On the use of adaptive media playout for inter-destination synchronization

[EN] Inter-Destination Multimedia Synchronization (IDMS) is essential in most of the emerging social multimedia applications. In this paper we present a novel Adaptive Media Playout (AMP) scheme that aims to acquire an overall synchronization status between distributed receivers by means of smoothly adjusting their playout timing. Simulation results show that the proposed solution minimizes long-term playout discontinuities (skips and/or pauses) which are subjectively more annoying to users than small variations in the media playout rate.This work was supported by the Universitat Politecnica de Valencia (UPV), under its R&D Support Program in the PAID-01-10 Project, and by Generalitat Valenciana, under its R&D Support Program in the GV 2010/009 Project.Montagud, M.; Boronat, F. (2011). On the use of adaptive media playout for inter-destination synchronization. IEEE Communications Letters. 15(9):863-865. https://doi.org/10.1109/LCOMM.2011.061611.110072S86386515

Enhanced adaptive RTCP-based inter-destination multimedia synchronization approach for distributed applications

[EN] Newer social multimedia applications, such as Social TV or networked multi-player games, enable independent groups (or clusters) of users to interact among themselves and share services within the context of simultaneous media content consumption. In such scenarios, concurrently synchronized playout points must be ensured so as not to degrade the user experience on such interaction. We refer to this process as Inter-Destination Multimedia Synchronization (IDMS). This paper presents the design, implementation and evaluation of an evolved version of an RTCP-based IDMS approach, including an Adaptive Media Playout (AMP) scheme that aims to dynamically and smoothly adjust the playout timing of each one of the geographically distributed consumers in a specific cluster if an allowable asynchrony threshold between their playout states is exceeded. For that purpose, we previously had also to develop a full implementation of RTP/RTCP protocols for NS-2, in which we included the IDMS approach as an optional functionality. Simulation results prove the feasibility of such IDMS and AMP proposals, by adopting several dynamic master reference selection policies, to maintain an overall synchronization status (within allowable limits) in each cluster of participants, while minimizing the occurrence of long-term playout discontinuities (such as skips/pauses) which are subjectively more annoying and less tolerable to users than small variations in the media playout rate.This work has been financed, partially, by Universitat Politecnica de Valencia (UPV), under its R&D Support Program in PAID-05-11-002-331 Project and in PAID-01-10. Authors also would like to thank the anonymous reviewers that helped to significantly improve the quality of the paper with their constructive comments.Montagud, M.; Boronat, F. (2012). Enhanced adaptive RTCP-based inter-destination multimedia synchronization approach for distributed applications. Computer Networks. 56(12):2912-2933. https://doi.org/10.1016/j.comnet.2012.05.00329122933561

Analysis, Deployment, and Evaluation of the Use of Network Simulation as a Learning Resource

This paper analyzes the benefits of using network simulation as a learning resource in the educational area of Telematics Engineering. Accordingly, a (students skills) practice program, which can be done using either network simulation or real equipment, has been introduced in the core subject Telematics Architectures and Networks (TAN) of the second year of the bachelor s degree in Telecommunications Systems, Sound, and Image Engineering. The satisfactory evaluation of this innovative teaching methodology is proved by the rating of the surveys answered by the students after the course completion.Montagud, M.; Boronat Segui, F. (2014). Analysis, Deployment, and Evaluation of the Use of Network Simulation as a Learning Resource. Rita -IEEE. 9(3):82-90. doi:10.1109/RITA.2014.2340011S82909

A customizable open-source framework for measuring and equalizing e2e delays in shared video watching

[EN] Low-latency and media sync are essential requirements to enable interactive multi-party services, such as Social TV. In this work, we present an open-source and customizable framework that allows measuring end-to-end (e2e) video delays and provides support for different types of media sync, including Inter-Destination Media Sync (IDMS). This framework can be used by researchers to investigate the suitability of different techniques for optimizing the system performance in terms of e2e delays and media sync.This work has been funded, partially, by UPV under its R&D Support Program in PAID-01-10 Project and by CWI under EU/FP7 REVERIE Project (ICT-2011-7-287723).Montagud, M.; Boronat, F.; Cesar, P. (2014). A customizable open-source framework for measuring and equalizing e2e delays in shared video watching. ACM. 95-96. https://doi.org/10.6084/m9.figshare.1032656S959

