MULTIPOINT DISTRIBUTION METHOD
The present invention is related to the field of the communications and the
transmission of digital data.
The invention relates in particular to a method for distributing digital data, at leas5 t
such as video data, preferably audio and video data.
Such a method will find a particular application, but in no way limited to, the
capture, transmission and distribution to the spectators of video data during events,
namely sports or music events, locally on spot within a sports or cultural arena, at the
10 place where said events are held. The invention is also likely to find an application during
events such as conventions, during a presentation, a lecture, a speech or any oratory
scene.
In a known way, during an event, for example a sports event taking place in a
stadium, the distribution of the video sequences captured in real time occurs through one
15 or more giant screens said place is provided with, even through monitors present at
different locations of the said place, as in the boxes. Such screens permit the
simultaneous as well as the deferred transmission of one sequence at a time, the selection
and displaying on this screen of the sequence being controlled by an operator in a control
room dedicated to the video.
20 Such a system requires the setting up of a dedicated infrastructure, inside the
place, expensive and complex to be managed, which does not give the spectator the
option as to the sequences that are distributed.
An existing solution for transmitting a data stream is described in US
2003/058866. This solution consists of a remote data transmission system, for
25 conventionally transmitting data via a network between two terminals.
Such a solution is not aimed at optimizing such a transfer in a particular localized
arena, in the meaning of the present invention, as this is the case during sports or music
events. This technology does not take into consideration the rights related to the contents
being transmitted, by limiting their storage time on the terminal.
30 The aim of the present invention is to cope with the drawbacks of the prior art by
providing the simultaneous distribution of several different video sequences directly to
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the spectators, i.e. the spectators at the level of their personal terminal, preferably their
cell phone or their tablet.
To this end, the invention uses an existing wireless telecommunication network,
namely a radio distribution network, in particular the mobile phone network. Thus, the
invention permits to simplify the infrastructure to be installed in the place where th5 e
event is held.
In addition, the invention provides a software application, which each user
terminal is provided with, permitting the latter to manage the distribution of one and/or
the other of said sequences. Each user can then choose to re-view a specific moment of
10 the event already passed, according to different viewing angles.
Moreover, such an application permits to control the distribution of each sequence
in order to permit the user to namely perform a slow-motion of said moment, or other
actions on the sequence he has selected.
To this end, the present invention relates to a method for distributing digital data
15 streams, at least such as video data, wherein:
- a simultaneous and continuous capture of at least two separate video sequences
is performed and they are converted as they are captured into at least two streams (3) of
digital data, at least such as video data;
- said digital streams (3) are continuously transmitted in multipoint distribution
20 from at least one transmission terminal (5) to at least two mobile terminals (6), located at
a distance, each terminal (6) being personal to a user (7), via a telecommunication
network (8);
- at the level of each terminal (6), said streams (3) are received and an interface
(9) for controlling their distribution is displayed.
25 Such a method is characterized in that:
- said interface (9) permits each user (7) to select one and/or the other of said
video sequences for its viewing at the level of his terminal (6) as well as to control the
distribution of said viewing by streaming at actual speed, or by stopping, slowing down,
accelerating the frame rate, and/or by choosing the direction of streaming, and/or by
30 selecting a moment of said sequence and in that it consists in:
- temporarily storing each stream (3) in a buffer (14) of the circular type, at the
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level of the internal memory of each terminal (6); and
- continuously deleting in time each stream (3) stored in said buffer (14) after a
time interval determined with respect to a duration defined for each video sequence, said
time interval corresponding to a duration from several minutes to several tens of minutes.
Moreover, according to other additional non-restrictive features, such a metho5 d
may consist in continuously deleting in time each stream stored in said buffer after a time
interval determined with respect to a duration defined for each video sequence.
In addition, said time interval may correspond to a duration from 10 to 20
minutes.
10 Thus, the invention technically permits to manage the rights related to the
distribution of the data captured during the event, ensuring their deletion.
Further features and advantages of the invention will become clear from the
following detailed description of non-restrictive embodiments of the invention, with
reference to the attached figure schematically showing a principle example of the
15 architecture of a mode of operation of the diffusion method according to the invention.
The present invention relates to the distribution of digital data.
Such a distribution is performed within the framework of events, in particular
sports events. Preferably, this distribution can occur within a sports arena or around a
field 1 for receiving the spectators who have come and watch and/or participate in this
20 event.
Such digital data can be at least video data. These video data can also be coupled
with sound data such as audio and/or image data, namely still images.
Said video data result from a capture consisting of an acquisition of video
sequences. Such an acquisition can be performed by adapted video capture means,
25 namely cameras 2, even, for the photos, adapted devices.
In the example shown, several cameras 2 arranged at different locations in the
sports arena, namely around the field 1, each perform an acquisition of a particular
sequence at a specific angle. All these acquisitions then form said capture that pretends to
be simultaneous and continuous.
