EP1964407A1

EP1964407A1 - Method for providing a multimedia media service on request, service platform, programme, and decoder for implementing said method

Info

Publication number: EP1964407A1
Application number: EP06841851A
Authority: EP
Inventors: Benoît SUZANNE; Halim Bendiabdallah
Original assignee: France Telecom SA
Current assignee: Orange SA
Priority date: 2005-12-19
Filing date: 2006-12-04
Publication date: 2008-09-03
Also published as: FR2895190A1; WO2007080244A1; JP2009520423A; CN101341751A; US20080313680A1

Abstract

The multimedia service on request is provided by multimedia data sources (3) each comprising at least one programe flow and an interactivity information file. The programme flow of a source is converted into a transport flow transmitted towards a user terminal by means of a telecommunication network. The service platform collects interaction orders from the user via the telecommunication network, and processes these orders in association with an interactivity information file of the source in order to control the transmitted transport flow.

Description

METHOD FOR PROVIDING A MULTIMEDIA SERVICE TO THE

REQUEST, SERVICE PLATFORM, PROGRAM AND DECODER

FOR THE IMPLEMENTATION OF THE METHOD

The present invention relates to the provision of multimedia services on demand via telecommunication networks. A particular field of application is that of digital television in which a widespread standard is MPEG2.

The MPEG2 system standard defines two types of multiplex digital streams: Transport Streams (TS) and Program Streams (PS). A "program" is defined as a set of elementary streams correlated temporally, that is to say carrying each information to be restored with respect to a common time base. A PS stream carries a single program in the form of packets of relatively large and possibly variable length. Program (PS) streams are typically used for storing programs on disk. Transport Streams (TS) consist of fixed-length packets belonging to one or more programs, and are used for transmission or broadcast over networks.

These multiplexed streams TS, PS are constructed from packaged elementary stream (PES). The raw elementary streams (ES) derived directly from the video or audio coding are first put into PES packets of variable length. The PES streams are then segmented to constitute the TS or PS packets to be multiplexed.

The MPEG2 standard is used in several multimedia content distribution systems, including DVD ("Digital Versatile Disc") and DVB ("Digital Video Broadcast").

The DVD is an optical recording medium disc on which programs are recorded in so-called VOB ("Video Object Block") files that correspond to PS stream packets. IFO files are also recorded on the disc and contain information on chapters, subtitle tracks and sound tracks. IFO files allow to offer the user navigation and interactivity elements, especially for the choice of languages or subtitles, sometimes for the choice of angles of the camera, for access to the main menu and to intermediate menus, to move forward or backward in program chapters, and so on.

In a DVD, the multimedia content (VOB), including sound, images and subtitles, is thus dissociated from the tree (IFO) between the different menus. The interactivity of the DVD is based on the display of the video sequence. IFO files are used to select portions of video to render according to the actions triggered by the user, usually using its remote control. The succession of different video portions creates interactivity through a navigation tree. The DVD player has five 16-bit registers to store any information to act on the tree followed in the IFO file according to the previous choices.

DVB is a standard for broadcasting digital television. The streams are broadcast in TS format, which allows to send several programs in a given bandwidth. The user thus receives a "bouquet" of strings and tables describing information such as names of the strings, names of the programs in progress, etc. These tables allow the user to locally select the channels to display.

DVB is also used to distribute digital television over telecommunication networks, including ADSL ("Asymmetric Digital Subscriber Line"). In this application, it is generally provided a TS stream per channel (SPTS stream, "Single Program Transport Stream"), the encryption being performed at the TS level. To view content, the user's decoder must receive a TS stream.

Video On Demand (VOD) services also use the DVB standard. In this application, the telecommunication network supports the Internet Protocol (IP), and the TS streams are broadcast in point-to-point mode. Once the transmission of the requested program has begun, the user can have playback, pause and fast forward or rewind features. These functionalities correspond to displacements with respect to the current position in the transport stream.

