ITUD20070095A1 - PROCEDURE TO CONVERT A SEQUENCE OF ELECTRONIC DOCUMENTS AND ITS APPARATUS - Google Patents

Description

Description of the invention having as title:

"PROCEDURE FOR CONVERTING A SEQUENCE OF ELECTRONIC DOCUMENTS AND RELATED EQUIPMENT"

FIELD OF APPLICATION

The present invention relates to a method and an apparatus for converting a sequence of electronic documents defined according to the SMIL language (Synchronized Multimedia Integration Language), or similar language, into an audio / video data stream.

The present invention is applied preferably, but not exclusively, in the sector of distribution and creation of audio files or multimedia video files comprising audiovisual contents of a complex and possibly interactive nature.

In the following, a video file means a file, for example compressed, containing a sequence of images, defined on the basis of IT standards, such as MPEG, AVI, MOV or the like; for audio file we mean a file, for example compressed, containing a sequence of audio samples, defined on the basis of IT standards, such as WAV, MP3.

By video stream, on the other hand, we mean a transmission of a sequence of data, for example compressed, containing a sequence of images, defined on the basis of telecommunications standards, such as H.263, YUV420P or others, and by audio stream we mean a transmission of a data sequence, for example compressed, containing a sequence of audio samples, defined on the basis of telecommunications standards, such as PCM16, AMR-NB.

STATE OF THE TECHNIQUE

There are known methods of distributing presentations or audio / video files, relating to audiovisual content, even complex ones. Said audiovisual contents are generally usable, through remote devices connected to the Internet or to other communication networks, including local ones, such as computers, fixed or cellular network videophones, television decoders. More generally, the known distribution methods normally comprise two phases: a first phase in which a request is made for specific audiovisual contents, carried out by an entity called Client, who wants to use said contents. The request is addressed to an entity, called a server, which acts as a distributor of said contents. The second phase consists of the response, from server to client, including said contents.

A frequently used method to perform the aforementioned distribution of presentations or audio / video files is based on SMIL language or similar. This language belongs to the family of markup languages and derives from the best known XML (Extensible Markup Language). One of the most used applications, based on the SMIL language, is the MMS (Multimedia Messagge System) message service of cellular telephony.

When the distribution of audiovisual contents takes place through SMIL type files, the SMIL language is interpreted, processed and reproduced once received by a Client. This language, therefore, allows to generate files that include all the information of the audiovisual contents and the additional information necessary for a correct reproduction of said contents.

A drawback of the use of this language is constituted by the fact that the Client is forced to perform complicated operations of interpretation and processing of this type of file, preparatory to the presentation of the audiovisual contents.

This feature forces the use of user terminals, or Clients in general, with increasingly higher processing powers, causing an increase in both the costs of the terminal and its consumption and, if these terminals have autonomous power supply, for example with battery, a decrease in operational autonomy.

A further drawback of the distribution of audiovisual contents using the SMIL language occurs in interactive applications for answering and managing menus, for example in the telephone or video telephone field. These applications, better known as IVR (Interactive Voice Response) or IW R (Interactive Voice and Video Response), work by means of a request procedure for receiving this type of file.

In fact, in said applications, during the presentation of a new menu following a specific user selection request, the background music and / or video contents are abruptly interrupted. This interruption is essentially attributable to the time interval necessary for the request for this type of file with new contents, for the reception of the file, for its interpretation, processing and reproduction. the quality of the service.

An object of the present invention is to develop a method and to provide an apparatus for converting electronic documents into a sequence of data conforming to an audio stream or a video stream, starting from the processing of a series of such documents defined according to SMIL language or similar language, which solves the indicated problems. In particular, the primary object of the invention is to allow the interconnection or reproduction of new audio / video sequences with sequences already in execution without interrupting the execution of the sequences already in progress.

In order to obviate the drawbacks of the known art and to obtain this and further objects and advantages, the Applicant has studied, tested and implemented the present invention.

