FR3114720A1 - Management of adaptive progressive downloading of content taking into account the quality of the signal exchanged between the client terminal and the network access point - Google Patents

Abstract

Managing adaptive progressive downloading of content taking into account the quality of the signal exchanged between the client terminal and the network access point The invention relates to a method for managing adaptive progressive downloading (HAS) of digital content from a content server (2) to a multimedia stream reader terminal (8). The content server (2) is present on a communication network (1), which the multimedia stream player terminal (8) accesses via a network access point (6). According to the invention, a selection of an encoding rate to be used for downloading at least one of the time segments takes account, not only of information relating to the bandwidth available on the network, between the server of content and the multimedia stream reader terminal (8), but also information relating to the quality of a signal exchanged between the access point and the multimedia stream reader terminal. Figure for abstract: Fig 1

Description

Management of adaptive progressive downloading of content taking into account the quality of the signal exchanged between the client terminal and the network access point

The field of the invention is that of digital multimedia content, namely digital audio and/or video content. More specifically, the invention relates to the supply of digital content accessible according to a technique known as adaptive progressive downloading, in a context where the content server is present on a communication network, to which the multimedia stream reader terminal accesses via from a network access point.

Prior art

Access to multimedia content, such as television or video on demand, is possible today, for most restitution terminals.

The terminal generally sends a request to a server, indicating the chosen content and it receives in return a stream of digital data relating to this content.

The terminal is suitable for receiving these digital contents in the form of multimedia data and for restoring them. This restitution consists of providing the terminal with the digital content in a form accessible to the user. For example, received data corresponding to a video are generally decoded, then restored at the terminal level in the form of a display of the corresponding video with its associated soundtrack. In the following, for the sake of simplicity, we will assimilate the digital content to a video and the restitution by the terminal, or consumption by the user of the terminal, to a visualization on the screen of the terminal.

The distribution of digital content is often based on client-server protocols of the HTTP (Hyper Text Transport Protocol) family. In particular, the downloading in progressive mode of digital content, also called streaming, makes it possible to transport and consume data in real time, i.e. the digital data is transmitted over the network and restored by the terminal as and as they arrive. The terminal receives and stores part of the digital data in a buffer memory before restoring it. This distribution mode is particularly useful when the bit rate available to the user is not guaranteed for the real-time transfer of the video, depending for example on the fluctuation of the available bandwidth.

Adaptive progressive downloading, in English HTTP Adaptive Streaming, abbreviated HAS, also makes it possible to broadcast and receive data according to different qualities corresponding for example to different speeds. These different qualities are described in a parameter file available for download on a data server, for example a content server. When the client terminal wishes to access a content, this description file makes it possible to select the correct format for the content to be consumed according to the available bandwidth or the storage and decoding capacities of the client terminal. This type of technique makes it possible in particular to take into account variations in bandwidth on the link between the client terminal and the content server.

There are several technical solutions to facilitate the distribution of such streaming content, such as the proprietary solutions Microsoft® Smooth Streaming, Apple® HLS, Adobe® HTTP Dynamic Streaming or the MPEG-DASH standard of the ISO/ IEC which will be described below. These methods propose to send the client one or more intermediate description files, also called documents or manifests, containing the addresses of the different segments with different qualities of the multimedia content.

Thus, the MPEG-DASH standard (for English “Dynamic Adaptive Streaming over HTTP”, in French “Dynamic adaptive streaming over HTTP”) is an audiovisual format standard for broadcasting on the Internet. It is based on the preparation of the content in different presentations of variable quality and speed, cut into short segments (of the order of a few seconds), also called “chunks”. Each of these segments is made available individually by means of an exchange protocol. The protocol mainly targeted is the HTTP protocol, but other protocols (eg FTP) can also be used. Segment organization and associated settings are published in a manifest in XML format.

The principle underlying this standard is that the MPEG-DASH client makes an estimate of the bandwidth available for the reception of the segments, and, according to the filling of its reception buffer, chooses, for the next segment to be loaded, a representation whose bit rate:

• ensures the best possible quality,
• and allows a reception delay compatible with the uninterrupted rendering of the content.

Thus, to adapt to the variation of network conditions, in terms of bandwidth, existing adaptive download solutions allow the client terminal to switch from one version of the content encoded at a certain bit rate, to another encoded at another throughput, during the download. Indeed, each version of the content is divided into segments of the same duration. To allow continuous playback of the content on the terminal, each segment must reach the terminal before its scheduled playback time. The perceived quality associated with a segment increases with the size of the segment, expressed in bits, but at the same time, larger segments require more transmission time, and therefore present an increased risk of not being received in time for continuous playback of content.

The rendering terminal must therefore find a compromise between the overall quality of the content, and its uninterrupted rendering, by carefully selecting the next segment to be downloaded, from among the various encoding rates offered. To do this, there are different algorithms for selecting the quality of the content according to the available bandwidth, which may present more or less aggressive strategies, or more or less secure, and which may have the objective of favoring the quality of the content. , or on the contrary to guarantee the fluidity of the reading of the content.

The consumption of digital content in adaptive progressive download (HAS) tends to become more democratic. It is used in particular by many streaming services (in French, streaming in continuous mode, or streaming), but also by certain TV decoders, or set-top-boxes, which use it to access delinearized content, such as video on demand (VOD), delayed broadcast of television programs (Replay), or even Network PVR-type offers (for "Network Personal Video Recorder", i.e. a digital content recording service, performed by the content provider itself rather than at the end user's home).

In addition, other devices such as real-time media streaming devices also access digital content in progressive adaptive download mode for real-time (or Live) television content. This is the case, for example, of the Chromecast® device developed by Google®, or the CléTV® from Orange®. Such devices, more generically referred to as Clef HDMI, can also be used to access video-on-demand type content.

Such devices are conventionally plugged into the HDMI port of a television and communicate, for example by Wi-Fi® connection or CPL (for “Power Line Communication”), with another device on the home communication network connected to a extended communication network (for example a smartphone-type smart phone, connected to a 4G mobile network or a home gateway, connected to a fiber or ADSL network (for “Asymmetric Digital Subscriber Line”)) , in order to play back, on the TV, the multimedia content received by a compatible software application. These devices will be referred to below under the generic designation of HDMI Key.

As indicated above, the different algorithms for selecting the quality of video content to be consumed in http Adaptive Streaming can present more or less aggressive strategies, in order to favor the quality of the content, or on the contrary to guarantee the fluidity of the reading. content.

