Experiments for analysis of video transmission via ATM

A large quantity of data of different types and priorities pass through on high-speed networks. A relevant part of these data, like continuous media (audio, video, and so), need a control of its Quality of Service (QoS). This paper describes experiments on the characteristics of the ATM network technology that provide support to quality video streaming transmission. The experiments were realized considering QoS, connection admission control, network congestion, transmission priorities and bandwidth demand associated to applications and network configuration. Three basic kinds of videos were analyzed-movies (smooth movies), sports (action movies) and talking head movies. Data about video transmission were collected from an ATM switch, showing results that can be used in the future on ATM channel mapping to multimedia data distribution (in applications like Interactive TV and Video-on-Demand, for example).Facultad de Informátic

Leveraging hybrid recommenders with multifaceted implicit feedback

Research into recommender systems has focused on the importance of considering a variety of users’ inputs for an efficient capture of their main interests. However, most collaborative filtering efforts are related to latent factors and implicit feedback, which do not consider the metadata associated with both items and users. This article proposes a hybrid recommender model which exploits implicit feedback from users by considering not only the latent space of factors that describes the user and item, but also the available metadata associated with content and individuals. Such descriptions are an important source for the construction of a user’s profile that contains relevant and meaningful information about his/her preferences. The proposed model is generic enough to be used with many descriptions and types and characterizes users and items with distinguished features that are part of the whole recommendation process. The model was evaluated with the well-known MovieLens dataset and its composing modules were compared against other approaches reported in the literature. The results show its effectiveness in terms of prediction accuracy.FAPESPCNPqCAPE

Experimentos para análise de transmissão de vídeo via ATM

Uma grande quantidade de dados de diferentes tipos e prioridades trafegam em redes de alta velocidade, sendo que um controle da Qualidade de Serviço se faz necessário para grande parte deles, como, por exemplo, dados de mídia contínua (áudio e vídeo). Este artigo descreve experiências sobre as características da tecnologia de rede ATM e o suporte que esta fornece para o transporte de streams de vídeo, considerando QoS, controle de admissão de conexões, congestionamento da rede, prioridades de transmissão, demanda de largura de banda associada às aplicações e configuração da rede. Três tipos básicos de vídeos foram analisados - filmes (smooth movie), esportes (action movie) e "talking head". Dados sobre a transmissão dos vídeo foram coletados em uma switch ATM, revelando resultados que podem ser utilizados futuramente no trabalho de mapeamento de canais ATM para distribuição de dados multimídia como TV Interativa e Video-on-DemandÁrea: Redes - Sistemas Operativos - Sistemas de Tiempo Real - Arquitectura de ProcesadoresRed de Universidades con Carreras en Informática (RedUNCI

KS-SIFT: a keyframe extraction method based on local features

In this work we propose a new keyframe extraction method based on SIFT local features. We extracted feature vectors from a carefully selected group of frames from a vídeo shot, analyzing those vectors to eliminate near duplicate keyframes, helping to keep a compact set. Moreover, as the keyframe extraction is based on local features, it keeps frames latent semantics and, therefore, helps to keep shot representativeness. We evaluated our method in the scene segmentation context, with videos from movies domain, developing a comparative study with three state of the art approaches based on local features. The results show that our method overcomes those approaches.FAPESP (grant 2012/19025-0)CNP

Experimentos para análise de transmissão de vídeo via ATM

Uma grande quantidade de dados de diferentes tipos e prioridades trafegam em redes de alta velocidade, sendo que um controle da Qualidade de Serviço se faz necessário para grande parte deles, como, por exemplo, dados de mídia contínua (áudio e vídeo). Este artigo descreve experiências sobre as características da tecnologia de rede ATM e o suporte que esta fornece para o transporte de streams de vídeo, considerando QoS, controle de admissão de conexões, congestionamento da rede, prioridades de transmissão, demanda de largura de banda associada às aplicações e configuração da rede. Três tipos básicos de vídeos foram analisados - filmes (smooth movie), esportes (action movie) e "talking head". Dados sobre a transmissão dos vídeo foram coletados em uma switch ATM, revelando resultados que podem ser utilizados futuramente no trabalho de mapeamento de canais ATM para distribuição de dados multimídia como TV Interativa e Video-on-DemandÁrea: Redes - Sistemas Operativos - Sistemas de Tiempo Real - Arquitectura de ProcesadoresRed de Universidades con Carreras en Informática (RedUNCI

