EP2932724A1 - Method for generating and transferring at least one data stream - Google Patents

Method for generating and transferring at least one data stream

Info

Publication number
EP2932724A1
EP2932724A1 EP13803000.2A EP13803000A EP2932724A1 EP 2932724 A1 EP2932724 A1 EP 2932724A1 EP 13803000 A EP13803000 A EP 13803000A EP 2932724 A1 EP2932724 A1 EP 2932724A1
Authority
EP
European Patent Office
Prior art keywords
packet
packets
stream
type
frame
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP13803000.2A
Other languages
German (de)
French (fr)
Inventor
Laurent Roul
Ludovic Poulain
Bernard Pichot
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Enensys Technologies SA
Original Assignee
Enensys Technologies SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Enensys Technologies SA filed Critical Enensys Technologies SA
Publication of EP2932724A1 publication Critical patent/EP2932724A1/en
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/61—Network physical structure; Signal processing
    • H04N21/6106—Network physical structure; Signal processing specially adapted to the downstream path of the transmission network
    • H04N21/6143—Network physical structure; Signal processing specially adapted to the downstream path of the transmission network involving transmission via a satellite
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
    • H04N21/647—Control signaling between network components and server or clients; Network processes for video distribution between server and clients, e.g. controlling the quality of the video stream, by dropping packets, protecting content from unauthorised alteration within the network, monitoring of network load, bridging between two different networks, e.g. between IP and wireless
    • H04N21/64784—Data processing by the network
    • H04N21/64792—Controlling the complexity of the content stream, e.g. by dropping packets
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
    • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
    • H04N21/643—Communication protocols
    • H04N21/64315—DVB-H

Definitions

  • the present invention relates to the field of broadcasting digital television programs and more particularly to a method for generating and transferring at least one data stream conforming to the DVB-T2 standard (Digital Video Broadcast in English).
  • DVB-S European Telecommunications Standards Institute
  • the programs consist of multiplexed audio and video streams to which signaling information in the form of signal tables known as SI / PSI tables (Service Information / Program Specify Information) is added.
  • SI / PSI tables Service Information / Program Specify Information
  • the resulting multiplexed stream is encapsulated in a transport layer conforming to MPEG-2 TS (Moving Picture Experts Group 2 Transport Stream) for broadcast.
  • MPEG-2 TS Motion Picture Experts Group 2 Transport Stream
  • the T2-MI stream comprises T2-MI data packets such as T2-MI timestamp synchronization packets, signaling packets including the current package named T2-MI Ll which gives information on the T2-MI flow structure and packets called baseband frames containing the MPEG-2 TS stream data of the different tunnels.
  • T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI L1 packet, and baseband frame packets.
  • the T2-MI streams are synchronized using the T2-MI timestamp packets so as to allow synchronous broadcasting within a Single Frequency Network (SFN) single frequency plate.
  • SFN Single Frequency Network
  • the T2-MI flows are conventionally transmitted to at least one satellite which in return broadcasts these flows in a given geographical area.
  • the streams broadcast by the at least one satellite are then received, modulated and retransmitted by terrestrial broadcasting stations.
  • the use of satellites in the transmission chain has an impact on the financial cost of transmission. Indeed, the cost price of a transmission via a satellite is a function of the bandwidth used for transmission. In addition, the bandwidth available within a satellite is limited, so it would be advisable to reduce the bandwidth required for the transmission of such T2-MI streams via a satellite.
  • the invention aims to solve the aforementioned problems by proposing a method of reducing the bit rate of a data stream conforming to the DVB-T2 standard transmitted via a satellite.
  • a method of transferring a data stream the data stream being frames, each frame containing a synchronization packet, a signaling packet providing information on the structure of the data stream and called packets.
  • baseband frames comprising data on audiovisual streams, characterized in that the method comprises the steps of:
  • the invention also relates to a device for transferring a data stream, the data stream consisting of frames, each frame containing a synchronization packet, a signaling packet giving information on the structure of the data stream and packets.
  • baseband frames comprising data on audiovisual streams, characterized in that the device comprises:
  • the bandwidth required for transmitting the data stream via a satellite is reduced while preserving the data necessary for synchronous broadcasting within a single-frequency SFN plate of the data stream.
  • the baseband frame packets belong to different tunnels and the packets of the first type are the packets of the same tunnel.
  • the data of the other tunnels may already be available on certain transmitters broadcasting a DVB-T2 radio signal, the bandwidth necessary for the transmission of the data stream through a satellite is greatly reduced.
  • a tunnel comprises data on audiovisual streams intended to be broadcast on a national scale and another tunnel comprises data on audiovisual streams intended to be broadcast on a local scale and the packets of the first type are packets belonging to the tunnel comprising data on audiovisual streams intended to be broadcast locally.
  • the method further comprises the steps of:
  • the method further comprises the steps of:
  • the modified data streams are fully compatible with the DVB-T2 standard.
  • the baseband frame packets are, according to their position in the frame, sequentially packets of the first type and packets of a second type, and the method furthermore comprises the steps of:
  • the invention also relates to a method for generating a stream from a first and a second stream of received data, said first and second streams being T2-MI type streams, the data streams consisting of frames, each frame containing a synchronization packet, a signaling packet giving information on the structure of the data stream and packets called band frames basic apparatus comprising data on audiovisual streams, characterized in that the method comprises the steps of:
  • the invention also relates to a device for generating a stream from two received data streams, the data streams consisting of frames, said first and second streams being T2-MI type streams, each frame containing a packet.
  • a signaling packet providing information on the structure of the data stream and packets called baseband frames comprising data on audiovisual streams, characterized in that the device comprises:
  • the bandwidth required to receive one of the data streams is reduced while preserving the data necessary for synchronous broadcasting within a single-frequency SFN plate of the data stream.
  • the insertion is performed by replacing in the data stream comprising the identifiers of packets of the first type, each packet identifying a packet of the first type by a baseband packet of the frame. the second stream whose synchronization packet is aligned with the synchronization packet of the frame of the first stream.
  • the insertion when generating a stream from two received data streams, one:
  • the frames of the first and second T2-MI streams have an identical duration.
  • the method further comprises the steps of:
  • the method further comprises the step of:
  • FIG. 1 illustrates the architecture of a DVB-T2 terrestrial broadcasting system according to the present invention
  • FIG. 2 shows a device for transferring a T2-MI stream according to a first embodiment of the present invention
  • FIG. 3 represents a device for reconstructing a DVB-T2 stream from at least one T2-MI stream according to the present invention
  • Figs. 4 show an example of a transfer algorithm of a DVB-T2 stream according to a first embodiment of the present invention
  • FIG. 5 represents an exemplary algorithm for reconstructing a DVB-T2 stream from at least one T2-MI stream according to the present invention
  • FIG. 6 shows an example of the structure of a T2-MI packet
  • Figs. 7a to 7h show different examples of T2-MI flows processed or generated according to the first embodiment of the present invention for reducing the rate of a T2-MI flow.
  • Fig. 1 illustrates the architecture of a DVB terrestrial broadcasting system.
  • a set of audio / video encoders 12a, 12b and 12c compresses the programs. These programs are then multiplexed by at least one multiplexer 11 which generates a Multiplex MPEG-2 MPTS (Multi-Program Transport Stream). At least one multiplex is then sent to at least one gateway T2 10a (T2 gateway in English) responsible for encapsulating at least multiplexed in at least one T2-MI stream.
  • T2 10a T2 gateway in English
  • the T2 gateway 10a reduces the bit rate of at least one T2-MI stream. At least one stream T2-MI whose bit rate is reduced is itself encapsulated in an MPTS stream. This mechanism is described in the document “Digital Video Broadcasting (DVB); Modulator Interface (T2-MI) for a second generation digital terrestrial television broadcasting system (DVB-T2) "referenced” DVB Document A136r2 ".
  • DVD Digital Video Broadcasting
  • T2-MI Modulator Interface
  • DVB-T2 digital terrestrial television broadcasting system
  • At least one T2-MI stream whose bit rate is reduced and encapsulated in at least one MPTS stream is for example sent to a plurality of transmitter modulators 16 for transmission on one or more regions and all the modulators 15 and transmitters of the same region or more precisely the same SFN plate transmits the modulated signal on the same frequency. It is therefore essential that the different modulators 15 of each transmitter 16 of the same region are finely synchronized so that SFN transmission by the different transmitters 16 goes smoothly.
  • the T2-MI stream has specific information and particularly particular synchronization information, typically the T2-MI packet called DVB-T2 timestamp, which implements a time stamp allowing this synchronization of DVB-T2 modulators. This synchronization is based on fact that timestamps, the DVB-T2 timestamp packets, are generated at a single point in the T2 gateway 10a upstream of the broadcast.
  • two T2 gateways 10a and 10 respectively transmit a T2-MI stream encapsulated in an MPTS stream.
  • each modulator 15 reconstructs a DVB-T2 stream from one or more T2-MI streams.
  • the T2 gateway 10a transmits at least one T2-MI stream whose bit rate is reduced via at least one link 13, or even 14.
  • the T2 gateway 10a transmits at least one T2-MI stream via the link 13, or even 14 and the T2 gateway 10b transmits at least one T2-MI stream via the link 17.
  • the link 13 is for example a satellite which receives the T2-MI stream whose bit rate is reduced and the retransmission to the modulators 15.
  • the links 14 and 17 are, for example, terrestrial links, such as wired links. Through the terrestrial link 14 or 17, another T2-MI flow whose rate is reduced according to the first embodiment or not according to the second embodiment can be transmitted to the modulator or modulators 15 if necessary.
  • FIG. 1 a single modulator 15 and a single transmitter 16 are shown for the sake of simplification.
  • Fig. 2 represents a device for transferring a T2-MI flow according to the first embodiment of the present invention.
  • the device for reducing the rate of a T2-MI flow is for example included in the T2 gateway 10a.
  • the device for reducing the throughput of a T2-MI stream may be a dedicated device.
  • the device for reducing the flow rate of a T2-MI flow 10a comprises a communication bus 201 to which a processor 200, a non-volatile memory 203, a random access memory 202, a communication or input interface 204 with the multiplexer are connected. 11 and a communication or output interface 205 with the modulator 15.
  • the non-volatile memory 203 stores the software modules implementing the invention, as well as the data for implementing the algorithm that will be described later with reference to FIGS. 4. More generally, the programs according to the present invention are stored in storage means. This storage means is readable by the microprocessor 200.
  • the software modules according to the present invention are transferred into the random access memory 202 which then contains the executable code of the invention as well as the data necessary for the implementation of the invention. .
  • the gateway T2 10a receives the original stream of one or more multiplexers 11.
  • the T2 gateway 10a transfers at least one stream whose bit rate is reduced to the modulator 15.
  • All or part of the steps of the algorithm described below with reference to FIGS. 4 can be implemented by software by executing the steps by a programmable device such as a microprocessor, a DSP (Digital Signal Processor), or a microcontroller or implemented in a component such as a Field Programmable Gate Array (FPGA) or a ASIC (Application-Specific Integrated Circuit).
  • a programmable device such as a microprocessor, a DSP (Digital Signal Processor), or a microcontroller or implemented in a component such as a Field Programmable Gate Array (FPGA) or a ASIC (Application-Specific Integrated Circuit).
  • FPGA Field Programmable Gate Array
  • ASIC Application-Specific Integrated Circuit
  • the T2 gateway 10a includes circuitry that allows the T2 gateway 10a to perform the steps of the algorithm of Figs. 4.
  • Fig. 3 represents a device for reconstructing a DVB-T2 stream from at least one T2-MI stream according to the present invention.
  • the device for reconstructing a DVB-T2 stream is for example included in the modulator 15.
  • the device for reconstructing a DVB-T2 stream may be a dedicated device.
  • the device for reconstructing a DVB-T2 stream 15 comprises a communication bus 301 to which a processor 300, a non-volatile memory 303, a random access memory 302, a signal receiving interface and an output interface 305 with a processor are connected.
  • transmitter 16 a communication bus 301 to which a processor 300, a non-volatile memory 303, a random access memory 302, a signal receiving interface and an output interface 305 with a processor are connected.
  • the non-volatile memory 303 stores the software modules implementing the invention, as well as the data enabling implementation of the algorithm which will be described hereinafter with reference to FIG. 5.
  • the programs according to the present invention are stored in storage means.
  • This storage means is readable by the microprocessor 300.
  • the software modules according to the present invention are transferred into the random access memory 302 which then contains the executable code of the invention as well as the data necessary for the implementation of the invention.
  • the modulator receives at least one T2-
  • the modulator 15 frequency transposes the reconstructed stream for an emission of the reconstructed stream and transposed into frequency by the transmitter 16.
  • All or part of the steps of the algorithm described below with reference to FIG. 5 may be implemented by software by executing the steps by a programmable device such as a microprocessor, a DSP (Digital Signal Processor), or a microcontroller or implemented in a component such as a Field Programmable Gate Array (FPGA) or ASIC (Application-Specific Integrated Circuit).
  • a programmable device such as a microprocessor, a DSP (Digital Signal Processor), or a microcontroller or implemented in a component such as a Field Programmable Gate Array (FPGA) or ASIC (Application-Specific Integrated Circuit).
