FR3124289A1 - Method for rendering, on a terminal of a spectator, a place grouping together several distinct spaces in which a spectator moves virtually - Google Patents

Abstract

Method for rendering, on a viewer's terminal, a place grouping together several distinct spaces in which a viewer moves virtually The invention relates to a method for rendering, on a terminal (108) of a viewer (SP1 ), of a location (100) in which the viewer (SP1) moves virtually, the location (100) grouping together several distinct spaces, the spaces being filmed by respective cameras (101, 102, 103, 104), said method being characterized in that it comprises the following phases: a phase of obtaining the description of different qualities of audiovisual streams filmed in the different spaces; a phase for recovering the virtual position of the spectator (SP1);a phase for selecting the streams received so that for a given space, at a given time, the management entity (200) requests to receive a single stream variable format audiovisual from the available audiovisual streams; and, a phase of requesting restitution of the location (100) on the terminal (108) of the viewer (SP1), using the selected audiovisual streams. Figure 1

Description

Method for rendering, on a terminal of a spectator, a place grouping together several distinct spaces in which a spectator moves virtually

The technical field is that of audiovisual filming, distribution and restitution of images.

More specifically, the invention relates to a process for rendering, on a terminal of a spectator, a place grouping together several distinct spaces in which a spectator moves virtually.

The places in question are, for example, trade fairs, in which several stands can be visited. The stands held by different exhibitors constitute distinct spaces. The places can also be commercial spaces, in which we will find shelves presenting goods for sale of a given category. The different rays are then also distinct spaces present in a given place. Another possibility to which the invention applies is that of cultural places such as museums or galleries, separated into several spaces such as rooms or even stands. Another possibility is that of an academic conference space in which different rooms where conferences are presented in parallel form distinct spaces. These examples are not limiting and many other places may be affected by the invention.

The invention relates to virtual tours of places. The fact that the place can be separated into several distinct spaces will make it possible to optimize the distribution of the video streams necessary for the virtual and interactive visit of these places. The invention consists of a process for rendering, on a viewer's terminal, a place grouping together several distinct spaces in which a viewer moves virtually, a process by means of which the video streams enabling the restitution of this place are broadcast in a optimized. The process and the broadcasting of the streams will allow several spectators to carry out an interactive and virtual visit of the place in parallel, the spectators using their respective terminals, on which the place will be reproduced.

State of the art

The health situation marked by the CoVid-19 pandemic shows the interest of being able to carry out virtual visits to places. A particularly popular mode of visit is the hybrid visit. In this mode, a certain number of visitors can access the place in person. To ensure a low density of visitors, which is desirable from a health point of view, the other visitors in hybrid mode carry out a virtual visit, remotely, by video means.

A first way to make a virtual visit is to have fixed cameras in several places of the place. A website can then be offered to virtual visitors, a site which will combine textual information on the place with the possibility of consulting video streams from fixed cameras. This solution uses proven technologies, but has the disadvantage of not allowing virtual visitors to wander randomly, unplanned, in the place, and to make unplanned encounters, unlike physical visitors.

Another means of carrying out virtual visits can then be to deploy robots in the place, which can be guided by visitors, who carry cameras. The virtual visit will consist for the visitor to guide the robot in the place, relying on the video stream of the camera to find his way around the place. The video (and sound) stream may allow the visitor guiding the robot to interact with exhibitors or other visitors, whether they are physically present in the place or represented by another robot. This solution allows virtual visitors to rediscover the spontaneity of a physical visit, and its random encounters. On the other hand, it involves a high material cost, caused by the use of robots, as well as a heavy load on the network resources of the place. Indeed, each virtual visitor requires the mobilization of a complete video stream, in both directions, between the place and the virtual visitor.

The invention improves the situation.

The Invention

According to a first functional aspect, the invention relates to a method for rendering, on a terminal of a spectator, a place in which the spectator moves virtually, the place grouping together several distinct spaces, the spaces being filmed by respective cameras, said method being characterized in that it comprises the following phases implemented by a management entity:

• a phase of obtaining the description of different qualities of audiovisual streams filmed in the different spaces, the different streams being re-encoded by one or more servers in variable formats requiring a greater or lesser bit rate;
• a phase of recovering the virtual position of the spectator in the restitution of the place, this virtual position being determined by the interactions of the spectator with the restitution of the place on the terminal;
• a phase of selection of the streams received so that for a given space, at a given time, the management entity requests to receive a single audiovisual stream of variable format from among the available audiovisual streams whose description is obtained in phase d obtaining, the selection of the stream from among the streams available for a given space being a function of the distance between, on the one hand, the virtual position of the spectator at the given moment in the virtual restitution of the place, position recovered in the recovery phase, and on the other hand, the virtual position of the given space in the place; and,
• a phase of requesting restitution of the place on the viewer's terminal, using the audiovisual streams selected in the selection phase to represent the distinct spaces filmed in the place.

