Abstract: A method and apparatus are provided for encapsulating a plurality of data substreams encoded in a bit stream, wherein the encoded data substream is obtained by entropy encoding of a symbol subsequence representing an image or a series of images. The method includes grouping data substreams into substream pairs according to an iterative traversal order predetermined from the plurality of substreams, and on the basis of a pair of the substreams, obtaining a symmetrical pair by reversing a data order making up the second substream of the pair. The obtained pairs are then concatenated within a sequence. The binary stream is created by encapsulating the sequence and information related to a number of substreams and related to the sizes of pairs of symmetrical substreams.

Abstract: Digital data blocks are encrypted, each data block that is to be encrypted being associated with a time reference. A value of an initialization vector Vi and an encryption key K are defined. Then, a counter C is obtained for each data block to be encoded, by combining the time reference and the value of the initialization vector. A series of binary encryption elements is obtained via an encryption function taking the encryption key K and counter C as input parameters. The data block is then encrypted by combining it with the series of binary encryption elements.

Abstract: A method and apparatus are provided for encapsulating a plurality of data substreams encoded in a bit stream, wherein the encoded data substream is obtained by entropy encoding of a symbol subsequence representing an image or a series of images. The method includes grouping data substreams into substream pairs according to an iterative traversal order predetermined from the plurality of substreams, and on the basis of a pair of the substreams, obtaining a symmetrical pair by reversing a data order making up the second substream of the pair. The obtained pairs are then concatenated within a sequence. The binary stream is created by encapsulating the sequence and information related to a number of substreams and related to the sizes of pairs of symmetrical substreams.

Abstract: A video stream is produced coded in a hierarchical manner in the form of a base stream and of an enhancement stream heightened along one dimension and transmitted via a packet transmission network according to a determined transmission protocol. At the level of a transmission entity, a first series is ordered according to a first order of coded packets, from an encoder. A series of packets is obtained, coded according to a second order by grouping said coded packets into groups of N packets, by traversing in the first order the coded packets of the first series, said N packets of one and the same group either all relating to the base stream or all relating to the enhancement stream. Thereafter, packets to be transmitted are composed, said packets comprising respectively as payload the groups of the series of coded packets.

Abstract: A method and apparatus are provided for the dynamic multiplexing of digital streams which are transmitted in the form of stream units in one channel, each of said stream units bearing a stream identifier which can be used to associate same with the corresponding digital stream. The allocation of an identifier to a digital stream is defined by an allocation table and can vary over time, in such a way as to enable dynamic multiplexing. The aforementioned allocation table bears a version number and, in order to indicate that a change in the version of the allocation table applies to a given digital stream, a burst is transmitted with at least one version change stream unit comprising the current identifier of said digital stream, an indicator which can be used to determine if the stream unit is a version change stream unit and the version number becoming applicable to said digital stream.

Abstract: Digital data blocks are encrypted, each data block that is to be encrypted being associated with a time reference. A value of an initialization vector VI and an encryption key K are defined. Then, a counter C is obtained for each data block to be encoded, by combining the time reference and the value of the initialization vector. A series of binary encryption elements is obtained via an encryption function taking the encryption key K and counter C as input parameters. The data block is then encrypted by combining it with the series of binary encryption elements.

Abstract: A method and apparatus are provided for the dynamic multiplexing of digital streams which are transmitted in the form of stream units in one channel, each of said stream units bearing a stream identifier which can be used to associate same with the corresponding digital stream. The allocation of an identifier to a digital stream is defined by an allocation table and can vary over time, in such a way as to enable dynamic multiplexing. The aforementioned allocation table bears a version number and, in order to indicate that a change in the version of the allocation table applies to a given digital stream, a burst is transmitted with at least one version change stream unit comprising the current identifier of said digital stream, an indicator which can be used to determine if the stream unit is a version change stream unit and the version number becoming applicable to said digital stream.

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.