  • FPGA Field Programmable Gate Array
  • ASIC Application-Specific Integrated Circuit
  • the modulator 15 includes circuitry which allows the modulator 15 to execute the steps of the algorithm of FIG. 5.
  • Fig. 4a shows an example of a transfer algorithm of a DVB-T2 stream according to the first embodiment of the present invention.
  • the present algorithm is executed by the processor 200 of the rate reduction device of a T2-MI stream.
  • step E40 the processor 200 receives from the multiplexer 11 at least one multiplex MPEG-2 MPTS format and generates at least one T2-MI stream.
  • a T2-MI stream includes T2-MI data packets such as T2-MI timestamp synchronization packets, signaling packets including the current L1 or L1PRE packet that provides information on the structure of the T2-MI stream and packets called Baseband Frames containing MPEG-2 TS stream data from one or more PLP tunnels.
  • the T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI L1 packet, and baseband frame packets.
  • the received T2-MI stream consists of packets of at least two different PLP tunnels as described with reference to FIG. 7a.
  • the received T2-MI stream consists of a first so-called main tunnel containing audiovisual programs to be broadcast at the national level and at least one second tunnel containing so-called regional audiovisual programs as described with reference. in FIG. 7a.
  • the received T2-MI stream consists of packets of a single PLP tunnel as described with reference to FIG. 7f.
  • the processor 200 identifies in the T2-MI stream generated packets said to be of a first type.
  • the so-called packets of the first type are, in the first example embodiment, the baseband frame packets of the first tunnel.
  • the so-called packets of the first type are, in the second exemplary embodiment, the baseband frame packets of the second tunnel containing so-called regional audio-visual programs.
  • the so-called packets of the first type are, in the third embodiment, the baseband frame packets that are counted by the processor 200 and identified as peers.
  • the baseband frame packets are, according to their position in the frame T2, sequentially packets of the first type and packets of a second type.
  • the processor 200 modifies the header of each T2-MI packet identified as a packet of the first type.
  • Fig. 6 shows an example of the structure of a T2-MI packet.
  • a T2-MI packet consists of a header 60, a payload field 61, a stuff field 62 and a redundancy field 63.
  • the header field 60 comprises a packet type identification sub-field 600, a packet counter sub-field 601, a sub-field 602 identifying the super-frame to which the packet belongs, a sub-field 603 reserved for future evolutions. and a subfield 604 which defines the length of the field 61 payload.
  • the 600 packet type sub-field is modified in step E42 by replacing the value of the field, conventionally 00 in hexadecimal with the value 40 in hexadecimal.
  • the value 40 is a value reserved for uses other than those conventionally defined by the DVB-T2 standard.
  • the processor 200 modifies the field 61 useful data by replacing all the useful data included in the field 61 by a information indicating that the packet is a packet of the first type, the information having a size smaller than the size of the payload replaced,
  • the information indicating that the packet is a packet of the first type is a single byte that identifies the first type of packet.
  • the processor 200 modifies the value of the redundancy field 63 as well as the value of the sub-field 604 by updating them so as to take into account the modifications previously made.
  • the processor 200 modifies in step E44 the contents of the current T2-MI packet L1.
  • a current T2-MI L1 packet includes information identifying the number of PLP tunnels included in the T2-MI stream.
  • the T2-MI stream originally consisting of two PLP tunnels has only one PLP tunnel.
  • the content of the current T2-MI L1 packet is then modified to take into account the modification.
  • the processor 200 copies for example, in the field
  • 61 useful data of the last packet of the first type the content of the payload field of the current T2-MI packet L1 and modifies, according to the example, the identifier included in the subfield 600 of the last packet of the first type, for example by setting the value 41 in hexadecimal.
  • the T2-MI flow thus consists of a smaller amount of data and is thus adapted to the bit rate of the link used for the transmission of said T2-MI flow.
  • the processor 200 forms two flows T2-MI and executes, parallel to the steps E42 to E44, the steps E46 to E49 of the algorithm of FIG. 4b.
  • step E46 the processor 200 identifies, in the generated T2-MI stream, so-called packets of a second type.
  • the so-called packets of the second type are, in the first exemplary embodiment, the baseband frame packets of the second tunnel.
  • the so-called packets of the second type are, in the third exemplary embodiment, the baseband frame packets that are counted by the processor 200 and identified as odd.
  • the processor 200 modifies the header of each T2-MI packet identified as a packet of the second type.
  • the 600 packet type sub-field is modified in step E47 by replacing the value of the field, conventionally 00 in hexadecimal with the value 40 in hexadecimal.
  • the value 40 is a value reserved for uses other than those conventionally defined by the DVB-T2 standard.
  • the processor 200 modifies the field 61 useful data by replacing all the useful data included in the field 61 by information indicating that the packet is a second type packet, the information having a smaller size to the size of the payload replaced,
  • the information indicating that the packet is a second type packet is a single octet identifying the second type of packet.
  • the processor 200 modifies the value of the redundancy field 63 as well as the value of the sub-field 604 by updating them so as to take into account the modifications previously made.
  • the processor 200 modifies in step E49 the contents of the current T2-MI packet L1.
  • a current T2-MI packet includes information identifying the number of PLP tunnels included in the T2-MI stream.
  • the T2-MI stream originally consists of two PLP tunnels and has only one PLP tunnel.
  • the contents of the current T2-MI package L1 are then modified to take into account the modification.
  • the processor 200 copies, for example in the field
  • 61 useful data of the last second type packet the contents of the payload field of the current T2-MI L1 packet and modifies the identifier included in the subfield 600 of the last packet of the first type, for example by setting the value 41 to hexadecimal.
  • Fig. 7a represents a T2-MI flow according to the first and second embodiments.
  • the received T2-MI stream consists of baseband frame packets of the first tunnel denoted PLPO and basic frame packets of the second tunnel denoted PLP1.
  • the T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI Ll packet, and baseband frame packets.
  • Fig. 7b shows a T2-MI flux formed according to the first and second embodiments of the present invention.
  • the PLPO baseband packets of the first tunnel are replaced by packets denoted Bo.
  • Fig. 7c represents a second T2-MI flux formed according to the first embodiment of the present invention.
  • the baseband packets PLP1 of the second tunnel are replaced by packets denoted Bo.
  • Fig. 7d represents a T2-MI flux formed according to the particular embodiment of the first embodiment of the present invention.
  • the PLPO baseband packets of the first tunnel are replaced by packets denoted Bo.
  • the value of the current L1PRE L1 packet is updated and is denoted LIPREm.
  • the useful data of the L1PRE packet of FIG. 7a are copied into the payload field 61 of the last packet of the first type denoted LIPREor.
  • the content of the payload field of the current T2-MI L1 packet LIPREm is updated according to the transmitted data parameters.
  • the identifier included in the subfield 600 of the last packet of the first type is modified by setting for example the value 41 in hexadecimal.
  • Fig. 7e represents a T2-MI flux formed according to the particular embodiment of the first and second embodiments of the present invention.
  • the baseband packets PLP1 of the second tunnel are replaced by packets denoted Bo.
  • the value of the current L1PRE L1 packet is updated and is denoted LIPREm.
  • the useful data of the L1PRE packet of FIG. 7a are copied into the payload field 61 of the last packet of the first type denoted LIPREor.
  • the content of the payload field of the current T2-MI L1 packet LIPREm is updated according to the transmitted data parameters.
  • the identifier included in the subfield 600 of the last packet of the second type is modified by setting for example the value 41 in hexadecimal.
  • Fig. 7f represents a T2-MI flow according to the third embodiment.
  • the received T2-MI stream consists of baseband frame packets of a single tunnel.
  • the T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI L1 packet, and baseband frame packets.
  • Fig. 7g represents a first T2-MI stream formed according to the third embodiment of the present invention.
  • Baseband packets identified as peer are replaced by packets denoted Bo.
  • Fig. 7h represents a second T2-MI flux formed according to the third embodiment of the present invention.
  • the baseband packets identified as odd are replaced by packets denoted Bo.
  • T2-MI flow is decomposed into two T2-MI flows.
  • a T2-MI stream according to the invention, can be decomposed into a larger number of T2-MI streams.
  • Fig. 5 represents an exemplary algorithm for reconstructing a DVB-T2 stream from at least one DVB-T2 stream according to the present invention.
  • the present algorithm is executed by the processor 300.
  • step E50 the processor 300 detects the reception of two T2-MI streams of which at least one T2-MI stream is formed by the T2 gateway 10a according to the present invention.
  • two T2-MI flows formed according to the algorithm of FIGS. 4a and 4b are received via links 13 and 14.
  • a T2-MI flow formed according to the algorithm of FIG. 4a is received via link 13 and a regional stream is received from a device not shown in FIG. 1.
  • the processor 300 performs, following step E50, the steps E51 to E53.
  • a first T2-MI stream is received by the link 13 and a second T2-MI stream is received by the link 17.
  • the frames of the first and second T2-MI streams have an identical duration.
  • the processor 300 reads the contents of the current T2-MI L1 packets of each of the first and second T2-MI streams.
  • the processor 300 moves from step E50 to step E51 and detects, in each frame T2, at least one T2-MI flow formed according to the algorithm of FIG. 4a or 4b, a LIPREor packet.
  • the processor 300 inserts in the field 61 of the LIPREm packet of the frame T2, the content of the field 61 of the LIPREor packet detected.
  • the processor 300 modifies the packet LIPREor replacing the content of the field 61 useful data of the last packet by stuffing data, modifies the identifier included in the subfield 600 of the last packet of the first type by setting example the value 00 in hexadecimal and updates field 62 and subfield 604.
  • the processor 300 goes from step E53 to step E54. According to the second embodiment, the processor 300 proceeds from step E50 to step E54.
  • step E54 the processor 300 aligns the two streams received in step E50. Alignment is performed by phasing the T2-MI timestamp packets of the T2 frames of each T2-MI stream.
  • the processor 300 aligns the two received streams by phasing the T2-MI timestamp packets of the T2 frames of each received T2-MI stream that have the same time stamping value or the nearest time stamping values that are closest .
  • the alignment is performed by phasing the current T2-MI packets T1 frames of each received T2-MI stream that have the same T2-MI counter value or T2-MI counter values which are the same. closer.
  • processor 300 can align the two received streams using other methods.
  • the processor 300 moves from step E54 to
  • step E55 the processor 300 identifies, in one of the T2-MI streams received from the gateway T2 10a, the first type packets by analyzing the useful data field 61 of the packets received.
  • the processor 300 proceeds from step E55 to step E56. According to the second embodiment, the processor 300 proceeds from step E54 to step E56.
  • step E56 the processor 300 inserts, in each frame T2 of a first received T2-MI stream, the baseband packets of the frame T2 of the second stream T2-MI whose package T2-MI is aligned with the T2-MI packet of the frame of the first T2-MI stream.
  • the processor 300 replaces, in the T2-MI stream comprising the first type packet identifiers, each packet of the first type by the packet of the second received T2-MI stream that is aligned with the identified first type packet. .
  • the step E54 is decomposed into two sub-steps.
  • the processor 300 replaces, in the stream T2-MI comprising the identifiers of packets of the first type, each packet of the first type identifying a packet of the first type by stuffing data whose size is equal to the size of the packets. other baseband packets included in the T2-MI stream.
  • the processor 300 replaces the padding data inserted in the previous substep by the packet of the second received T2-MI stream that is aligned with the identified first-type packet.
  • the processor 300 inserts, more precisely, adds, in each frame T2 of a first received T2-MI stream, the baseband packets of the frame T2 of the second stream T2-MI whose package T2- MI is aligned with the T2-MI packet of the frame of the first T2-MI stream following the baseband packets of the T2 frame of the first T2-MI stream.
  • the processor 300 modifies the content of the current T2-MI L1 packets of the first T2-MI stream so as to take into account the addition of the baseband packets of the frame T2 of the second stream T2-MI in the frames T2 of the first stream T2-MI.
  • the processor 300 updates the counters of each T2-MI packet of the T2-MI stream in which the baseband packets of the second T2-MI stream have been added.
  • the processor 300 can delete the packets associated with at least one of the tunnels.
  • the processor 300 can only add the packets associated with a part of the PLP physical layer tunnels of the second T2-MI stream.

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Abstract

The present invention concerns a method for generating a stream from first and second received data streams, the data streams consisting of frames, each frame containing a synchronisation packet, a signalling packet giving information on the structure of the data stream and packets called baseband frames. The method comprises the steps of: -aligning (E54) the two received data streams by bringing the synchronisation packets or the signalling packets of the frames of each data stream into phase, -identifying (E55), in one of the received data streams, baseband packets identifying packets of a first type, -inserting (E56), into each frame of the first received stream, baseband packets of the frame of the second stream of which the synchronisation packet is aligned with the synchronisation packet of the frame of the first stream.

Description

Procédé de génération et de transfert d'au moins un flux de données  Method for generating and transferring at least one data stream
La présente invention concerne le domaine de la diffusion de programmes de télévision numérique et plus particulièrement un procédé de génération et de transfert d'au moins un flux de données conforme à la norme DVB-T2 {Digital Video Broadcast en anglais). The present invention relates to the field of broadcasting digital television programs and more particularly to a method for generating and transferring at least one data stream conforming to the DVB-T2 standard (Digital Video Broadcast in English).