Thanks to the invention, spectators will obtain audiovisual streams filming the distinct spaces of a place, these streams being of variable bit rate. These streams will allow the viewer to take a virtual tour of the place and the audiovisual streams received by the viewer will be selected according to the distance between the virtual position of the viewer and that of the filmed space. This variability of streams makes it possible to optimize the bit rate necessary for the viewer. It is a dedicated management entity that implements the process by obtaining the description of the different stream formats available, by retrieving the viewer's virtual position, by selecting the streams according to the virtual distance between the viewer and the filmed space, and finally by requesting the restitution of the place on the spectator's terminal.

According to a first particular mode of implementation of the invention, the selection among the variable bit rate streams re-encoded from the stream produced by a camera filming a given space consists in taking the lowest bit rate stream when a spectator is furthest away in the virtual restitution of the filmed space, and to take streams of increasingly high bit rate as a spectator approaches in the virtual restitution of the filmed space.

Thanks to this first mode, the management entity can optimize the bit rate of the streams broadcast to the viewer's terminal. Indeed, the management entity recovers the virtual position of the spectator in the virtual restitution of the place and can from there select the flows which correspond to the spaces visible by the spectator in the restitution. As the viewer virtually approaches a filmed space in the restitution of the location, the management entity will select streams with more detailed resolution. It will therefore be transmitted to the viewer's terminal only the streams it needs, which optimizes the transmission.

According to a second particular mode of implementation of the invention, which may be implemented alternatively or cumulatively with the previous mode, the broadcasting of the variable bit rate streams between, on the one hand, the server or servers which have re- encoded the variable bit rate streams, and, on the other hand, the spectators' terminals, implements a content distribution network, also called CDN (for Content Delivery Network in English).

In this second embodiment, the method uses a content distribution network (CDN, for Content Delivery Network ) in order to broadcast the re-encoded streams of variable bit rate from the restored location. The advantage of this embodiment is to use a proven and effective method for broadcasting audiovisual streams to a large number of viewers.

According to a third particular mode of implementation of the invention, which may be implemented alternatively or cumulatively with the previous modes, the method comprises, at the request of the terminal of a spectator, a passage in a so-called mode of interaction , in which a direct audiovisual communication is established between on the one hand said terminal of a spectator and on the other hand a camera filming a space distinct from the place, the communication using only one of the streams broadcast from the place.

Thanks to this particular mode of implementation of the invention, the viewer can enter into communication with one or more correspondents located in the place. This may be, for example, a correspondent who holds a stand at a trade show if the filmed space with which the viewer's terminal comes into contact is this stand. To optimize the distribution of streams from the location, a single stream will be used for communication.

According to a fourth particular mode of implementation of the invention, which can be implemented cumulatively with the previous mode, the request is transmitted following pointing in the virtual restitution of the place of the part corresponding to the stream from a camera filming a separate space and in that this score triggers on the one hand a transmission of a request to cut the variable bit rate streams broadcast to the viewer's terminal by the content distribution network and on the other hand a request to establishment of audiovisual communication in real time between the viewer's terminal and the camera which films the distinct space pointed to during said pointing.

Thanks to this mode, it is the spectator who will be able to trigger the transition to so-called interaction mode. Following the virtual exploration of the returned location, the viewer can decide to directly question a correspondent located in a filmed space separate from the location, for example the manager of a stand in the case where the location is a trade show. In an optimized way, switching to so-called interaction mode will limit the broadcast to the viewer to a single stream, the one that is useful for communication. Furthermore, the use of a content delivery network (CDN) introduces a latency of a few seconds, which is not a problem for the restitution of the place, but which would prevent the establishment of a communication between the spectator and a correspondent. in filmed space. This is why switching to the so-called interaction mode includes cutting off the streams broadcast via the content delivery network (CDN) to the viewer to establish direct communication.

According to a fifth particular mode of implementation of the invention, which can be implemented cumulatively with the previous mode, the transmission of the request is scheduled to take place at a given date and time.