However, the user has no access to features related to a chapter of multimedia content, a choice of spoken languages or subtitles, a choice of camera angles, etc. , such as those he is used to when viewing a DVD. The interactivity of VOD services therefore remains very limited.

Today, some VOD offers include, after transmission of the requested program, the sending of a DVD disc to the user. This will then benefit from the interactivity of the DVD, but not at the time of its first viewing of the program. In addition, such an offer has the disadvantage of requiring that the content be sent twice to the user, in two different forms.

An object of the present invention is to improve the interactivity of programs transmitted in an on-demand delivery service. More particularly, it is desired to tend towards the level of interactivity offered when viewing a DVD.

It is thus proposed a method of providing an on-demand multimedia service from multimedia data sources each comprising at least one program stream and an interactivity information file. According to the invention, the method comprises the following steps:

- converting a program stream of at least one source into a transport stream;

transmitting the transport stream to a user terminal via a telecommunication network;

- collect interaction commands from the user via the telecommunication network; and - AT -

processing the interaction commands collected in relation to the interactivity information files of said source to control the transport stream transmitted via the telecommunication network.

The method makes it possible to emulate multimedia interaction functions of a first type on a transmission architecture of a second type, not designed to support such functions, by remote processing of the interaction commands entered by the user.

The multimedia interaction functions of the first type may especially be those offered by a DVD, while the architecture of the second type may be that of DVB. These two systems, not compatible with each other, still share the PES level of the MPEG2 standard, which allows the conversion of the program stream into a transport stream using conventional MPEG2 demultiplexers and multiplexers. In this application, the interactivity information files correspond to the IFO files of the DVD, which are interpreted at the level of the VOD service platform in order to offer the user the desired interactivity. Since the encoding level of a DVD is generally higher than that of DVB digital television, it also results in a better quality of the video and audio content returned, at the cost of greater bandwidth consumption.

The method advantageously makes it possible to remotely exploit the interactive content of a film (multi angle, chapiter, ...), the interactive content of a DVD (bonus, games, making of, trailers, ...), all types of existing games on DVD, all types of edutainment content existing on DVD and generally all types of content taking advantage of the interactivity offered by the DVD system.

In a first embodiment of the method, the multiplexing operation for the construction of the transport stream is carried out on the fly. The conversion of the program stream into a transport stream then comprises pre-storing multimedia files obtained from the multimedia data source and interactivity information files of said source and, in response to an interaction command. collected and treated in relation with a stored interactivity information file, multiplexing said multimedia files to form the transport stream transmitted via the telecommunication network.

Multimedia files can in particular correspond to PS stream packets. The copy phase of the program streams is very simple in this embodiment. In the application of the invention to contents available on DVD, the on-the-fly multiplexing of the transport stream makes it possible to interpret the IFO files in the same way as in a standard DVD player.

In another embodiment, the construction of the transport stream is performed beforehand, the interactivity information files being converted to be adapted to the format of the transport streams. The method then includes adapting the interactivity information file to the transport stream format and storing the transport stream and the adapted interactivity information file, and processing the collected interaction commands includes an interpretation. said commands in relation to the interactivity information file for controlling the reading and transmission of the stored transport stream.

This embodiment reduces the complexity of the service platform because it eliminates the real time remultiplexing operation that requires significant computing capacity.

Another aspect of the invention relates to a service platform for providing an on-demand multimedia service from multimedia data sources each comprising at least one program stream and one information file of interactivity. This platform comprises: means for converting a program stream of at least one source into a transport stream; means for transmitting the transport stream to a user terminal via a telecommunication network; means for receiving interaction commands from the user via the telecommunication network; and means for processing the interaction commands collected in connection with a file interactivity information of said source for controlling the transport stream transmitted through the telecommunication network.

