WO2021084184A1

WO2021084184A1 - Method for broadcasting a video by a client device, client device and associated system

Info

Publication number: WO2021084184A1
Application number: PCT/FR2020/051872
Authority: WO
Inventors: Jean-Bernard LEDUBY; Martin CONAN
Original assignee: Orange
Priority date: 2019-10-28
Filing date: 2020-10-16
Publication date: 2021-05-06
Also published as: FR3102595A1; FR3102595B1

Abstract

The invention relates to a method for broadcasting, by a client device (11), a video acquired by a virtualisation platform (12) from a video platform (13) and transmitted, in the form of a video stream, to a virtualisation application (APP_VIR) of the client device. Said method includes, on receipt, by the virtualisation application, of information about a change in the video broadcasting mode: - a discovery (E10), by the virtualisation application, of a video application (APP_VID) of the client device, and, if the discovery is positive: - a transmission (E20) of information to the video application, - an access (E30), by the video application, to the video according to said information, - a broadcast (E40), by the video application and in replacement of the transmitted video stream, of the video according to said information.

Description

Title of the invention: Method of broadcasting a video by a client device, client device and associated system

Prior art

The present invention belongs to the general field of the broadcasting of video content.

It relates more particularly to a method of broadcasting a video acquired by an office virtualization platform to a video platform and transmitted, in the form of a video stream, from the virtualization platform to a client device. The invention finds a particularly advantageous application, although in no way limiting, for applications in which the client device is a thin client, such as in particular a television decoder (also called "Set Top Box" in the English literature) connected to display means.

Computer virtualization technology is well known today. In its main general, it consists in creating and executing, on the same virtualization platform (commonly called “host machine”), one or more virtual representations of a computer or of its various resources, such as for example an operating system. , a server, a desktop, a storage system, a network, etc. These simulated resources are in all points identical to their physical versions located on the client side.

The virtualization platform conventionally behaves a plurality of layers, including in particular:

- a virtualization layer (also called "Virtual Machine Manager" in the English literature) or hypervisor, and

- a layer of one or more virtual machines.

Each virtual machine runs a single operating system instance, called a guest operating system, and operates independently of the other virtual machines of the virtualization platform. Each guest operating system requires an isolated virtual machine for it to run. The virtualization software layer (or hypervisor), on the other hand, is a layer that runs under virtual machines and provides the execution environment.

Virtualization technology can be declined according to different types, such as for example server virtualization, network virtualization, storage virtualization, and the like.

For example, desktop virtualization (also referenced by "VDI", acronym of the English expression "Virtual Desktop Infrastructure") corresponds to the practice of hosting a desktop operating system in a running virtual machine execution on a hardware layer of a virtualization platform, such as typically a remote server in a data center (“datacenter” in the English literature), from a dedicated hardware or software program. In this way, a user's personalized desktop (such as a Windows PC environment), with its applications and access to its data, is executed in a virtual machine on a server, and thus remains accessible from a client device remote from the virtualization platform as well as capable of communicating and exchanging data with the latter.

[0007] The advantages of desktop virtualization are well known. We can mention in particular the accessibility to a virtual office and its applications from a smartphone, a tablet, a PC, or even an HTML5 web browser; better data security (due to the remote access to the virtualization platform); remote secure access to a corporate office environment, etc.

Of course, desktop virtualization, just like virtualizations of another type, also lends itself to remote playback of video content. Thus, when a user of a client device wishes to watch a video via the virtual environment created by the virtualization platform, the latter acquires said video from a video platform, such as for example a server owned by a content provider. video (ex: Youtube, Netflix, etc.). The video thus acquired is transmitted, in the form of a video stream, from the virtualization platform to a virtualization application of the client device. The implementation of such a video stream is carried out in a manner known per se by real-time encoding techniques.

[0009] The broadcast of the video, via said video stream, is also carried out according to a predetermined display mode, for example a window of a native video player attached to the video platform and ultimately occupying a fraction of a screen fitted to the client device. However, when the user wishes to modify this display mode, for example when switching the video to full screen, the quality of the rendering of the broadcast is affected (unadjusted resolution leading to a non-graphic rendering. optimized). Such degradation results not only from certain limitations of the communication network (poor quality of service, transmission delays of the stream too long, jitter, etc.) but also above all from the real-time encoding of the video stream which is not suitable. to such a modification of the display mode.