Thanks to this embodiment, it is possible to program switches in so-called interaction mode for given spectators to given correspondents in distinct filmed spaces, without explicit intervention by the spectators. The interest of this mode is to facilitate the virtual visit of the place in the case of the trade show for a spectator who will schedule the appointments he wishes to have, or register for a standard visit already scheduled. The programming of the scales makes it possible to optimize the diffusion of the flows.

According to a first material aspect, the invention relates to a management entity implementing a method for rendering on a terminal of a spectator a place in which the spectator moves virtually, the place grouping together several distinct spaces, the spaces being filmed by respective cameras, said entity comprising the following modules:

• a module for obtaining the description of different qualities of audiovisual streams filmed in the different spaces, the different streams being re-encoded by one or more servers in variable formats requiring a greater or lesser bit rate;
• a module for recovering the virtual position of the spectator in the restitution of the place, this virtual position being determined by the interactions of the spectator with the restitution of the place on the terminal;
• a module for selecting the streams received so that for a given space, at a given time, the management entity requests to receive a single audiovisual stream of variable format from among the audiovisual streams available whose description is obtained by the module obtaining, the selection of the stream from among the streams available for a given space being a function of the distance between, on the one hand, the virtual position of the spectator at the given moment in the virtual restitution of the place, position recovered by the recovery module, and on the other hand, the virtual position of the given space in the place; and,
• a module for requesting restitution of the place on the viewer's terminal, using the audiovisual streams selected by the selection module to represent the distinct spaces filmed in the place.

According to a second hardware aspect, depending on the first hardware aspect, the invention relates to a viewer terminal comprising a management entity according to the first hardware aspect, entity implementing a method for rendering on the terminal a place in which the viewer moves virtually, the place bringing together several distinct spaces, the spaces being filmed by cameras.

Thanks to this material aspect, the management entity is included in the spectator's terminal on which the place is virtually restored, grouping together several distinct spaces, a place visited virtually by the spectator. This aspect makes it possible to integrate the management entity into the viewer's terminal and to achieve a simplified deployment of the restitution process.

Spectator terminals can be any type of terminal. For example, they may be personal computers, of the workstation or laptop type. It can also be tablet-type computers. It can also be mobile phones with computing capabilities such as ordiphones (for smartphones in English) or phablets (for phablets in English), namely an intermediate terminal between a ordiphone and a tablet as regards the screen size.

According to another hardware aspect, depending on the first hardware aspect, the invention relates to a server comprising a management entity according to the first hardware aspect, entity implementing a method for rendering on the terminal a place in which the spectator moves virtually, the place grouping together several distinct spaces, the spaces being filmed by cameras.

Thanks to this hardware aspect, it is possible in the hardware architecture implementing the method to separate the entity implementing the restitution method from the terminal on which the virtual restitution of the location is carried out. A server can group together one or more management entities which will implement the restitution method on several spectator terminals. The server can be a hardware server deployed in the exhibition venue or, on the contrary, close to the spectators' terminals. The server can also be a virtual server, deployed in a cloud computing infrastructure.

According to another hardware aspect, the invention relates to a computer program capable of being implemented by a management entity, the program comprising code instructions which, when implemented by a processor, implement the restitution method defined above.

The computer program may be developed in any type of computer language, whether compiled or interpreted or any combination of the two.

Finally, according to another material aspect, the invention relates to a data medium on which is recorded a computer program comprising a sequence of instructions for the implementation of the restitution method defined above when it is loaded into and executed by a processor.

Data carriers can be any entity or device capable of storing programs. For example, the media may comprise a storage medium, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or else a magnetic recording medium such as a hard disk. On the other hand, the media can be transmissible media such as an electrical or optical signal, which can be conveyed via an electrical or optical cable, by radio or by other means. The programs according to the invention can in particular be downloaded from an Internet-type network. Alternatively, the information carrier may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

The invention will be better understood on reading the following description, given by way of example, and made with reference to the appended drawings in which:

represents a place in which there are several distinct spaces filmed by cameras, the place being visited virtually by a first spectator and a second spectator being in interaction with a correspondent located in the place.

illustrates a possible example of restitution of a space distinct from the place in the form of three-dimensional brick.

illustrates a possible example of virtual rendering of the location on a viewer's terminal, by performing a virtual fly-over of the location.

illustrates another possible example of virtual restitution of the location on a spectator's terminal, by carrying out a virtual exploration of the location at ground level.

illustrates a possible man-machine interface for a spectator on the one hand and an exhibitor in charge of a space separate from the venue on the other.

