A³TV–Anytime,AnywhereandbyAnyoneTV

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A³TV –Anytime, Anywhere and by Anyone TV

Felipe Soares de Oliveira

Digital Video Application Lab Federal University of Paraíba Campus I – João Pessoa/PB - Brazil

+55 (083) 3216-7093 ramal 26

felipe@lavid.ufpb.br

Carlos Eduardo C. F. Batista

+55 (083) 3216-7093 ramal 26

bidu@lavid.ufpb.br

Guido Lemos de Souza Filho

+55 (083) 3216-7093 ramal 26

guido@lavid.ufpb.br

ABSTRACT

The cultural paradigm we experience today is absolutely different from that one where television and all its formats were created: Internet and all its functionalities have improved communication and the broadcast services nowadays are, also, not the same as they were. Television has found its way of neo-omnipresence – not only by its now old standards, but using the global network to reach every single worldwide untouched spot. Parallel to all this, what was predicted by almost two decades ago has come finally true: collaboration and collectivity are the new recognizable patterns of the World Wide Web ethics. These patterns, these ways, have received the alias of Web 2.0, and represent, now, what is the newest among Internet subjectivity standards. This paper, therefore, seeks to demonstrate the likely changes unleashed by the mixing of these technologic formats with TV. The proposed application, called A³TV (formerly known as RNPTV), developed under Brazilian National Research Network (Rede Nacional de Ensino e Pesquisa – RNP) supervision, aims to scale the TV experience, by bringing its content anytime (delivering it in a service integrated with video-on-demand), accessible from anywhere (different platforms and with viewers globally spread) and made by anyone (being able to be managed by users on an Internet community).

Categories and Subject Descriptors

C.2.1 [Computer-communication Networks]: Network

Architecture and Design - distributed networks. D.2.11 [Software

Engineering]: Software Architectures - Domain-specific architecture. H.5.1 [Information Interfaces and Presentation]:

Multimedia Information Systems – video, audio input/output. H5.3 [Group and Organization Interfaces]: Web-based

interaction.

General Terms

Human Factors, Performace.

Keywords

Communication Systems, Collaborative work, Social TV.

1. INTRODUCTION

The ever-changing TV industry has been, in these past twenty years, the purest reflex of information flow improvement. It is, therefore, natural to expect that, with all this considerable changing in the ways things work for information industry, that TV itself would be almost obligated to evolve, given the concepts that daily flourish, modifying itself to the audience needs and – more importantly – wants. Spreading audiovisual content worldwide with click-velocity is now available for everyone, not only for big media conglomerates. On daily basis, communication theories speak of horizontality of information, which is primarily given to us by Internet, and consists of one publishing anything with virtually no censure, where this information would be available for free access, all around the globe. This perspective then, absolutely changes the mass media modus operandi, in which information flows vertically, from big industry conglomerates to our houses, through radio receivers, TV receivers, newspapers, etc.

We walk again toward an era where opinion is far more important then the 'plain information' itself. In other words, the indication of a friend is becoming worthier than the headlines of New York Times. In a certain way, media power is relocating itself, switching places from big conglomerates to the user/viewer’s hands. This is a historical fact, as virtually nowadays anyone can make content that can be seen by any user connected to the Internet. When we focus on subcultures niches, it is easy to perceive how the behavior of producers and consumers changes and content produced by communities is, sometimes, more easily assimilated by themselves than content produced by the distant and unattached media conglomerates. We define a CommuTV as the merge between the stability and formats associated with television with the dynamics and multiplicity of services found on the Web 2.0. A CommuTV is aimed to be produced collaboratively by communities and consumed by a group of users who can interact with each other and provide real-time feedback for the producers – a CommuTV is produced by communities, for communities.

Thinking about this, the Brazilian National Research Network (Rede Nacional de Ensino e Pesquisa – RNP), through the Digital Television Workgroup (Grupo de Trabalho de Televisão Digital – GTTV), worked on the design and implementation of the A³TV (Anytime, Anywhere and by Anyone), which uses the RNP Digital Video Network (DVN) infrastructure [1], and is destined to provide platforms that make possible – and foment – the TV broadcast over the Internet with content produced, defined and consumed by Internet communities.

