produced independently of (1) the substituted image content and (2) the contents of the images to which it refers.

Abstract: A numerical or digital transmission system uses an adaptative coding, of log information, which is sampled and transformed by an orthogonal transformation. The coding has a rate of data flow or delivery, which is reduced by orthogonal transformation with an adaptative threshold. In each scanning field, the binary elements of the coefficients are obtained by a basic coding with a quantification pitch 2S, (S being a whole number either positive or null). A complementary coding is transmitted. The complementary coding is obtained by adding binary elements of weights 2S-1 for each one of the coefficients, until the transmission capacity of the channel is filled. The coefficients are taken in chronological order. The invention is applicable to digital television, but also the coding may be used for transmission of high fidelity sound.