EXPOSURE OF THE FOUND

The present invention is expressed and characterized in the main claims. Other innovative features of the invention are expressed in the secondary claims.

In accordance with the aforementioned object, a method according to the present invention can be used to convert one or more electronic documents, and / or one or more sequences thereof, defined according to SMIL language or similar language, into a data flow. The data stream consists of one or more audio streams and / or one or more video streams, including one or more content that can also be reproduced simultaneously, such as a title superimposed on a video contribution, intended for the distribution of presentations of audiovisual content. , and not only.

An electronic document defined according to SMIL language or similar language, on which the present invention is applied, is composed of at least two elements. A first element consists of a header, which defines the number and type of audiovisual content contained in this document.

A second element of said document consists of a body, comprising the audiovisual contents.

According to a characteristic of the method according to the present invention, the audio streams and / or the video streams, intended for the presentation of audiovisual contents, are not rigidly predefined at the beginning of their reproduction, but are constituted by pre-ordered sequences which in their together they make up the audio / video file. These flows can be modified, for example following a specific request, during the reproduction itself, thus making the presentation of the audiovisual contents dynamic, for example by increasing and / or modifying, during reproduction, the sequence of conversion of electronic documents based on the insertion of a new audio / video sequence that interconnects with the sequence already in progress. This feature allows to transform the audio stream or the video stream during its reproduction, without perceptible interruption in the reproduction itself, in compliance with the specific audiovisual contents defined in the sequence of electronic documents subjected to increase and / or modification.

The method according to the present invention, to achieve the above, comprises at least a first step, in which a request is generated for the distribution of a presentation of audiovisual contents contained in an electronic document, defined according to the SMIL language or similar language. In this first phase, moreover, the presentation of audiovisual contents is structured according to at least one session comprising a plurality of operating states, and is preferably set to an initial rest state.

According to a variant, the request for such presentation is sent by a requesting entity called Client to a distributing entity, called server.

According to a further characteristic of the aforesaid method, the aforementioned session also comprises a plurality of tasks designed to regulate the mode of reproduction of said audiovisual contents. Each of these tasks is activated when at least one event occurs, and at the end of this task at least one further event is generated. The aforementioned events are designed to change the status of one or more specific tasks and, therefore, the status of such presentation.

The method according to the present invention further comprises the following steps:

- a second phase in which the aforementioned session is passed into a state of preparation for the reproduction of the aforementioned audiovisual contents; in this second phase, following an operation to verify the syntactic correctness of the electronic document, by analyzing the header of the document, the audiovisual contents and the relative reproduction parameters are identified. In this second phase, following the aforementioned analysis, a specific sequence of entities is also configured, also called a sequence of filters, intended to process the audiovisual contents included in the body of the document. Also in this second phase, by analyzing the body of the document, a table is generated whose content defines the set of transitions allowed for the session. Therefore, the aforementioned table defines a list of specific tasks and, for each of these tasks, the list of specific events admissible for the session.

- a third phase in which the session is made to pass into a state of reproduction, activating an initial task, defined during the second phase. This initial task, according to the information contained in the aforementioned table, initiates the specific tasks set up for the generation of an audio stream or a video stream, according to the sequence defined in the list of tasks and related events contained in the aforementioned table. These audio or video streams are generated by processing the audiovisual content, included in the document, by means of the aforementioned sequence of filters.

According to a further variant of the invention, all the activities indicated above are managed at the server level, thus allowing to reduce the requests for computing capacity at the Client level.

According to a variant of the present invention, the audio stream or the video stream, obtained from the conversion of the electronic document, can be distributed according to a real-time mode, such as distribution by means of RTP or RTSP (Reai Time Protocol or Reai Time Streaming Protocol) to a Client, or according to a local mode, such as for the generation of a video file or an audio file.