30 According to the example, three different video sequences are acquired, but the
invention provides for performing a simultaneous and continuous capture from at least
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two different video sequences, namely from two different cameras 2 and therefore from
two different viewing angles. A larger number of video captures can be performed,
depending on the means used for this purpose, namely the number of cameras 2.
Moreover, the sequences are converted as they are captured into at least two
streams 3 of digital data, at least such as video data. A possible conversion 4 can consis5 t
of a step of compressing the data, in order to optimize their transmission via a network.
This compression can occur in real time through a system such as an audio/video
encoder, so as to convert each stream 3 into an encoded stream.
Other conversions 4 are possible, which consist in processing said data, namely
10 the insertion of self-correction codes in order to cope with the transmission errors via
wireless networks. Such a processing can be performed in part directly at the levels of the
cameras 2 or in part at the level of a remote centralized location, such as for example in a
control room.
Then, the invention provides for continuously transmitting said digital streams 3
15 from at least one transmission terminal 5 to at least two mobile terminals 6 located at a
distance, each terminal being personal to a user 7. The latter is preferably a spectator who
has come and attend the event, located in the sports arena where said event takes place,
namely in the stadium 1 or near the field, namely in the stands or the boxes.
In addition, this transmission step is performed via a telecommunications network
20 8. In the meaning of the present invention, said network 8 is a wireless radio network.
Preferably, such a network may be dedicated to mobile telephony. Therefore, said
terminal 6 is formed of a receiver capable of being connected to such a telephony
network 8, preferably a cell phone such as a "smartphone" (for "intelligent phone"), or to
a tablet.
25 According to an alternative embodiment, depending on the place where the event
is held, another type of network can be used, namely wireless LAN, such as "Wifi" or
"WiMAX".
In particular, the invention provides for transmitting said streams 3 by means of a
transmission technology of the "multipoint" type, or "multipoint" or "group"
30 transmission. This kind of distribution uses a single transmitter, in the form of said
transmission terminal, sending at least one signal 13 to several receivers, i.e. the
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terminals 6. In fact, this is a "point to multipoint" communication. In particular, each
stream 3 can be converted into a signal 13 that is specific to it. Then there are as many
signals 13 as there are streams 3.
Preferably, the invention uses a technology such as "Multimedia Broadcast
Multicast Services" (MBMS) of the fourth generation mobile telephony network5 s
(4G/LTE for "Long Term Evolution").
After sending the streams 3, these are received at the level of said terminal 6 and
an interface 9 for controlling their distribution is displayed.
Such an interface 9 may consist of a software application incorporated into said
10 terminal 6 and dedicated. In particular, said application can be previously installed and
performed from the memory of the terminal 6.
In particular, the performing of said application can start a client request within
the above-mentioned multicast communication system. A step of identifying and/or
authenticating the user 7 may be required, e.g. within the framework of a subscription to
15 a service, in particular a paid service, in order to obtain the receiving of said streams 3
and the viewing of said sequences.
Moreover, said application permits, on the one hand, to manage the receiving of
the streams 3, namely in order to convert them for distributing the sequences they
correspond to. Then the display means of the terminal 6, i.e. its screen 10, permits to
20 view said sequences after conversion of the streams 3.
A simple conversion consists only in reading directly the encoded stream. In fact,
part of the software application is capable of transcribing and reading the encoded stream,
without any other additional processing, preferably continuously as it is received.
A possible conversion can consist of a decoding of the stream, namely in real
25 time.
Another type of conversion can consist in correcting the data packets of the
streams 3, namely in case of absence of or error in some packets.
On the other hand, the application permits the user 7 to choose the playback mode
for one or several video sequences corresponding to said streams 3 being received. To
30 this end, said screen 10 may be designed as a touch screen, while the interface 9 has
selectable elements, such as icons or buttons, forming the means for controlling the
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distribution of one or several sequences.
As such, the invention is characterized in that said interface 9 permits said user 7
to select one and/or the other of said video sequences for its viewing at the level of said
terminal 6. To this end, said interface 9 includes a first menu 11 for selecting the
sequence the user 7 wants to view. In the example shown, this is the last sequence tha5 t
was selected for its viewing on the screen 10 of the terminal 6.
In addition, the interface 9 also permits to control the distribution of said viewing
by scrolling at actual speed, or by stopping, slowing down, accelerating the frame rate,
and/or by choosing the direction of scrolling, and/or choosing a moment of said
10 sequence. In other words, a second menu 12 permits to control all the aspects of reading
of the previously selected sequence.
