FR2758634A1 - Decoder for tele-display data diffused over communication network - Google Patents

Abstract

The decoder (1) processes data diffused in real time by a central server (2) via a communication network (3). The decoder includes a communication port (4) receiving the data transmitted over the network. A communication module (5) stores in memory, the data received by the communication port and manages the communication protocol between the decoder and the server. A master module (10) activates the modules (11i) and puts them into communication with the decoder and ensures the communication between the modules. A module (12) produces the display scenarios corresponding to a sequence of determined images, from data received and with commands emitted from the master module to restore the images in the form of cyclic pages for display. A scenario management module (6) analyses and interprets the image frames received from the server via the communication module and also ensures maintenance of the communication between the communication module and the server. A display module (7) displays the images on a display at a rate determined by the master module.

Description

 The present invention relates to a remote display decoder processing information broadcast by a central server via a communication network.

 The decoder is intended to be integrated or associated with a terminal, itself associated with a computer, or with a microcomputer.

 The decoded information is then transmitted to one or more display units.

 The present invention also relates to a terminal equipped with such a decoder, and a remote display system comprising a plurality of terminals according to the invention, organized in networks and controlled locally or remotely from a single central server. Data is transmitted in real time between the server and the various terminals on the network.

 The information transmitted by the central server is of various types such as, for example, alpha-mosaic characters according to videotex coding, image frames or else mixed information composed of information coded according to the videotex standard and images.

 The areas of application include in particular the remote display of information intended for the general public such as auctions, promotion of new products, entertainment in public places, information relating to rail traffic intended for users and traffic regulators, ...

 At the present time, there are different methods of viewing an image on a screen of a terminal or of a microcomputer.

 Among these processes, three families of processes stand out.

 The display and coding characteristics of these families are defined by the European Post and Telecommunications Commission (CEPT) in its recommendation T / CD06-01 corresponding to the videotex standard).

These families of processes are
- the alpha-mosaic approach (Chapter 1 of the said recommendation)
- the geometric approach (Chapter 2 of the said recommendation)
- the photographic approach (Chapter 3 of the said recommendation).

 In alpha-mosaic techniques, the terminal basically manages a space composed of characters, which can be taken in different fonts, and endowed with attributes (underlining, inversion, blinking, sizes, colors, ...). The French standard "TELETEL" notably defines terminals which comply with chapter 1 of the above-mentioned recommendation.

 In geometric techniques, the terminal is a graphical type tool, managing a space of points, endowed with colors; he has all the necessary intelligence to allow him to decode and execute the elaborate drawing commands which are transmitted to him (lines, surfaces, circles, texts, ...).

 Photographic techniques allow coding of any image or document and its point-to-point transmission to a rendering terminal (which can be a console or a printing device); faxing falls into this category.

 These various visualization techniques can be implemented both in a terminal devoid of local intelligence or, on the contrary, in a microcomputer.

This is how the terminal can be dedicated to mass communication, the specifications of which are decided once and for all (this is the case of the terminal
Minitel, to French Teletel standards, designed initially to replace the telephone directory); in this case it will most often be devoid of local intelligence, despite a few high-end variants including calendar functions, automatic calls, etc.

 On the contrary, it may be that all or part of the dialogue with the user is decentralized to local stations.

 In this case, we will have stations built around a real microcomputer, capable of being downloaded both the messages to be broadcast and all the data which define the logic of their broadcast.

 The terminals are in the form of "passive" displays which have the sole function of generating characters.

 The display logic and the database of events to be displayed are managed at the plurality of local, almost autonomous stations, organized around a centralized system.

 Logical events and graphic events are the responsibility of the local station.

 This structure does not allow downloads in real time, between the central system and the various local stations, of images requiring very high speed capacities to a large number of display points (several hundred).

 The need arises in particular in the remote display application of information on rail traffic intended for users where a large number of display points are operated.

 The data relating to the position of each train in a region must be transmitted to the regional server in real time and allow updating, also in real time, of the timetables posted on the platforms or in the controllers' offices.

 The object of the present invention is to overcome this drawback in particular.

To this end, the subject of the invention is a remote display decoder processing information broadcast in real time by a central server via a communication network, and comprising
- a communication port receiving the information transmitted by the network,
a communication module storing on a storage unit the information received by the communication port and managing the communication protocol between the decoder and the server,
a master module whose function is to activate the modules to be put into communication within the decoder, and to ensure communication between these modules,
a module developing display scenarios corresponding to sequences of determined images, on the basis of the information received and of commands issued by the master module, to restore the images in the form of cyclically updated pages,
a scenario management module analyzing and interpreting the frames of the images received from the server via the communication module on the one hand, and ensuring on the other hand the communication between the communication module and the server, and
- a display module making it possible to display the images on a display device at a rate imposed by the master module (10).