According to a variant of the present invention, this sequence of filters is composed of at least three filters. A first filter is designed to extract audio or video or audio / video data from an audio file or video file, and to transform them by decoding, resampling or resizing. A second filter, consisting of an audio mixer filter or a video mixer filter, is designed to receive various audio or video streams at the input, producing a single audio or video stream at the output. Finally, a third filter transforms the output audio or video stream of this second filter into a stream acceptable to the Client of the presentation of multimedia audiovisual content.

According to a variant of the present invention, the set of the aforementioned filters, used to generate the sequence of filters, is composed of at least three subsets. The first subset is made up of filters basically predisposed to extraction operations, from an audio or video file, of audio or video or audio / video data. This first subset is also designed for synchronization operations of two or more audio or video streams and for transmission and reception of audio or video streams, using protocols such as RTP / UDP or RTP / TCP (Reai Time Protocol / User Data Protocol o Reai Time Protocol / Transmission Control Protocol).

A second subset of filters is designed for specific operations on video streams, such as compression and decompression. These operations are also intended to transform video streams into different formats, or to transform a series of images encoded according to common electronic formats, such as files with JPG or BMP extension, into video streams.

Finally, a third subset of filters is designed for operations on audio streams, such as compression and decompression. These operations are also intended to transform the aforementioned audio sequences into different formats.

In accordance with the aforementioned purpose, the present invention also relates to an apparatus for converting an electronic document into an audio / video data stream, defined according to the SMIL language or similar language, and composed of a header, which defines the number and type of audiovisual content contained in the aforementioned document, and by a body, which includes said audiovisual content.

According to the present invention, the apparatus comprises first electronic means suitable for receiving a request for distributing audiovisual contents contained in said electronic document.

According to a further variant of the present invention, the apparatus further comprises:

second electronic means adapted to collect and analyze the document stored in electronic storage means and to generate a session representing the aforementioned presentation of audiovisual contents. These second electronic means are also able to generate a specific sequence of entities, also called a sequence of filters, designed to process the audiovisual contents included in the body of the aforementioned document and to generate a table that defines the transition states of the aforementioned presentation of audiovisual contents. and related tasks, together with related events;

- third electronic means designed to make the session pass into a state of reproduction, transforming the tasks and related events, defined in this table, into commands given to the sequence of filters in order to convert the electronic document into an audio or video data stream , and - fourth electronic means for distributing such audio or video data stream.

ILLUSTRATION OF DRAWINGS

These and other characteristics of the present invention will become clear from the following description of some preferential embodiments, given by way of non-limiting example, with reference to the attached drawings in which:

- fig. 1 illustrates a flow diagram of an audiovisual content distribution method according to the current technique;

- fig. 2 illustrates a flow diagram of the method for converting electronic documents according to the present invention into an audio / video data flow;

- fig. 3 schematically illustrates an apparatus for converting electronic documents according to the present invention into an audio / video data stream.

DESCRIPTION OF AN EMBODIMENT

PREFERENTIAL OF THE FOUND

With reference to the attached figures, a method 10 and an apparatus 11 according to the present invention can be used to convert a sequence of one or more electronic documents 12, defined according to the SMIL (Synchronized Multimedia Integration Language) into an audio / video data stream. or similar language, including a header 13 and a body 14.

According to an embodiment, the method 10 according to the present invention has been implemented on an apparatus 11, for example a server, with x86 hardware architecture (with Intel and AMD processors), on Windows XP and Linux operating systems, but it is clear that it can also be implemented with different architectures and on other operating systems.

According to the preferential embodiment of the method 10 according to the present invention, the conversion of an electronic document 12 into an audio / video data stream takes place by means of a session 30 defined by at least four states 31: - a rest state, in which the session 30 was created;

- a processing state, in which an electronic document 12 is processed;

a playback state, in which the audio / video stream is played;

- a state of termination, in which session 30 comes to an end.