[0010] Thus, and in general, virtualization, due to the real-time encoding of data inherent in the implementation of said video stream, still struggles to provide satisfactory results with regard to the distribution of content. video.

Disclosure of the invention The object of the present invention is to remedy all or part of the drawbacks of the prior art, in particular those set out above, by proposing a solution which allows, for a client device connected to a virtualization platform, to improve the rendering of a video broadcast on the client device side.

To this end, and according to a first aspect, the invention relates to a method of broadcasting, by a client device, a video acquired by a virtualization platform from a video platform and transmitted, in the form of a video stream, from the virtualization platform to a virtualization application of the client device, the broadcasting of the video by the virtualization platform conforming to a first broadcasting mode and the video stream comprising a first item of information relating to a storage location video at the video platform level. In addition, said method comprises, during the transmission of the video stream and on reception, by the virtualization application, of a second item of information relating to a change from said first broadcasting mode to a second broadcasting mode:

a step of discovering, by the virtualization application, a video application of the client device, said video application being able to broadcast and control the broadcasting of the video from the video platform, and, if the discovery is positive:

a step of transmission, by the virtualization application to the video application, of said first and second information,

- a step of access, by the video application and from the video platform, to the video according to the first information,

a stage of broadcasting, by the video application and replacing the transmitted video stream, of the video from the video platform, said broadcasting being adapted as a function of the second item of information.

[0013] Thus, in accordance with said broadcasting method, it is proposed to replace the video stream originating from the virtualization platform by a broadcast emanating from the single video application belonging to the client device. In other words, the rendering and the control of the broadcasting of this video are delegated to said video application, so that the virtualization platform no longer plays the role of intermediary between the client device and the video platform. Proceeding in this way makes it possible to obtain a raw broadcast of the video. The term “raw” refers here to the fact that the real-time encoding undergone by the video when it is transmitted in the form of a stream is now absent at the level of the client device.

[0014] Due to this delegation of rendering and control of the broadcast of the video to the video application of the client device, the invention offers the advantageous possibility of eliminating all or part of the effects leading to the degradation of the broadcast during the change of broadcasting mode and linked, in particular, to the real-time encoding of the video stream. In fact, by providing the client device with a suitable video application, the latter is able to manage in an improved manner (ie without real-time encoding) said change of broadcasting mode, such as for example the passage from a reduced broadcasting window to a full screen mode.

In particular embodiments, the diffusion method may further include one or more of the following characteristics, taken in isolation or in any technically possible combination.

In particular embodiments, the method also comprises:

- during the broadcasting of the video by the video application, a step of reception, by the video application, of a third item of information relating to a change from said second broadcasting mode to said first broadcasting mode,

a step of resuming, by the virtualization platform and replacing the video broadcast by the video application, the broadcasting of the video acquired and transmitted in the form of the video stream, said broadcasting being adapted as a function of the third item of information.

[0017] According to such arrangements, the broadcasting method according to the invention is advantageously reversible as regards the support for rendering and for controlling the broadcasting of the video. In other words, when returning to the first display mode, the rendering and the control of the video are again delegated to the virtualization platform via the video stream, which advantageously makes it possible not to unnecessarily request the resources of the device. client vi running the video application.

In particular embodiments, the first and second broadcast modes correspond respectively to a broadcast of the video in a first and a second broadcast areas, the size of the first area being less than the size of the second zone.

In particular embodiments, the discovery step is based on the DIAL protocol.

In particular embodiments, said first item of information corresponds to an identifier.

According to a second aspect, the invention relates to a computer program comprising instructions for implementing the broadcasting method according to the invention when said program is executed by a computer.

This program can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in n ' any other desirable shape. According to a third aspect, the invention relates to an information or recording medium readable by a computer on which a computer program according to the invention is recorded.