 The decoder may further include a clock module making it possible to send the current time to a determined recipient module at a determined time interval.

 I1 may also further include a graphics card disposed at the output of the display module making it possible to adapt the display to a specific display device.

 This graphics card is for example a card allowing the display of text and images of photographic quality compatible with computer standards in terms of image viewing.

 The invention further relates to a remote display terminal comprising a decoder coupled to a display device.

 The display device is for example a standard television set and the graphics card is a card allowing the display of text and images of photographic quality compatible with computer standards in terms of image display.

 Finally, the invention also relates to a system for remotely displaying information broadcast in real time by a central server via a communication network, characterized in that it comprises a plurality of terminals according to any one of the claims, organized networked around the central server (2), locally managing graphic events, logical events being relegated to the level of the central server.

 An advantage of the present invention is to allow both remote commands and local display possibilities according to an intelligent dialogue between a server and a plurality of display points according to predetermined scenarios.

These scenarios correspond for example to determined image sequences in the form of a page of information displayed on a monitor or screen.
Standard TV.

 The images are displayed suddenly, cyclically, screen page by screen page. They are broadcast in real time from the server to the various display points which manage the sequence of pages themselves.

 The modular architecture of the decoder according to the invention makes it possible to split the operation of the decoder into two distinct functional assemblies, a first for the definition of the scenarios and a second for the display of the pages.

 Such a solution makes it possible to dispense with the connection protocols with the server.

 The decoder according to the invention behaves like a physical buffer arranged between the server and the display in which an autonomous logic processes the image received for the presentation and the permanent refreshment of the image to be displayed.

 The local level is very powerfully structured to manage multiple graphic events (several scenarios that coexist and take control on a simple command).

 The "logical" events are relegated to the central level, that is to say to the server level.

 According to the invention, a large number of terminals can thus be managed in real time by a single server.

 Finally, the present invention allows the compatibility of video with computer standards in terms of image display (VGA, EGA, ...).

Other advantages and characteristics of the present invention will appear more clearly on reading the description which follows, made with reference to the appended figures which represent
FIG. 1, a block diagram of the architecture of a remote display decoder according to the invention,
FIG. 2, a block diagram illustrating the operation of the master module of the decoder according to the invention,
FIG. 3, a block diagram illustrating the operation of the scenario management module of a decoder according to the invention,
FIG. 4, a block diagram illustrating the operation of the “scenario” module of the decoder according to the invention,
FIG. 5, a block diagram illustrating the operation of the display module of the decoder according to the invention, and
- Figure 6, a block diagram illustrating the operation of the decoder clock module according to the invention.

 In these figures, the homologous elements are designated by the same reference.

 The decoder according to the invention receives from the server the information necessary for the composition of the image to be displayed and validates by the interpretation of a list of a determined number of parameters, the integrity of the latter.

 It can thus receive one or more images, store them in memory, and finally display them according to the mode of use and the predefined display scenario.

 The storage capacity of the decoder is not limited and allows, if necessary, the storage of already composed images.

The main functionalities of the decoder according to the invention can be summarized in three main phases
- the first phase consists of connecting to the network via a communication interface managing protocols, commands and data, and interpretation;
- the second phase consists in the reception and interpretation of the data received from the network allowing the preparation of the pages according to a programmed scenario; and
- the third phase consists of the display of the pages by the display via a display card or graphics card (driver) with resident and / or programmable fonts.

 The architecture of a decoder 1 according to the invention is illustrated in FIG. 1.

 The decoder 1 is delimited by a discontinuous closed line.

 The decoder 1 receives the information transmitted by a server 2 via a communication network 3, for example the X25 network, via the communication port 4 of the decoder 1.

 The data received via this communication port 4 is transmitted to a communication module 5 which interfaces with the server 2.

 This module 5 stores on a storage unit, not shown, such as a disk, the information received and manages the communication protocol between the server 2 and the decoder 1.

 The information is then transmitted from the communication module 5 to a scenario management module 6 providing the interface between the communication module 5 and a display module 7.

 The output signals from the display module 7 are then transmitted to a display 8 such as for example a monitor which can receive, for example either directly information in VGA format or via a display card 9 DRIVER, adapted the type of information to display and the type of display used.

 The detailed operation of the decoder 1 according to the invention is described below with reference to FIGS. 2 to 6.

 The operation of the master module 10 is described below with reference to FIG. 2. Its function is to activate all the modules listed in its parameter file, then to ensure communication between the various modules lli.

 The master module 10 sends CMDE commands in the form of files to the Ili modules and receives on return the STATUS state of the latter in the form of files.

 On the other hand, this module 10 can execute command files.