Thus, a selection algorithm favoring the quality of the video returned to the user will always opt for the selection of an encoding rate as close as possible to the bandwidth available between the client terminal and the content server. The user is thus assured of always benefiting from the best quality reproduction of the content he is viewing. However, at the slightest disruption of the network affecting the available bandwidth, the video may freeze (phenomenon known as "freezing"), which is detrimental to the quality of the user's experience.

Conversely, if the selection algorithm favors the fluidity of the image to avoid these harmful phenomena of "freezing", the encoding bit rates selected for the downloading of the video segments are always chosen while maintaining a significant safety margin. in relation to the bandwidth available between the client terminal and the content server. The user then visualizes a video with a lower quality of reproduction, but which has every chance of remaining fluid, because the HAS client embedded in the multimedia stream player terminal will have more latitude to adapt and preserve storage buffers available segments, in case of bandwidth fluctuation.

The disturbances likely to affect the content distribution network, between the content server and the client terminal, and which may occur when video content is returned to the client, are of two types:

• a reduction in the available bandwidth, linked to the sharing of the latter between a plurality of users. Thus, a user can start viewing video content whose encoding rate is 8 Mb/s, being the only one to use a connection with the content server which has a bandwidth of 10 Mb/s. However, if another user, present for example on the same domestic communication network, in turn begins to play a video in HAS adaptive progressive download mode, the 10Mb/s bandwidth will have to be shared more or less equitably between both users, and the first of them is going to have to consume a lower quality video to maintain smooth playback.
• A disturbance related to the connectivity between the multimedia stream player terminal and the access point to the wide area communication network on which the content server is located. Indeed, the quality of the signal exchanged between the client terminal and the access point can fluctuate, depending on phenomena of electromagnetic noise, or masking of the access point, which can reduce the signal level received by the client terminal. , and therefore strongly impact the throughput available on the link between the client terminal and the access point to the extended communication network. This is particularly observed when the client terminal is connected via Wi-Fi to a residential gateway of a home network.

If the sharing of the bandwidth between several users is taken into account by the HAS selection algorithms to choose the encoding rate of the content segments to be downloaded, the quality of the signal exchanged between the client terminal and the access point to the communication network on which the content server is located is not a parameter considered directly by the HAS content selection algorithms. Indeed, the latter consider that the network and the quality of transmission on the latter are faultless, and the quality of the signal is therefore taken into account only by rebound effect, in the evaluation of the reception time of segments of content. by the client terminal.

There is therefore a need for an HAS adaptive progressive download management technique which does not have these drawbacks of the prior art. There is in particular a need for such a technique which makes it possible to optimize the quality of the user experience, by guaranteeing the maintenance of fluidity in the reading of the content displayed, regardless of the fluctuations in the quality of the signal exchanged between the multimedia stream player terminal and the access point to the communication network on which the content server is located. Such an access point can be a residential gateway, in the case where the client terminal is located in a local or domestic network, or a base station, in the case where the client terminal is a mobile terminal which accesses the content in 4G or 5G for example.

The invention meets this need by proposing a method for managing the adaptive progressive downloading (HAS) of digital content from a content server to a multimedia stream player terminal. The digital content is associated with a digital content description file, comprising a list of time segments of the content each associated with several encoding bit rates of the content. The content server is present on a communication network, which the multimedia stream reader terminal accesses via a network access point. A selection of an encoding rate to be used for downloading at least one of the time segments takes account of information relating to the bandwidth available on the network, between the content server and the multimedia stream reader terminal .
According to the invention, this selection also takes into account information relating to the quality of a signal exchanged between the access point and the multimedia stream reader terminal.

Thus, the invention is based on an entirely new and inventive approach to the management of adaptive progressive downloading of content between a content server and a multimedia stream player terminal. Indeed, the method according to one embodiment of the invention makes it possible, for the selection of the encoding bit rate of the content segments to be downloaded, to take into account, not only the end-to-end bandwidth, between the contents and the client terminal, but also the quality of the signal exchanged between the access point and the client terminal.

Unlike conventional HAS selection algorithms, which only use information relating to the bandwidth available between the content server and the client terminal, but not its possible instability, to choose the optimal selection policy content segments, and decide on its level of aggressiveness, the technique according to one embodiment of the invention proposes to refine this selection by also taking into account the quality of the signal exchanged between the client terminal and the point of access. The quality of the user experience is thus advantageously optimized, avoiding the phenomena of video "freezing", which can occur when the quality of the signal deteriorates between the client terminal and the access point (for example between the HDMI key and residential gateway). In other words, the technique according to one embodiment of the invention makes it possible to take into account not only the bandwidth available between the server and the client terminal, but also its potential instability, which can result from the low quality of the signal exchanged between the terminal and the access point. Indeed, in the case of a low quality signal, the bandwidth can vary downwards very quickly and suddenly.

According to one embodiment, the information relating to the quality of a signal exchanged is obtained by determining at least one signal quality indicator between the multimedia stream reader terminal and the access point. This or these quality indicators can be obtained by calculation or by measurement, and are chosen to make it possible to evaluate with efficiency and reliability the level of quality of the signal between the access point and the client terminal.

Thus, according to one embodiment, the quality indicator is a metric, at the level of the physical layer 1 of the OSI model (from the English "Open Systems Interconnection", basic reference model for the interconnection of open systems, which is a network connection standard for all computer systems), a link between the multimedia stream player terminal and the access point. Whatever the nature of the link between the client terminal and the access point, and the communication and connectivity technology used for this link, it is thus possible to develop a quality indicator that reliably reflects the level of quality. of the signal exchanged.

In particular, according to one embodiment, the signal exchanged between the access point and the multimedia stream reader terminal belongs to the group comprising:

• a Wi-Fi type signal, for example conforming to an IEEE 802.11 standard;
• a Power Line Carrier type signal, for example conforming to an IEEE 1905.1 standard;
• a mobile radio communication signal of the 3G, 3G+, H+ 4G, 5G type, etc.

More specifically, when the signal exchanged between the access point and the multimedia stream player terminal is a Wi-Fi® signal, and the access point is a home gateway, determines two Wi-Fi® signal quality indicators:

- a signal-to-noise ratio associated with the Wi-Fi signal (SNR for “Signal To Noise Ratio”);

- a measurement of the power level in reception of the Wi-Fi signal (RSSI for “Received Signal Strength Indication”).