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2. RELATED WORK

Above some works with significant similarities to A³TV’s approach are presented, in order to establish its relevance compared to the state of the art.

Current TV [2] is cable television with a supporting website from where users can upload content that eventually will be broadcasted through U.S.’s major cable networks. Current broadcasts regular TV shows and content created by users (called VC² Producers), in a form of "pods" (short programs), which are on a variety of subject matter and can have three to seven minutes length. The content is filtered by users on Current's website through a voting process, but the final decision on what content is to be broadcasted is done by Current's on-air programming department – thus users have marginal influence on what is being actually transmitted.

The AmigoTV service [3] offers communication in real time tied with a transmission of TV content. AmigoTV enhances the TV experience by allowing its users to communicate while watching a TV channel, but the users are still viewers. The AmigoTV is based on an client-server architecture, with the following main components: (i) IM/Presence – Module for instant messaging and distribution of the status of presence of all the users in the AmigoTV sessions, using the XMPP protocol (Extensible Messaging and Presence Protocol) [4], which is based in XML, and facilitates future integrations and growth in the service; (ii) Audioconferencig – AmigoTV supports audio communication, with resources to diminish delays and losses of packages in the communication. Traditional models of audio-conference use a star topology where the distribution and mixing of the audio flows are executed in a centered node. This approach lacks of scalability, which is a main requirement on the TV context, since the number of users may grow significantly in a short period.

3. A³TV SERVICE ARCHTECTURE

The second generation of online services, commonly known as Web 2.0, has, as its main feature, the improvement of information publishing, sharing and organization forms, besides the augmentation of interaction between agents of the process – what occurs, then, is the composition of a collaborative and personalized content, created and managed by communities of people who share the same interests, based in dynamic data according to the preferences of them [5].

Internet is based in models that deny linearity, replicating the network and its context in each node created [6]. Basing ourselves, then, in the media convergence experienced nowadays, this context provides new solutions of interactivity and allows the building of a decentralized environment which combines the stability and operational aspects of television world with the dynamics, innovation and multiplicity of services found on Internet. This results in the fact that television – the most popular medium ever – lives, now, a whole new phase in its history, with changes propelled especially for the Internet.

Internet Communities are social relations established through the cyberspace [6]. On the cyberspace an individual can choose which kind of community he or she should take part, and may find people to share and discuss ideas, mediated by a Computer. Collaborative environments are one of the main concepts of the new model of the Web. This intertwining of the services offered

by the concept of a collaborative Web 2.0 and the actual standards of television, therefore, may combine and turn in what is believed to be the next step of TV technology.

Taking that into account, the A³TV was conceived as a virtual environment for the development and administration of a "CommuTV": the combination of a video broadcast with a social network tool, allowing users of an Internet community to manage what is being broadcasted – users are able to be more participative compared to the other approaches. To achieve this, the A³TV is divided in layers, where each layer provides services for the subsequent layer of the architecture. This approach offers flexibility and independence for the services, since each layer work as an independent subsystem. The service architecture (Figure 1) is divided in six layers: administration, content feed, adaptation, distribution, interaction and presentation.

Figure 1. A³TV architecture in a block diagram

3.1 Administration

The channels will be generated from content supplied from the users associates to the A³TV, so, when allowed, a piece of content (an audio or video file or a reference for a stream) may be used to compose one CommuTV channel’s schedule. Inside of each community there are three basic levels of user hierarchy: owner - the user which originally created the CommuTV and is responsible for managing and distributing the specific roles for the CommuTVs participants and possesses rights to execute all available functionalities; the user - that will be able to be attached to a set of functionalities (aggregated as roles) and finally the viewer, who are users that cannot take active part on the CommuTV however are able access the transmitted content. Thus, each CommuTV may have a particular policy on how the hierarchy is managed, and how to deal who is responsible for which activity.