Detailed description of one or more embodiments of the invention

The represents a place 100 and a management entity 200. The management entity 200 implements the method which will make it possible to restore the place 100 on the terminals 108 and 107, terminals associated respectively with the spectators SP1 and SP2.

The viewer SP1 takes a virtual tour of the place 100 via his terminal 108. The terminal 108 is a terminal making it possible to offer the viewer SP1 an immersive experience, called virtual reality, but the invention can be applied to any type of terminal, such as for example a personal computer, of the workstation or laptop type. It can also be a tablet type computer. It can also be a mobile phone with computing capabilities such as a ordiphone (for smartphone in English) or a phablet (for phablet in English), namely an intermediate terminal between a ordiphone and a tablet in regarding screen size.

The virtual restitution of the place 100 on the terminal 108 of the viewer SP1 is based on audio-visual streams from separate spaces of the place 100 filmed by respective cameras 101, 102, 103 and 104. The streams from the cameras 101, 102, 103 and 104 are re-encoded by an SRV server into several streams of variable bit rate. A single SRV server is represented in the , but other real-time broadcasting architectures are possible, using several servers. The variable bit rate of the re-encoded streams is represented in the by the variable thickness of the lines coming from the server SRV for each stream coming from the cameras 101, 102, 103 and 104.

The management entity 200 implements the location restitution process 100 on the terminal 108 of the viewer SP1 via four modules:

• the module 201 obtains the description of the different qualities of available audio-visual streams re-encoded by the server SRV from the cameras 101, 102, 103 and 104;
• the module 202 retrieves the virtual position of the spectator SP1 in the rendering of the place 100 on the terminal 108, this virtual position being determined by the interactions of the spectator SP1 with the rendering of the place 100 on the terminal 108;
• the module 203 selects from among the available streams re-encoded by the server SRV, the description of which was obtained by the module 201, streams according to the virtual position of the spectator SP1 in the restitution of the place 100 on the terminal 108, position retrieved by module 202; and,
• the module 204 requests the restitution of the place 100 on the terminal 108 of the viewer SP1 using the streams selected by the module 203.

The streams selected by the module 203 are broadcast by a content delivery network CDN (for Content Delivery Network in English). The content distribution network CDN is included in a wider communication network INT, here the Internet network. Any type of communication network can be envisaged between the place 100 and the terminals 108 and 107 of the spectators SP1 and SP2, for example a private connection, of the WAN type (for Wide Area Network in English) or else a local area network LAN (for Local Area Network in English) if the viewers are close to location 100.

The spectator SP2, meanwhile, is placed in a so-called interaction mode. The fact that SP2 is in an interaction mode can take place after a virtual visit by the spectator SP2 of the place 100, a visit similar to that carried out by the spectator SP1. The viewer SP2 has the terminal 107 which is a portable computer, but the invention can be applied to any type of terminal, such as for example a computer of the workstation type. It can also be a tablet type computer. It can also be a mobile phone with computing capabilities such as a ordiphone (for smartphone in English) or a phablet (for phablet in English), namely an intermediate terminal between a ordiphone and a tablet in regarding screen size. The viewer SP2 also has a camera 106, for example of the webcam type, but which can be any type of camera, integrated or not in the terminal 107.

The viewer SP2 is placed in a mode of interaction with the correspondent COR who is filmed in the place 100 by the camera 105. A point-to-point type audiovisual stream is established between the camera 105 on the one hand and the camera 106 and the terminal 107 of the viewer SP2 on the other hand. This flow is carried by the communication network INT, here the Internet network. Any type of communication network can be envisaged between the place 100 and the terminal 107 of the viewer SP2, for example a private link, of the WAN type (for Wide Area Network in English) or else a local network LAN (for Local Area Network in English). English) if the viewer SP2 is close to location 100. On the other hand, the point-to-point communication between the correspondent COR and the viewer SP2 cannot go through the CDN content delivery network because this would introduce too much latency, detrimental to communication.