Historiquement, l'ETSI (European Télécommunications Standards Institute en anglais) a proposé une première norme, DVB-S, pour la diffusion de programmes par satellite. Cette norme a été déclinée dans les normes DVB-C pour la diffusion par réseau câblé et DVB-T pour la diffusion terrestre. Nous appellerons ces normes, normes DVB de première génération.  Historically, the European Telecommunications Standards Institute (ETSI) has proposed a first standard, DVB-S, for broadcasting satellite programs. This standard has been adopted in the DVB-C standards for cable and DVB-T broadcasting for terrestrial broadcasting. We will call these standards, first generation DVB standards.
Ces normes partagent un socle commun. Les programmes sont composés de flux audio et vidéo multiplexés auxquels sont ajoutées des informations de signalisation sous la forme de tables de signalisation connues sous le nom de tables SI/PSI (Service Information / Program Spécifie Information en anglais). Le flux multiplexé résultant est encapsulé dans une couche de transport conforme à la norme MPEG-2 TS (Moving Picture Experts Group 2 Transport Stream) pour la diffusion. Ces normes ont connu un succès certain et constituent une technologie de diffusion télévisuelle largement répandue. These standards share a common foundation. The programs consist of multiplexed audio and video streams to which signaling information in the form of signal tables known as SI / PSI tables (Service Information / Program Specify Information) is added. The resulting multiplexed stream is encapsulated in a transport layer conforming to MPEG-2 TS (Moving Picture Experts Group 2 Transport Stream) for broadcast. These standards success and a widespread TV broadcasting technology.
Aujourd'hui, une nouvelle génération de ces normes est développée. En particulier, la diffusion terrestre est normalisée sous la forme d'une norme DVB-T2. Cette nouvelle norme permet d'agréger au sein d'un même flux plusieurs tunnels couche physique appelés PLP (Physical Loyer Pipe en anglais). Chacun de ces tunnels couche physique est constitué d'un multiplexe de programmes dans un flux de transport de type MPEG-2 TS disposant de ses propres paramètres de modulation. Ces tunnels sont rassemblés au sein d'un flux appelé flux T2-MI (Modulator Interface). Le flux T2-MI est lui-même encapsulé dans une nouvelle couche de type MPTS (Multiple Program Transport Stream). Le flux T2-MI comprend des paquets de données T2-MI tels que des paquets de synchronisation T2-MI timestamp, des paquets de signalisation dont le paquet nommé T2-MI Ll courant qui donne des informations sur la structure du flux T2-MI et des paquets appelés trames bandes de base (Baseband Frame en anglais) contenant les données des flux MPEG-2 TS des différents tunnels. Les paquets T2-MI sont organisés en trames T2, chaque trame T2 contient un paquet T2-MI timestamp, un paquet T2-MI Ll courant et des paquets trames bandes de base.  Today, a new generation of these standards is being developed. In particular, terrestrial broadcasting is standardized in the form of a DVB-T2 standard. This new standard makes it possible to aggregate within the same stream several physical layer tunnels called PLP (Physical Loyer Pipe). Each of these physical layer tunnels consists of a multiplex of programs in an MPEG-2 TS transport stream having its own modulation parameters. These tunnels are gathered in a stream called T2-MI stream (Modulator Interface). The T2-MI stream is itself encapsulated in a new MPTS (Multiple Program Transport Stream) type layer. The T2-MI stream comprises T2-MI data packets such as T2-MI timestamp synchronization packets, signaling packets including the current package named T2-MI Ll which gives information on the T2-MI flow structure and packets called baseband frames containing the MPEG-2 TS stream data of the different tunnels. The T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI L1 packet, and baseband frame packets.
Les flux T2-MI sont synchronisés à l'aide des paquets T2-MI timestamp de façon à permettre une diffusion synchrone au sein d'une plaque mono fréquence SFN {Single Frequency Network en anglais). Ces plaques sont constituées d'une pluralité d'émetteurs diffusant le même signal radio DVB-T2 sur la même fréquence. Ce mode de diffusion n'est possible que si les émetteurs sont synchronisés et que les signaux radio DVB-T2 émis sont identiques au bit près, sous peine de générer des interférences dans les zones couvertes par les émissions d'au moins deux émetteurs.  The T2-MI streams are synchronized using the T2-MI timestamp packets so as to allow synchronous broadcasting within a Single Frequency Network (SFN) single frequency plate. These plates consist of a plurality of transmitters broadcasting the same DVB-T2 radio signal on the same frequency. This broadcasting mode is only possible if the transmitters are synchronized and the DVB-T2 radio signals transmitted are identical to the nearest bit, as this may cause interference in the areas covered by the emissions of at least two transmitters.
Les flux T2-MI sont classiquement transmis à au moins un satellite qui en retour diffuse ces flux dans une zone géographique donnée. Les flux diffusés par le au moins un satellite sont ensuite reçus, modulés et retransmis par des stations de diffusion terrestre.  The T2-MI flows are conventionally transmitted to at least one satellite which in return broadcasts these flows in a given geographical area. The streams broadcast by the at least one satellite are then received, modulated and retransmitted by terrestrial broadcasting stations.
L'utilisation de satellites dans la chaîne de transmission a un impact sur le coût financier de la transmission. En effet, le prix de revient d'une transmission par l'intermédiaire d'un satellite est fonction de la bande passante utilisée pour la transmission. De plus, la bande passante disponible au sein d'un satellite est limitée, il serait donc judicieux de réduire la bande passante nécessaire à la transmission de tels flux T2-MI par l'intermédiaire d'un satellite. The use of satellites in the transmission chain has an impact on the financial cost of transmission. Indeed, the cost price of a transmission via a satellite is a function of the bandwidth used for transmission. In addition, the bandwidth available within a satellite is limited, so it would be advisable to reduce the bandwidth required for the transmission of such T2-MI streams via a satellite.
L'invention vise à résoudre les problèmes susmentionnés en proposant un procédé de réduction du débit d'un flux de données conforme à la norme DVB-T2 transmis par l'intermédiaire d'un satellite.  The invention aims to solve the aforementioned problems by proposing a method of reducing the bit rate of a data stream conforming to the DVB-T2 standard transmitted via a satellite.
L'invention concerne un procédé de transfert d'un flux de données, le flux de données étant constitué de trames, chaque trame contenant un paquet de synchronisation, un paquet de signalisation donnant des informations sur la structure du flux de données et des paquets appelés trames bandes de base comprenant des données sur des flux audiovisuels, caractérisé en ce que le procédé comporte les étapes de :  A method of transferring a data stream, the data stream being frames, each frame containing a synchronization packet, a signaling packet providing information on the structure of the data stream and called packets. baseband frames comprising data on audiovisual streams, characterized in that the method comprises the steps of:
- identification parmi les paquets trames bandes de base de paquets d'un premier type,  - identification among packets frames baseband packets of a first type,
- modification de l'entête de chaque paquet trames bandes de base identifié comme paquet du premier type,  - modification of the header of each packet baseband frames identified as a packet of the first type,
- remplacement des données utiles comprises dans un champ données utile de chaque paquet identifié par une information indiquant que le paquet est un paquet du premier type, l'information indiquant que le paquet est un paquet du premier type ayant une taille inférieure à la taille des données utiles remplacées,  replacing the useful data included in a useful data field of each packet identified by information indicating that the packet is a packet of the first type, the information indicating that the packet is a packet of the first type having a size less than the size of the replaced useful data,
- transfert du flux de données modifié.  - transfer of the modified data stream.
L'invention concerne aussi un dispositif de transfert d'un flux de données, le flux de données étant constitué de trames, chaque trame contenant un paquet de synchronisation, un paquet de signalisation donnant des informations sur la structure du flux de données et des paquets appelés trames bandes de base comprenant des données sur des flux audiovisuels, caractérisé en ce que le dispositif comporte :  The invention also relates to a device for transferring a data stream, the data stream consisting of frames, each frame containing a synchronization packet, a signaling packet giving information on the structure of the data stream and packets. called baseband frames comprising data on audiovisual streams, characterized in that the device comprises:
- des moyens d'identification parmi les paquets trames bandes de base de paquets d'un premier type,  means for identifying among packets frames base bands of packets of a first type,
- des moyens de modification de l'entête de chaque paquet trames bandes de base identifié comme paquet du premier type,  means for modifying the header of each baseband frame packet identified as a packet of the first type,
- des moyens de remplacement des données utiles comprises dans un champ données utile de chaque paquet identifié par une information indiquant que le paquet est un paquet du premier type, l'information indiquant que le paquet est un paquet du premier type ayant une taille inférieure à la taille des données utiles remplacées, - des moyens de transfert du flux de données modifié. means for replacing the useful data included in a useful data field of each packet identified by information indicating that the packet is a packet of the first type, the information indicating that the packet is a packet of the first type having a size less than the size of the payload replaced, means for transferring the modified data stream.
Ainsi, la bande passante nécessaire à la transmission du flux de données par l'intermédiaire d'un satellite est réduite tout en préservant les données nécessaires à la diffusion synchrone au sein d'une plaque mono fréquence SFN du flux de données.  Thus, the bandwidth required for transmitting the data stream via a satellite is reduced while preserving the data necessary for synchronous broadcasting within a single-frequency SFN plate of the data stream.
Selon un mode particulier de réalisation de l'invention, les paquets trames bandes de base appartiennent à différents tunnels et les paquets du premier type sont les paquets d'un même tunnel.  According to a particular embodiment of the invention, the baseband frame packets belong to different tunnels and the packets of the first type are the packets of the same tunnel.
Ainsi, en ne transmettant que des données d'un seul tunnel, les données des autres tunnels pouvant être déjà disponibles sur certains émetteurs diffusant un signal radio DVB-T2, la bande passante nécessaire à la transmission du flux de données par l'intermédiaire d'un satellite est grandement réduite.  Thus, by transmitting only data from a single tunnel, the data of the other tunnels may already be available on certain transmitters broadcasting a DVB-T2 radio signal, the bandwidth necessary for the transmission of the data stream through a satellite is greatly reduced.
Selon un mode particulier de réalisation de l'invention, un tunnel comprend des données sur des flux audiovisuels destinés à être diffusés à une échelle nationale et un autre tunnel comprend des données sur des flux audiovisuels destinés à être diffusés à une échelle locale et les paquets de premier type sont des paquets appartenant au tunnel comprenant des données sur des flux audiovisuels destinés à être diffusés à l'échelle locale.  According to a particular embodiment of the invention, a tunnel comprises data on audiovisual streams intended to be broadcast on a national scale and another tunnel comprises data on audiovisual streams intended to be broadcast on a local scale and the packets of the first type are packets belonging to the tunnel comprising data on audiovisual streams intended to be broadcast locally.
Ainsi, en ne transmettant que des données du tunnel comprenant des données sur des flux audiovisuels destinés à être diffusés à une échelle nationale, la bande passante nécessaire à la transmission du flux de données est grandement réduite.  Thus, by transmitting only data from the tunnel comprising data on audiovisual streams intended to be broadcast on a national scale, the bandwidth necessary for the transmission of the data stream is greatly reduced.
Selon un mode particulier de réalisation de l'invention, le procédé comporte en outre les étapes de :  According to a particular embodiment of the invention, the method further comprises the steps of:
- identification, parmi les paquets trames bandes de base, de paquets d'un second type, les paquets du second type appartenant à un tunnel différent du tunnel auquel les paquets du premier type appartiennent,  identification, among the baseband frame packets, of packets of a second type, the packets of the second type belonging to a tunnel different from the tunnel to which the packets of the first type belong,
- modification de l'entête de chaque paquet trames bandes de base identifié comme paquet de second type,  - modification of the header of each packet baseband frames identified as a second type packet,
- remplacement des données utiles comprises dans un champ données utile de chaque paquet de second type identifié par une information indiquant que le paquet est un paquet de second type, l'information indiquant que le paquet est un paquet du second type ayant une taille inférieure à la taille des données utiles remplacées,  replacing the useful data included in a useful data field of each packet of the second type identified by information indicating that the packet is a second type packet, the information indicating that the packet is a packet of the second type having a size less than the size of the payload replaced,
- transfert d'un autre flux de données modifié.  - transfer of another modified data stream.
Ainsi, il est possible de transmettre l'autre flux de données modifié par l'intermédiaire d'une autre liaison dont le coût d'utilisation est moindre. Selon un mode particulier de réalisation de l'invention, le procédé comporte en outre les étapes de : Thus, it is possible to transmit the other modified data stream via another link whose cost of use is lower. According to a particular embodiment of the invention, the method further comprises the steps of:
- insertion, pour chaque trame du tunnel auquel les paquets du premier type appartiennent, des données comprises dans le paquet de signalisation de la trame du tunnel dans le champ de données utiles d'un paquet de premier type de la trame du tunnel,  inserting, for each frame of the tunnel to which the packets of the first type belong, data included in the signaling packet of the tunnel frame in the payload field of a first type packet of the tunnel frame,
- insertion, pour chaque trame du tunnel auquel les paquets du second type appartiennent, des données comprises dans le paquet de signalisation de la trame du tunnel dans le champ de données utiles d'un paquet de second type de la trame du tunnel,  inserting, for each frame of the tunnel to which the packets of the second type belong, data included in the signaling packet of the tunnel frame in the payload field of a second type packet of the tunnel frame,
- modification des paquets de signalisation de chaque trame du tunnel auquel les paquets du premier type appartiennent et des paquets de signalisation de chaque trame du tunnel auquel les paquets de second type appartiennent.  modification of the signaling packets of each tunnel frame to which packets of the first type belong and signaling packets of each frame of the tunnel to which packets of the second type belong.