Furthermore, a session 30, according to the illustrated embodiment, comprises a series of tasks 33, which can be substantially summarized as follows:

reproduction task 33a, used to reproduce an audiovisual content; the reproduction task 33a substantially consists of a video file or an audio file;

- Stop task 33b, used to cause termination of another task 33 in execution;

- Clear task 33f used to cause the termination of any task 33 in execution;

- Sequence 33d task, used to define a list of tasks to be performed in sequence;

- Parallel task 33e, used to define a list of tasks to be performed simultaneously;

The sequence 33d and parallel 33e tasks are also called parent tasks; the tasks defined within the respective lists of the aforementioned sequence tasks 33d and parallel task 33e are called child tasks.

Each of the tasks 33 can be modified by means of events 34 which can be basically summarized as:

- Start event 34a, used to start playing a task 33;

- Stop event 34b, used to request the termination of a task 33.

- Immediate Stop event 34c, used to immediately terminate a task 33 without waiting for the end of its execution, regardless of any other Stop events 34a envisaged for the specific task to be terminated.

The events 34 associated with each task 33 are divided into four lists of events 35 summarized as follows:

list of Start Active Events 35a consisting of the events 34 that the specific task 33 generates during its execution;

- list of End 35b Active Events, consisting of the events 34 that the specific task generates at the end of its execution;

- list of Start Passive Events 35c, consisting of the list of events 34 that the specific task receives before starting its execution;

- list of Passive Events of End 35d, consisting of the events that require the termination, during execution, of the specific task 33; the specific task ends its execution when it receives all the foreseen Stop events 34b, or when it receives an immediate Stop event 34c.

The method 10 according to the present invention comprises the following steps:

- a first phase in which, by means of first electronic means 20, the request for the distribution of audiovisual contents included in an electronic document 12 defined according to the SMIL language or similar language is acquired, and in which a session 30 is generated;

a second step in which, by taking this document 12 from electronic storage means 24, by means of second electronic means 21 a syntactic analysis of the document 12 is performed, in order to verify its validity and therefore its conformity to the desired standard;

a third step in which, again by means of said second electronic means 21, an analysis of the header 13 of the electronic document 12 is performed in order to define the specific audio or video contents and the relative reproduction parameters; in this third step one or more sequence of filters 15 is also defined to be used for the reproduction of the specific audio or video contents;

- a fourth phase in which, by means of these second electronic means 21, an analysis of the body 14 of the electronic document 12 is carried out in order to define a list of tasks 33 of the session 30 and of events 34, and to define the sequence of filters 15 to be apply to convert audiovisual content into an audio / video stream; in this fourth phase the list of tasks 33 and events 34 admissible for session 30 is summarized in the form of a table.

In this fourth phase the body of the electronic document 12 is translated into a sequence task 33d, which represents the main task of the session 30. Furthermore, each element of the body 14 that identifies audio, video, text or timed playback contributions is separated from specific XML "tags" according to SMIL language, is translated into a task 33 according to the rules described below and according to the hierarchy of the electronic document 12:

- if the element of the electronic document 12 is of the "seq" type, ie of sequence, it is translated into a sequence task 33d;

- if the element of the electronic document 12 is of the "par" type, ie parallel, it is translated into a parallel task 33e;

- if the element of the electronic document 12 is of type "msa: Stop", it is translated into a Stop task 33b.

- if the element of the electronic document 12 is of type "msa: Clear", it is translated into a Clear task 33b.

- any other element of the electronic document 12, attributable to recognized elements such as "ref", "audio", "video", "text" are translated into Reproduction tasks 33a, while unrecognized elements are ignored.

Subsequently, for each of the tasks 33, again analyzing the body 14 of the electronic document 12, one or more of the following events 34 are defined:

a Start event 34a of the list of Active events of End 35b, addressed to the next child task 34 of the parent task 33, if this is a sequence task 33d;

- a Stop event 34b of the list of active events of End 35b, addressed to the parent task 33, if this is a Parallel task 33e and has as attribute "endsync" without any value or with a value equal to "last";

- a Start event 34a of the list of Passive Start events 35c addressed respectively by the parent task 33, if this is a parallel task 33e, or by the immediately preceding child task, if the parent task 34 is a sequence task 33d.

