Patent ID: 6826185
Filing Date: 2004-11-30
Classification: H04L,H04N

Abstract:
Equipment for remultiplexing encoded audio-video streams transmitted within a switched digital video broadcasting system, each containing multiple programs (multiprogram transport streams), in which program information is transmitted in packets each including a packet identifier supplying information as to the program identity the packet refers to and a payload containing program data or stream structure service information, the equipment being inclusive of:syntactical analysis and reception means (AS; FL1 . . . FLn, MS1 . . . MSn) suitable to receive a plurality of such streams, separate in each flow packets, hereinafter referred to as â€œdata packetsâ€ , which can be forwarded directly to output stream generation means (CF; AA, MC, TU), from packets hereinafter referred to as â€œservice packetsâ€ , which must be forwarded to a control device (MP) to be submitted to processing, in particular for updating service information to reflect the composition of output streams; means (ME) for temporary storage of data packets, separately for each input stream; said output stream generation means (CA; AA, MA, TU) to generate and send to serve users output streams obtained starting from the packets stored in said temporary memories (ME) and from the processed service packets, said output streams being single or multi-program streams at a lower band than input streams; said control device (MP) that is suitable to receive the service packets from syntactical analysis and reception means (AS; FL1 . . . FLn, MS1 . . . MSn), to identify individual streams making up the multiprogram streams, to perform updating of service information and drive temporary memory means (ME) and output stream generation means (CF; AA, MC, TU) so as to enable the creation of single or multi-program streams for different users, wherein: said output stream generation means (CA; AA, MA, TU) are suitable to create ATM streams by transferring packets related to the same program or group of programs to ATM cells related to one or more virtual channel and multiplexing said virtual channels into multiple itineraries each containing programs of the same input stream, such output stream generation means (CF; AA, MC, TU) being suitable to perform, during ATM stream generation, a two-step control of the band associated to each ATM stream by reading the packets allocated to different virtual channels in such a fashion as to limit the peak band of each virtual channel to a first programmable value not exceeding the band available on ATM stream transport lines and by performing statistical multiplexing of the virtual channels into virtual itineraries and such that the overall band transmitted to each virtual itinerary does not exceed the peak band available for the itinerary; and said temporary memory means (ME) are suitable to store data packets in individual logical queues for a program or group of programs managed by connected lists of pointers each identifying a memory area containing a packet replicated as many times as the number of virtual channels into which a packet is to be entered.