In a particular embodiment of the invention, the selection module 203 of the variable bit rate streams re-encoded by the server SRV will implement a selection according to the distance between the virtual position of the spectator SP1 in the restitution of the place 100 on the terminal 108 and the virtual position of the space filmed by one of the cameras 101, 102, 103 and 104, namely that the selection will consist of taking the lowest bit rate stream the further the virtual position of the spectator SP1 is of the virtual position of the filmed space. In the example illustrated by the , we see that the management entity 200 has selected for the stream from the camera 101 a stream re-encoded by the SRV server with a higher bit rate than for the stream from the camera 104 re-encoded by the SRV server, which is graphically translated by a thicker line. This translates that, in the virtual restitution of the place 100 on the terminal 108, the spectator SP1 is closer to the space filmed by the camera 101 than to the space filmed by the camera 103.

Furthermore, no stream re-encoded by the server SRV from the stream filmed by the camera 102 is selected by the selection module 203 of the management entity. This reflects the fact that the space filmed by the camera 102 is not visible to the viewer SP1 in the virtual restitution of the place 100 on the terminal 108.

The clear advantage of the invention here is the optimization of the broadcasting of audio-visual streams. Indeed, only the streams necessary for the restitution of the 100 are broadcast via the INT communication network and the CDN content distribution network, which makes it possible to avoid network saturation. The use of the CDN content delivery network is particularly suited to this context.

As already seen, the invention includes the possibility of switching to a so-called interaction mode. The shows that the terminal 107 of the spectator SP2 has passed into such a mode of interaction with the camera 105 located in the place 100, a camera which films a space where a correspondent COR is located.

The transition from a virtual visit of the place 100 to the so-called interaction mode takes place, in one embodiment, following a request from the terminal 107 of a viewer SP2. In one embodiment, this request consists of a pointing in the virtual restitution of the place 100 of the space filmed by the camera 105. This pointing can in particular be carried out by the viewer SP2. In this embodiment, the spectator SP2 decides during his virtual visit of the place 100 to switch to an interaction mode, for example because he wants to enter into communication with a correspondent COR who is in the space filmed by the camera 105.

Of course, this example is not limiting. In another embodiment, switching to an interaction mode is programmed to take place at a specific date and time. This passage can be programmed by the viewer SP2 or else by the correspondent COR. In a context where the place 100 is for example a trade show, one can have either the spectator SP2 who programs a series of virtual visits of different stands, or the correspondent COR, who is in charge of a stand in the place 100 which schedules a series of virtual meetings with a series of business prospects.

In all cases, switching to an interaction mode implies that all of the streams which do not come from the camera 105 with which the point-to-point communication is established are no longer selected by the management entity 200 and addressed to the terminal 107 of the viewer SP2. Furthermore, the stream that is used for point-to-point communication between the camera 105 and the terminal 107 of the viewer SP2 as well as the camera 106 must no longer go through the content distribution network CDN because this type of network introduces a detrimental latency. to real-time communication. On the other hand, the flow in question always passes through the communication network INT.

This embodiment is of course not limiting. It is for example possible that the virtual restitution of the place 100 on the terminal 107 of the viewer SP2 continues, for example in a smaller window of his screen, while he is otherwise in point-to-point communication with the correspondent COR filmed by the camera 105. The advantage of this embodiment is to keep a view of the events that take place elsewhere in the place 100. In this case, the streams other than the stream used for point-to-point communication with the camera 105 remain of course selected by the management entity 200 according to the virtual position of the spectator SP2 in the restitution of the place 100.

In one embodiment, the management entity 200 is part of the terminal 108 on which the location 100 is virtually rendered. The advantage of this embodiment is to achieve strong integration between the terminal 108 on which the location is rendered 100 and the management entity 200 which implements the restitution method.

As already specified, the terminal can be any type of terminal, such as for example a terminal 108 making it possible to offer the spectator SP1 an immersive experience, called virtual reality, but also for example a personal computer, of the workstation type (not represented on the ) or laptop computer 107. It can also be a tablet-type computer (not shown in the figure). ). It can also be a mobile phone with computing capabilities such as a smartphone (for smartphone in English), not shown in the figure. , or a phablet (for phablet in English), not represented on the , namely an intermediate terminal between a smartphone and a tablet in terms of screen size. The viewer SP2 can also have access to a camera 106, for example of the webcam type or any other type of camera, this camera being or not integrated into the terminal 107 or 108 of the viewer SP1 or SP2.

In another embodiment, the management entity 200 is included in a server not represented on the . The management entity 200 will then communicate with the terminal 108 via a communication link (not represented on the ) which can use for example the INT network. The advantage of this mode is to separate the entity 200 implementing the restitution method from the terminal 108 on which the virtual restitution of the place 100 is carried out. A server can group together one or more management entities 200 which will implement the restitution method on several spectator terminals, namely 107 and 108 in the . The server can be a hardware server deployed in the exhibition space 100 or on the contrary near the spectator terminals 107 and 108. The server can also be a virtual server, deployed in a cloud computing infrastructure (for cloud computing in English).