The signal-to-noise ratio, also called signal-to-noise ratio, is indeed an indicator of the quality of the transmission of information conveyed by an electrical or radioelectric signal. This is the power ratio between:

• the maximum amplitude signal received by the client terminal for which the distortion at the output remains below a limit value;
• background noise, which generally corresponds to the signal present at the output of the client terminal in the absence of a signal at the input.

It is usually expressed in decibels (dB). The level of ambient noise (for example the level of electromagnetic noise generated by other Wi-Fi equipment which transmits near the client terminal) influences the value of the SNR.

In addition, the masking of the Wi-Fi access point by an obstacle (for example the body of a user passing on the path between the client terminal and the access point) reduces the level of signal received, and influences therefore the value of the RSSI.

It therefore appears that these two combined quality indicators make it possible to reliably assess the two types of phenomena likely to affect the quality of the Wi-Fi signal.

According to one embodiment, a value of the signal quality indicator(s) defines a signal quality level, and the signal quality level is mapped to the encoding bit rates of the content.

Thus, different threshold values of the quality indicator(s) can be defined, which define several ranges of values that are associated with different levels of signal quality. For example, in the case of a Wi-Fi signal, three threshold values can be defined for the SNR on the one hand, and for the RSSI on the other. Depending on the values measured for the SNR and for the RSSI, and their relative position with respect to the established thresholds, a level of quality of the Wi-Fi signal is deduced therefrom, which can for example be qualified as good, average, weak or insufficient. These signal quality levels can advantageously be associated with the different levels of encoding bitrates proposed in the manifest file associated with the content. Thus, a quality level qualified as good will, for example, allow access to all the levels of encoding bitrates proposed in the manifest file, while a low or insufficient level will limit the access of the client terminal to the encoding bitrates the weakest of the manifest file, in order to guarantee the fluidity of the reading.

More specifically, the encoding bit rate of the content corresponding to the quality level of the signal is a maximum encoding bit rate to which the selection is limited.

Thus, for content available for download at four levels of encoding bitrates (for example at 256 kb/s (kilobits per second) (Resolution 1, or level 1, denoted N1), 512 kb/s (N2), 1024 kb/s (N3) and 2048 kb/s (level 4, N4), and for a signal whose quality level can be described as insufficient, weak, average or good, the following correspondence can be made:

• for an “insufficient” quality level signal, content segments cannot be downloaded above 256;
• for a “low” quality level signal, the HAS selection algorithm must limit the encoding bit rate of the segments to be downloaded to 512;
• for a “medium” quality level signal, it will be possible to download content segments up to a maximum encoding bitrate of 1024;
• Finally, a good quality signal will allow the HAS selection algorithm to have an aggressive policy, likely to select the maximum content encoding bitrate of 2048.

More generally, regardless of the number of encoding bitrate levels offered in the content manifest file, a "mapping" of these bitrate levels and the quality levels of the signal exchanged between the client terminal and the access point, as defined by the values of the quality indicator(s) used.

According to a first embodiment, the determination of the signal quality indicator is implemented in the multimedia stream reader terminal. According to another embodiment,

the determination of the signal quality indicator is implemented in the access point.

This determination takes place for example each time a content segment is downloaded, or periodically, independently of the segment download. Of course, the threshold values of the quality indicators to be considered to determine the signal quality level are not the same depending on whether the determination takes place in the client terminal or in the access point.

The invention also relates to a device for managing the adaptive progressive downloading (HAS) of digital content from a content server to a multimedia stream player terminal. The digital content is associated with a digital content description file, comprising a list of time segments of the content each associated with several encoding bitrates of the content. The content server is present on a communication network, which the multimedia stream player terminal accesses via a network access point. Such a device comprises a module for selecting an encoding rate to be used for downloading at least one of the time segments taking account of information relating to the bandwidth available on the network, between the content server and the multimedia stream player terminal. According to the invention, such a selection module also takes into account information relating to the quality of a signal exchanged between the access point and the multimedia stream reader terminal.

Such a progressive downloading management device is in particular configured to implement the management method described previously.

The invention also relates to a multimedia stream player terminal which comprises an adaptive progressive downloading management device as described previously.

The invention also relates to a computer program product comprising program code instructions for implementing a method as described previously, when it is executed by a processor.

The invention also relates to a recording medium readable by a computer on which is recorded a computer program comprising program code instructions for the execution of the steps of the adaptive progressive downloading management method according to the invention such as described above.

Such 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 USB key or a hard disk.

On the other hand, such a recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means, so that the program computer it contains is executable remotely. The program according to the invention can in particular be downloaded onto a network, for example the Internet network.

Alternatively, the recording medium may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the aforementioned display control method.

The adaptive progressive downloading management device, the multimedia stream player terminal and the aforementioned corresponding computer program have at least the same advantages as those conferred by the adaptive progressive downloading management method according to the present invention.

Presentation of figures

Other aims, characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of a simple illustrative example, and not limiting, in relation to the figures, among which:

presents an example of a progressive download architecture based on the use of adaptive progressive download according to an embodiment of the invention;

illustrates an architecture of a multimedia stream player terminal of the ;

describes in the form of a block diagram the process for taking into account, in the selection of content segments to be downloaded, the quality of the signal exchanged between the multimedia stream player terminal and the network access point according to an embodiment of invention;

presents an example of signal quality indicators in the case of a Wi-Fi connection between the multimedia stream player terminal and the access point in the example network of the .

Detailed Description of Embodiments of the Invention

The general principle of the invention is based, in the context of HAS-type adaptive progressive downloading of content, on taking into account the quality of the signal exchanged between a client terminal and the access point to the communication network to which belongs to the content server, to adapt the algorithm for selecting the encoding bitrates of the content segments to be downloaded.

Indeed, according to the prior art, only the bandwidth available between the content server and the client terminal is taken into account by the HAS selection algorithms, by determining the time required to download the various content segments. The HAS selection algorithms, embedded in the multimedia stream reader terminals, adapt, more or less quickly, the level of encoding bit rate of the segments to be downloaded, according to any drops in available bit rate, with the aim of preventing the video does not freeze during its rendering to the client.

However, disturbances affecting the signal exchanged between the multimedia stream player terminal and the access point to the server network are likely to cause the available bit rate to drop very quickly, and in any event faster than the adaptation time. necessary for existing HAS selection algorithms.