3.2 Content Feed

The content availability of the production entities are done by content suppliers which are entities responsible for storing and providing the access to audiovisual content database. Examples of such systems are the RNP’s Digital Video Network (DVN) [1], or external sources, like for example the Youtube1_{. This content is} provided by two different approaches: on demand and live. In a CommuTV context, the content to be accessed by users can be either by the content suppliers located in Digital Video Network servers, or by external servers, located outside the DVN. In addition to live video or on demand video servers, the service is capable of aggregating conventional TV channels, through processes of codification using specific software and hardware.

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3.3 Adaptation Layer

The video collection provided by content suppliers many times is heterogeneous, indicating a diversity of formats and codifications. Parallel to this, the information about the video – called metadata – may be incomplete or not exist. The adaptation layer is then responsible for recognizing the format and/or video codification and the metadata of the content suppliers, adapting the video to the service standards.

3.3.1 Encoding

The objective of adaptation in the codification is to recognize the maximum of video and audio standards, as much for reading as for the generation of new videos in other standards. Amongst many standards available, some have more prominence, for their great popularity, such as: Windows Media Video, DivX, XviD, Flash Video, MPEG-1, MPEG-2, among others.

3.3.2 Metadata

Each video in a distribution service has catalog and identification metadata associated. These metadata may have been supplied by the video owner, like name, author, creation date, but are also inherent data of the video, like frames per second, resolution, size, bits per second rate. To provide the interaction model commonly available on digital TV, a catalog scheme of metadata to the multimedia objects is necessary, in order to facilitate the access.

3.3.3 Profiling

The customization service provides the option of profile creation for the use with the service, enabling the choice of favorite programs and channels, content commenting, censorship, interface customization and content rating. The profile is also used on the interaction service, as described on its subsection.

3.4 Distribution Layer

The RNP Digital Video Network (DVN) is used to distribute video on CommuTV service. It was developed with the intention to offer a network infrastructure, servers and equipments to support experiments involving capturing, recovering and live video transmission and video on-demand (VoD). The Figure 2 illustrates the video distribution architecture, with multiple levels.

Figure 2. DVN distribution Architecture with two different video streams being transmitted.

The current architecture of the distribution service offered by the DVN [1] is based on a multiple level structure of distribution: server-proxy, proxy-proxy and proxy-client, where you can find many proxy-proxy distribution levels. The video servers act as sources for the digital videos, which can come from local stored files (video on-demand) or from capturing devices (live video). The idea is that the collaborating institutions (content suppliers) responsible for the user application services keep their own associated servers and resourcs. Each proxy implements a cache (stored in volatile memory for live videos and in disk for videos on-demand), used for the most accessed videos in its audience area. The architecture allows cascade proxy connections, thus configuring a hierarchy for multiple levels of cache. The main advantage of this approach that the traffic distribution in the RNP backbone is optimized [1]. The DVN server-proxy implementation has two modules based on a single architecture: the JDVoD [7] that offers support to videos on-demand distribution, and the JDLive [1] that offers support for live video transmission. The server’s current versions were developed in Java, implementing support for multiple protocols for input (IBP, HTTP, UDP) and output (HTTP and UDP).

3.5 Presentation Layer

This layer comprises the services to the final users. System access interfaces, with the presentation of visual content through players, search systems, personalization, management, among others, must be presented to the user. A CommuTV in the service may offer its content through different ways: Direct Stream – From where the client uses a third-party player to view the video stream; CommuTV Portal – From where the client a accesses a video stream through a web interface, which also offers a social network tool; Direct Stream Regular TV reception (terrestrial, cable and satellite) – The content of a CommuTV video stream may be transmitted through a regular TV channel. A TV Broadcast Gateway receives the stream and encodes it, in order to be modulated and transmitted on the channel.

3.6 Interaction Layer

The customization service supplies the option of creation of user profiles, which allows customization of the service (portal look and feel, favorite media), and also the interaction between users. The Interaction layer allows the creation of virtual communities attached to a particular TV channel, enabling the interaction between its managing users and other users. The TV channel can be managed and produced by many users (a community), geographically dispersed, with the possibility of having feedback from the viewers using the same service. Users can communicate through the community forum and through a messaging system which allows direct communication between users (instant messaging) and synchronous conferencing organized on IRC (Internet Relay Chat) fashioned channels (or chat rooms), where the CommuTV hierarchy applies.