For each of the sequence tasks 33d, one or more of the following events 34 are defined:

- a Start event 34a, from the list of Active events of Start35a, destined for the first task 33 child of the specific sequence task 33d;

- an Immediate Stop event 34c of the list of End Active Events 35b destined for each task 34 child of the sequence task 33d;

- a Stop event 34b, from the list of passive events of End 35d, intended for the specific sequence task 33d and having as a source the last task 33 child of the specific sequence task 33d

For each of the parallel tasks 33e one or more of the following events 34 are defined:

- a Start event 34a, from the list of active Start events 35a, addressed to each of the tasks 33 included within the list of the specific parallel task 33e;

- an Immediate Stop event 34c, from the list of End 35a active events, addressed to each of the tasks 33 children of the specific parallel task 33e;

- an Immediate Stop event 34c, from the list of passive events of End 35d addressed to each of the child tasks, if the parallel task 33e has as attribute "endsync" a value equal to "first";

- a Stop event 34b, from the list of passive events of End 35d addressed to each of the child tasks, if the parallel task 33e has as attribute "endsync" a value equal to "last", or unspecified;

For each of the Play 33a or Clear 33c tasks, one or more of the following 34 events are defined:

- if the "begin" attribute is specified and this contains a SMIL event of the start type or of the timed type, then a Start event 34a is generated from the list of Passive Start events 35c having as source the task specified in the SMIL event; for the source task, on the other hand, a start event 34a is generated, from the list of active start events 35a, destined for task 33 with the "begin" attribute;

- if the "begin" attribute is specified and this contains a SMIL event of type end, then a Start event 34a from the list of Passive Start 35c events is generated having as source the task specified in the SMIL event; for the source task, on the other hand, a start event 34a is generated, from the list of active events of end 35b, destined for task 33 with the "begin" attribute.

The method 10 further comprises a fifth phase in which, by means of third electronic means 22, the session is made to pass into a state of reproduction and the audiovisual contents are processed through this sequence of filters, producing an audio / video stream.

In a sixth phase of the process 10, by means of fourth electronic means 24, the audio / video stream is reproduced and said table is dynamically updated by deleting the tasks 33 and the related events 34 which have been performed, until reaching, in the absence of requests for modification of the playback of the audio / video stream, of the end of the playback.

In this sixth phase, the execution of tasks 33, and the recursive management of events 34 is carried out according to the rules summarized below: - an initial task 33 is performed, identified among those that have no event 34 in the list of passive start events 35c;

- when a Task generates a start type event 34a intended for a specific task, then the corresponding start event 34a is eliminated from the list of Passive Start events 35c of the specific recipient task 33; moreover, if the list of Passive Start events 35c of the recipient task 34 is not empty, the management of the start event 34a is interrupted; furthermore, if the specific task 33 is a reproduction task 33a or a Clear task 33c and the sequence of filters 15, to which the specific task 33 must be connected for the generation of the output data stream, is currently occupied by a another task 33, then an immediate Stop event 34c is generated towards task 33 which occupies the sequence of filters 15; this Immediate Stop event is generated recursively until the specific sequence of filters 15 is freed; moreover, if the specific task 33 is a reproduction task 33a, a specific sequence of filters 15 intended for its reproduction is generated; all the events 34 contained in the list of active start events 35a of the specific task 33 are managed recursively;

- when a task 33 generates a Stop event 33b, intended for a specific task 33, then the corresponding event 34 is eliminated from the list of Passive End 35d events of the specific target task 33; moreover, if the list of Passive End 35d events of the specific recipient task 34 is not empty, the management of the stop event 34b is interrupted; furthermore, if the specific task is of reproduction 33a, it is interrupted and the currently used filter sequence 15 is freed; all the events 34 contained in the list of active events of end 35b of the specific task 33 are managed recursively;