In a non-restrictive way, it is possible for the user, through an icon or a play
button 120, to start playing the video sequence. Another icon or stop button 121 permits
to stop the playback, making a freeze frame or pause at a specific moment. Another icon
15 or button 122 permits to scroll forward, while yet another one 123 permits to scroll
backward. It is then also possible to perform temporally an increasing, but also
decreasing playback in time, by changing the direction of scrolling. An additional icon or
button 124 can also permit to manage the frame rate, by accelerating or decelerating it, in
order to obtain a slow-motion that can reach an image-wise playback of the sequence.
20 Finally, another icon or button 125, namely in the form of a scroll bar, permits to select a
specific moment of the video sequence, then to apply one and/or the other of the previous
controls.
Thus, the user can see at will a specific moment of the event he is attending, by
fully controlling the distribution and watching according to several viewing angles
25 corresponding to each sequence. In the example of a sports event, such as a sports
meeting between two teams, the user can then see and view again an action in all its
details.
According to a particular embodiment, not shown, the interface 9 permits to
control the distribution of the simultaneous viewing of two sequences. In fact, a second
30 menu can be doubled in order to separately manage the control of the playback of each
sequence, which is displayed simultaneously on said screen 10. This peculiarity permits
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the user to compare at the same time several viewing angles.
It is therefore possible to synchronize the two sequences so that their playing back
occurs from a same moment.
To this end, the invention consists in temporarily storing each stream 3 in a buffer
14 of the circular type, at the level of the internal memory of said terminal 6. Such 5 a
buffer 14 is similar to a circular or rotary "buffer” the memory space of which is limited
to a predefined size. In case of saturation of this memory space, the new data "replace"
the oldest data, namely by crushing the corresponding memory space.
In other words, the invention consists in deleting continuously in time each stream
10 3 stored in said buffer 14 after a time interval determined with respect to a duration
defined for each video sequence. Such duration may namely correspond to a size of each
sequence, depending on the video format of its stream 3.
In particular, according to the preferred embodiment, said time interval may
correspond to a duration from several minutes to several tens of minutes, namely from 10
15 to 20 minutes.
Furthermore, the invention provides for limiting the storage time of the digital
data being transmitted and read at the level of each terminal 6. This peculiarity permits to
eliminate the problems related to the management of the distribution rights by providing
a technical solution that progressively deletes the data received by each terminal 6, i.e.
20 the video sequences.
Therefore, the replacement of old data of each stream 3 by the arrival of new data
of that same stream 3 in said buffer 14 simulates a delete operation 15, as shown
schematically.
Moreover, it is possible to consider, at the end of the event the user 7 is attending,
25 to continue the transmission of the streams 3, without content, for a given and sufficient
period of time, in order to continue the crushing and this deletion of all previous data,
until the memory is empty of all content.
In addition, it is also possible to remotely control, through a specific signal
incorporated in one of said streams 3, the stopping of said software application and its
30 closing, in order to fully empty the buffer 14, thus ensuring the destruction of the data it
contains.
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According to a simplified embodiment, after a period of time, upon closing said
application, the voluntary or forced disconnection of the user 7, the buffer is emptied of
any data it contains.
In view of the above, the invention permits to significantly reduce the amount of
data transmitted on said network 8, limiting the risk of saturation of passband. I5 n
addition, since the management by the user 7 is performed locally at the level of the
terminal 6, no other communication tool or protocol is required, thus avoiding a remote
execution on a dedicated server.
Thus, the method according to the present invention permits a spectator to indeed
10 see again a past moment of an event he is attending, according to the viewing angle he
desires.

We Claim:
1. A method for distributing to the spectators digital data streams, at least such as
video data, during events locally on spot within a sports or cultural arena, method
5 wherein:
- a simultaneous and continuous capture of at least two separate video sequences
is performed and they are converted as they are captured into at least two streams (3) of
digital data, at least such as video data;
- said digital streams (3) are continuously transmitted in multipoint distribution
10 from at least one transmission terminal (5) to at least two mobile terminals (6), located at
a distance; each terminal (6) being personal to a user (7), via a telecommunication
network (8);
- at the level of each terminal (6), said streams (3) are received and an interface
(9) for controlling their distribution is displayed; wherein:
- said interface (9) permits each user (7) to select one and/or the 15 other of said
20
video sequences for· its viewing at thelevel of his terminal' (6) as well as to control the
distribution of said viewing by streaming at actual speed, or by stopping, slowing down,
accelerating the frame rate, and/or by choosing the direction of streaming, and/or by
selecting a moment of said sequence and in thatit consists in:
- temporarily storing each stream (3)in a buffer (14) of the circular type, at the
level of the internal memory of each terminaltri); and
- continuously deleting in time each stream (3) stored in said buffer (14) after a
time interval determined with respect to a duration defined for each video sequence, said
time interval corresponding to a duration from several minutes to several tens of minutes.
25
2. The distribution method according to claim 1, wherein said time interval
corresponds to a duration from 10 to 20