Experiments for analysis of video transmission via ATM

A large quantity of data of different types and priorities pass through on high-speed networks. A relevant part of these data, like continuous media (audio, video, and so), need a control of its Quality of Service (QoS). This paper describes experiments on the characteristics of the ATM network technology that provide support to quality video streaming transmission. The experiments were realized considering QoS, connection admission control, network congestion, transmission priorities and bandwidth demand associated to applications and network configuration. Three basic kinds of videos were analyzed-movies (smooth movies), sports (action movies) and talking head movies. Data about video transmission were collected from an ATM switch, showing results that can be used in the future on ATM channel mapping to multimedia data distribution (in applications like Interactive TV and Video-on-Demand, for example).Facultad de Informátic

Web Videos: concerns about accessibility based on User Centered Design

Recently, the production and availability of multimedia Web content, as videos, have increased. In this scenario it is important to consider accessibility requirements so that any user can whelm the barriers to access content regardless of the limitations imposed by either deficiency or some temporary restriction. One of the main barriers found in the current players is the restriction to make videos accessible on the Web and little research on how to overcome those limitations has been conducted. This paper describes the three phases of User Centered Design, in which an evaluation with real users of an accessible video player is conducted. A video player, called Facilitas, is proposed in order to provide the rationale of how some of those barriers or limitations could be overcome. Its controls are new and different from the ones in other players. We have observed that by reducing accessibility barriers, the design process leads to an improved product in terms of usability. A user testing is described to explain which controls users frequently use to complete a task.CAPES (PEC-PG)5th International Conference on Software Development and Technologies for Enhancing Accessibility and Fighting Info-exclusion (DSAI 2013). \ud Vigo, Spain. 13-15 november 2013

An accessible video player for older people: issues from a user test

There is a huge availability of videos that have been produced in a very fast and wide way, along with the popularity of Internet. This scenario should be carefully considered by the video authors since many users have different needs. It is important to keep in mind the accessibility requirements so that any user can overcome the barriers to access content regardless of their limitations imposed by either impairment or some temporary restriction. The current video players present barriers for many people, especially to the elderly, and one of the main barriers is the restriction to reproduce videos accessible on the Web. This paper describes a research, and the design and evaluation of an accessible video player (called Facilitas), in which a user test with older people is conducted. As a result, we discuss the issues reported by older people and the controls that were developed to assist them.CAPES (PEC-PG)5th International Conference on Software Development and Technologies for Enhancing Accessibility and Fighting Info-exclusion (DSAI 2013).\ud Vigo, Spain. 13-15 november 2013

Metadata utilization in the video servers access management.

A experiência com autoria de material didático multimídia para propósitos educacionais mostra um grande problema: como prover uma maneira de tratar objetos multimídia de modo que usuários inexperientes (como professores) possam estar aptos a projetar e construir suas próprias apresentações? A criação de tais apresentações envolve fatores como armazenamento, entrega, busca e apresentação de material multimídia (vídeo em especial). Uma infra-estrutura básica que armazene e entregue eficientemente os dados de vídeo é necessária, porém, outro ponto importante é organizar esses dados armazenados no servidor de forma a facilitar seu acesso por parte dos usuários. Neste trabalho, isto é alcançado através do uso de um sistema interativo de recuperação e gerenciamento de informações projetado para facilitar o acesso a itens (ou parte deles) armazenados no servidor. A principal característica de tal sistema é o uso de uma base de metadados contendo os atributos dos vídeos armazenados no servidor. Buscas podem ser feitas por título, assunto, tamanho, autor, conteúdo ou, mais importante no caso de material didático, por cenas ou frames específicos. O sistema foi implementado segundo uma abordagem cliente/servidor utilizando a linguagem de programação JAVA. A comunicação entre clientes e servidores é realizada através do uso do Visibroker 3.0, que é uma ferramenta de programação para Objetos Distribuídos segundo o padrão CORBA. O acesso aos dados a partir da base de metadados é realizado através do uso de um driver PostgreSQL que segue a API JDBC. Para propósitos de avaliação do sistema um player foi construído utilizando a ferramenta Java Media Framework (JMF). Foi realizada uma análise para a verificação do impacto da utilização das tecnologias CORBA e JDBC no sistema. Foi detectado que a utilização da tecnologia JDBC impõe um atraso muito mais significante que a utilização da tecnologia CORBA. Outra conclusão é que a utilização de metadados provê uma melhor interatividade em buscas, permite economia de tempo durante o processo de edição e provê economia de espaço de armazenamento através do compartilhamento de objetos como vídeos, cenas e frames.The experience with authoring multimedia material for educational purposes shows a major problem: how to provide an easy and efficient way to handle multimedia objects in a manner that non-expert users (namely school teachers) can be able to design and build their own presentations? The creation of this presentations involves factors like storage, delivery, search and presentation of multimedia material (video in special). A basic infra-structure that stores and efficiently deliver the video data is needed. However, another important point is the organization of these data stored into the server in a way to facilitate the access to them from the users. In the system wich is the subject of this work, this is achived through the use of an interactive information management and retrieval system designed to facilitate the access to items (or parts of the items) stored in the server. The main characteristic of the system is the use of a metadata base which contains attributes of the videos stored in the server. Searches can be made by title, subject, length, author, content or, most important in the didatic multimedia material case, by a specific scene or frame. The system was built with JAVA programming language in a client/server way. The communication between clients and servers is realized through the use of the Visibroker 3.0, which is a Distributed Objects programming tool according to the CORBA standard. The data access from the metadata base use a PostgreSQL driver which follows the JDBC API. For evaluation purposes a playback tool was built using Java Media Framework (JMF). An analisys was carried out to verify the impact of the utilization of CORBA and JDBC technologies in the system. It was detected that JDBC technology utilization imposes a much more significate delay than the CORBA technology utilization. Another conclusion is that metadata utilization provide better interactivity searches, making the editing process faster and save storage space through the sharing of objects like videos, scenes and frames