According to the different embodiments of the invention, the quality of this signal is therefore taken into account when selecting the video segments to be downloaded, in order to filter, or weight, the target encoding bit rate levels, depending of this measured quality. When the quality of the signal is mediocre, or bad, such a solution results, of course, in a degradation of the quality of reproduction of the video content, but also in a smoother playback of the content, which is no longer interrupted by problems. of "freezing" video, which significantly increases the quality of the user's experience.

We now present, in relation to the , an example of a progressive download architecture based on the use of adaptive progressive download according to the invention.

The terminal 3, for example a smart phone of the "Smartphone" type, the terminal 4, for example a laptop computer, and the terminal 8, for example an HDMI key connected to a television set 5, are in this example located in a network (LAN, 10) controlled by a home gateway 6. The context of the local network is given by way of example and could easily be transposed to an Internet network of the “best effort” type, a company network, or a network 3G, 3G+, 4G or 5G type mobile radio communication, etc.

A digital content server 2 is located according to this example in the wide area network (WAN, 1). The content server 2 receives, for example, digital television content channels from a broadcast television network, not shown, and/or videos on demand, and makes them available to client terminals.

More generally, we are interested, in the context of the present invention, in the case of a multimedia stream player terminal which wishes to access the content present on a content server 2, belonging to a communication network 1. The player terminal multimedia stream (8 for example) accesses the network 1 via an access point 6.

Furthermore, although the illustrates the case of a local network 10, in which the access point 6 is a residential gateway, it will be understood that the invention also applies to the case where the access point 6 is a base station of a radio communication network of the 3G, 3G+, 4G or 5G type for example, which a mobile client terminal (for example a “smartphone” or smart phone 3) accesses to obtain the downloading of content from a content server 2 present on this network.

The client terminals 3, 4 and 8 can enter into communication with the content server 2 to receive one or more contents (films, documentaries, advertising sequences, etc.). In general, a terminal sends a request to a server, indicating the chosen content and it receives in return a stream of digital data relating to this content. In the context of a local communication network, such a request passes through the network access gateway, for example the residential gateway. More generally, such a request passes through the access point 6 to the wide area network 1.

The terminal is suitable for receiving these digital contents in the form of multimedia data and for restoring them. This restitution consists of providing the terminal with the digital content in a form accessible to the user. For example, received data corresponding to a video are generally decoded, then restored at the terminal level in the form of a display of the corresponding video with its associated soundtrack.

It is common, in this client-server context, to use, in order to exchange the data between the client terminals 3, 4 and 8 and the server 2, an adaptive progressive downloading technique, in English "adaptive streaming", based on the http protocol, and abbreviated as HAS. This type of technique makes it possible in particular to offer a good quality of content to the user by taking into account the bandwidth variations which may occur on the global link between the client terminal 3, 4 and 8 and the content server 2.

Conventionally, different qualities can be encoded for the same content of a channel, corresponding for example to different bitrates. More generally, we will speak of quality to refer to a certain resolution of the digital content (spatial, temporal resolution, level of quality associated with video and/or audio compression) with a certain bit rate. Each quality level is itself cut on the content server into time segments (or “fragments” of content, in English “chunks”, these three words being used interchangeably throughout this document).

The description of these different qualities and the associated temporal segmentation, as well as the content fragments, are described for the client terminal and made available to it via their Internet addresses (URI: Universal Resource Identifier). All of these parameters (qualities, fragment addresses, etc.) are generally grouped together in a parameter file, called the description file. It should be noted that this parameter file can be a computer file or a set of information descriptive of the content, accessible at a certain address.

These fragments or “chunks” comprise a set of data representative of the content. In the example of a video, each “chunk” of the video notably comprises a first image called an “I” image, or intra, and one or more images which can be predicted from this I image by estimation/compensation of movement.

Terminals 3, 4 and 8 have their own characteristics in terms of decoding capability, display, etc. In a context of progressive adaptive downloading, they can adapt their requests to receive and decode the content requested by the user at the quality that suits them best. In our example, and according to the technique of the prior art, if the content is available at 512 kb/s (kilobits per second) (Resolution 1, or level 1, denoted D1), 1024 kb/s (D2), 2048 kb/s (D3) and the client terminal has a bandwidth of 3000 kb/s, it can request the content at any rate below this limit, for example 2048 kb/s. In general, “Ci@Dj” denotes the content number i with the quality j (for example the j-th quality level Dj described in the description file). In the rest of the description, we are more particularly interested in the HDMI 8 Key, which is for example an Orange® TV Key®.

The access point 6 is in this example a domestic gateway which ensures the routing of the data between the extended network 1 and the local network 10, manages the digital contents by ensuring in particular their reception from the network. Their decoding is carried out by a multimedia stream reader integrated into the HDMI Key 8. Alternatively, one can also consider any other multimedia stream reader terminal present in the local network 10, in particular at the level of an STB type element (of English Set-Top-Box, French adapter box) or game console (not shown) associated with a television.

In this example, to view content, the terminal 8 first interrogates the service gateway 6 to obtain an address of the description document 7 of the desired content (for example, C1). The service gateway 6 responds by providing the terminal with the address of the description file 7. In what follows, it will be assumed that this file is a manifest type file according to the MPEG-DASH standard (denoted “C.mpd”) and will refer interchangeably, depending on the context, to the expression “description file” or “manifest”.

Alternatively, this file can be retrieved directly from a local Internet server or external to the local network, or already be on the service gateway or on the terminal at the time of the request.

An example of a manifest file (MPD) conforming to the MPEG-DASH standard and comprising the description of content available in three different qualities (D1 = 512 kb/s, D2 = 1024 kb/s, D3 = 2048 kb/s) of content fragmented is presented in appendix 1 . This simplified manifest file describes digital content in XML (eXtended Markup Language) syntax, comprising a list of content in the form of fragments conventionally described between an opening tag (<SegmentList>) and a closing tag (</SegmentList>). Cutting into fragments makes it possible in particular to adapt finely to fluctuations in bandwidth. Each fragment corresponds to a certain duration (“duration” field) with several quality levels and makes it possible to generate their addresses (URL – Uniform Resource Locator). This generation is done in this example using the elements "BaseURL"("HTTP://server.com") which indicates the address of the content server and "SegmentURL" which lists the complementary parts of the addresses of the different fragments :
- “C1_512kb_1.mp4” for the first fragment of the “C1” content at 512 kilobits per second (“kb”) in MPEG-4 format (“mp4”),
- “C1_512kb_2.mp4” for the second fragment,
- etc.