 At startup, the master module 10 finds in the parameters file the number of modules to be managed as well as the data relating to these modules.

 All lli modules are in a sub-directory.

 For each lli module, the parameters file specifies the name of the directory and the name of the file to be executed to launch the lli module.

 At the end of loading of the modules lli or by actuating an external start-up command on the module 10, the latter sends a start-up command to each of them.

 The lli modules can suspend their execution on receipt of a stop command.

 The master module 10 sends this command to all the modules 11i when an external stop command is actuated.

 Finally, the modules lli are deactivated on receipt of an end of execution command.

 Before deactivation, all the data files of the directory of the master module 10 are erased. The master module 10 sends this command to all the modules 11i when an external command for end of execution is actuated.

 The operation of the scenario module 12 of a decoder according to the invention is described below with reference to FIG. 3.

 The scenario module 12 determines the sequence of execution of the display of the pages according to a given cycle and the display mode.

 These each correspond to the execution of a predefined scenario 13 in the form of a file.

 The very modular structure of the decoder 1 according to the invention makes it possible to split its operation into two distinct parts.

 The first part concerns the definition of scenarios.

A predefined scenario 13 includes for example instructions of the type
"display page P1 for x seconds, then display page P3 for y seconds, etc."
The page numbers Pn and the timers x, y are parameters of the program executed by the scenario module 12.

 The scenario module 12 makes it possible to execute a predefined scenario cyclically.

 This cycle is used to send orders to modules.

These orders will be interpreted by the addressee module 14.

 In this way, a new module 14 with a specific syntax can be managed by the scenario module 12 without modification thereof.

 The scenario module 12 is active on receipt of a start command sent by the master module 10.

 The operating parameters file is loaded into module 12 by this command.

 The file relating to a predefined scenario 13 is reloaded at each cycle. This file can thus be changed at any time.

 As soon as the current scenario 13 is finished, a new scenario is taken into account.

 Upon receipt of a stop command issued by the master module 10, the execution of the module 12 is suspended.

 On receipt of an end of execution command sent by the master module 10, the scenario module 12 ends its execution.

Above the scenario called "application", there is a scenario called scenario "system" whose functions are as follows
- monitoring of the connection to the local network entry point (X25),
- continuous automatic restart and reconnection
- blackout of the screens in the event of prolongation of the disconnection (the time delay being configurable), and
- regeneration of one's own system after a determined number of attempts and timeouts.

 The "system" scenario is open to other local or non-local alarm functionalities, diversion on emergency lines.

 With regard to the display of pages, the operation is the result of successive evolutions of a basic version which was initially intended to manage DRCS graphics (English abbreviation meaning "dynamically redefinable character set"), on public terminals and which composed entire pages drawing from RAM, the graphic units to be assembled.

 An important innovation brought to this version consists in loading into the RAM of DRCS fonts as a graphics unit, these fonts being optimized in size of memory occupancy.

 It is therefore the "character generator" function which is thus integrated into an architecture of networks of the X25 type in particular.

 From this first level, the decoder 1 according to the invention benefits from complete programming flexibility: a new display model can be created using market composition tools in a few hours, a complete font in less than eight days without any specific programming other than that of the scenario on the one hand and the corresponding server commands on the other.

 From there and once the display is definitively in service, all that remains is to gradually replace, in the most absolute compatibility of successive versions, the page created and the scenario 13 which corresponds to it, the particularities and above all the specific optimizations. to the application.

 Indeed, the image coded graphically zone by zone at the level of the server 2 would be too heavy in the event of permanent transfer in real time.

 In applications where this is justified, some simple optimizations to integrate into the architecture and extremely efficient allow to achieve the compaction necessary for the "telecommunication" version of the image.

 This compaction can be carried out using a module not shown dedicated to compaction, a first level of which would consist in transferring to the decoder 1 only the variable part of the image, the screen being associated by the interpreter with the page of the scenario concerned.

 This compaction is compatible with different applications.

 In a second level, compaction consists in pushing the first level even further, taking into account the behavior of the page depending on the application.

 The operation of the scenario management module 6 of a decoder according to the invention is described below with reference to FIG. 4.

 This module analyzes and interprets the frames of the images received from the server 2 via the communication module 5 of the decoder 1.

 The frames are received and acknowledged by the communication module 5 and transmitted to the scenario management module 6 in a file 15 (TRA-xxx).

 The communication between the communication module 5 and the scenario management module 6 is done through a set of command files (CMDE) and states (STATUS).

 On the other hand, the scenario management module 6 maintains communication between the communication module 5 and the server 2.

 The connection states (STATUS) received from the communication module 5 are analyzed and an appropriate action is taken to re-establish the connection in the event of a break.

 The communication between the scenario management module 6 and the master module 10 is based on the same principle as the communication between the scenario management module 6 and the communication module 5.