4. A³TV SYSTEM MODULES

A³TV was developed and designed according to the Service Architecture, presented in item 3. The Figure 3 presents A³TV’s architecture, which is then detailed.

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Figure 3. A³TV System Modules

4.1 Video Source

The system keeps a collection of registered videos, which allows video retrieval from the Digital Video Network (DVN); or from external sources. The service provides functionalities to integrate external content, recovering metadata from the multimedia object original source automatically, increasing the service flexibility. It is also the entity responsible to manage the access to the information regarding the video collection. Insertion, retrieval, update and deletion of information are services handled by the Metadata Manager, enabling data validation before actually executing the user’s request. To enable these services, it receives the information from the user and, in case it is considered valid, it opens a communication session with the database and executes the requested operation. A³TV keeps a repository of the information related to the stored videos and channels. The metadata manager also handles information regarding the channels created by the users of the service (schedules, content, etc). In A³TV System modules the metadata model used was the TV-Anytime [8], to guarantee the interoperability with systems using such description.

4.2 User Management System

The User Management System is responsible for the storage and maintenance of users’ information and permissions within the service. The permissions are based on division of responsibilities model, where each user has specific roles associated. Each role represents a set of permissions to execute operations within the system in a way that the user can only access the areas of the system defined to his/her roles. In order to accomplish this specification of the system, the Authentication and Access Control Middleware (MACA) is used. The MACA provides user authentication and access control services for legacy applications or in the development stage. It is also platform and programming language independent. The MACA follows the Role Based Access Control (RBAC) [9] model standardized by the National Institute Standards and Technology (NIST).

4.3 CommuTV Modules

A CommuTV can be created by the A³TV users, which has its focus on the content being transmitted, which can be audiovisual streams constituted of programs made by different producers, with different encoding standards. Besides the difference between the

standards, these programs are found in different servers, not necessarily inside the RNP’s digital video network. A CommuTV can also have live programs on its schedule, with proper references to the source of the stream and definitions of beginning and end time. Therefore, mechanisms to acquire programs, to control the execution of the videos and to transcode these videos are essential part of the system. A CommuTV also provides mechanisms for communication between its users, which may have associated roles within a particular CommuTV, in order to operate it.

4.3.1 Content Acquisition

As previously mentioned, the videos that are part of the schedule of a CommuTV are not necessarily located in RNP’s servers. This characteristic was defined during the system analysis period, since, besides avoiding possible storage limitations that could eventually arise, it allows partnerships with different content producers and the shared content could be included in RNP’s channel program schedule, what can be considered one of the main features of the system.

During its initialization, the system checks for the presence of program schedules starting after its initialization date and time, ordered by their starting time. In case any program is found, the Execution Controller, an entity responsible for the execution and the control of the duration of each video in the schedule and its programs, waits for the schedule's start time to begin the activities. Once in time of starting its execution, the controller checks the program list present in the schedule, asks the Metadata Manager for some information regarding these programs and prepares a list with this data. Amongst this data, the URI indicating the video's address, its duration and the date and time of its beginning and ending in the program schedule can be found. Besides this, the controller needs to be aware whether the video is a live video or not, in order to decide to control or not the duration of the video's execution.

With this set of information related to the videos in the program schedule, the controller is ready to start playing the program schedule and transcoding the videos. The controller asks the Transcoding System for the creation of a playlist with the addresses of the videos included in the program guide, while the Transcoding System is the entity responsible for generating the channel's video streaming with the videos included in the playlist, performing the transcoding during the execution of the playlist. For videos on demand, which are always played until the end, there is no need to verify the duration of the execution of each video. Thus, for this case, the Execution Controller only waits the tasks performed by the Transcoding System on the videos. As the Transcoding System keeps transcoding a given video until the stream of data of this video is interrupted, it is necessary that the Execution Controller intervenes in the control of the transcoding of live videos, so that these have their transmission finished in the appropriated time, defined in the program schedule. Otherwise, the transcoding process of live videos could remain being done longer than defined, corrupting the program schedule.