Once it has the fragment addresses corresponding to the desired content, the access point 6 proceeds to obtain the fragments via a download to these addresses. It should be noted that this download takes place here, traditionally, through an HTTP URL, but could also take place through a universal address (URI) describing another protocol (dvb://monsegmentdecontent for example).

The television set 5, via its connection to the HDMI key 8 by plugging into its HDMI port, is used to render a video on demand. Subsequently, this television program is referred to as content C1. Such C1 content is described in a manifest file 7.

As a variant, it will be noted that the content C1 can also be a television program broadcast on a deferred basis, or a personal video of the user, or any other multimedia content of fixed duration, for which the invention also applies.

In one example, a user wishes to view multimedia content, such as a video, on his television set 5 connected to an HDMI key 8. The HDMI key 8 is connected via WiFi® directly to the residential gateway 6. Alternatively, the key HDMI 8 could also comply with the IEEE 1905.1 standard, and be connected to the residential gateway 6 by Power Line Communication technology.

The content fragments obtained by the residential gateway 6 are for example transmitted via WiFi® to the HDMI key 8, which controls their display on the television screen 5, for restitution to the user after decoding by an integrated multimedia stream player to the HDMI key 8.

However, this transmission of the fragments from the residential gateway 6 to the HDMI key 8 is likely to be disrupted, depending on the Wi-Fi connectivity between the gateway and the HDMI key. Indeed, the quality of the Wi-Fi signal exchanged between these two devices can be impacted by the level of electromagnetic noise in the network 10 (which can increase sharply if another Wi-Fi device transmits in the network 10, for example if the smartphone 3, located near the CléTV® 8 will play a YouTube® video); it can also be disturbed by a sharp drop in the signal level received by the HDMI Key 8 (for example in the event of masking of the Wi-Fi 6 access point, which can occur when a user moves around in the domestic environment , and that his body temporarily hides the domestic gateway 6 from the CléTV® 8).

In the event of a disturbance on the local network 10, the bit rate available for the HDMI Key 8 can then drop sharply, causing the user to experience an unpleasant video "freeze" phenomenon, in which the content freezes momentarily on the television screen. 5. To avoid this inconvenience, and to ensure smooth playback of the content in all circumstances, it is proposed to take into account the quality indicators of the signal exchanged between the multimedia stream player terminal and the access point to the wide area network 1, when the selection of content fragments, and more particularly when selecting their encoding bitrate.

There represents an architecture of a multimedia stream reader terminal according to such an embodiment of the invention, for example the HDMI 8 key of the , or a set-top box type adapter box, game console, etc. The following describes more particularly the example of the HDMI Key 8, for example an Orange® TV Key®.

It conventionally comprises memories M associated with a processor CPU. The memories can be of the ROM ( Read Only Memory ) or RAM ( Random Access Memory ) type, or else Flash. The HDMI key 8 communicates with an access point to the extended Internet network, for example the residential gateway 6, via the WIFI module for local wireless communication.

As a variant, the communication between the HDMI key 8 and the gateway 6 could take place via a Power Line Carrier type technology conforming to the IEEE 1905.1 standard: in this case, in the architecture of the , the WIFI module would be replaced by a CPL module.

In another variant, the multimedia stream reader terminal whose architecture is presented in could be a mobile phone, such as the smart phone of the . In this case, the architecture of the could include an RC radio communication module, for the communication of the terminal with the base station of a 4G or 5G network, in parallel with, or instead of the WIFI module.

The HDMI key 8 further comprises an HAS adaptive progressive download module capable of requesting a progressive download of one of the contents at one of the qualities offered in a description file 7. This description file 7 can be recorded for example in the M memories of the HDMI 8 key or be outside.

The HDMI key 8 also includes a DET-Q module for determining one or more signal quality indicators exchanged between the WIFI module (or as a CPL or RC variant) and the access point to the extended communication network 1, for example residential gateway 6.

It also includes a DISP module for controlling the display of the content on a screen of a restitution terminal, for example the smart telephone 3 or the television set 5. Such a DISP module is a module for managing the interface with the user's rendering terminal, by which the HDMI key 8 obtains, for example, information on the user's possible interactions with the rendering terminal (action on the television remote control, for example by pressing the volume key or a key channel change, or selection in a menu highlighted on the television screen of a content to be downloaded), and by which it can control the display on the screen of the rendering terminal of pop-up windows, it making it possible to deliver messages, in particular information on the quality of the signal exchanged with the residential gateway.

It further comprises a module SEL for selecting a maximum encoding bit rate or a maximum resolution authorized for downloading the content, depending on the quality information provided by the module DET-Q. The module SEL drives the adaptive progressive downloading module HAS, in order to force the latter to request a progressive downloading of the content at a quality, proposed in the description file 7, lower than the optimal quality to which it could claim, in the case where the quality of the Wi-Fi signal exchanged with the residential gateway is not optimal.

The HDMI key 8 according to one embodiment of the invention can also contain other modules such as a hard disk (not shown) for storing video fragments, a content access control module, a data processing module commands received from a tablet or smartphone on which the HDMI key control application is installed, thanks to which the user can control its operation, etc. Indeed, such an HDMI key 8 does not generally contain an I/O interface module, and it is the I/O interface module of the user's smart telephone 3 or of his tablet 4, or of the television 5, which is used by the latter to choose, for example, its content.

It will be noted that the term module can correspond both to a software component and to a hardware component or a set of hardware and software components, a software component itself corresponding to one or more programs or computer or more generally to any element of a program capable of implementing a function or a set of functions as described for the modules concerned. In the same way, a hardware component corresponds to any element of a hardware (or hardware) assembly capable of implementing a function or a set of functions for the module concerned (integrated circuit, smart card, memory card, etc. .).

More generally, such an HDMI 8 key comprises a random access memory (for example a RAM memory), a processing unit equipped for example with a CPU processor, and controlled by a computer program, representative of the progressive download management module adaptive HAS, stored in a read only memory (for example a ROM memory or a hard disk). On initialization, the code instructions of the computer program are for example loaded into the RAM before being executed by the processor CPU of the processing unit. The RAM contains in particular the manifest 7 description file. The processor of the processing unit controls the determination of the quality indicators of the signal exchanged with the access point to the extended communication network, the display of pop-up windows on the screen of the restitution terminal, and the restriction of the quality of the content downloaded according to the quality of the Wi-Fi signal, through the choice of the time segments and the associated encoding bit rates to be downloaded, and the transmission corresponding commands to the HAS client module.