Yet another aspect of the invention relates to a computer program for installation in a service platform for providing an on-demand multimedia service from multimedia data sources each comprising at least one program stream and an interactivity information file. The program includes instructions for controlling the following steps when executing the program by a platform processing unit: - transmitting to a user terminal, via a telecommunication network, a stream transport obtained by converting a program stream of at least one source;

- collect interaction commands from the user via the telecommunication network; and - processing the interaction commands collected in relation to an interactivity information file of said source for controlling the transport stream transmitted through the telecommunication network.

The invention also relates to a digital television decoder, comprising: - a communication interface with a platform for providing multimedia service on demand via a telecommunication network;

means for receiving a transport stream representing a program requested by a user, comprising interactive menus, decoding the transport stream and restoring the requested program; and

means for receiving interaction commands from the user in connection with said interactive menus and transmitting messages that echo said commands to the platform via the telecommunication network. The invention also relates to a method for processing multimedia data in a digital television decoder, comprising the following steps:

receiving, from a multimedia service providing platform on demand, via a telecommunication network, a transport stream representing a program requested by a user, including interactive menus;

- decode the transport stream and return the requested program;

receiving interaction commands from the user in relation to said interactive menus;

transmitting via the telecommunications network messages that reflect said commands, said messages being adapted to be processed by the platform in relation to an interactivity information file associated with the program for controlling the transport stream transmitted by via the telecommunication network.

Another aspect of the invention relates to a computer program for installation in a digital television decoder, comprising instructions for controlling the following steps during a program execution by a platform processing unit:

receiving, from a multimedia service providing platform on demand, via a telecommunication network, a transport stream representing a program requested by a user, including interactive menus; - decode the transport stream and return the requested program;

transmitting via the telecommunications network messages that reflect said commands, said messages being adapted to be processed by the platform in relation to an interactivity information file associated with the program for controlling the transport stream transmitted by via the telecommunication network. Other features and advantages of the present invention will become apparent in the following description of nonlimiting exemplary embodiments, with reference to the appended drawings, in which:

FIG. 1 is a block diagram of an exemplary VOD service platform according to the invention;

FIG. 2 is a simplified block diagram of an exemplary digital television decoder according to the invention; and

FIG. 3 is a block diagram of another example of a VOD service platform according to the invention. With reference to FIG. 1, a service platform 1 comprises a network interface 2 for communicating with user terminals. The telecommunications network used is for example an IP network over ADSL.

The service platform according to the invention exploits interactive contents available on recording media 3 of the DVD type or the like. In the embodiment illustrated in FIG. 1, a preliminary step of the method consists in recording the contents of the DVDs 3 in a database 4 of the platform, stored on hard disks. For each DVD disk, the database 4 stores all the VOB files, which contain PS stream packets, as well as the corresponding Interactivity Information (IFO) files.

The platform 1 further comprises a video on demand (VOD) server 5. In a conventional manner, the server 5 is adapted to present to the users a video interface which enables them to select the requested contents and to carry out the corresponding transactions. . The server 5 manages the VOD sessions of the different users and controls the playback of audio and video files corresponding to the content requested by the users. In this case, these files are stored in the database 4 in PS format, and the VOD server 5 must be adapted to perform the addressing of the stream in PS format.

The PS stream whose reading is controlled by the server 5 is submitted to a MPEG2 6 remultiplexer which converts it into a stream TS single program (SPTS) suitable for DVB transmission. The MPEG2 remultiplexing operation is conventional. The PES packets are extracted from the PS stream with the corresponding time markers, and then these are used to multiplex the PES packets into a TS stream. The TS stream thus constructed is transmitted to the user concerned via the interface 2 and the telecommunications network.

Figure 2 shows schematically the DVB decoder 10 which is equipped with a user. Its network interface 11 retrieves the received TS stream, and provides it to the MPEG2 demultiplexing and decoding module 12. This module 12 renders the audio and video signals that are supplied to the television 20 of the user. In the context of the present invention, the demultiplexing and decoding module 12 may be standard.

The user interface typically comprises an infrared remote control 21 which, according to the actions of the user, sends different signals picked up by an infrared detector 13 of the decoder 10.