- when a task 33 generates an Immediate Stop event 34c, intended for a specific task 33, if the latter is a Reproduction task 33a, then it is interrupted and the sequence of filters 15, currently engaged by the recipient task, is freed; furthermore, all the events 34 contained in the list of active events of end 35b of the specific recipient task 33 are managed recursively;

- the timed activation events 34 contained in the Active Start event lists of a specific task, are activated at the playback time indicated by the specific timed event 34;

- at the end of the execution of a specific task 33, all the events in the list of End 35d active events of the specific task 33 are generated;

- during the execution of a task 33, all the events in the list of End 35d active events of the specific task 33 are generated, at the specific reproduction instant indicated in the SMIL "dur" attribute or in the "end" SMIL attribute.

In this sixth phase, each request for modification of the reproduction, generated for example by a Client requesting the presentation of audiovisual contents included in a series of electronic documents 12 not included in the original sequence, is managed by switching the session 30 to said processing state . Thanks to this, the new sequence can be interconnected to the original sequence without requiring the playback of the original sequence itself to be stopped, and in any case without the user perceiving the superimposition of the new sequence to the original one. The process 10 resumes from the second phase which leads to a new processing of the modified sequence of electronic documents 12 and an update of the table, deleting tasks and events that are no longer useful and inserting the new tasks 33 and events 34.

If, for example, in the sixth stage of reproduction of an electronic document 12, comprising audio contributions to the video vi, the presentation of a new electronic document 12 comprising audio contributions a2 and text tl is requested, the procedure 10 provides for the interruption, through the events 34 set up for this purpose, of the reproduction of only the different contribution of the new electronic document 12. In particular, the procedure returns to the analysis phase of the new document, updating the contents of the table with the new tasks 33 and related events 34, and activating a reproduction that leaves the reproduction of the video contribution unaltered, by interconnecting the audio contributions a2 and text tl in the output data stream, without perceptible interruption in the use of the video component of the contribution vi.

It is clear that modifications and / or additions can be made to the method 10 and to the apparatus 11 according to the present invention, without thereby departing from the scope of the present invention.

It is also clear that, although the invention has been described with reference to specific examples, a person skilled in the art will certainly be able to realize many other equivalent forms of device and method for converting electronic documents defined according to an audio / video data stream. the SMIL language or similar language, all falling within the scope of the present invention.

Claims (19)