The illustrates a way in which a space distinct from the place 100 can be rendered on the terminal 108 of the spectator SP1. In this embodiment, the filmed space is restored in the form of a three-dimensional brick.

In the case illustrated, the location 100 is a trade show and the spaces filmed are various commercial exhibition stands. This example is in no way limiting of the embodiment which is illustrated in . The place 100 can equally well be a museum and the filmed spaces of the particular rooms, or any other example of a place 100 separated into distinct spaces.

In the embodiment, the space is filmed horizontally by a camera placed at human height, as shown in the LIV image in the left part of the . As already indicated, the space is a commercial exhibition stand. In addition to the LIV audio-visual stream, the exhibitor responsible for the stand must provide two additional images which may be a text MSG1 or a photograph MSG2. A smaller or larger number of images can be provided by the exhibitor knowing that the restitution process will fill in the gaps with default images. These images can be, for example, advertising messages in a commercial context or any other message. Other choices of images can be made, such as an animated image, or an audio-visual stream.

From the audio-visual stream LIV and the images MSG1 and MSG2, the terminal 108 of the spectator SP1 will construct the image of a three-dimensional brick, restored on the terminal. The LIV flux is used to render the longest side of the three-dimensional brick, to give the impression of an exhibition stand. Other restitution geometries are possible. The management entity 200 selects the quality and therefore the bit rate of the audio-visual stream LIV according to the virtual distance of the spectator SP1 with the virtual restitution of the filmed space in three-dimensional brick.

The illustrates a way in which the place 100 can be rendered from the rendering of distinct spaces in the form of three-dimensional bricks as illustrated by the .

The three-dimensional bricks are placed in the virtual restitution of the place 100 in the same way as the corresponding commercial exhibition stands or distinct filmed spaces are placed in the place 100. The virtual restitution of the place 100 is then a perspective image of the overview by the spectator SP1 of place 100, in which the distinct spaces filmed are restored by a three-dimensional brick. The interaction of the viewer SP1 with the terminal 108 will enable him to move virtually in the virtual restitution of the place 100. The management entity 200 will select the LIV streams making it possible to build the three-dimensional bricks according to the distance between the virtual position of the spectator SP1 and the restitution in the form of a three-dimensional brick of the space filmed by the LIV stream.

The illustrates another way in which the place 100 can be rendered from the rendering of distinct spaces in the form of three-dimensional bricks as illustrated by the .

The three-dimensional bricks are placed in the virtual restitution of the place 100 in the same way as the commercial exhibition stands or corresponding filmed distinct spaces are placed in the place 100. The virtual restitution of the place 100 is then a perspective image in in which the spectator SP1 is placed at the height of a man and explores the place 100, in which the distinct spaces filmed are restored by a three-dimensional brick. The interaction of the spectator SP1 with the terminal 108 will allow him to move virtually in the virtual restitution of the place 100, while remaining at eye level, as if he were performing a virtual walk. As in the other embodiments, the management entity 200 will select the LIV streams making it possible to construct the three-dimensional bricks according to the distance between the virtual position of the viewer SP1 and the restitution in the form of a three-dimensional brick of space filmed by the LIV stream.

In other possible embodiments, the three-dimensional bricks corresponding to filmed spaces will not be placed in the virtual restitution of location 100 in the same way as the filmed spaces are located in location 100.

For example, in one embodiment, this may be the viewer SP1 who chooses the spaces he wishes to see rendered in the virtual rendering of the place 100 on the terminal 108. In this embodiment, the viewer SP1 can organize the bricks three-dimensional images that restore filmed spaces unrelated to the situation of the filmed spaces in location 100.

In another embodiment, the layout of the three-dimensional bricks corresponds to appointments made by the viewer SP1 with correspondents COR located in separate filmed spaces of the location 100. The viewer SP1 may have programmed a series of virtual visits and meetings with COR correspondents. The encounters between the spectator SP1 and these Cor correspondents will take place in the so-called interaction mode. To move from one meeting to another, the viewer SP1 will move around in the virtual rendering of location 100, in which the three-dimensional bricks corresponding to the distinct filmed spaces where the correspondents COR with whom the viewer SP1 has appointments are placed according to a layout consistent with the succession of appointments and not according to the actual layout of the distinct spaces filmed in location 100.