The decoder 10 comprises a communications software layer 14, generally based on an application of the HyperText Mark-up Language ("HTML") browser type 14. The browser 14 is informed of certain user control signals sensed by the detector 13. signals refer for example to pause / play or fast forward / rewind commands, that the browser 14 translates into HTML requests transmitted via the interface 11 and the telecommunications network according to the HTTP ("HyperText Transfer Protocol") protocol. These requests are interpreted at the level of the VOD server 5 and give rise to corresponding modifications of the reading of the multimedia stream in the database 4.

According to the invention, the user commands that the browser 14 of the decoder 10 echoes in HTML requests transmitted over the network, also include interaction commands that are related to the interactivity information encountered in the DVDs. Thus, commands such as chapter changes or commands that can be selected from on-screen DVD menus result in specific HTML queries that will be interpreted by a user. module 7 added to the VOD server in the service platform 1. The user thus has the opportunity to navigate in the menu tree of the DVD he is viewing.

The interpreter module 7 analyzes the interaction commands received in the HTML requests in relation to the IFO file, stored in the database 4, which corresponds to the video sequence being transmitted.

The IFO 7 interpreter is similar to the one commonly found in DVD players. For each current DVD session for a user, he notably allocates a memory area to emulate the five 16-bit registers storing the information that makes it possible to act on the tree followed in the IFO file according to the previous choices.

Thus, each command of the user can be interpreted to control the addressing of the stream being played according to the chapter of the DVD, to select audio or subtitle files corresponding to languages chosen by the user, to select portions of video corresponding to camera angles selected by the user, ...

Depending on the result of the interpretation of the commands, the VOD server 5 controls the reading in memory of the PS stream to be supplied to the remultiplexer 6. FIG. 3 illustrates another possible architecture of the VOD service platform according to the invention. In this platform 30, the remultiplexing of the stream PS, read on a DVD 3, into a stream TS is performed not in real time during a VOD session, but in the preliminary phase of recording the content of the disc 3. There is therefore a lower speed constraint on the MPEG2 remultiplexer 31.

The multimedia streams are thus recorded in the format TS in the database 32 of the platform 30. The addressing of the stream used in the IFO files of the DVD must be modified to take account of the reordering of the stream. This modification is performed by an adaptation module 33 in parallel with the remultiplexing operation. The adapted IFO files are stored in the database 32 in relation to the corresponding sequences of the stream TS. The IFO interpreter 34 of the platform 30 then exploits the adapted IFO files in order to address to the VOD server 35 the addressing parameters of the stored stream TS. In this embodiment, the VOD server 35 may be of a conventional type for controlling the reading in TS stream memory. The embodiment of FIG. 3 has the advantages of making it possible to use a VOD server on the market and to avoid the real time remultiplexing operation, which is relatively expensive in computing capacity.

In practice, in one or other of the embodiments described, the invention may be implemented by means of computer programs executed by a plurality of processors of the service platform 1, 30 and designed to complete the functionalities of the VOD server 5, 35 in terms of interpreting IFO files and remultiplexing.

The invention has been described above in the context of DVD and DVB standards. Naturally, it is not limited to these standards. The invention is particularly applicable to all types of interactive content recording media (HD-DVD, BIu Ray, ...).

On the other hand, the user equipment can have very different shapes. For example, the decoder 10 may be part of a terminal, which may for example be a microcomputer whose screen and sound card are used for the reproduction of multimedia content and whose user interface (keyboard, mouse, etc.). is used to enter interaction commands. The terminal may in another embodiment be a television, a set-top box or a mobile terminal such as a telephone.

Claims

A method of providing an on-demand multimedia service from multimedia data sources (3) each comprising at least one program stream and an interactivity information file, the method comprising the steps of:

- converting a program stream of at least one source into a transport stream;

transmitting the transport stream to a user terminal (10) via a telecommunication network; - collect interaction commands from the user via the telecommunication network; and

processing the interaction commands collected in relation to an interactivity information file of said source for controlling the transport stream transmitted via the telecommunication network.