Web-based Platform for Subtitles Customization and Synchronization in Multi-Screen Scenarios

[EN] This paper presents a web-based platform that enables the customization and synchronization of subtitles on both single- and multi-screen scenarios. The platform enables the dynamic customization of the subtitles format (font family, size, color...) and position according to the users preferences and/or needs. Likewise, it allows configuring the number of subtitles lines to be presented, being able to restore the video playout position by clicking on a specific one. It also allows the simultaneous selection of various subtitle languages, and applying a delay offset to the presentation of subtitles. All these functionalities can also be available on (personal) companion devices, allowing the presentation of subtitles in a synchronized manner with the ones on the main screen and their individual customization. With all these functionalities, the platform enables personalized and immersive media consumption experiences, contributing to a better language learning, social integration and an improved Quality of Experience (QoE) in both domestic and multi-culture environments.This work has been funded, partially, by the Fondo Europeo de Desarrollo Regional (FEDER) and the Spanish Ministry of Economy and Competitiveness, under its R&D&I Support Program, in project with Ref. TEC2013- 45492-R, and by Fundación Española para la Ciencia y Tecnología (FECYT) , in project with Ref. FCT-15-9579Montagud, M.; Boronat, F.; González, J.; Pastor, J. (2017). Web-based Platform for Subtitles Customization and Synchronization in Multi-Screen Scenarios. ACM Digital Library. 81-82. https://doi.org/10.1145/3084289.3089913S8182M. Armstrong, et al., "Understanding the Diverse Needs of Subtitle Users in a Rapidly Evolving Media Landscape", IBC 2015, Amsterdam, September 2015.A. Brown, et al, "Dynamic Subtitles: The User Experience". ACM TVX '15, pp. 103--112, Brussels (Belgium), June 2015.Y. Hu, et al. "Speaker-Following Video Subtitles", TOMCCAP, 11, 2, Article 32, 17 pages, January 2015.M. Montagud, et al., "Use of Web Components to Develop Interactive, Customizable and Multi-Device Video Consumption Platforms", Applications and Usability of Interactive TV, Springer, V.605, 2016.A. Rodriguez, et al., "Subtitle Synchronization across Multiple Screens and Devices", Sensors, 12(7), 87108731, June 2012

Design, Development and Assessment of Control Schemes for IDMS in a Standardized RTCP-based Solution

[EN] Currently, several media sharing applications that allow social interactions between distributed users are gaining momentum. In these networked scenarios, synchronized playout between the involved participants must be provided to enable truly interactive and coherent shared media experiences. This research topic is known as Inter-Destination Media Synchronization (IDMS). This paper presents the design and development of an advanced IDMS solution, which is based on extending the capabilities of RTP/RTCP standard protocols. Particularly, novel RTCP extensions, in combination with several control algorithms and adjustment techniques, have been specified to enable an adaptive, highly accurate and standard compliant IDMS solution. Moreover, as different control or architectural schemes for IDMS exist, and each one is best suited for specific use cases, the IDMS solution has been extended to be able to adopt each one of them. Simulation results prove the satisfactory responsiveness of our IDMS solution in a small scale scenario, as well as its consistent behavior, when using each one of the deployed architectural schemes.This work has been financed, partially, by Universitat Politecnica de Valencia (UPV), under its R&D Support Program in PAID-01-10. TNO's work has been partially funded by European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. ICT-2011-8-318343 (STEER Project). CWI's work has been partially funded by the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. ICT-2011-7-287723 (REVERIE Project).Montagud Aguar, M.; Boronat Segui, F.; Stokking, H.; Cesar, P. (2014). Design, Development and Assessment of Control Schemes for IDMS in a Standardized RTCP-based Solution. Computer Networks. 70:240-259. https://doi.org/10.1016/j.comnet.2014.06.004S2402597