There only illustrates one particular way, among several possible, of making a multimedia stream reader terminal, so that it performs the steps of the method detailed below, in relation to the (in any of the different embodiments, or in a combination of these embodiments). Indeed, these steps can be carried out either on a reprogrammable calculation machine (a PC computer, a DSP processor or a microcontroller) executing a program comprising a sequence of instructions, or on a dedicated calculation machine (for example a set of logic gates like an FPGA or an ASIC, or any other hardware module).

We now present, in relation to the , an example of taking into account, when selecting the fragments of content to be downloaded, the quality of the signal exchanged between a multimedia stream reader terminal 30, for example the HDMI key 8, and an access point, for example the residential gateway 6, from the .

The multimedia stream reader terminal 30 is connected to a restitution terminal TX (for example the HDMI key 8 is connected to the television set 5 via an HDMI link). It comprises a DISP 300 interface module with the restitution terminal TX, a DET-Q 301 module for determining one or more quality indicators of the Wi-Fi signal exchanged with the access point, an SEL 302 module for selection of a maximum encoding rate authorized for downloading, depending on this quality, and a HAS 303 client module.

A content server 2 exposes a video C1 in the form of “chunks” C1 _i @Nj encoded at different encoding bit rates Nj, where the index i denotes a temporal identifier of the “chunk” C1 _i @Nj.

According to the prior art, a HAS client module is responsible for coming to retrieve its “chunks” from the content server 2 by choosing the video quality Nj according to the available network resource. We will not describe here in more detail the way in which the HAS client module chooses the encoding bit rate of the next video fragment to be downloaded: there are indeed many algorithms allowing this choice to be made, whose strategies are more or less secure. or aggressive. It is however recalled that, most often, the general principle of such algorithms is based on the downloading of a first fragment at the lowest encoding rate proposed in the manifesto, and on the evaluation of the recovery time of this first fragment. . Based on this, the HAS client module evaluates whether, based on the size of the fragment and the time taken to retrieve it, the network conditions allow the next fragment to be downloaded at a higher encoding rate. Some algorithms rely on gradually increasing the quality level of downloaded content fragments; others propose more risky approaches, with jumps in the levels of the encoding bit rates of the successive fragments.

In the classic case, if a video “chunk” lasts 3 seconds, the recovery of the “chunk” by the HAS client module must not exceed 3 seconds, in order to allow uninterrupted restitution of the content by the terminal 30. It is therefore appropriate for the HAS client module to operate the best compromise between playback quality, and therefore encoding bit rate, as high as possible, and fragment download time, which must be low enough to allow continuous playback on the restitution terminal TX.

In the embodiment illustrated in the , on the other hand, the HAS 303 client module may not control the downloading of the fragment at the optimal encoding bit rate, in order to avoid the video "freeze" phenomena which could occur in the event of degradation of the quality of the Wi-Fi signal , as described in more detail below.

During a step referenced 310, the HAS module 303 retrieves the manifest file 7 in order to discover the available fragments of the video content C1, and the different associated video qualities Nj.

Consider, for example, the case of a customer who wishes to watch a video on demand (VOD), using his CléTV® 8 connected via Wi-Fi to his home gateway 6.

It is assumed that on the HDMI 8 Key that he wants to use, the multimedia stream transport technology is of the HAS type with five levels of encoding bitrate and resolution available, as illustrated in the .

So, in the example of the , the content C1 is for example offered in the form of fragments of duration 3s, with a first encoding rate N1 = 600 kb/s, a second encoding rate N2 = 1200 kb/s, a third encoding rate N3 = 2100 kbps, etc.

In a normal operating mode, not illustrated on the , the HAS module 303 performs the downloading, for example, of successive fragments C11@N1 (i.e. the first time fragment at an encoding rate of 600 kb/s), then C12@N3 (i.e. the second time fragment at a rate of encoding of 2100 kb/s), then C13@N3 (i.e. the third temporal fragment at an encoding rate of 2100 kb/s), ...

The various fragments downloaded by the HAS 303 client module are transmitted to the DISP 300 interface module for their restitution to the user on the screen of the restitution terminal TX.

The algorithm implemented by the HAS client module 303 to determine which fragment at which encoding bitrate should be downloaded in normal operating mode (i.e. apart from taking into account the quality indicators provided by the DET-Q module 301) can be one of the already existing algorithms of the prior art. This algorithm will therefore not be described here in more detail.

At the same time, in accordance with , the DET-Q module 301 determines one or more quality indicators of the signal exchanged between the multimedia stream reader terminal 30, and the access point to the extended communication network 1, for example the residential gateway 6.

These quality indicators of course depend on the type of signal exchanged between the client terminal 30 and the access point, and on the associated technology. Nevertheless, whatever this technology, these quality indicators are most often to be found in the link metrics proposed at the level of the physical layer of the OSI model.

Thus, for a Power Line Carrier link conforming to the IEEE 1905.1 AMLE standard, between the client terminal 30 and the home gateway 6, the quality indicators measured by the DET-Q module 301 can be chosen from:

• a number of packet errors (in English “Packet errors”);
• a number of packets transmitted (“Transmitted packets”);
• the MAC throughput capacity, expressed in Mbps (“MAC Throughput capacity”);
• the availability of the link (expressed as a percentage of the time the link is inactive);
• the PHY rate.

When the client terminal 30 is a mobile terminal which exchanges a 4G or 5G type radio communication signal with a base station forming an access point to the extended communication network 1, the quality indicators measured by the DET-Q module 301 may for example also be the SNR and RSSI. Taking these quality indicators into account, in this 4G or 5G context, advantageously makes it possible to anticipate the case where the mobile user passes through a tunnel or enters an underground car park, for example.

Finally, in the case of a Wi-Fi signal, we can consider, for example, the following two quality indicators:

• the signal-to-noise ratio (SNR) measured by the DET-Q module 301, which corresponds to the difference expressed in decibels between the signal received by the WIFI module of the client terminal 30 and the background noise;
• the power level in reception of the Wi-Fi signal received by the client terminal 30 coming from the gateway 6 (RSSI for “Received Signal Strength Indication”).