Ainsi, les flux de données modifiés sont totalement compatibles avec la norme DVB-T2.  Thus, the modified data streams are fully compatible with the DVB-T2 standard.
Selon un mode particulier de réalisation de l'invention, les paquets trames bandes de bases sont, selon leur position dans la trame, séquentiellement paquets du premier type et paquets d'un second type et le procédé comporte en outre les étapes de :  According to a particular embodiment of the invention, the baseband frame packets are, according to their position in the frame, sequentially packets of the first type and packets of a second type, and the method furthermore comprises the steps of:
- modification de l'entête de chaque paquet trames bandes de base identifié comme paquet de second type,  - modification of the header of each packet baseband frames identified as a second type packet,
- remplacement des données utiles comprises dans un champ données utile de chaque paquet de second type identifié par une information indiquant que le paquet est un paquet de second type, l'information indiquant que le paquet est un paquet du second type ayant une taille inférieure à la taille des données utiles remplacées,  replacing the useful data included in a useful data field of each packet of the second type identified by information indicating that the packet is a second type packet, the information indicating that the packet is a packet of the second type having a size less than the size of the payload replaced,
- transfert d'un autre flux de données modifié.  - transfer of another modified data stream.
Ainsi, il est possible de répartir une partie du flux de données entre plusieurs liaisons. Il est possible de transmettre l'autre flux de données modifié par l'intermédiaire d'une autre liaison dont le coût d'utilisation est moindre.  Thus, it is possible to distribute a part of the data stream between several links. It is possible to transmit the other modified data stream via another link whose cost of use is lower.
L'invention concerne également un procédé de génération d'un flux à partir d'un premier et d'un second flux de données reçus, lesdits premier et second flux étant des flux de type T2-MI, les flux de données étant constitués de trames, chaque trame contenant un paquet de synchronisation, un paquet de signalisation donnant des informations sur la structure du flux de données et des paquets appelés trames bandes de base comprenant des données sur des flux audiovisuels, caractérisé en ce que le procédé comporte les étapes de : The invention also relates to a method for generating a stream from a first and a second stream of received data, said first and second streams being T2-MI type streams, the data streams consisting of frames, each frame containing a synchronization packet, a signaling packet giving information on the structure of the data stream and packets called band frames basic apparatus comprising data on audiovisual streams, characterized in that the method comprises the steps of:
- alignement (E54) des deux flux de données reçus en mettant en phase les paquets de synchronisation ou les paquets de signalisation des trames de chaque flux de données,  aligning (E54) the two data streams received by phasing the synchronization packets or signaling packets of the frames of each data stream,
- ajout (E56), dans chaque trame du premier flux reçu, des paquets bandes de base de la trame du second flux dont le paquet de synchronisation est aligné avec le paquet de synchronisation de la trame du premier flux à la suite des paquets bande de base de la trame du premier flux reçu.  adding (E56), in each frame of the first received stream, baseband packets of the frame of the second stream whose synchronization packet is aligned with the frame synchronization packet of the first stream following the packet packets of base of the frame of the first received stream.
L'invention concerne aussi un dispositif de génération d'un flux à partir de deux flux de données reçus, les flux de données étant constitués de trames, lesdits premier et second flux étant des flux de type T2-MI, chaque trame contenant un paquet de synchronisation, un paquet de signalisation donnant des informations sur la structure du flux de données et des paquets appelés trames bandes de base comprenant des données sur des flux audiovisuels, caractérisé en ce que le dispositif comporte :  The invention also relates to a device for generating a stream from two received data streams, the data streams consisting of frames, said first and second streams being T2-MI type streams, each frame containing a packet. synchronization method, a signaling packet providing information on the structure of the data stream and packets called baseband frames comprising data on audiovisual streams, characterized in that the device comprises:
- des moyens d'alignement des deux flux de données reçus en mettant en phase les paquets de synchronisation ou les paquets de signalisation des trames de chaque flux de données reçu qui ont la même valeur de marquage temporel,  means for aligning the two data streams received by phasing the synchronization packets or the signaling packets of the frames of each received data stream which have the same time stamping value,
- des moyens d'alignement des deux flux de données reçus en mettant en phase les paquets de synchronisation ou les paquets de signalisation des trames de chaque flux de données,  means for aligning the two data streams received by phasing the synchronization packets or the signaling packets of the frames of each data stream,
- des moyens d'ajout, dans chaque trame du premier flux reçu, des paquets bandes de base de la trame du second flux dont le paquet de synchronisation est aligné avec le paquet de synchronisation de la trame du premier flux à la suite des paquets bandes de base de la trame du premier flux reçu.  means for adding, in each frame of the first received stream, baseband packets of the frame of the second stream whose synchronization packet is aligned with the packet of synchronization of the frame of the first stream following the packets bands base of the frame of the first stream received.
Ainsi, la bande passante nécessaire à la réception d'un des flux de données est réduite tout en préservant les données nécessaires à la diffusion synchrone au sein d'une plaque mono fréquence SFN du flux de données.  Thus, the bandwidth required to receive one of the data streams is reduced while preserving the data necessary for synchronous broadcasting within a single-frequency SFN plate of the data stream.
Selon un mode particulier de réalisation de l'invention, l'insertion est effectuée en remplaçant dans le flux de données comprenant les identifiants de paquets de premier type, de chaque paquet identifiant un paquet de premier type par un paquet bande de base de la trame du second flux dont le paquet de synchronisation est aligné avec le paquet de synchronisation de la trame du premier flux. Selon un mode particulier de réalisation de l'invention, lors de la génération d'un flux à partir de deux flux de données reçus, on : According to a particular embodiment of the invention, the insertion is performed by replacing in the data stream comprising the identifiers of packets of the first type, each packet identifying a packet of the first type by a baseband packet of the frame. the second stream whose synchronization packet is aligned with the synchronization packet of the frame of the first stream. According to one particular embodiment of the invention, when generating a stream from two received data streams, one:
- détecte, dans chaque trame d'un des flux, un paquet ayant un identifiant prédéterminé,  detects, in each frame of one of the streams, a packet having a predetermined identifier,
- insère dans un champ de données du paquet de signalisation de la trame, de données comprises dans un champ de données du paquet ayant l'identifiant prédéterminé,  inserts into a data field of the signaling packet of the frame, data included in a data field of the packet having the predetermined identifier,
- insère dans un champ de données du paquet ayant l'identifiant prédéterminé des données de bourrage,  inserts padding data into a data field of the packet having the predetermined identifier,
- mo difie Γ identifiant prédéterminé .  - modifies Γ predetermined identifier.
Selon un mode particulier de réalisation de l'invention, les trames du premier et du second flux T2-MI ont une durée identique.  According to a particular embodiment of the invention, the frames of the first and second T2-MI streams have an identical duration.
Selon un mode particulier de réalisation de l'invention, le procédé comporte en outre les étapes de :  According to a particular embodiment of the invention, the method further comprises the steps of:
- lecture du contenu des paquets T2-MI Ll courant de chacun des premier et second flux T2-MI,  reading the content of the current T2-MI L1 packets of each of the first and second T2-MI streams,
- modification, à partir du contenu des paquets T2-MI Ll courant de chacun des premier et second flux T2-MI lus, du contenu des paquets T2-MI Ll courant du premier flux T2-MI de manière à prendre en compte l'ajout des paquets bandes de base de la trame T2 du second flux T2-MI dans les trames T2 du premier flux T2-MI.  modifying, from the content of the current T2-MI packets T1 of each of the first and second T2-MI streams read, the content of the current T2-MI packets T1 of the first stream T2-MI so as to take account of the addition baseband packets of the T2 frame of the second T2-MI stream in the T2 frames of the first T2-MI stream.
Selon un mode particulier de réalisation de l'invention, le procédé comporte en outre l'étape de :  According to a particular embodiment of the invention, the method further comprises the step of:
- mise à jour des compteurs de chaque paquet T2-MI du flux T2-MI dans lequel les paquets bandes de base du second flux T2-MI ont été ajoutés.  updating the counters of each T2-MI packet of the T2-MI stream in which the baseband packets of the second T2-MI stream have been added.
Les caractéristiques de l'invention mentionnées ci-dessus, ainsi que d'autres, apparaîtront plus clairement à la lecture de la description suivante d'un exemple de réalisation, ladite description étant faite en relation avec les dessins joints, parmi lesquels :  The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being given in relation to the attached drawings, among which:
la Fig. 1 illustre l'architecture d'un système de diffusion terrestre DVB-T2 selon la présente invention;  FIG. 1 illustrates the architecture of a DVB-T2 terrestrial broadcasting system according to the present invention;
la Fig. 2 représente un dispositif de transfert d'un flux T2-MI selon un premier mode de réalisation de la présente invention ;  FIG. 2 shows a device for transferring a T2-MI stream according to a first embodiment of the present invention;
la Fig. 3 représente un dispositif de reconstruction d'un flux DVB-T2 à partir d'au moins un flux T2-MI selon la présente invention ; les Figs. 4 représentent un exemple d'algorithme transfert d'un flux DVB-T2 selon un premier mode de réalisation de la présente invention ; FIG. 3 represents a device for reconstructing a DVB-T2 stream from at least one T2-MI stream according to the present invention; Figs. 4 show an example of a transfer algorithm of a DVB-T2 stream according to a first embodiment of the present invention;
la Fig. 5 représente un exemple d'algorithme de reconstruction d'un flux DVB- T2 à partir d'au moins un flux T2-MI selon la présente invention ;  FIG. 5 represents an exemplary algorithm for reconstructing a DVB-T2 stream from at least one T2-MI stream according to the present invention;
la Fig. 6 représente un exemple de la structure d'un paquet T2-MI ;  FIG. 6 shows an example of the structure of a T2-MI packet;
les Figs. 7a à 7h représentent différents exemples de flux T2-MI traités ou générés par selon le premier mode de réalisation de la présente invention pour réduire le débit d'un flux T2-MI . La Fig. 1 illustre l'architecture d'un système de diffusion terrestre DVB- Figs. 7a to 7h show different examples of T2-MI flows processed or generated according to the first embodiment of the present invention for reducing the rate of a T2-MI flow. Fig. 1 illustrates the architecture of a DVB terrestrial broadcasting system.
T2 selon la présente invention. T2 according to the present invention.
En amont, un ensemble d'encodeurs audio/vidéo 12a, 12b et 12c réalise la compression des programmes. Ces programmes sont alors multiplexés par au moins un multiplexeur 11 qui génère un multiplexe au format MPTS (Multi-Program Transport Stream en anglais) MPEG-2. Au moins un multiplexe est alors envoyé à au moins une passerelle T2 10a (T2 gateway en anglais) chargée d'encapsuler au moins multiplexe dans au moins un flux T2-MI.  Upstream, a set of audio / video encoders 12a, 12b and 12c compresses the programs. These programs are then multiplexed by at least one multiplexer 11 which generates a Multiplex MPEG-2 MPTS (Multi-Program Transport Stream). At least one multiplex is then sent to at least one gateway T2 10a (T2 gateway in English) responsible for encapsulating at least multiplexed in at least one T2-MI stream.
Selon un premier mode de réalisation, la passerelle T2 10a réduit le débit d'au moins un flux T2-MI. Au moins un flux T2-MI dont le débit est réduit est lui-même encapsulé dans un flux MPTS. Ce mécanisme est décrit dans le document « Digital Video Broadcasting (DVB); Modulator Interface (T2-MI) for a second génération digital terrestrial télévision broadcasting System (DVB-T2) » référencé « DVB Document A136r2 ».  According to a first embodiment, the T2 gateway 10a reduces the bit rate of at least one T2-MI stream. At least one stream T2-MI whose bit rate is reduced is itself encapsulated in an MPTS stream. This mechanism is described in the document "Digital Video Broadcasting (DVB); Modulator Interface (T2-MI) for a second generation digital terrestrial television broadcasting system (DVB-T2) "referenced" DVB Document A136r2 ".
Au moins un flux T2-MI dont le débit est réduit et encapsulé dans au moins un flux MPTS est par exemple émis à destination de plusieurs modulateurs 15 d'émetteurs 16 pour une émission sur une ou plusieurs régions et l'ensemble des modulateurs 15 et des émetteurs d'une même région ou plus précisément de la même plaque SFN transmet le signal modulé sur une même fréquence. Il est donc primordial que les différents modulateurs 15 de chaque émetteur 16 d'une même région soient finement synchronisés pour que l'émission SFN par les différents émetteurs 16 se passe sans problème. À cette fin, le flux T2-MI dispose d'informations spécifiques et particulièrement d'informations de synchronisation particulière, typiquement le paquet T2-MI appelé DVB-T2 timestamp, qui implémente un marquage temporel permettant cette synchronisation des modulateurs DVB-T2. Cette synchronisation repose sur le fait que des étiquettes temporelles, les paquets DVB-T2 timestamp, sont générés en un point unique dans la passerelle T2 10a en amont de la diffusion. At least one T2-MI stream whose bit rate is reduced and encapsulated in at least one MPTS stream is for example sent to a plurality of transmitter modulators 16 for transmission on one or more regions and all the modulators 15 and transmitters of the same region or more precisely the same SFN plate transmits the modulated signal on the same frequency. It is therefore essential that the different modulators 15 of each transmitter 16 of the same region are finely synchronized so that SFN transmission by the different transmitters 16 goes smoothly. For this purpose, the T2-MI stream has specific information and particularly particular synchronization information, typically the T2-MI packet called DVB-T2 timestamp, which implements a time stamp allowing this synchronization of DVB-T2 modulators. This synchronization is based on fact that timestamps, the DVB-T2 timestamp packets, are generated at a single point in the T2 gateway 10a upstream of the broadcast.