The information or recording medium can be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or else a magnetic recording means, for example a floppy disk or a disk. hard.

On the other hand, the information or recording medium can be a transmissible medium such as an electrical or optical signal, which can be conveyed via an electrical or optical cable, by radio or by other means. . The program according to the invention can in particular be downloaded from an Internet type network.

[0026] Alternatively, the information or recording medium can 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.

According to a fourth aspect, the invention relates to a client device for broadcasting a video acquired by a virtualization platform to a video platform and transmitted, in the form of a video stream, from the virtualization platform to a virtualization application of the client device, the broadcasting of the video by the virtualization platform conforming to a first broadcasting mode and the video stream comprising a first item of information relating to a storage location of the video at the level of the video platform . In addition, said virtualization application includes:

a reception module, configured to receive, during the transmission of the video stream, a second piece of information relating to a change from said first broadcasting mode to a second broadcasting mode,

a discovery module, configured to discover, during the transmission of a video stream to the client device 11, a video application of the client device, said video application being able to broadcast and control the broadcasting of the video from the video platform,

a transmission module, configured to transmit, during the transmission of the video stream and in the event of positive discovery, said first and second information to the video application, and said video application comprises:

- an access module, configured to access, during the transmission of the video stream and from the video platform, to the video according to the first information,

- a broadcasting module, configured to broadcast, replacing the transmitted video stream, the video from the video platform, said broadcast being adapted as a function of the second item of information.

In particular embodiments, the client device corresponds to a television decoder connected to display means.

According to a fifth aspect, the invention relates to a system comprising a client device according to the invention as well as a virtualization platform and a video platform.

Brief description of the drawings

Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate an exemplary embodiment thereof without any limiting nature. In the figures:

[Fig. 1] FIG. 1 schematically represents a particular embodiment of a broadcasting system according to the invention;

[Fig. 2] FIG. 2 schematically represents an example of the hardware architecture of a client device of the broadcasting system;

[Fig. 3] FIG. 3 represents, in the form of a flowchart, the main steps of a broadcasting method according to the invention;

[Fig. 4] FIG. 4 schematically represents a particular embodiment of the diffusion method of FIG. 3.

Description of the embodiments

FIG. 1 schematically represents a particular embodiment of a diffusion system 10 according to the invention.

As illustrated by FIG. 1, the system 10 comprises a virtualization platform 12. The remainder of the description relates more specifically to an office virtualization platform 12 comprising, in a manner known per se, several layers (not shown in the figures) including in particular a virtualization layer corresponding to a hypervisor as well as a layer of several virtual machines, including at least one virtual machine dedicated to the virtualization of the desktop of a client device, as described in more detail below.

It should be noted that the number of virtual machines, when there are several, does not constitute a limitation of the invention. In addition, nothing excludes either considering a desktop virtualization platform comprising a single virtual machine, the latter therefore corresponding to the virtual machine dedicated to desktop virtualization. More generally, no limitation is attached to the type of said virtualization platform, the invention in fact remaining applicable in the context of server virtualization, network virtualization, storage virtualization, and the like. Those skilled in the art know how to adapt the following description to a type other than that of desktop virtualization.

Each virtual machine of the desktop virtualization platform 12 runs on a hardware layer of said platform. In the present embodiment, said hardware layer corresponds to a remote server located in a data center. No limitation is however attached to the nature of said material layer, which may for example take the form of a PC type computer.

The system 10 also includes a video platform 13, that is to say a computer platform especially dedicated to the archiving and supply of video content. In the example of FIG. 1, the video platform 13 is remote from the desktop virtualization platform 12. It is owned and managed by a video content provider capable of being viewed on demand (such as for example Youtube, Netflix, etc. etc.) or even an online video game broadcasting company, etc. It corresponds to a fleet of servers on which said video content is stored. Said video platform 13 also makes it possible to have access to videos broadcast live.

The desktop virtualization platform 12 and the video platform 13 both include communication means configured to exchange data between them (link 20 in FIG. 1) via a communication network.