Indeed, the signal-to-noise ratio fluctuates according to the level of ambient electromagnetic noise, and deteriorates in particular when the client terminal 30 is subject to disturbances due to neighboring equipment which also transmits via Wi-Fi, whether by another equipment of the local network 10 (for example the tablet 4), or the neighbour's home gateway, for example.

The RSSI can be degraded in the event of masking of the Wi-Fi access point, for example when the body of a user of the network 10 moves and temporarily conceals the residential gateway 6, seen from the client terminal 30.

The values measured by the DET-Q 301 module make it possible to determine a general level of quality of the Wi-Fi signal, as illustrated in the .

In this figure, the abscissa axis shows the SNR value measured by the DET-Q 301 module, expressed in decibels, and the ordinate axis shows the RSSI value, also expressed in decibels.

For each of these two indicators, three threshold levels are defined, denoted by T1, T2 and T3 for the SNR, and S1, S2 and S3 for the RSSI. For example, in the network context of the , the inventors of this patent application have established that the values of these thresholds can be set at:

• S1=-76dB, S2=-70dB and S3=-50dB;
• T1=18dB, T2=25dB and T3=35dB.

It should be noted that these values are suitable for a video type service, but could be less for example for a simple email sending service.

Depending on the respective values of these two quality indicators, four levels of quality of the Wi-Fi signal are thus defined, denoted Q1 to Q4. It should be noted that one can of course also choose a different granularity of the number of quality levels, by choosing a higher number of threshold values Si and Ti, or on the contrary lower, according to the needs.

So, in the example of the , for a measured value of the SNR between T1 and T2, and a measured value of the RSSI lower than S1, the level of quality of the Wi-Fi signal exchanged between the client terminal 30 and the gateway 6 will take the value Q1, corresponding to the level of the lowest quality. For a measured SNR value greater than T3, and a measured RSSI value between S2 and S3, the quality level of the Wi-Fi signal exchanged between the client terminal 30 and the gateway 6 will take the value Q3. When the measured SNR is greater than T3, and the measured RSSI is greater than S3, then the maximum Q4 quality level of the Wi-Fi signal is reached.

For simplification, these different levels of quality Q1 to Q4 can for example be qualified as insufficient quality for Q1, low for Q2, average for Q3 and good for Q4.

We can of course proceed in the same way regardless of the number of quality indicators measured, by associating cross-checking of ranges of values of these indicators with quality levels of the Wi-Fi signal.

The values of the quality indicators are measured by the DET-Q module 301, which can determine the resulting quality level Qi, before transmitting it to the selection module SEL 302. Alternatively, the DET-Q module 301 measures the values of the quality indicators, and transmits them to the selection module SEL 302, which is responsible for determining the resulting quality level Qi.

Depending on the quality level Qi evaluated, the selection module SEL 302 is liable to restrict the client module HAS 303, for the downloading of the content segments.

In a first variant, a maximum percentage of the measured bandwidth to be used for downloading the segments is associated with the Wi-Fi quality level Qi. So :

• For the quality level Q1, it is considered that 75% of the bandwidth measured by the HAS 303 client module can be used for downloading segments, without risking a harmful phenomenon where the video freezes during playback;
• For the Q2 quality level, it is considered reasonable not to use more than 50% of the bandwidth measured by the HAS 303 client module;
• For the Q3 quality level, the encoding rate of the content segments downloaded by the HAS 303 client module is limited, so that they do not consume more than 40% of the measured bandwidth;
• Finally, for the lowest quality level Q4, the selection module SEL 302 restricts the client module HAS 303 so that the resources consumed during the downloading of the segments of the content C1 do not exceed 25% of the measured bandwidth.

In this first variant (not represented on the ), there is therefore an exchange of data between the selection module SEL 302 and the HAS client module 303: for example, the bandwidth measured by the HAS client module 303 is communicated to the selection module SEL 302, which calculates, depending on the Qi quality level, and the associated percentage of recommended bandwidth consumption, the maximum encoding bitrate of the next segment of content that the HAS client module 303 can download. Alternatively, this calculation can take place in the HAS client module 303, if the selection module SEL 302 provides it with the information necessary to do so.

In another variant, the selection module SEL 302 performs a “mapping”, or a matching, of the quality levels Qi of the Wi-Fi signal and the quality levels Nj of the content C1.

Thus, for a quality level Q1 of the Wi-Fi signal, the selection module SEL 302 limits the maximum encoding bit rate of the segments to be downloaded by the HAS client module 303 to the resolution level N1 of the content C1; for a quality level Q2, the selection module SEL 302 sets at level N2 the maximum encoding bit rate of the segments to be downloaded by the client module HAS 303; for a Q3 quality level, the HAS 303 client module is authorized to download C1 content segments up to the encoding rate of level N3, if the measured bandwidth allows it; finally, for a Q4 Wi-Fi signal quality, the HAS 303 client module will be able to download the segments of the content C1 at any one of the resolution levels N1 to N4, depending on the available network resources.

The maximum encoding bit rate value selected by the selection module SEL 302, as a function of the Wi-Fi quality level Qi, is communicated to the HAS module 303, so as to restrict the downloading of content fragments at this bit rate. maximum encoding.

Thus, as illustrated in the , the HAS client module 303 will successively download (312) the fragments C12@N3, C13@N3, C14@N2, C15@N1 and C16@N3, that is to say, download the fragment of the best possible quality in depending on the network constraints, but also taking into account the Qi quality of the Wi-Fi signal evaluated at each segment download.

Content segments that appear crossed out on the correspond to the encoding bit rates prohibited by the selection module SEL 302, in view of the quality of the Wi-Fi signal evaluated by the module DET-Q 301.

Thus, for the second segment C1 ₂ , the encoding rates N4 and N5 are prohibited, because the level of Wi-Fi quality evaluated by the selection module SEL 302 on the basis of the measurements of the module DET-Q 301 is of level Q3. The HAS client module 303 then downloads the content segment C1 ₂ @N3, which corresponds to the maximum encoding bit rate to which it can claim.

For the third segment C1 ₃ , the Wi-Fi quality level improved, and moved to Q4; only the N5 resolution level is therefore prohibited for downloading. However, the available bandwidth, as measured by the HAS client module 303 has dropped, so the latter chooses to download the segment C1 ₃ @N3.