How to Perform AMP? Cubic Adjustments for Improving the QoE

[EN] Adaptive Media Playout (AMP) consists of smoothly and dynamically adjusting the media playout rate to recover from undesired (e.g., buffer overflow/underflow or out-of-sync) situations. The existing AMP solutions are mainly characterized by two main aspects. The first one is their goal (e.g., keeping the buffers¿ occupancy into safe ranges or enabling media synchronization). The second one is the criteria that determine the need for triggering the playout adjustments (e.g., buffer fullness or asynchrony levels). This paper instead focuses on a third key aspect, which has not been sufficiently investigated yet: the specific adjustment strategy to be performed. In particular, we propose a novel AMP strategy, called Cubic AMP, which is based on employing a cubic interpolation method to adjust a deviated playout point to a given reference. On the one hand, mathematical analysis and graphical examples show that our proposal provides superior performance than other existing linear and quadratic AMP strategies in terms of the smoothness of the playout curve, while significantly outperforming the quadratic AMP strategy regarding the duration of the adjustment period and without increasing the computational complexity. It has also been proved and discussed that higher-order polynomial interpolation methods are less convenient than cubic ones. On the other hand, the results of subjective tests confirm that our proposal provides better Quality of Experience (QoE) than the other existing AMP strategies.This work has been funded, partially, by the “Fondo Europeo de Desarrollo Regional (FEDER)” and the Spanish Ministry of Economy and Competitiveness, under its R&D&I Support Program, in project with Ref. TEC2013-45492-R.Montagud, M.; Boronat, F.; Roig, B.; Sapena Piera, A. (2017). How to Perform AMP? Cubic Adjustments for Improving the QoE. Computer Communications. 103:61-73. https://doi.org/10.1016/j.comcom.2017.01.017S617310

Accessible scenic arts and Virtual Reality: A pilot study with aged people about user preferences when reading subtitles in immersive environments

El auge de los desarrollos tecnológicos en realidad virtual y otras formas de contenido inmersivo, como el video 360º, se ha convertido en un reto para el concepto de liveness en las artes escénicas, y resulta necesaria una revisión en los estudios de traducción audiovisual. La inclusión de estudios de recepción de subtítulos en este nuevo medio basado en realidad virtual es necesario. En el campo específico de los estudios de accesibilidad en los medios de comunicación, la accesibilidad en los medios inmersivos se encuentra aún en un estado embrionario. Este artículo explora las preferencias de dos opciones de subtítulos: subtítulos para sordos y discapacitados auditivos y subtítulos en lectura fácil, elaborados para un vídeo en 360º de la ópera Roméo et Juliette, interpretada en el Gran Teatre del Liceu durante la temporada 2017/2018. El estudio se preparó y se realizó con personas de entre 50 y 79 años de edad, con el objetivo de determinar las opciones de subtitulación preferidas por las personas mayores.The technological advancements in virtual reality and other forms of immersive content such as 360º video are triggering the concept of liveness in the scenic arts, and deserve in-depth consideration in audiovisual translation studies. The reception of subtitles in this new VR-based media needs to be studied. In the specific field of media accessibility, accessibility in immersive media much research needs to be done. This article explores the preferences of two subtitle options: Subtitles for the D/deaf and hard-of-hearing and Easy-to-Read in a 360º video of Roméo and Juliette the opera, played at the Gran Teatre del Liceu during the 2017/2018 season. A pilot study was prepared and conducted with the aim of determining which subtitling options are preferred by users aged between 50 and 79.This work has been funded by European Union’s Horizon 2020 program, under agreement nº 761974 (ImAc project). Dr. Estella Oncins is member of TransMedia Catalonia, an SGR research group funded by “Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya” (2017SGR113)