In the embodiment described here, the communication network considered is of the Internet type, and the communication means are based in particular on a communication interface suitable for said data exchange. Also, each video stored by the video platform 13 is associated with a storage location at the level of the latter, this storage location being accessible via an identifier corresponding to a URL address (acronym of the English expression "Uniform Resource Locator Which is unique to it. Through this URL, the desktop virtualization platform 12 can acquire a video from the video platform 13.

No limitation is attached to the nature of the communication interface between the platforms, which can be wired or wireless, and can implement any protocol known to those skilled in the art (Ethernet, Wifi, Bluetooth , 3G, 4G, 5G, etc.). In addition, the invention is not limited to an Internet network, any other network (IP, owner, etc.) can be envisaged, so that the storage location can be accessible via information corresponding to a more general identifier. than a URL address, such as for example a URI (acronym of the Anglo-Saxon expression "Uniform Resource Identifier"). Furthermore, nothing excludes either having, according to any technically operative consideration, an alternative embodiment according to which the video platform 13 would not be remote from the desktop virtualization platform 12, but on the contrary hosted by the latter.

The system 10 also includes a client device 11 owned by a user. The remainder of the description is aimed more specifically at a client device 11 corresponding to a television decoder 110 of the “Set Top Box” type connected to display means such as for example a television screen 111. Said display means are here remote. of the television decoder 110 and connected to the latter in a wired manner. In general, said television decoder 110 is able to receive a video transmitted in the form of a video stream (link denoted "FLUX" in FIG. 1) as well as to process this video stream in order to transmit it to said means of 'display so that it is broadcast.

The choice consisting in considering a client device 11 corresponding to a television decoder connected to display means constitutes only one variant embodiment of the invention. Thus, other variant embodiments can be envisaged, such as, for example, a client device corresponding to a mobile phone of the smartphone type, a touchscreen tablet, a connected television, a PC of the PC type, a connected television key (also referred to as "dongle TV ”in Anglo-Saxon literature), etc.

[0043] FIG. 2 diagrammatically represents an example of the hardware architecture of the client device 11, more particularly of the television decoder 110. As illustrated by FIG. 2, the television decoder 110 comprises, in particular, a processor 1, a RAM 2, ROM 3 and non-volatile memory 4.

The read only memory 3 of the television decoder 110 constitutes a recording medium according to the invention, readable by the processor 1 and on which is recorded a computer program PROG according to the invention, comprising instructions for the execution of the steps of a broadcasting method according to the invention. The program PROG defines functional modules (not shown in the figures) of the television decoder 110, which are based on or control the hardware elements 2 to 4 of the latter. These functional modules are distributed according to different applications (ie sets of instructions) of the television decoder 110, namely an APP_VIR virtualization application as well as an APP_VID video application capable of broadcasting and controlling the broadcasting of a video from the video platform. 13.

The APP_VIR virtualization application comprises:

a reception module, configured to receive, during the transmission of a video stream to the client device 11, one or more information, for example information relating to a change in a video broadcasting mode acquired by the desktop virtualization platform 12 from the video platform 13, a discovery module, configured to discover, during the transmission of a video stream to the client device 11, the video application APP_VID of the client device 11,

a transmission module, configured to transmit, during the transmission of a video stream to the client device 11 and when the video application APP_VID has been discovered, information to the video application APP_VID.

The APP_VID video application, for its part, comprises:

an access module, configured to access, during the transmission of a video stream to the client device 11 and to the video platform 13, to a video hosted by the video platform 13 and from which said video stream is transmitted,

a broadcast module, configured to broadcast, replacing said transmitted video stream, the video from the video platform 13, said broadcast being able to be adapted as a function of at least one piece of information received from the virtualization application APP_VIR, such as, for example, information relating to a change in the broadcasting mode of a video acquired by the desktop virtualization platform 12 from the video platform 13.

The APP_VIR virtualization application forms the interface of the client device 11 with the desktop virtualization platform 12. For this purpose, the APP_VIR virtualization application makes it possible to generate a connection of the client device 11 with the virtualization platform office 12 via the implementation of a remote interface protocol (also called “RUI” protocol, acronym of the English expression “Remote User Interface”).