Selon un second de réalisation, deux passerelles T2 10a et 10 transmettent respectivement un flux T2-MI encapsulé dans un flux MPTS.  According to a second embodiment, two T2 gateways 10a and 10 respectively transmit a T2-MI stream encapsulated in an MPTS stream.
Selon la présente invention, chaque modulateur 15 reconstruit un flux DVB-T2 à partir d'un ou plusieurs flux T2-MI.  According to the present invention, each modulator 15 reconstructs a DVB-T2 stream from one or more T2-MI streams.
Selon le premier mode de réalisation, la passerelle T2 10a émet au moins un flux T2-MI dont le débit est réduit par l'intermédiaire d'au moins une liaison 13, voire 14.  According to the first embodiment, the T2 gateway 10a transmits at least one T2-MI stream whose bit rate is reduced via at least one link 13, or even 14.
Selon le second mode de réalisation, la passerelle T2 10a émet au moins un flux T2-MI par l'intermédiaire de la liaison 13, voire 14 et la passerelle T2 10b émet au moins un flux T2-MI par l'intermédiaire de la liaison 17.  According to the second embodiment, the T2 gateway 10a transmits at least one T2-MI stream via the link 13, or even 14 and the T2 gateway 10b transmits at least one T2-MI stream via the link 17.
La liaison 13 est par exemple un satellite qui reçoit le flux T2-MI dont le débit est réduit et le réémet à destination des modulateurs 15.  The link 13 is for example a satellite which receives the T2-MI stream whose bit rate is reduced and the retransmission to the modulators 15.
Les liaisons 14 et 17 sont par exemple des liaisons terrestres, telles que des liaisons filaires. Par l'intermédiaire de la liaison terrestre 14 ou 17, un autre flux T2- MI dont le débit est réduit selon le premier mode de réalisation ou non selon le second mode de réalisation peut être transmis à destination du ou des modulateurs 15 si besoin.  The links 14 and 17 are, for example, terrestrial links, such as wired links. Through the terrestrial link 14 or 17, another T2-MI flow whose rate is reduced according to the first embodiment or not according to the second embodiment can be transmitted to the modulator or modulators 15 if necessary.
Dans la Fig. 1, un seul modulateur 15 et un seul émetteur 16 sont représentés par soucis de simplification.  In FIG. 1, a single modulator 15 and a single transmitter 16 are shown for the sake of simplification.
La Fig. 2 représente un dispositif de transfert d'un flux T2-MI selon le premier mode de réalisation de la présente invention.  Fig. 2 represents a device for transferring a T2-MI flow according to the first embodiment of the present invention.
Le dispositif de réduction du débit d'un flux T2-MI est par exemple compris dans la passerelle T2 10a. Bien entendu, le dispositif de réduction du débit d'un flux T2-MI peut être un dispositif dédié.  The device for reducing the rate of a T2-MI flow is for example included in the T2 gateway 10a. Of course, the device for reducing the throughput of a T2-MI stream may be a dedicated device.
Le dispositif de réduction du débit d'un flux T2-MI 10a comporte un bus de communication 201 auquel sont reliés un processeur 200, une mémoire non volatile 203, une mémoire vive 202, une interface de communication ou d'entrée 204 avec le multiplexeur 11 et une interface de communication ou de sortie 205 avec le modulateur 15.  The device for reducing the flow rate of a T2-MI flow 10a comprises a communication bus 201 to which a processor 200, a non-volatile memory 203, a random access memory 202, a communication or input interface 204 with the multiplexer are connected. 11 and a communication or output interface 205 with the modulator 15.
La mémoire non volatile 203 mémorise les modules logiciels mettant en œuvre l'invention, ainsi que les données permettant de mettre en œuvre l'algorithme qui sera décrit par la suite en référence aux Figs. 4. De manière plus générale, les programmes selon la présente invention sont mémorisés dans un moyen de stockage. Ce moyen de stockage est lisible par le microprocesseur 200. The non-volatile memory 203 stores the software modules implementing the invention, as well as the data for implementing the algorithm that will be described later with reference to FIGS. 4. More generally, the programs according to the present invention are stored in storage means. This storage means is readable by the microprocessor 200.
Lors de la mise sous tension de la passerelle T2 10a, les modules logiciels selon la présente invention sont transférés dans la mémoire vive 202 qui contient alors le code exécutable de l'invention ainsi que les données nécessaires à la mise en œuvre de l'invention.  When the gateway T2 10a is powered up, the software modules according to the present invention are transferred into the random access memory 202 which then contains the executable code of the invention as well as the data necessary for the implementation of the invention. .
Par l'intermédiaire de l'interface 204, la passerelle T2 10a reçoit le flux d'origine d'un ou plusieurs multiplexeurs 11.  Through the interface 204, the gateway T2 10a receives the original stream of one or more multiplexers 11.
Par l'intermédiaire de l'interface 205, la passerelle T2 10a transfère au moins un flux dont le débit est réduit à destination du modulateur 15.  Via the interface 205, the T2 gateway 10a transfers at least one stream whose bit rate is reduced to the modulator 15.
Tout ou partie des étapes de l'algorithme décrit par la suite en regard des Figs. 4 peut être implémenté par logiciel en exécutant les étapes par un dispositif programmable tel qu'un microprocesseur, un DSP {Digital Signal Processor), ou un microcontrôleur ou implémenté dans un composant tel qu'un FPGA (Field- Programmable Gâte Array) ou un ASIC (Application-Specific Integrated Circuit).  All or part of the steps of the algorithm described below with reference to FIGS. 4 can be implemented by software by executing the steps by a programmable device such as a microprocessor, a DSP (Digital Signal Processor), or a microcontroller or implemented in a component such as a Field Programmable Gate Array (FPGA) or a ASIC (Application-Specific Integrated Circuit).
En d'autres mots, la passerelle T2 10a comporte de la circuiterie qui permet à la passerelle T2 10a d'exécuter les étapes de l'algorithme des Figs. 4.  In other words, the T2 gateway 10a includes circuitry that allows the T2 gateway 10a to perform the steps of the algorithm of Figs. 4.
La Fig. 3 représente un dispositif de reconstruction d'un flux DVB-T2 à partir d'au moins un flux T2-MI selon la présente invention.  Fig. 3 represents a device for reconstructing a DVB-T2 stream from at least one T2-MI stream according to the present invention.
Le dispositif de reconstruction d'un flux DVB-T2 est par exemple compris dans le modulateur 15. Bien entendu, le dispositif de reconstruction d'un flux DVB-T2 peut être un dispositif dédié.  The device for reconstructing a DVB-T2 stream is for example included in the modulator 15. Of course, the device for reconstructing a DVB-T2 stream may be a dedicated device.
Le dispositif de reconstruction d'un flux DVB-T2 15 comporte un bus de communication 301 auquel sont reliés un processeur 300, une mémoire non volatile 303, une mémoire vive 302, une interface de réception de signaux et une interface de sortie 305 avec l'émetteur 16.  The device for reconstructing a DVB-T2 stream 15 comprises a communication bus 301 to which a processor 300, a non-volatile memory 303, a random access memory 302, a signal receiving interface and an output interface 305 with a processor are connected. transmitter 16.
La mémoire non volatile 303 mémorise les modules logiciels mettant en œuvre l'invention, ainsi que les données permettant de mettre en œuvre l'algorithme qui sera décrit par la suite en référence à la Fig. 5.  The non-volatile memory 303 stores the software modules implementing the invention, as well as the data enabling implementation of the algorithm which will be described hereinafter with reference to FIG. 5.
De manière plus générale, les programmes selon la présente invention sont mémorisés dans un moyen de stockage. Ce moyen de stockage est lisible par le microprocesseur 300. Lors de la mise sous tension du modulateur 15, les modules logiciels selon la présente invention sont transférés dans la mémoire vive 302 qui contient alors le code exécutable de l'invention ainsi que les données nécessaires à la mise en œuvre de l'invention. More generally, the programs according to the present invention are stored in storage means. This storage means is readable by the microprocessor 300. When the modulator 15 is powered up, the software modules according to the present invention are transferred into the random access memory 302 which then contains the executable code of the invention as well as the data necessary for the implementation of the invention.
Par l'intermédiaire de l'interface 304, le modulateur reçoit au moins un flux T2- Via the interface 304, the modulator receives at least one T2-
MI, par l'intermédiaire de la liaison 13 voire de la liaison 14 selon le premier mode de réalisation ou par l'intermédiaire des liaisons 13 et 17 selon le second mode de réalisation. MI, through the link 13 or even the link 14 according to the first embodiment or through the links 13 and 17 according to the second embodiment.
Par l'intermédiaire de l'interface 305, le modulateur 15 transpose en fréquence le flux reconstruit pour une émission du flux reconstruit et transposé en fréquence par l'émetteur 16.  Via the interface 305, the modulator 15 frequency transposes the reconstructed stream for an emission of the reconstructed stream and transposed into frequency by the transmitter 16.
Tout ou partie des étapes de l'algorithme décrit par la suite en regard de la Fig. 5 peuvent être implémentées par logiciel en exécutant les étapes par un dispositif programmable tel qu'un microprocesseur, un DSP {Digital Signal Processor), ou un microcontrôleur ou implémenté dans un composant tel qu'un FPGA (Field- Programmable Gâte Array) ou un ASIC (Application-Specific Integrated Circuit).  All or part of the steps of the algorithm described below with reference to FIG. 5 may be implemented by software by executing the steps by a programmable device such as a microprocessor, a DSP (Digital Signal Processor), or a microcontroller or implemented in a component such as a Field Programmable Gate Array (FPGA) or ASIC (Application-Specific Integrated Circuit).
En d'autres mots, le modulateur 15 comporte de la circuiterie qui permet au modulateur 15 d'exécuter les étapes de l'algorithme de la Fig. 5.  In other words, the modulator 15 includes circuitry which allows the modulator 15 to execute the steps of the algorithm of FIG. 5.
La Fig. 4a représente un exemple d'algorithme de transfert d'un flux DVB-T2 selon le premier mode de réalisation de la présente invention.  Fig. 4a shows an example of a transfer algorithm of a DVB-T2 stream according to the first embodiment of the present invention.
Plus précisément, le présent algorithme est exécuté par le processeur 200 du dispositif de réduction de débit d'un flux T2-MI.  More specifically, the present algorithm is executed by the processor 200 of the rate reduction device of a T2-MI stream.
A l'étape E40, le processeur 200 reçoit du multiplexeur 11 au moins un multiplexe au format MPTS MPEG-2 et génère au moins un flux T2-MI.  In step E40, the processor 200 receives from the multiplexer 11 at least one multiplex MPEG-2 MPTS format and generates at least one T2-MI stream.
Un flux T2-MI comprend des paquets de données T2-MI tels que des paquets de synchronisation T2-MI timestamp, des paquets de signalisation dont le paquet nommé Ll courant ou L1PRE qui donne des informations sur la structure du flux T2-MI et des paquets appelés trames bandes de base (Baseband Frame en anglais) contenant les données des flux MPEG-2 TS d'un ou plusieurs tunnels PLP. Les paquets T2-MI sont organisés en trames T2, chaque trame T2 contient un paquet T2-MI timestamp, un paquet T2-MI Ll courant et des paquets trames bandes de base.  A T2-MI stream includes T2-MI data packets such as T2-MI timestamp synchronization packets, signaling packets including the current L1 or L1PRE packet that provides information on the structure of the T2-MI stream and packets called Baseband Frames containing MPEG-2 TS stream data from one or more PLP tunnels. The T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI L1 packet, and baseband frame packets.
Selon un premier exemple de réalisation, le flux T2-MI reçu est constitué de paquets d'au moins deux tunnels PLP différents comme cela est décrit en référence à la Fig. 7a. Selon un second exemple de réalisation, le flux T2-MI reçu est constitué d'un premier tunnel dit principal contenant des programmes audiovisuels devant être diffusés au niveau national et au moins un second tunnel contenant des programmes audiovisuels dits régionaux comme cela est décrit en référence à la Fig. 7a. According to a first exemplary embodiment, the received T2-MI stream consists of packets of at least two different PLP tunnels as described with reference to FIG. 7a. According to a second exemplary embodiment, the received T2-MI stream consists of a first so-called main tunnel containing audiovisual programs to be broadcast at the national level and at least one second tunnel containing so-called regional audiovisual programs as described with reference. in FIG. 7a.
Selon un troisième exemple de réalisation, le flux T2-MI reçu est constitué de paquets d'un seul tunnel PLP comme cela est décrit en référence à la Fig. 7f.  According to a third exemplary embodiment, the received T2-MI stream consists of packets of a single PLP tunnel as described with reference to FIG. 7f.