4.3.2 CommuTV Operation

The available functionalities reflect on which activities could be carried through in a CommuTV. The Owner of the CommuTV groups activities in roles, that could be delegated the users of the

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CommuTV, defining their permissions over the CommuTV. The permissions for the CommuTV operation are:

1) Management of the channel’s schedules – A³TV provides a tool which allows the user to associate the registered videos (which may come from different sources – see Content

Acquisition) to a particular CommuTV’s program schedule.

The permission of management may be divided in time slots and each of these may be managed by multiple users. 2) Management of the forum and the chat rooms of the

CommuTV.

3) Management of the users’ permissions for the CommuTV.

4.3.3 Portal

The portal is the application responsible for the final user interaction interface. It supports searches and shows visualizations in the available channels. It enables the interaction between the service users, the show classification and the content managing. The portal provides an electronic programming guide responsible for presenting the program grid of all CommuTVs, allowing the user to collect information interactively. The portal presents, as an important feature, the video stream in a multimedia player embedded in its main page (Figure. 4); the Web EPG, a tool that allows the user to navigate through the program guide; a set of partner channels, grouped by the bit rate of their video stream; and a tool developed to ease the generation of the channel’s schedules. The Web EPG also includes an interface to the interaction module, throughout the users of the service can communicate.

Figure 4. A³TV Portal Main Page

4.3.4 Interaction Module

Apart from the CommuTV forum, the communication between the users are handled by a network of XMPP [4] servers, and the A³TV Portal provides an interface so that users can communicate privately (Instant Messaging) and in chat rooms. The network may be used by external applications, so a CommuTV may provide different interfaces for user communication, using different resources – this was validated by integrating the ICSpace [10] communication tool with a CommuTV on the A³TV.

4.3.5 Broadcast Module

The Broadcast Module is responsible to convert the video stream generated by the CommuTV so that it can be modulated and

broadcasted to a TV network. This module allows that the content of a CommuTV is made available through a TV network.

5. CONCLUSION AND FUTURE WORKS

The following paper has presented A³TV, which is a system that allows the integration and distribution of web-based TV channels and ordinary TV channels via Internet. A service distribution architecture definition was detailed, having being modeled in layers that work as independent subsystems, giving more development flexibility to the applications of the service. The CommuTV service was proposed as an application using the DVN of RNP, modeled over the service architecture layers. A set of user support tools was developed to ensure the creation of new channels and the managing of the service, as long as the interaction user-service and user-user, the latter through the A³TV portal itself. Currently, some tests of Digital TV transmission from hybrid networks are being made using CommuTV, in order to validate Ginga’s (Brazilian Digital TV middleware) multinetwork capability [11]. An integration between the Ginga middleware and A³TV Portal is being planned, so that the CommuTVs may have interactive programs on their schedule – A³TV Portal will support the exhibition of interactive videos.

6. REFERENCES

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[3] COPPENS, T., VANPARIJS, F., HANDEKYN, K.. AmigoTV: A Social TVExperience Through Triple-Play Convergence. 2005.

[4] SAINT-ANDRE, P. “RFC 3920 Extensible Messaging and Presence Protocol (XMPP): Core”, Request For Comments, IETF.

[5] O'REILLY, Tim. What Is Web 2.0 - Design Patterns and Business Models for the Next Generation of Software. O'Reilly Publishing, 2005.

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[9] MOTTA, G. H. M. B. ; FURUIE, Sérgio Shiguemi . Um Modelo de Autorização Contextual para o Controle de Acesso Baseado em Papéis. In: XX Simpósio Brasileiro de Redes de Computadores: WSeg'2002 - II Workshop em Segurança de Sistemas Computacionais, Búzios - RJ, 2002. [10] TAVARES, T. A.; ARAÚJO, A.; SOUZA FILHO, G. L. de.

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[11] SOUZA FILHO, G. L. de, LEITE, L. E. C., BATISTA, C. E. C. F. Ginga-J: The Procedural Middleware for the Brazilian Digital TV System. In: Journal of the Brazilian Computer Society, no 4, Vol 12, (ISSN 0104-6500) pp. 47-56. March, 2007. Porto Alegre, RS, Brazil.