Context-based content personalization and adaptation for Interactive TV

O trabalho apresentado nesta tese trata do desenvolvimento de técnicas com suporte à ciência de contexto, baseadas nos padrões MPEG-4 e MPEG-7, para personalizar e adaptar conteúdo em TV Interativa. Um dos desafios dessa área é desenvolvimento de programas personalizados com rico conteúdo multimídia, com alta interatividade e que, além disso, sejam acessíveis a partir de uma variedade de dispositivos (fixos ou móveis), atendendo às expectativas de interação e de acesso dos usuários. Grande parte do problema está no fato de que os modos encontrados na literatura para representar, descrever e compor programas de TV Interativa não oferecem suporte a contexto, não permitem a separação entre descrições de programas e descrições de objetos e possuem baixa granulosidade de segmentação. Essas características dificultam e, em alguns casos, impedem o desenvolvimento de aplicações avançadas em TV Interativa. As técnicas desenvolvidas neste trabalho são baseadas em esquemas de descrição, compatíveis com o padrão MPEG-7, e na segmentação de programas em objetos MPEG-4. Os esquemas são utilizados para descrever a estrutura, a composição e a semântica de programas e de seus objetos componentes. Também foi definida e implantada uma infra-estrutura para produção, distribuição e consumo de programas. A utilização conjunta da infra-estrutura e das técnicas permite o desenvolvimento de aplicações avançadas em TV Interativa. Como um exemplo dessas aplicações, foi desenvolvido um serviço automático para personalizar e adaptar programas de TV Interativa, permitindo que um usuário possa acessar, sob demanda, programas especialmente produzidos para ele, contendo apenas assuntos de seu interesse e permitindo que o acesso possa ser realizado por dispositivos fixos ou móveis.The work presented in this thesis developed techniques with context-awareness support, based on the MPEG-4 and MPEG-7 standards, in order to personalize and to adapt Interactive TV content. One of the challenges in this area is the development of personalized programs with rich multimedia content, high interactivity and accessibility through a variety of devices (mobile and non-mobile). Most part of the problem is that the approaches found in literature do not provide context support, do not allow separation between programs and objects descriptions and have low level of segmentation granularity. These features make difficult or impossible, in some cases, the development of Interactive TV applications. The techniques developed in this work are based on MPEG-7 compliant schemes and on programs segmentation into MPEG-4 objects. The schemes are used to describe structure, composition and semantics of programs and component objects. An infra-structure to creation, delivery and consumption of Interactive TV programs was also defined. The joint utilization of infra-structure and techniques allows for the development of Interactive TV advanced applications. As an example of these applications, this work developed an automatic Interactive TV personalization and adaptation service. This service allows a user to access, on-demand, a program specially designed to match his interests and allowing content access through devices with mobile and non-mobile features