A l'étape suivante E41 le processeur 200 identifie dans le flux T2-MI généré, des paquets dits d'un premier type.  In the next step E41 the processor 200 identifies in the T2-MI stream generated packets said to be of a first type.
Les paquets dits du premier type sont, dans le premier exemple de réalisation, les paquets trames bandes de base du premier tunnel.  The so-called packets of the first type are, in the first example embodiment, the baseband frame packets of the first tunnel.
Les paquets dits du premier type sont, dans le second exemple de réalisation, les paquets trames bandes de base du second tunnel contenant des programmes audiovisuels dits régionaux.  The so-called packets of the first type are, in the second exemplary embodiment, the baseband frame packets of the second tunnel containing so-called regional audio-visual programs.
Les paquets dits du premier type sont, dans le troisième exemple de réalisation, les paquets trames bandes de base qui sont comptés par le processeur 200 et identifiés comme pairs. En d'autres termes, les paquets trames bandes de bases sont, selon leur position dans la trame T2, séquentiellement paquets du premier type et paquets d'un second type.  The so-called packets of the first type are, in the third embodiment, the baseband frame packets that are counted by the processor 200 and identified as peers. In other words, the baseband frame packets are, according to their position in the frame T2, sequentially packets of the first type and packets of a second type.
A l'étape suivante E42, le processeur 200 modifie l'entête de chaque paquet T2- MI identifié comme paquet du premier type.  In the next step E42, the processor 200 modifies the header of each T2-MI packet identified as a packet of the first type.
La Fig. 6 représente un exemple de la structure d'un paquet T2-MI.  Fig. 6 shows an example of the structure of a T2-MI packet.
Un paquet T2-MI est constitué d'un entête 60, d'un champ de données utiles 61, d'un champ de bourrage 62 et d'un champ 63 de redondance.  A T2-MI packet consists of a header 60, a payload field 61, a stuff field 62 and a redundancy field 63.
Le champ d' entête 60 comprend un sous champ 600 d'identification du type de paquet, un sous champ 601 de compteur paquet, un sous champ 602 identifiant la super trame à laquelle appartient le paquet, un sous champ 603 réservé pour des évolutions futures et un sous champ 604 qui définit la longueur du champ 61 données utiles.  The header field 60 comprises a packet type identification sub-field 600, a packet counter sub-field 601, a sub-field 602 identifying the super-frame to which the packet belongs, a sub-field 603 reserved for future evolutions. and a subfield 604 which defines the length of the field 61 payload.
Le sous champ 600 type de paquet est modifié à l'étape E42 en remplaçant la valeur du champ, classiquement 00 en hexadécimal par la valeur 40 en hexadécimal. La valeur 40 est une valeur réservée pour d'autres utilisations que celles classiquement définies par la norme DVB-T2.  The 600 packet type sub-field is modified in step E42 by replacing the value of the field, conventionally 00 in hexadecimal with the value 40 in hexadecimal. The value 40 is a value reserved for uses other than those conventionally defined by the DVB-T2 standard.
A l'étape suivante E43, le processeur 200 modifie le champ 61 données utiles en remplaçant l'ensemble des données utiles comprises dans le champ 61 par une information indiquant que le paquet est un paquet du premier type, l'information ayant une taille inférieure à la taille des données utiles remplacées, In the next step E43, the processor 200 modifies the field 61 useful data by replacing all the useful data included in the field 61 by a information indicating that the packet is a packet of the first type, the information having a size smaller than the size of the payload replaced,
Par exemple, l'information indiquant que le paquet est un paquet du premier type est un unique octet qui identifie le premier type de paquet.  For example, the information indicating that the packet is a packet of the first type is a single byte that identifies the first type of packet.
A cette même étape E43, le processeur 200 modifie la valeur du champ 63 de redondance ainsi que la valeur du sous champ 604 en mettant à jour celles-ci de manière à prendre en compte les modifications précédemment effectuées.  At this same step E43, the processor 200 modifies the value of the redundancy field 63 as well as the value of the sub-field 604 by updating them so as to take into account the modifications previously made.
Dans un mode particulier de réalisation du premier exemple de réalisation, le processeur 200 modifie à l'étape E44 le contenu du paquet T2-MI Ll courant. Un paquet T2-MI Ll courant comporte des informations identifiant le nombre de tunnels PLP compris dans le flux T2-MI.  In a particular embodiment of the first exemplary embodiment, the processor 200 modifies in step E44 the contents of the current T2-MI packet L1. A current T2-MI L1 packet includes information identifying the number of PLP tunnels included in the T2-MI stream.
Selon le premier exemple de réalisation, le flux T2-MI originellement constitué de deux tunnels PLP ne comporte plus qu'un tunnel PLP. Le contenu du paquet T2- MI Ll courant est alors modifié pour prendre en compte la modification.  According to the first exemplary embodiment, the T2-MI stream originally consisting of two PLP tunnels has only one PLP tunnel. The content of the current T2-MI L1 packet is then modified to take into account the modification.
Selon le mode particulier, le processeur 200 copie par exemple, dans le champ According to the particular mode, the processor 200 copies for example, in the field
61 données utiles du dernier paquet de premier type, le contenu du champ données utiles du paquet T2-MI Ll courant et modifie, selon l'exemple, l'identifiant compris dans le sous champ 600 du dernier paquet de premier type en mettant par exemple la valeur 41 en hexadécimal. 61 useful data of the last packet of the first type, the content of the payload field of the current T2-MI packet L1 and modifies, according to the example, the identifier included in the subfield 600 of the last packet of the first type, for example by setting the value 41 in hexadecimal.
Le flux T2-MI est ainsi constitué d'une quantité moins importante de données et est ainsi adapté au débit de la liaison utilisée pour la transmission dudit flux T2-MI.  The T2-MI flow thus consists of a smaller amount of data and is thus adapted to the bit rate of the link used for the transmission of said T2-MI flow.
Selon les premier et troisième exemples de réalisation, le processeur 200 forme deux flux T2-MI et exécute, parallèlement aux étapes E42 à E44, les étapes E46 à E49 de l'algorithme de la Fig. 4b.  According to the first and third exemplary embodiments, the processor 200 forms two flows T2-MI and executes, parallel to the steps E42 to E44, the steps E46 to E49 of the algorithm of FIG. 4b.
A l'étape E46, le processeur 200 identifie dans le flux T2-MI généré, des paquets dits d'un second type.  In step E46, the processor 200 identifies, in the generated T2-MI stream, so-called packets of a second type.
Les paquets dits du second type sont, dans le premier exemple de réalisation, les paquets trames bandes de base du second tunnel.  The so-called packets of the second type are, in the first exemplary embodiment, the baseband frame packets of the second tunnel.
Les paquets dits du second type sont, dans le troisième exemple de réalisation, les paquets trames bandes de base qui sont comptés par le processeur 200 et identifiés comme impairs.  The so-called packets of the second type are, in the third exemplary embodiment, the baseband frame packets that are counted by the processor 200 and identified as odd.
A l'étape suivante E47, le processeur 200 modifie l'entête de chaque paquet T2- MI identifié comme paquet du second type. Le sous champ 600 type de paquet est modifié à l'étape E47 en remplaçant la valeur du champ, classiquement 00 en hexadécimal par la valeur 40 en hexadécimal. La valeur 40 est une valeur réservée pour d'autres utilisations que celles classiquement définies par la norme DVB-T2. In the next step E47, the processor 200 modifies the header of each T2-MI packet identified as a packet of the second type. The 600 packet type sub-field is modified in step E47 by replacing the value of the field, conventionally 00 in hexadecimal with the value 40 in hexadecimal. The value 40 is a value reserved for uses other than those conventionally defined by the DVB-T2 standard.
A l'étape suivante E48, le processeur 200 modifie le champ 61 données utiles en remplaçant l'ensemble des données utiles comprises dans le champ 61 par une information indiquant que le paquet est un paquet de second type, l'information ayant une taille inférieure à la taille des données utiles remplacées,  In the next step E48, the processor 200 modifies the field 61 useful data by replacing all the useful data included in the field 61 by information indicating that the packet is a second type packet, the information having a smaller size to the size of the payload replaced,
Par exemple, l'information indiquant que le paquet est un paquet de second type est un unique octet qui identifie le second type de paquet.  For example, the information indicating that the packet is a second type packet is a single octet identifying the second type of packet.
A cette même étape E48, le processeur 200 modifie la valeur du champ 63 de redondance ainsi que la valeur du sous champ 604 en mettant à jour celles-ci de manière à prendre en compte les modifications précédemment effectuées.  At this same step E48, the processor 200 modifies the value of the redundancy field 63 as well as the value of the sub-field 604 by updating them so as to take into account the modifications previously made.
Dans un mode particulier de réalisation du premier exemple de réalisation, le processeur 200 modifie à l'étape E49 le contenu du paquet T2-MI Ll courant. Un paquet T2-MI courant comporte des informations identifiant le nombre de tunnels PLP compris dans le flux T2-MI. Le flux T2-MI est originellement constitué de deux tunnels PLP et ne comporte plus qu'un tunnel PLP. Le contenu du paquet T2-MI Ll courant est alors modifié pour prendre en compte la modification.  In a particular embodiment of the first exemplary embodiment, the processor 200 modifies in step E49 the contents of the current T2-MI packet L1. A current T2-MI packet includes information identifying the number of PLP tunnels included in the T2-MI stream. The T2-MI stream originally consists of two PLP tunnels and has only one PLP tunnel. The contents of the current T2-MI package L1 are then modified to take into account the modification.
Selon le mode particulier, le processeur 200 copie, par exemple dans le champ According to the particular mode, the processor 200 copies, for example in the field
61 données utiles du dernier paquet de second type le contenu du champ données utiles du paquet T2-MI Ll courant et modifie l'identifiant compris dans le sous champ 600 du dernier paquet de premier type en mettant par exemple la valeur 41 en hexadécimal. 61 useful data of the last second type packet the contents of the payload field of the current T2-MI L1 packet and modifies the identifier included in the subfield 600 of the last packet of the first type, for example by setting the value 41 to hexadecimal.
La Fig. 7a représente un flux T2-MI conforme au premier et au second exemples de réalisation.  Fig. 7a represents a T2-MI flow according to the first and second embodiments.
Le flux T2-MI reçu est constitué de paquets trames bandes de base du premier tunnel notés PLPO et de paquets de trames de base du second tunnel notés PLPl . Les paquets T2-MI sont organisés en trames T2, chaque trame T2 contient un paquet T2- MI timestamp, un paquet T2-MI Ll courant et des paquets trames bandes de base The received T2-MI stream consists of baseband frame packets of the first tunnel denoted PLPO and basic frame packets of the second tunnel denoted PLP1. The T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI Ll packet, and baseband frame packets.
PLPO et PLPl . PLPO and PLPl.
La Fig. 7b représente un flux T2-MI formé selon le premier et le second exemples de réalisation de la présente invention. Les paquets bandes de base PLPO du premier tunnel sont remplacés par des paquets notés Bo. Fig. 7b shows a T2-MI flux formed according to the first and second embodiments of the present invention. The PLPO baseband packets of the first tunnel are replaced by packets denoted Bo.
La Fig. 7c représente un second flux T2-MI formé selon le premier exemple de réalisation de la présente invention.  Fig. 7c represents a second T2-MI flux formed according to the first embodiment of the present invention.
Les paquets bandes de base PLP1 du second tunnel sont remplacés par des paquets notés Bo.  The baseband packets PLP1 of the second tunnel are replaced by packets denoted Bo.
La Fig. 7d représente un flux T2-MI formé selon le mode particulier de réalisation du premier exemple de réalisation de la présente invention.  Fig. 7d represents a T2-MI flux formed according to the particular embodiment of the first embodiment of the present invention.
Les paquets bandes de base PLPO du premier tunnel sont remplacés par des paquets notés Bo. La valeur du paquet Ll courant L1PRE est mise à jour et est notée LIPREm. Les données utiles du paquet L1PRE de la Fig. 7a sont copiées dans le champ données utiles 61 du dernier paquet de premier type noté LIPREor. Le contenu du champ données utiles du paquet T2-MI Ll courant noté LIPREm est mis à jour en fonction des paramètres de données transmises. L'identifiant compris dans le sous champ 600 du dernier paquet de premier type est modifié en mettant par exemple la valeur 41 en hexadécimal.  The PLPO baseband packets of the first tunnel are replaced by packets denoted Bo. The value of the current L1PRE L1 packet is updated and is denoted LIPREm. The useful data of the L1PRE packet of FIG. 7a are copied into the payload field 61 of the last packet of the first type denoted LIPREor. The content of the payload field of the current T2-MI L1 packet LIPREm is updated according to the transmitted data parameters. The identifier included in the subfield 600 of the last packet of the first type is modified by setting for example the value 41 in hexadecimal.
La Fig. 7e représente un flux T2-MI formé selon le mode particulier de réalisation du premier et du deuxième exemples de réalisation de la présente invention.  Fig. 7e represents a T2-MI flux formed according to the particular embodiment of the first and second embodiments of the present invention.