For example, said remote interface protocol is the RDP protocol (acronym of the English expression "Remote Desktop Protocol"). The choice of such a protocol constitutes only one variant embodiment of the invention, and other protocols can still be envisaged (ICA for “Independent Computing Architecture”, XRT for “Extended Remote Technology”, etc.).

Thus, said remote interface protocol makes it possible to generate an RUI connection between the APP_VIR virtualization application of the client device 11 and the office virtualization platform 12, this connection being suitable for exchanging data. In particular, this connection is suitable for transmitting, from the desktop virtualization platform 12, a video stream encoding a video acquired from the video platform 13.

The APP_VID video application forms, for its part, the interface of the client device 11 with the video platform 13. For this purpose, the client device 11 comprises communication means 5 configured to exchange data (link 30 in FIG. 1) with the video platform 13 via a communication network.

In the embodiment described here, the communication network considered for exchanges between the client device 11 and the video platform 13 is also of the Internet type, and the communication means are based in particular on a communication interface suitable for said data exchange.

No limitation is attached to the nature of the communication interface between the client device 11 and the video platform 13, which can be wired or wireless, and can implement any protocol known to those skilled in the art. business (Ethernet, Wifi, Bluetooth, 3G, 4G, 5G, etc.). In addition, the invention is not limited to an Internet network, any other network (IP, owner, etc.) that can be envisaged. More particularly, nothing excludes that the communication network between the client device 11 and the video platform 13 differs from the communication network between the desktop virtualization platform 12 and the video platform 13.

FIG. 3 represents, in the form of a flowchart, the main steps of the broadcasting method according to the invention, as they are implemented by the client device 11 of the system 10.

Said broadcasting method is implemented after a video has been acquired by the desktop virtualization platform 12 from the video platform 13, for example following the choice made by the user to view said video via the client device 11 that it holds (choice made thanks to a user interface of a type known per se). This acquired video is transmitted, in the form of a video stream, from the desktop virtualization platform 12 to the virtualization application APP_VIR of the client device 11 to be broadcast by the latter.

In addition, the video stream includes a first item of information INFO_1 relating to a video storage location at the level of the video platform 13.

For the remainder of the description, and in no way limiting, we consider an example of implementation in which the video considered is a video hosted on a Youtube server to which the desktop virtualization platform 12 has access via the URL associated with said video. In other words, said first information INFO_1 corresponds here to said URL address.

According to the invention, the broadcasting of the video by the virtualization platform 12 conforms to a first broadcasting mode.

In the exemplary implementation described here, it is considered that said first broadcast mode corresponds to a broadcast of the video in a first broadcast zone. More particularly, when the video stream is received by the television decoder 110, via its virtualization application APP_VIR, the video is displayed on the screen 111 in a portion thereof which corresponds, from the point of view of the size , to said first diffusion zone.

No limitation is attached to the nature of said first broadcasting mode which may be relative, according to other examples, to a given resolution of the video, to a given reading speed of the video, and the like. For the remainder of the description, it is also considered that a second item of information INFO_2 relating to a change from said first broadcasting mode to a second broadcasting mode is received by the virtualization application APP_VIR. In the exemplary implementation considered here, said second broadcast mode corresponds to a broadcast of the video in a second broadcast zone, the size of the first zone being smaller than the size of the second zone. More specifically, said second broadcasting mode corresponds to full screen broadcasting.

Thus, the broadcasting method is described here by considering that said second information item INFO_2 has already been received by the virtualization application APP_VIR, and that its implementation therefore takes place directly following this reception. It should however be noted that such considerations do not limit the invention, it being understood that nothing excludes considering, according to an alternative implementation, that the broadcasting method comprises a step of receiving said second information. INFO_2.

The broadcasting method therefore comprises a step E10 of discovery, by the virtualization application APP_VIR, of the video application APP_VID of the client device 11. Said step E10 (also denoted "APP_VIR: FIND APP_VID" in FIG. 3) is implemented by the discovery module of the APP_VIR virtualization application.