The illustrates a possible embodiment of the invention as regards the man-machine interface made available on the one hand to the spectators SP1, SP2, SP3, SP4, SP5, SP6 and SP7, and on the other hand to the correspondent COR which is located in a space separate from the place 100 and is filmed by the camera 101. The correspondent COR is in a mode of interaction with the viewer SP1. This implies that the communication stream between COR and SP1 is an AV audio-visual stream so that COR and SP1 can communicate orally. Conversely, the spectators SP2, SP3, SP4, SP5, SP6 and SP7 take a virtual tour and find themselves close in their virtual restitution to the space distinct from the place 100 in which the correspondent COR filmed by the camera 101 is located. viewers SP2, SP3, SP4, SP5, SP6 and SP7, the stream received VID is only video, without audio, to preserve the confidentiality of exchanges between COR and SP1. In one embodiment, the choice of whether or not to restrict the audio-visual stream from the camera 101 which films the space distinct from the place 100 in which the COR correspondent is located is made by said COR correspondent or by a person in charge of said space.

In the embodiment illustrated by the , the spectators SP1, SP2, SP3, SP4, SP5, SP6 and SP7, the virtual restitution of the place 100 is limited to a stream captured by the camera 101, whether this stream is audio-visual AV or video only VID, following a placement of the virtual positions of the spectators SP1, SP2, SP3, SP4, SP5, SP6 and SP7 in the virtual restitution of the place 100 in maximum proximity to the virtual restitution of the space filmed by the camera 101.

In one embodiment still illustrated by the , the spectators SP1, SP2, SP3, SP4, SP5, SP6 and SP7 are filmed by a camera, for example a web camera like the camera 106 of the . Spectators SP1, SP2, SP3, SP4, SP5, SP6 and SP7 have feedback in their man-machine interface indicating to them the image filmed by their camera in the upper right corner of the screen. Still in this embodiment, the correspondent COR is informed on a man-machine interface illustrated in the right part of the that the spectators SP1, SP2, SP3, SP4, SP5, SP6 and SP7 are in a virtual position very close to the virtual restitution of the space distinct from the place 100 filmed by the camera 101 in which the correspondent COR is located, this information being given by the return of the cameras which film the spectators SP1, SP2, SP3, SP4, SP5, SP6 and SP7 in the man-machine interface of the correspondent COR. In another embodiment, the spectators who are not filmed by cameras are represented by default images or avatars of their choice.

In one embodiment still illustrated by the , the correspondent COR has a terminal (not shown in the figure) and a request from said terminal allows passage into a so-called mode of interaction with a spectator whose virtual position in the restitution of the place 100 is very close to the space distinct from the place 100 filmed by the camera 101 in which the correspondent COR is located, and the said request is transmitted following a pointing in the man-machine interface of the correspondent COR towards an image of a spectator.

In one embodiment still illustrated by the , the man-machine interface made available to the correspondent COR highlights the viewer SP1 who is in interaction mode with the correspondent COR. In the , this highlighting is illustrated by a thick frame around the filmed image of the spectator SP1 in the man-machine interface, but any other mode of graphic representation is possible.

Finally, let us point out here that, in this text, the term "module" can correspond either to a software component or to a hardware component or a set of hardware and software components, a software component itself corresponding to one or more programs or computer sub-programs or more generally to any element of a program capable of implementing a function or a set of functions as described for the modules concerned. In the same way, a hardware component corresponds to any element of a hardware (or hardware) assembly capable of implementing a function or a set of functions for the module concerned (integrated circuit, smart card, memory card, etc. .).

Claims (11)

Method for rendering, on a terminal (108) of a spectator (SP1), a place (100) in which the spectator (SP1) moves virtually, the place (100) grouping together several distinct spaces, the spaces being filmed by respective cameras (101, 102, 103, 104), said method being characterized in that it comprises the following phases implemented by a management entity (200):

• a phase of obtaining the description of different qualities of audiovisual streams filmed in the different spaces, the different streams being re-encoded by one or more servers (SRV) in variable formats requiring a greater or lesser bit rate;
• a phase of recovering the virtual position of the spectator (SP1) in the restitution of the place (100), this virtual position being determined by the interactions of the spectator (SP1) with the restitution of the place (100) on the terminal (108);
• a phase of selecting the streams received so that for a given space, at a given time, the management entity (200) requests to receive a single audiovisual stream of variable format from among the available audiovisual streams whose description is obtained in the obtaining phase, the selection of the stream from among the streams available for a given space being a function of the distance between, on the one hand, the virtual position of the spectator (SP1) at the given moment in the virtual restitution of the place (100), position recovered in the recovery phase, and on the other hand the virtual position of the given space in the place (100); and,
• a phase of requesting restitution of the place (100) on the terminal (108) of the viewer (SP1), using the audiovisual streams selected in the selection phase to represent the distinct spaces filmed in the place (100).