Les paquets bandes de base PLP1 du second tunnel sont remplacés par des paquets notés Bo. La valeur du paquet Ll courant L1PRE est mise à jour et est notée LIPREm. Les données utiles du paquet L1PRE de la Fig. 7a sont copiées dans le champ données utiles 61 du dernier paquet de premier type noté LIPREor. Le contenu du champ données utiles du paquet T2-MI Ll courant noté LIPREm est mis à jour en fonction des paramètres de données transmises. L'identifiant compris dans le sous champ 600 du dernier paquet de second type est modifié en mettant par exemple la valeur 41 en hexadécimal.  The baseband packets PLP1 of the second tunnel are replaced by packets denoted Bo. The value of the current L1PRE L1 packet is updated and is denoted LIPREm. The useful data of the L1PRE packet of FIG. 7a are copied into the payload field 61 of the last packet of the first type denoted LIPREor. The content of the payload field of the current T2-MI L1 packet LIPREm is updated according to the transmitted data parameters. The identifier included in the subfield 600 of the last packet of the second type is modified by setting for example the value 41 in hexadecimal.
La Fig. 7f représente un flux T2-MI conforme au troisième exemple de réalisation.  Fig. 7f represents a T2-MI flow according to the third embodiment.
Le flux T2-MI reçu est constitué de paquets trames bandes de base d'un unique tunnel. Les paquets T2-MI sont organisés en trames T2, chaque trame T2 contient un paquet T2-MI timestamp, un paquet T2-MI Ll courant et des paquets trames bandes de base.  The received T2-MI stream consists of baseband frame packets of a single tunnel. The T2-MI packets are organized in T2 frames, each T2 frame contains a T2-MI timestamp packet, a current T2-MI L1 packet, and baseband frame packets.
Les paquets trames bandes de bases sont notés ΒΒ0 à BB5. La Fig. 7g représente un premier flux T2-MI formé selon le troisième exemple de réalisation de la présente invention. The baseband frame packets are denoted by ΒΒ0 to BB5. Fig. 7g represents a first T2-MI stream formed according to the third embodiment of the present invention.
Les paquets bandes de base identifiés comme pairs sont remplacés par des paquets notés Bo.  Baseband packets identified as peer are replaced by packets denoted Bo.
La Fig. 7h représente un second flux T2-MI formé selon le troisième exemple de réalisation de la présente invention.  Fig. 7h represents a second T2-MI flux formed according to the third embodiment of the present invention.
Les paquets bandes de base identifiés comme impairs sont remplacés par des paquets notés Bo.  The baseband packets identified as odd are replaced by packets denoted Bo.
Il est à remarquer ici que les exemples donnés en référence aux Figs. 7 sont des exemples dans lesquels le flux T2-MI est décomposé en deux flux T2-MI. Bien entendu un flux T2-MI, selon l'invention, peut être décomposé en un nombre plus important de flux T2-MI.  It should be noted here that the examples given with reference to FIGS. 7 are examples in which the T2-MI flow is decomposed into two T2-MI flows. Of course, a T2-MI stream, according to the invention, can be decomposed into a larger number of T2-MI streams.
La Fig. 5 représente un exemple d'algorithme de reconstruction d'un flux DVB- T2 à partir d'au moins un flux DVB-T2 selon la présente invention.  Fig. 5 represents an exemplary algorithm for reconstructing a DVB-T2 stream from at least one DVB-T2 stream according to the present invention.
Plus précisément, le présent algorithme est exécuté par le processeur 300.  More specifically, the present algorithm is executed by the processor 300.
A l'étape E50, le processeur 300 détecte la réception de deux flux T2-MI dont au moins un flux T2-MI est formé par la passerelle T2 10a selon la présente invention.  In step E50, the processor 300 detects the reception of two T2-MI streams of which at least one T2-MI stream is formed by the T2 gateway 10a according to the present invention.
Selon les premier et troisième exemples de réalisation du premier mode de réalisation, deux flux T2-MI formés selon l'algorithme des Figs. 4a et 4b sont reçus par l'intermédiaire des liaisons 13 et 14.  According to the first and third exemplary embodiments of the first embodiment, two T2-MI flows formed according to the algorithm of FIGS. 4a and 4b are received via links 13 and 14.
Selon le second exemple de réalisation du premier mode de réalisation, un flux T2-MI formé selon l'algorithme de la Fig. 4a est reçu par l'intermédiaire de la liaison 13 et un flux régional est reçu d'un dispositif non représenté en Fig. 1.  According to the second embodiment of the first embodiment, a T2-MI flow formed according to the algorithm of FIG. 4a is received via link 13 and a regional stream is received from a device not shown in FIG. 1.
Selon le mode particulier du premier exemple de réalisation, le processeur 300 effectue, suite à l'étape E50, les étapes E51 à E53.  According to the particular embodiment of the first exemplary embodiment, the processor 300 performs, following step E50, the steps E51 to E53.
Selon le second mode de réalisation, un premier flux T2-MI est reçu par la liaison 13 et un second flux T2-MI est reçu par la liaison 17.  According to the second embodiment, a first T2-MI stream is received by the link 13 and a second T2-MI stream is received by the link 17.
Il est à remarquer ici que dans le second mode de réalisation les trames du premier et du second flux T2-MI ont une durée identique.  It should be noted here that in the second embodiment the frames of the first and second T2-MI streams have an identical duration.
A cette même étape, le processeur 300 lit le contenu des paquets T2-MI Ll courant de chacun des premier et second flux T2-MI.  At this same step, the processor 300 reads the contents of the current T2-MI L1 packets of each of the first and second T2-MI streams.
Selon le premier mode de réalisation, le processeur 300 passe de l'étape E50 à l'étape E51 et détecte, dans chaque trame T2 d'au moins un flux T2-MI formé selon l'algorithme de la Fig. 4a ou 4b, un paquet LIPREor. A l'étape suivante E52, le processeur 300 insère dans le champ 61 du paquet LIPREm de la trame T2, le contenu du champ 61 du paquet LIPREor détecté. According to the first embodiment, the processor 300 moves from step E50 to step E51 and detects, in each frame T2, at least one T2-MI flow formed according to the algorithm of FIG. 4a or 4b, a LIPREor packet. In the next step E52, the processor 300 inserts in the field 61 of the LIPREm packet of the frame T2, the content of the field 61 of the LIPREor packet detected.
A l'étape suivante E53, le processeur 300 modifie le paquet LIPREor remplaçant le contenu du champ 61 données utiles du dernier paquet par des données de bourrage, modifie l'identifiant compris dans le sous champ 600 du dernier paquet de premier type en mettant par exemple la valeur 00 en hexadécimal et met à jour le champ 62 et le sous champ 604.  In the next step E53, the processor 300 modifies the packet LIPREor replacing the content of the field 61 useful data of the last packet by stuffing data, modifies the identifier included in the subfield 600 of the last packet of the first type by setting example the value 00 in hexadecimal and updates field 62 and subfield 604.
Selon le premier mode de réalisation, le processeur 300 passe de l'étape E53 à l'étape E54. Selon le second mode de réalisation, le processeur 300 passe de l'étape E50 à l'étape E54.  According to the first embodiment, the processor 300 goes from step E53 to step E54. According to the second embodiment, the processor 300 proceeds from step E50 to step E54.
A l'étape E54, le processeur 300 aligne les deux flux reçus à l'étape E50. L'alignement est effectué en mettant en phase les paquets T2-MI timestamp des trames T2 de chaque flux T2-MI.  In step E54, the processor 300 aligns the two streams received in step E50. Alignment is performed by phasing the T2-MI timestamp packets of the T2 frames of each T2-MI stream.
Par exemple, le processeur 300 aligne les deux flux reçus en mettant en phase les paquets T2-MI timestamp des trames T2 de chaque flux T2-MI reçu qui ont la même valeur de marquage temporel ou des valeurs de marquage temporel qui sont les plus proches.  For example, the processor 300 aligns the two received streams by phasing the T2-MI timestamp packets of the T2 frames of each received T2-MI stream that have the same time stamping value or the nearest time stamping values that are closest .
En variante, l'alignement est effectué en mettant en phase les paquets T2-MI Ll courant des trames T2 de chaque flux T2-MI reçu qui ont la même valeur de compteur T2-MI ou des valeurs de compteur T2-MI qui sont les plus proches.  Alternatively, the alignment is performed by phasing the current T2-MI packets T1 frames of each received T2-MI stream that have the same T2-MI counter value or T2-MI counter values which are the same. closer.
Il est à remarquer ici que le processeur 300 peut aligner les deux flux reçus en utilisant d'autres méthodes.  It should be noted here that the processor 300 can align the two received streams using other methods.
Selon le premier mode de réalisation, le processeur 300 passe de l'étape E54 à According to the first embodiment, the processor 300 moves from step E54 to
E55. E55.
A l'étape E55, le processeur 300 identifie, dans un des flux T2-MI reçu de la passerelle T2 10a, les paquets de premier type en analysant le champ de données utiles 61 des paquets reçus.  In step E55, the processor 300 identifies, in one of the T2-MI streams received from the gateway T2 10a, the first type packets by analyzing the useful data field 61 of the packets received.
Selon le premier mode de réalisation, le processeur 300 passe de l'étape E55 à l'étape E56. Selon le second mode de réalisation, le processeur 300 passe de l'étape E54 à l'étape E56.  According to the first embodiment, the processor 300 proceeds from step E55 to step E56. According to the second embodiment, the processor 300 proceeds from step E54 to step E56.
A l'étape E56, le processeur 300 insère, dans chaque trame T2 d'un premier flux T2-MI reçu, les paquets bandes de base de la trame T2 du second flux T2-MI dont le paquet T2-MI est à aligné avec le paquet T2-MI de la trame du premier flux T2-MI. Selon le premier mode de réalisation, le processeur 300 remplace dans le flux T2-MI comprenant les identifiants de paquets de premier type chaque paquet de premier type par le paquet du second flux T2-MI reçu qui est aligné avec le paquet de premier type identifié. In step E56, the processor 300 inserts, in each frame T2 of a first received T2-MI stream, the baseband packets of the frame T2 of the second stream T2-MI whose package T2-MI is aligned with the T2-MI packet of the frame of the first T2-MI stream. According to the first embodiment, the processor 300 replaces, in the T2-MI stream comprising the first type packet identifiers, each packet of the first type by the packet of the second received T2-MI stream that is aligned with the identified first type packet. .
Dans une variante du premier mode de réalisation, l'étape E54 est décomposée en deux sous étapes.  In a variant of the first embodiment, the step E54 is decomposed into two sub-steps.
Dans une première sous étape, le processeur 300 remplace dans le flux T2-MI comprenant les identifiants de paquets de premier type, chaque paquet de premier type identifiant un paquet de premier type par des données de bourrage dont la taille est égale à la taille des autres paquets bandes de base compris dans le flux T2-MI.  In a first sub-step, the processor 300 replaces, in the stream T2-MI comprising the identifiers of packets of the first type, each packet of the first type identifying a packet of the first type by stuffing data whose size is equal to the size of the packets. other baseband packets included in the T2-MI stream.
Dans une seconde sous étape, le processeur 300 remplace les données de bourrage insérées à la sous étape précédente par le paquet du second flux T2-MI reçu qui est aligné avec le paquet de premier type identifié.  In a second substep, the processor 300 replaces the padding data inserted in the previous substep by the packet of the second received T2-MI stream that is aligned with the identified first-type packet.
Selon le second mode de réalisation, le processeur 300 insère, plus précisément ajoute, dans chaque trame T2 d'un premier flux T2-MI reçu, les paquets bandes de base de la trame T2 du second flux T2-MI dont le paquet T2-MI est aligné avec le paquet T2-MI de la trame du premier flux T2-MI à la suite des paquets bandes de base de la trame T2 du premier flux T2-MI. A partir du contenu des paquets T2-MI Ll courant de chacun des premier et second flux T2-MI lus à l'étape E50, le processeur 300 modifie le contenu des paquets T2-MI Ll courant du premier flux T2-MI de manière à prendre en compte l'ajout des paquets bandes de base de la trame T2 du second flux T2-MI dans les trames T2 du premier flux T2-MI. Le processeur 300 met à jour les compteurs de chaque paquet T2-MI du flux T2-MI dans lequel les paquets bandes de base du second flux T2-MI ont été ajoutés.  According to the second embodiment, the processor 300 inserts, more precisely, adds, in each frame T2 of a first received T2-MI stream, the baseband packets of the frame T2 of the second stream T2-MI whose package T2- MI is aligned with the T2-MI packet of the frame of the first T2-MI stream following the baseband packets of the T2 frame of the first T2-MI stream. From the contents of the current T2-MI L1 packets of each of the first and second T2-MI streams read at step E50, the processor 300 modifies the content of the current T2-MI L1 packets of the first T2-MI stream so as to take into account the addition of the baseband packets of the frame T2 of the second stream T2-MI in the frames T2 of the first stream T2-MI. The processor 300 updates the counters of each T2-MI packet of the T2-MI stream in which the baseband packets of the second T2-MI stream have been added.
II est à remarquer ici que si le premier flux T2-MI comporte plusieurs tunnels couche physique PLP, le processeur 300 peut supprimer les paquets associés à au moins un des tunnels.  It should be noted here that if the first T2-MI stream comprises several PLP physical layer tunnels, the processor 300 can delete the packets associated with at least one of the tunnels.