For the fourth segment C1 ₄ , the level of Wi-Fi quality has deteriorated again, for example because the client terminal 30 experiences ambient electromagnetic noise, linked to the proximity of another piece of equipment transmitting in Wi-Fi: it is evaluated by the selection module SEL 302 at level Q2, and the maximum encoding bit rate to which the client module HAS 303 can claim is therefore N2. It therefore downloads segment C1 ₄ @N2.

As the neighboring noisy equipment is silent, the quality of the Wi-Fi signal increases again, settling at the Q4 level, when downloading the fifth segment. The HAS client module 303 could therefore claim any one of the resolution levels N1, N2, N3 and N4 of the content C1. However, the measured available bandwidth having decreased (for example due to sharing of network resources with other users), the HAS client module 303 opts for the downloading of the segment C1 ₅ @N1 at the highest encoding rate. low of manifest file 7.

Finally, before downloading the sixth segment C1 ₆ , the Wi-Fi quality level is evaluated as good, corresponding to a level Q4, which the selection module SEL 302 associates with a maximum authorized encoding rate N4. The HAS client module 303 can therefore download any one of the segments C1 ₆ @N1 to C1 ₆ @N4. After measuring the available bandwidth, the choice of the content segment to be downloaded by the HAS selection algorithm falls on the segment C1 ₆ @N3.

The quality level of the downloaded segments is thus advantageously adapted according to the quality of the Wi-Fi signal, in order to guard against a possible problem of Wi-Fi connectivity which could harm the user's viewing experience. In other words, depending on the assessed Wi-Fi quality level, a filtering of the encoding bit rate of the segments is carried out, as determined by the HAS client module 303 taking into account only the available bandwidth, such as measured at each segment download.

Indeed, when the quality of the Wi-Fi signal is good, the bandwidth between the residential gateway and the client terminal 30 is stable. On the other hand, if this signal is of poor quality, it is advisable to have a less aggressive strategy of selection of segments in HAS, to anticipate a possible deterioration.

Thus, at each segment download, or periodically, the available bandwidth is conventionally measured, but also the quality indicators of the Wi-Fi signal, and the encoding bitrate values obtained by the selection algorithm are weighted. Classic HAS, based on the estimated Wi-Fi quality level. The quality of the segments downloaded by the HAS client module 303 is then reduced, compared to the technique of the prior art, but allows a more fluid reading of the content on the terminal TX 5. Indeed, one thus gets rid of the videos that momentarily freeze, improving the user experience.

It will be noted that in a variant, not shown in the figures, the measurement of the quality indicators of the signal exchanged between the multimedia stream reader terminal and the access point can be performed in the access point itself. The threshold values proposed above must of course be adapted accordingly. In addition, these values, or the level of quality deduced therefrom, must be provided to the multimedia stream reader terminal, so that they are taken into account in the selection of the encoding bit rates of the content segments to be downloaded.

In its various embodiments, the present invention can be implemented on adapter boxes or decoders ("set top boxes"), on the Orange® CléTV®, on game consoles and generally on all terminals consuming videos in HAS via an access point to a communication network.

APPENDIX 1: sample manifest file

Claims (13)

Method for managing the adaptive progressive downloading (HAS) of digital content (C1) from a content server (2) to a multimedia stream player terminal (8; 30),
said digital content being associated with a description file (7) of said digital content, comprising a list of time segments of said content each associated with several encoding bit rates of said content,
said content server (2) being present on a communication network (1), which said multimedia stream reader terminal (8; 30) accesses via an access point (6) to said network,
a selection of an encoding rate to be used for downloading at least one of said time segments taking account of information relating to the bandwidth available on said network, between the content server and the multimedia stream reader terminal ,
characterized in that said selection also takes into account information relating to the quality of a signal exchanged between said access point and the multimedia stream reader terminal. Management method according to claim 1,characterized in thatsaid Information relating to the quality of a signal exchanged is obtained by determining at least one signal quality indicator between the multimedia stream reader terminal and the access point. Management method according to Claim 2, characterized in that the said quality indicator is a metric, at the level of the physical layer 1 of the OSI model, of a link between the said multimedia stream player terminal and the said access point. Management method according to any one of Claims 1 to 3,characterized in thatsaid signal exchanged between said access point and the multimedia stream reader terminal belongs to the group comprising:

• a Wi-Fi type signal;
• a Power Line Carrier type signal;
• a mobile radio signal.

Management method according to claim 4, characterized in that said signal exchanged between said access point and the multimedia stream reader terminal (8) is a Wi-Fi® signal, said access point is a home gateway (6 ) and in that two Wi-Fi® signal quality indicators are determined:
a signal-to-noise ratio associated with said Wi-Fi signal (SNR for “Signal To Noise Ratio”);
- A measurement of the power level in reception of said Wi-Fi signal (RSSI for English "Received Signal Strength Indication"). Management method according to any one of Claims 2 to 5, characterized in that a value of said at least one signal quality indicator defines a quality level (Qi) of said signal, and in that a setting is made in correspondence of said quality level (Qi) of said signal and of said encoding bit rates (Ni) of the content. Management method according to Claim 6, characterized in that the said encoding bit rate of the content corresponding to the said quality level of the said signal is a maximum encoding bit rate to which the said selection is limited. Management method according to any one of Claims 1 to 7, characterized in that the determination of the signal quality indicator is implemented in the said multimedia stream reader terminal. Management method according to any one of Claims 1 to 7, characterized in that the determination of the signal quality indicator is implemented in the said access point. Computer program product comprising program code instructions for implementing a method according to any one of claims 1 to 9, when executed by a processor. Device for managing adaptive progressive downloading (HAS) of digital content from a content server (2) to a multimedia stream player terminal,
said digital content being associated with a description file (7) of said digital content, comprising a list of time segments of said content each associated with several encoding bit rates of said content,
said content server being present on a communication network (1), which said multimedia stream reader terminal accesses via an access point (6) to said network,
said device comprising a selection module (SEL 302) of an encoding rate to be used for downloading at least one of said time segments taking account of information relating to the bandwidth available on said network, between the server content and the multimedia stream player terminal,
characterized in that said selection module (SEL 302) also takes into account information relating to the quality of a signal exchanged between said access point and the multimedia stream reader terminal. Device for managing adaptive progressive downloading according to Claim 11, characterized in that it is configured to implement the management method according to any one of Claims 1 to 9. Multimedia stream player terminal characterized in that it comprises an adaptive progressive download management device according to claim 11 or 12.