The method of claim 1, wherein the conversion of the program stream into a transport stream comprises pre-storing media files obtained from the multimedia data source (3) and interactivity information files of said source and, in response to an interaction command collected and processed in relation to a stored interactivity information file, multiplexing said multimedia files to form the transport stream transmitted through the telecommunication network.

The method of claim 1, further comprising the steps of: - adapting the interactivity information file to the format of the transport stream; and

storage of the transport stream and the adapted interactivity information file, wherein the processing of the collected interaction commands includes an interpretation of said commands in relation to the interactivity information file for controlling the reading and transmission of the stored transport stream.

The method of any of the preceding claims, wherein the multimedia data sources comprise optical recording media (3).

5. Service platform (1; 30) for providing an on-demand multimedia service from multimedia data sources (3) each comprising at least one program stream and one interactivity information file , the platform comprising:

means (6; 31) for converting a program stream of at least one source into a transport stream;

means (2) for transmitting the transport stream to a user terminal via a telecommunication network;

means (2) for receiving interaction commands from the user via the telecommunication network; and

means (5, 7; 34, 35) for processing the interaction commands collected in relation to an interactivity information file of said source for controlling the transport stream transmitted via the telecommunication network.

The service platform according to claim 5, wherein the means for converting the program stream into a transport stream comprises means (4) for pre-storing multimedia files obtained from the multimedia data source (3). ) and interactivity information files of said source, and means (6) for multiplexing said multimedia files in response to an interaction command collected and processed in relation to an interactivity information file stored to form the transport stream transmitted via the telecommunication network.

7. Service platform according to claim 5, further comprising means (33) for adapting the interactivity information file in the format of the transport stream and means (32) for storing the transport stream and of the adapted interactivity information file, in which the means for processing the collected interaction commands comprise means (7) for interpreting said commands in relation to the interactivity information file for controlling the reading of the stream stored transport and feed the transmission means (2).

8. Computer program for installation in a service platform (1; 30) for providing an on-demand multimedia service from multimedia data sources (3) each comprising at least one program stream and one file interactivity information, the program comprising instructions for controlling the following steps when executing the program by a platform processing unit: - transmitting to a user terminal (10), by the intermediate of a telecommunication network, a transport stream obtained by converting a program stream of at least one source;

The program of claim 8, wherein multimedia files obtained from the multimedia data source (3) and interactivity information files of said source are previously recorded, the program further comprising instructions for multiplexing the multimedia files recorded to form the transport stream transmitted via the telecommunication network.

The program of claim 8, wherein the interactivity information file is adapted to the format of the transport stream and the stream transport and the adapted interactivity information file are previously recorded, the processing of the interaction commands collected including an interpretation of said commands in relation to the interactivity information file to control the reading and the transmission of the flow of data. transport stored.

11. Digital television decoder (10) adapted to implement a method according to any one of claims 1 to 4, comprising:

- a communication interface (11) with an on-demand multimedia service providing platform (1; 30) via a telecommunication network;

means (12) for receiving a transport stream representing a program requested by a user, comprising interactive menus, decoding the transport stream and restoring the requested program; and - means (13-14) for receiving interaction commands from the user in connection with said interactive menus and transmitting messages transmitting said commands to the platform (1; 30) via the network telecommunication.

A method of processing multimedia data in a digital television decoder (10), comprising the steps of:

receiving, from a multimedia on-demand service providing platform (1; 30), via a telecommunication network, a transport stream representing a program requested by a user, comprising interactive menus;

- decode the transport stream and return the requested program;

transmitting via the telecommunications network messages that echo said commands, said messages being adapted to be processed by the platform in relation to a file; interactivity information associated with the program for controlling the transport stream transmitted through the telecommunication network.

13. Computer program for installation in a digital television decoder (10), comprising instructions for controlling the following steps during a program execution by a platform processing unit:

- decode the transport stream and return the requested program;