De même, il est à remarquer ici que si le second flux T2-MI comporte plusieurs tunnels couche physique PLP, le processeur 300 peut n'ajouter que les paquets associés à une partie des tunnels couche physique PLP du second flux T2-MI.  Similarly, it should be noted here that if the second T2-MI stream comprises several PLP physical layer tunnels, the processor 300 can only add the packets associated with a part of the PLP physical layer tunnels of the second T2-MI stream.

Claims

REVENDICATIONS
1) Procédé de génération d'un flux à partir d'un premier et d'un second flux de données reçus, lesdits premier et second flux étant des flux de type T2-MI, les flux de données étant constitués de trames, chaque trame contenant un paquet de synchronisation, un paquet de signalisation donnant des informations sur la structure du flux de données et des paquets appelés trames bandes de base comprenant des données sur des flux audiovisuels, caractérisé en ce que le procédé comporte les étapes de : 1) A method of generating a stream from a first and a second stream of received data, said first and second streams being T2-MI type streams, the data streams consisting of frames, each frame containing a synchronization packet, a signaling packet giving information on the structure of the data stream and packets called baseband frames comprising data on audiovisual streams, characterized in that the method comprises the steps of:
- alignement (E54) des deux flux de données reçus en mettant en phase les paquets de synchronisation ou les paquets de signalisation des trames de chaque flux de données,  aligning (E54) the two data streams received by phasing the synchronization packets or signaling packets of the frames of each data stream,
- ajout (E56), dans chaque trame du premier flux reçu, des paquets bandes de base de la trame du second flux dont le paquet de synchronisation est aligné avec le paquet de synchronisation de la trame du premier flux à la suite des paquets bandes de base de la trame du premier flux reçu.  adding (E56), in each frame of the first received stream, baseband packets of the frame of the second stream whose synchronization packet is aligned with the packet of synchronization of the frame of the first stream following the packet packets of base of the frame of the first received stream.
2) Procédé selon la revendication 1, caractérisé en ce que l'insertion est effectuée en remplaçant dans le flux de données comprenant les identifiants de paquets de premier type, chaque paquet identifiant un paquet de premier type par un paquet bande de base de la trame du second flux dont le paquet de synchronisation est aligné avec le paquet de synchronisation de la trame du premier flux. 2) Method according to claim 1, characterized in that the insertion is performed by replacing in the data stream comprising the identifiers of packets of the first type, each packet identifying a packet of the first type by a baseband packet of the frame the second stream whose synchronization packet is aligned with the synchronization packet of the frame of the first stream.
3) Procédé selon la revendication 2, caractérisé en ce que le procédé comporte en outre les étapes de : 3) Method according to claim 2, characterized in that the method further comprises the steps of:
- détection, dans chaque trame d'un des flux, d'un paquet ayant un identifiant prédéterminé,  detecting, in each frame of one of the streams, a packet having a predetermined identifier,
- insertion (E52) dans un champ de données du paquet de signalisation de la trame, de données comprises dans un champ de données du paquet ayant l'identifiant prédéterminé,  inserting (E52) into a data field of the signaling packet of the frame, data included in a data field of the packet having the predetermined identifier,
- insertion (E53) dans un champ de données du paquet ayant l'identifiant prédéterminé de données de bourrage,  inserting (E53) into a data field of the packet having the predetermined identifier of stuffing data,
- modification de l'identifiant prédéterminé. 4) Procédé selon la revendication 1, caractérisé en ce qu'au moins un des deux flux reçu est obtenu d'un dispositif distant, ledit dispositif distant effectuant préalablement au transfert dudit flux les étapes de : - modification of the predetermined identifier. 4) Method according to claim 1, characterized in that at least one of the two streams received is obtained from a remote device, said remote device performing prior to the transfer of said stream the steps of:
- identification (E41) parmi les paquets trames bandes de base de paquets d'un premier type,  - identification (E41) among packets frames baseband packets of a first type,
- modification (E42) de l'entête de chaque paquet trames bandes de base identifié comme paquet du premier type,  modification (E42) of the header of each packet baseband frames identified as a packet of the first type,
- remplacement (E43) des données utiles comprises dans un champ données utile de chaque paquet identifié par une information indiquant que le paquet est un paquet du premier type, l'information indiquant que le paquet est un paquet du premier type ayant une taille inférieure à la taille des données utiles remplacées,  replacing (E43) the useful data included in a useful data field of each packet identified by information indicating that the packet is a packet of the first type, the information indicating that the packet is a packet of the first type having a size less than the size of the payload replaced,
- transfert du flux de données modifié.  - transfer of the modified data stream.
5) Procédé selon la revendication 4, caractérisé en ce que les paquets trames bandes de base appartiennent à différents tunnels et en ce que les paquets du premier type sont les paquets d'un même tunnel. 5) Method according to claim 4, characterized in that the baseband frame packets belong to different tunnels and in that the packets of the first type are the packets of the same tunnel.
6) Procédé selon la revendication 5, caractérisé en ce qu'un tunnel comprend des données sur des flux audiovisuels destinés à être diffusés à une échelle nationale et un tunnel comprend des données sur des flux audiovisuels destinés à être diffusés à une échelle locale et en ce que les paquets de premier type sont des paquets appartenant au tunnel comprenant des données sur des flux audiovisuels destinés à être diffusés à l'échelle locale. 7) Procédé selon la revendication 5, caractérisé en ce que le procédé comporte en outre les étapes de : 6) Method according to claim 5, characterized in that a tunnel comprises data on audiovisual streams intended to be broadcast on a national scale and a tunnel includes data on audiovisual streams intended to be broadcast on a local scale and in that the first type packets are packets belonging to the tunnel comprising data on audiovisual streams intended to be broadcast locally. 7) Method according to claim 5, characterized in that the method further comprises the steps of:
- identification, parmi les paquets trames bandes de base, de paquets d'un second type, les paquets du second type appartenant à un tunnel différent du tunnel auquel les paquets du premier type appartiennent,  identification, among the baseband frame packets, of packets of a second type, the packets of the second type belonging to a tunnel different from the tunnel to which the packets of the first type belong,
- modification de l'entête de chaque paquet trames bandes de base identifié comme paquet de second type,  - modification of the header of each packet baseband frames identified as a second type packet,
- remplacement des données utiles comprises dans un champ données utile de chaque paquet de second type identifié par une information indiquant que le paquet est un paquet de second type, l'information indiquant que le paquet est un paquet du second type ayant une taille inférieure à la taille des données utiles remplacées, replacement of the useful data comprised in a useful data field of each packet of the second type identified by information indicating that the packet is a second type packet, the information indicating that the packet is a packet of the second type having a size smaller than the size of the replaced payload,
- transfert d'un autre flux de données modifié. 8) Procédé selon la revendication 7, caractérisé en ce que le procédé comporte en outre les étapes de :  - transfer of another modified data stream. 8) Method according to claim 7, characterized in that the method further comprises the steps of:
- insertion, pour chaque trame du tunnel auquel les paquets du premier type appartiennent, des données comprises dans le paquet de signalisation de la trame du tunnel dans le champ de données utiles d'un paquet de premier type de la trame du tunnel,  inserting, for each frame of the tunnel to which the packets of the first type belong, data included in the signaling packet of the tunnel frame in the payload field of a first type packet of the tunnel frame,
- insertion, pour chaque trame du tunnel auquel les paquets du second type appartiennent, des données comprises dans le paquet de signalisation de la trame du tunnel dans le champ de données utiles d'un paquet de second type de la trame du tunnel,  inserting, for each frame of the tunnel to which the packets of the second type belong, data included in the signaling packet of the tunnel frame in the payload field of a second type packet of the tunnel frame,
- modification des paquets de signalisation de chaque trame du tunnel auquel les paquets du premier type appartiennent et des paquets de signalisation de chaque trame du tunnel auquel les paquets de second type appartiennent.  modification of the signaling packets of each tunnel frame to which packets of the first type belong and signaling packets of each frame of the tunnel to which packets of the second type belong.
9) Procédé selon la revendication 2, caractérisé en ce que les paquets trames bandes de bases sont, selon leur position dans la trame, séquentiellement paquets du premier type et paquets d'un second type et en ce que le procédé comporte en outre les étapes de : 9) Method according to claim 2, characterized in that the baseband frame packets are, according to their position in the frame, sequentially packets of the first type and packets of a second type and in that the method further comprises the steps from:
- modification de l'entête de chaque paquet trames bandes de base identifié comme paquet de second type,  - modification of the header of each packet baseband frames identified as a second type packet,
- remplacement des données utiles comprises dans un champ données utile de chaque paquet de second type identifié par une information indiquant que le paquet est un paquet de second type, l'information indiquant que le paquet est un paquet du second type ayant une taille inférieure à la taille des données utiles remplacées,  replacing the useful data included in a useful data field of each packet of the second type identified by information indicating that the packet is a second type packet, the information indicating that the packet is a packet of the second type having a size less than the size of the payload replaced,
- transfert d'un autre flux de données modifié.  - transfer of another modified data stream.
10) Procédé selon la revendication 1, caractérisé en ce que les trames du premier et du second flux T2-MI ont une durée identique. 11) Procédé selon la revendication 1 ou 10, caractérisé en ce que le procédé comporte en outre les étapes de : 10) Method according to claim 1, characterized in that the frames of the first and second T2-MI flow have an identical duration. 11) Method according to claim 1 or 10, characterized in that the method further comprises the steps of:
- lecture du contenu des paquets T2-MI Ll courant de chacun des premier et second flux T2-MI,  reading the content of the current T2-MI L1 packets of each of the first and second T2-MI streams,
- modification, à partir du contenu des paquets T2-MI Ll courant de chacun des premier et second flux T2-MI lus, du contenu des paquets T2-MI Ll courant du premier flux T2-MI de manière à prendre en compte l'ajout des paquets bandes de base de la trame T2 du second flux T2-MI dans les trames T2 du premier flux T2-MI. 12) Procédé selon la revendication 11, caractérisé en ce que le procédé comporte en outre l'étape de :  modifying, from the content of the current T2-MI packets T1 of each of the first and second T2-MI streams read, the content of the current T2-MI packets T1 of the first stream T2-MI so as to take account of the addition baseband packets of the T2 frame of the second T2-MI stream in the T2 frames of the first T2-MI stream. 12) Method according to claim 11, characterized in that the method further comprises the step of:
- mise à jour des compteurs de chaque paquet T2-MI du flux T2-MI dans lequel les paquets bandes de base du second flux T2-MI ont été ajoutés. 13) Dispositif de génération d'un flux à partir de deux flux de données reçus, les flux de données étant constitués de trames, lesdits premier et second flux étant des flux de type T2-MI, chaque trame contenant un paquet de synchronisation, un paquet de signalisation donnant des informations sur la structure du flux de données et des paquets appelés trames bandes de base comprenant des données sur des flux audiovisuels, caractérisé en ce que le dispositif comporte :  updating the counters of each T2-MI packet of the T2-MI stream in which the baseband packets of the second T2-MI stream have been added. 13) Device for generating a stream from two received data streams, the data streams consisting of frames, said first and second streams being T2-MI type streams, each frame containing a synchronization packet, a signaling packet providing information on the structure of the data stream and packets called baseband frames including data on audiovisual streams, characterized in that the device comprises:
- des moyens d'alignement des deux flux de données reçus en mettant en phase les paquets de synchronisation ou les paquets de signalisation des trames de chaque flux de données reçu qui ont la même valeur de marquage temporel,  means for aligning the two data streams received by phasing the synchronization packets or the signaling packets of the frames of each received data stream which have the same time stamping value,
- des moyens d'alignement des deux flux de données reçus en mettant en phase les paquets de synchronisation ou les paquets de signalisation des trames de chaque flux de données,  means for aligning the two data streams received by phasing the synchronization packets or the signaling packets of the frames of each data stream,
- des moyens d'ajout, dans chaque trame du premier flux reçu, des paquets bandes de base de la trame du second flux dont le paquet de synchronisation est aligné avec le paquet de synchronisation de la trame du premier flux à la suite des paquets bandes de base de la trame du premier flux reçu.  means for adding, in each frame of the first received stream, baseband packets of the frame of the second stream whose synchronization packet is aligned with the packet of synchronization of the frame of the first stream following the packets bands base of the frame of the first stream received.
14) Système comportant un dispositif de génération d'un flux selon la revendication 13, comportant un dispositif de transfert d'un flux de données, ledit dispositif de transfert comportant: - des moyens d'identification parmi les paquets trames bandes de base de paquets d'un premier type, 14) System comprising a device for generating a stream according to claim 13, comprising a device for transferring a data stream, said transfer device comprising: means for identifying among packets frames base bands of packets of a first type,
- des moyens de modification de l'entête de chaque paquet trames bandes de base identifié comme paquet du premier type,  means for modifying the header of each baseband frame packet identified as a packet of the first type,
- des moyens de remplacement des données utiles comprises dans un champ données utile de chaque paquet identifié par une information indiquant que le paquet est un paquet du premier type, l'information indiquant que le paquet est un paquet du premier type ayant une taille inférieure à la taille des données utiles remplacées,  means for replacing the useful data included in a useful data field of each packet identified by information indicating that the packet is a packet of the first type, the information indicating that the packet is a packet of the first type having a size less than the size of the payload replaced,
- des moyens de transfert du flux de données modifié.  means for transferring the modified data stream.
EP13803000.2A 2012-12-13 2013-12-12 Method for generating and transferring at least one data stream Ceased EP2932724A1 (en)

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