Such a discovery step E10 is for example implemented according to a protocol similar to the DIAL protocol (acronym of the English expression "Discovery And Launch"). According to this example, the video application APP_VID available to the video decoder 110 and therefore discovered corresponds to an application officially distributed by Youtube to allow the playback of videos hosted by the video platform 13.

Of course, no limitation is attached to the discovery protocol that can be implemented in order to discover the application, apart from the fact that this protocol makes it possible to discover a video application capable of broadcasting and controlling the video hosted by the video platform 13. For example, said discovery protocol may correspond to the DLNA protocol (acronym of the English expression “Digital Living Network Alliance”), AirPlay, and the like. Similarly, the discovered video application may differ from said Youtube application and correspond, for example, to a web video player based on the HTML 5 data format.

At the end of the discovery step E10, the APP_VID video application having been discovered (positive result of the discovery step E10), the broadcasting method comprises a transmission step E20, by the APP_VIR virtualization application to the APP_VID video application, of said first and second information. Said step E20 (also denoted "TX INFO_1 & INFO_2, APP_VIR ->APP_VID" in FIG. 3) is implemented by the transmission module of the virtualization application APP_VIR. Thus, on receipt of the second information INFO_2, the virtualization application APP_VIR is responsible for transmitting the information that it has obtained to the video application APP_VID with the aim that the latter is responsible for the effective broadcasting of the video as described below.

The broadcasting method then comprises a step E30 of access, by the video application APP_VID and from the video platform 13, to the video as a function of the first item of information INFO_1. Said step E30 (also denoted “APP_VID: ACC VIDEO / INFO_1” in FIG. 3) is implemented by the access module of the video application APP_VID.

The video application therefore uses the URL address which was transmitted to it by the APP_VIR virtualization application to have access to the video corresponding to the video stream received by the television decoder 110 and hosted by the video platform .

Following said access to the video from the video platform 13, the broadcasting method comprises a broadcasting step E40, by the video application APP_VID and replacing the video stream transmitted, of the video from the video platform 13, said broadcast being adapted as a function of the second information item INFO_2. Said step E40 (also noted “APP_VID:

DIFF VIDEO / INFO_2 ”in FIG. 3) is implemented by the broadcasting module of the video application APP_VID.

It is therefore understood that the video application APP_VIP replaces the virtualization application APP_VIR so as to take over, directly from the video platform 13, the broadcasting of the video. In other words, the rendering and the control of the video are delegated to the video application APP_VIP, the video stream being interrupted. Proceeding in this way is particularly advantageous insofar as the APP_VID video application, when appropriately programmed, can read and broadcast the video without any real-time encoding, of the type carried out for formatting. video stream, is necessary.

In the present example of implementation, and as mentioned above, the second item of information INFO_2 relates to a switch to full screen. Thus, the APP_VID video application takes control of the video to display it on the entire screen 111 connected to the television decoder 110. Insofar as said APP_VID video application is officially distributed by Youtube, it makes it possible to broadcast the video in full screen with a much better rendering than that which would have been obtained from a full screen change of the video stream. In addition, if the video corresponds to a live video, said APP_VID video application also makes it possible to optimize the video latency.

It should be noted that the invention has been described so far by considering the discovery step E10 returned a positive result. It will nevertheless be understood that if the client device 11 does not include any video application, or even possibly includes a video application which is not capable of broadcasting and controlling the broadcasting of a video from the video platform 13, step E10 then returns a negative result. In this case, since the video streaming cannot be delegated to an appropriate video application, the video stream is not interrupted.

FIG. 4 schematically represents a particular embodiment of the diffusion method of FIG. 3.

As illustrated by FIG. 4, the broadcasting method also comprises, in this particular embodiment, during the broadcasting of the video by the video application APP_VID (step E40), a step E50 of reception, by the video application APP_VID, of a third item of information INFO_3 relating to a change from said second broadcasting mode to said first broadcasting mode. Said step E50 (also denoted “APP_VID: RX INFO_3” in FIG. 3) is implemented by a module for receiving the video application APP_VID.

By way of illustration, and with reference to the implementation example detailed previously, said third item of information INFO_3 corresponds to a reduction in the size of the video, via a switch from full screen (second broadcasting mode) to a display window corresponding to the first diffusion zone (first diffusion mode).