Restitution method according to Claim 1, characterized in that the selection among the re-encoded variable bit rate streams from the stream produced by a camera (101, 102, 103, 104) filming a given space consists in taking the stream of lowest bit rate when a spectator (SP1) is furthest away in the virtual restitution of the filmed space, and to take increasingly high bit rate streams as a spectator (SP1) brings closer in the virtual restitution of the filmed space. Restitution method according to Claims 1 to 2, characterized in that the broadcasting of the variable bit rate streams between, on the one hand, the server or servers (SRV) which have re-encoded the variable bit rate streams, and, on the other hand, on the other hand, the terminals (108) of the spectators (SP1), implement a content distribution network (CDN), also called CDN (for Content Delivery Network in English). Restitution method according to Claims 1 to 3, characterized in that it comprises, at the request of the terminal (107) of a viewer (SP2), a passage into a so-called interaction mode, in which a direct audiovisual communication is established between on the one hand said terminal (107) of a spectator (SP2) and on the other hand a camera (105) filming a space separate from the place (100), the communication using only one of the streams broadcast from the place ( 100). Restitution method according to Claim 4, characterized in that the request is transmitted following pointing in the virtual restitution of the place (100) of the part corresponding to the stream coming from a camera (105) filming a distinct space and in that this score triggers on the one hand a transmission of a request to cut the variable bit rate streams broadcast to the terminal (107) of the viewer (SP2) by the content delivery network (CDN) and on the other hand a request to ''establishment of an audiovisual communication in real time between the terminal (107) of the spectator (SP2) and the camera (105) which films the distinct space pointed to during said pointing. Restitution method according to Claim 4, characterized in that the transmission of the request is programmed to take place at a given date and time. Management entity (200) implementing a method for rendering on a terminal (108) of a spectator (SP1) a place (100) in which the spectator (SP1) moves virtually, the place (100) grouping together several spaces distinct, the spaces being filmed by respective cameras (101, 102, 103, 104), said entity (200) comprising the following modules:

• a module (201) for obtaining the description of different qualities of audiovisual streams filmed in the different spaces, the different streams being re-encoded by one or more servers (SRV) in variable formats requiring a greater or lesser bit rate;
• a module (202) for recovering the virtual position of the spectator (SP1) in the restitution of the place (100), this virtual position being determined by the interactions of the spectator (SP1) with the restitution of the place (100) on the terminal ( 108);
• a module (203) for selecting the streams received so that for a given space, at a given time, the management entity (200) requests to receive a single audiovisual stream of variable format from among the available audiovisual streams whose description is obtained by the obtaining module (201), the selection of the stream from among the streams available for a given space being a function of the distance between, on the one hand, the virtual position of the spectator (SP1) at the given moment in the virtual restitution of the place (100), position retrieved by the recovery module (202), and on the other hand the virtual position of the space given in the place (100); and,
• a module (204) requesting restitution of the place (100) on the spectator's terminal (SP1), using the audiovisual streams selected by the selection module (203) to represent the distinct spaces filmed in the place (100).

Terminal (108) of spectator (SP1) comprising a management entity (200) according to claim 7 implementing a method for rendering on the terminal (108) a place (100) in which the spectator (SP1) moves virtually, the place (100) grouping together several distinct spaces, the spaces being filmed by cameras (101, 102, 103, 104). Server comprising a management entity (200) according to claim 7 implementing a method for rendering on the terminal (108) of a spectator (SP1) a place (100) in which the spectator (SP1) moves virtually, the place (100) grouping together several distinct spaces, the spaces being filmed by cameras (101, 102, 103, 104). Computer program capable of being implemented by a management entity (200) according to claim 7, said program comprising instructions which, when implemented by a processor, implement a method of rendering according to claim 1 . Data carrier on which is recorded a computer program comprising a sequence of instructions for the implementation of the restitution method according to claim 1 when it is loaded into and executed by a processor.