 When the module 6 is launched, it launches the communication module 5. The latter must be in a sub-directory of the scenario management module 6.

 Connection to server 2 is requested on receipt of a start command issued by the communication module 5.

 The connection procedure is managed using a state machine.

 On receipt of a stop command sent by the master module 10, a disconnection command is transmitted to the communication module 5.

 On receipt of a deactivation command sent by the master module 10, the deactivation command is transmitted to the communication module 5 and the scenario management module 6 ends its execution.

 During the established communication phase, the scenario management module 6 analyzes the frames (TRA-xxx) received from the server 2 via the communication module 5 and distributes the pages (PAGE 1) implemented by the different scenarios.

 The operation of the display module 7 of a decoder 1 according to the invention is described below with reference to FIG. 5.

 This module 7 makes it possible to display videotex codes and images on a display device 8.

 The display devices can be a 50 Hertz, 100 Hertz TV, a VGA screen, ...

 Several graphic cards (DRIVER) 9 can be used, in particular a display card marketed by the applicant under the name AMPH.

 This card allows the display of photographic quality images on a standard television while remaining compatible with computer standards in terms of image viewing (VGA, EGA, etc.).

 The definition of the images displayed on the television is 768 x 288 for sixteen colors and 384 x 288 for 256 colors.

 The latter is used by the display module 7.

 The module 7 is active on reception of a start command sent by the master module 10.

 When module 7 starts, the operating parameters file is loaded.

 Upon receipt of a stop command issued by the master module, the execution of module 7 is suspended.

 Upon receipt of an end of execution command issued by the master module 10, the module 7 ends its execution.

 A clock module 16 can be integrated into the decoder 1 according to the invention.

 The operation of the clock module is described below with reference to FIG. 6.

 The clock module 16 makes it possible to send the current time to a recipient module 14 via a file (CLOCK) also represented in FIG. 5.

 The module 16 accepts two commands, one to validate the sending of the time, another to inhibit it.

 The clock module 16 is active on reception of a start command sent by the master module 10.

 When module 16 starts, the clock parameters file 17 is loaded.

 On receipt of a stop command issued by the master module 10, the execution of the module 16 is suspended.

 On reception of an end of execution command sent by the master module 10, the clock module 16 ends its execution.

 A module 11i can ask the clock module 16 to validate the sending of the time information to the addressee module 14 specified in the parameter file by a parameter corresponding to the addressee module 14.

 The validation command is active.

 The commands to take the time into account are for example sent to the addressee module 14 according to regular determined time intervals.

 A module 11i can request the clock module 16 to inhibit the sending of the time information to the recipient module 14 specified in the parameter file by the parameter relating to the recipient module 14.

 The validation command is then deactivated.

Claims (7)

 1. Remote display decoder (1) processing information broadcast in real time by a central server (2) via a communication network (3), characterized in that it comprises:  - a communication port (4) receiving the information transmitted by the network (3),  a communication module (5) storing on a storage unit the information received by the communication port (4) and managing the communication protocol between the decoder (1) and the server (2),  a master module (10) having the function of activating the modules (li) to be put into communication within the decoder (1), and of ensuring communication between these modules (it),  - a module (12) developing display scenarios corresponding to sequences of determined images, on the basis of the information received and of commands issued by the master module (10), for restoring the images in the form of pages cyclically delivered to day,  - a scenario management module (6) analyzing and interpreting the frames of the images received from the server (2) via the communication module (5) on the one hand, and on the other hand ensuring the maintenance of communication between the module communication (5) and the server (2), and  - a display module (7) making it possible to display the images on a display device (8) at a rate imposed by the master module (10).  2. Decoder (1) according to claim 1, characterized in that it further comprises a clock module (16) making it possible to send the current time to a destination module (14) determined at a determined time interval.  3. Decoder (1) according to any one of claims 1 and 2, characterized in that it further comprises a graphics card (9) disposed at the output of the display module (7) making it possible to adapt the display to a determined display device (8).  4. Decoder (1) according to claim 3, characterized in that the graphic card (9) is a card allowing the display of text and images of photographic quality compatible with computer standards in terms of image display.  6. Remote display terminal, characterized in that it includes a decoder (1) according to any one of claims 1 to 5 coupled to a display device (8).  7. Terminal according to claim 6, characterized in that the display device (8) is a standard television set and in that the graphics card (9) is a card allowing the display of text and images of compatible photographic quality IT standards for image viewing.  8. Remote display system for information broadcast in real time by a central server (2) via a communication network (3), characterized in that it comprises a plurality of terminals according to any one of claims 6 and 7, organized in a network around the central server (2), locally managing graphic events; the logical events being relegated to the level of the central server.