In addition, in accordance with the mode of implementation illustrated by FIG. 4, the broadcasting method also comprises a recovery step E60 (also denoted "DIFF FLUX" in FIG. 3), by the virtualization platform 12 and replacing the video broadcast by the video application APP_VID, the broadcast of the video acquired and transmitted in the form of the video stream, said broadcast being adapted as a function of the third item of information INFO_3.

This particular embodiment is therefore advantageous in that it allows the broadcasting method to be reversible with regard to taking charge of rendering and controlling the broadcasting of the video.

Claims

[Claim 1] A method of broadcasting, by a client device (11), a video acquired by a virtualization platform (12) from a video platform (13) and transmitted, in the form of a video stream, from the virtualization platform to a virtualization application (APP_VIR) of the client device, the broadcasting of the video by the virtualization platform conforming to a first broadcasting mode and the video stream comprising a first item of information (INFO_l) relating to a location of storage of the video at the level of the video platform, said method comprising, during the transmission of the video stream and on reception, by the virtualization application, of a second item of information (INFO_2) relating to a change of said first mode of distribution in a second mode of distribution:

a step (E10) of discovery, by the virtualization application, of a video application (APP_VID) of the client device, said video application being capable of broadcasting and controlling the broadcasting of the video from the video platform, and, if the discovery is positive:

- a step (E20) of transmission, by the virtualization application to the video application, of said first and second information,

- a step (E30) of access, by the video application and from the video platform, to the video according to the first information,

a step (E40) of broadcasting, by the video application and replacing the transmitted video stream, of the video from the video platform, said broadcasting being adapted as a function of the second information.

[Claim 2] A method according to claim 1, said method also comprising:

- during the broadcasting of the video by the video application, a step (E50) of reception, by the video application, of a third item of information (INFO_3) relating to a change from said second broadcasting mode to said first broadcasting mode diffusion,

a step (E60) of resuming, by the virtualization platform and replacing the video broadcast by the video application, the broadcasting of the video acquired and transmitted in the form of the video stream, said broadcasting being adapted according to the third information.

[Claim 3] A method according to any one of claims 1 to 2, wherein the first and second broadcast modes correspond respectively to a broadcast of the video in a first and a second broadcast areas, the size of the first area being greater than the size of the second zone.

[Claim 4] A method according to any one of claims 1 to 3, wherein the discovery step is based on the DIAL protocol.

[Claim 5] A method according to any one of claims 1 to 4, wherein said first information corresponds to an identifier.

[Claim 6] A computer program comprising instructions for carrying out a broadcasting method according to any one of claims 1 to 5 when said program is executed by a computer.

[Claim 7] A computer readable recording medium on which a computer program according to claim 6 is recorded.

[Claim 8] Client device (11) for broadcasting a video acquired by a virtualization platform (12) to a video platform (13) and transmitted, in the form of a video stream, from the virtualization platform to a virtualization application (APP_VIR) of the client device, the broadcasting of the video by the virtualization platform conforming to a first broadcasting mode and the video stream comprising a first item of information (INFO_l) relating to a video storage location at the level of the video platform, said virtualization application comprising:

- a reception module, configured to receive, during the transmission of the video stream, a second item of information (INFO_2) relating to a change from said first broadcasting mode to a second broadcasting mode,

a discovery module, configured to discover, during the transmission of a video stream to the client device 11, a video application (APP_VID) of the client device, said video application being able to broadcast and control the broadcasting of the video from the video platform,

a transmission module, configured to transmit, during the transmission of the video stream and in the event of positive discovery, said first and second information to the video application, said video application comprising:

a broadcast module, configured to broadcast, replacing the transmitted video stream, the video from the video platform, said broadcast being adapted as a function of the second item of information.

[Claim 9] A client device (11) according to claim 8, said client device corresponding to a television decoder connected to display means. [Claim 10] A broadcast system (10) comprising a client device (11) according to any one of claims 8 to 9 as well as a virtualization platform (12) and a video platform (13).