CLAIMS 1. Procedure for converting a sequence of electronic documents (12), defined according to the SMIL (Synchronized Multimedia Integration Language) or similar language and composed of at least one heading (13) and a body (14), into a stream of data that can be reproduced on at least one Client terminal, consisting of one or more audio streams and / or one or more video streams, including audiovisual content that can be reproduced simultaneously, characterized by the fact that said data stream, which is not predefined at the start of said reproduction, is modified and / or integrated during said reproduction, without actual and / or perceptible interruption, by increasing and / or modifying said sequence of electronic documents with one or more sequences deriving from a request of said Client terminal. 2 . Process as in claim 1 characterized in that it comprises at least a first phase in which a request is generated for a distribution of a presentation of audiovisual contents included within said electronic document (12), and that said presentation of audiovisual contents is structured according to a session (30) comprising a plurality of operating states (31) and a plurality of tasks (33), suitable for regulating the mode of reproduction of said audiovisual contents, said tasks (33) being activated by a specific event (34) and term by generating a further specific event (34); 3. Process as in claim 2 characterized in that it also comprises a second step in which, by analyzing the header (13) of said electronic document (12), said audiovisual contents and the relative reproduction parameters are identified and a specific sequence of filters (15) suitable for processing said audiovisual contents and in which by analyzing the body (14) of said electronic document (12) a table is generated whose content defines the set of transitions allowed for said session (30), in the form of a list of said tasks (33) and related events (34). 4. Process as in claim 3 characterized by the fact that it also includes a third phase in which said tasks (33) predisposed to the generation of an audio stream or a video stream are activated, according to said list of tasks (33) and related events (34) contained in said table, processing said audiovisual contents by means of said sequence of processing filters (15). 5. Process as per one of the preceding claims, characterized in that said request for distribution of audiovisual content takes place by a requesting entity, called Client, to a distributing entity called server. 6. Process according to claim 4 characterized in that said tasks (33) comprise a reproduction task suitable for reproducing an audio or video contribution, a Stop task suitable for terminating any other task in execution, a Sequential task which defines a set of tasks (33) to be performed according to a predetermined order and a parallel task that defines a set of tasks (33) to be performed simultaneously. 7. Process as in claim 6, characterized by the fact that said events (34) comprise a Start event suitable for initiating the reproduction of a specific task, a Stop event suitable for requesting the termination of a specific task (33) and a Stop event Immediate act to request the immediate termination of a specific task (33). 8. Process according to one of the preceding claims, characterized in that said audio stream or said video stream are distributed according to RTP, RTSP internet protocols or protocols dedicated to real-time distribution. 9. Process according to one of the preceding claims, characterized in that said audio stream or said video stream are distributed locally for the generation of an audio file or a video file. 10. Process as in any one of the preceding claims, characterized by the fact that said sequence of filters (15) comprises at least one filter predisposed to extraction operations from an audio file or a video file of audio or video or audio / video data, which it also includes an audio or video mixer filter designed for synchronization of two or more audio or video streams and which also includes a filter for the transmission of audio or video streams using RTP or RTSP internet protocols. 11. Process according to claim 10 characterized by the fact that said sequence of filters (15) comprises at least one filter designed to receive audio or video streams by means of RTP or RTSP internet protocols. 12. Process as in claim 10 characterized in that said sequence of filters (15) comprises at least one filter designed to compress and decompress audio or video streams. 13. Process according to claim 10 characterized in that said sequence of filters (15) comprises at least one filter designed to convert audio or video streams into audio or video streams with a different format. 14. Process as in claim 10 characterized in that said sequence of filters (15) comprises at least one filter designed to transform a series of images encoded according to common electronic formats into a video stream. 15. Apparatus for converting a sequence of electronic documents (12), defined according to the SMIL (Synchronized Multimedia Integration Language) or similar language and composed of at least one heading (13) and a body (14), into a stream of data, not predefined at the beginning of the reproduction, consisting of one or more audio streams and / or one or more video streams, comprising audiovisual contents that can be reproduced simultaneously, characterized in that it includes electronic means able to modify said data flow, without interruption during the reproduction, by increasing and / or modifying the sequence of said electronic documents (12). 16. Apparatus as in claim 15 characterized by the fact that it comprises at least first electronic means (20) suitable for receiving a request for distribution of said audiovisual contents contained in said document (12) and which comprises second electronic means (21) suitable for picking up said document (12) by electronic storage means (24), to analyze the header (13) of said document (12), to generate a session (30) representing said presentation, to generate said sequence of filters (15), and to generate a table defining the transition states (31) of such presentation of audiovisual content and the related tasks (33) together with the related events (34); 17. Apparatus as per claim 16 characterized by the fact that it comprises third electronic means (22) adapted to make said session (30) pass through a state (31) of reproduction by transforming said tasks (33) and the related events (34) defined within said table in commands given to said sequence of filters (15) in order to convert said electronic document (12) by means of said sequence of filters (15) into an audio stream and / or into a video stream. 18. Apparatus as in claim 16 characterized in that it comprises fourth electronic means (23) suitable for distributing said audio stream and / or said video stream. 19. Process for converting a sequence of electronic documents (12), defined according to the SMIL (Synchronized Multimedia Integration Language) or similar language into an audio stream or a video stream and related apparatus, substantially as described, with reference to the attached drawings .