Saving bitrate vs. pleasing users : where is the break-even point in mobile video quality?

This paper presents a comprehensive study to find the most efficient bitrate requirement to deliver mobile video that optimizes bandwidth, while at the same time maintains good user viewing experience. In the study, forty participants were asked to choose the lowest quality video that would still provide for a comfortable and long-term viewing experience, knowing that higher video quality is more expensive and bandwidth intensive. This paper proposes the lowest pleasing bitrates and corresponding encoding parameters for five different content types: cartoon, movie, music, news and sports. It also explores how the lowest pleasing quality is influenced by content type, image resolution, bitrate, and user gender, prior viewing experience, and preference. In addition, it analyzes the trajectory of users’ progression while selecting the lowest pleasing quality. The findings reveal that the lowest bitrate requirement for a pleasing viewing experience is much higher than that of the lowest acceptable quality. Users’ criteria for the lowest pleasing video quality are related to the video’s content features, as well as its usage purpose and the user’s personal preferences. These findings can provide video providers guidance on what quality they should offer to please mobile users.

Everything is political

Everything is Political Ben Eltham, Kieran Lord, Jeff Brand, Truna. Chair: Daniel Golding Videogames don’t exist in isolation. They are part of artistic, cultural, and political spheres – even if some would much rather they weren’t. This panel takes a look at the way videogames are used as political tools and how we as developers and critics can better engage with that, and perhaps wrestle some of the conversation back into our hands.

Journeys with friends

Journeys with Friends Truna aka J. Turner, Giselle Rosman and Matt Ditton Panel Session description: We are no longer an industry (alone) we are a sector. Where the model once consisted of industry making games, we now see the rise of a cultural sector playing in the game space – industry, indies (for whatever that distinction implies) artists (another odd distinction), individuals and well … everyone and their mums. This evolution has an affect – on audiences and who they are, what they expect and want, and how they understand the purpose and language of these “digital game forms’; how we talk about our worlds and the kinds of issues that are raised; on what we create and how we create it and on our communities and who we are. This evolution has an affect on how these works are understood within the wider social context and how we present this understanding to the next generation of makers and players. We can see the potential of this evolution from industry to sector in the rise of the Australian indie. We can see the potential fractures created by this evolution in the new voices that ask questions about diversity and social justice. And yet, we still see a ‘solution’ type reaction to the current changing state of our sector which announces the monolithic, Fordist model as desirable (albeit in smaller form) – with the subsequent ramifications for ‘training’ and production of local talent. Experts talk about a mismatch of graduate skills and industry needs, insufficient linkages between industry and education providers and the need to explore opportunity for the now passing model in new spaces such as adver-games and serious games. Head counts of Australian industry don’t recognise trans media producers as being part of their purview or opportunity, they don’t count the rise of the cultural playful game inspired creative works as one of thier team. Such perspectives are indeed relevant to the Australian Games Industry, but what about the emerging Australian Games Sector? How do we enable a future in such a space? This emerging sector is perhaps best represented by Melbourne’s Freeplay audience: a heady mix of indie developers, players, artists, critical thinkers and industry. Such audiences are no longer content with an ‘industry’ alone; they are the community who already see themselves as an important, vibrant cultural sector. Part of the discussion presented here seeks to identify and understand the resources, primarily in the context of community and educational opportunities, available to the evolving sector now relying more on the creative processes. This creative process and community building is already visibly growing within the context of smaller development studios, often involving more multiskilling production methodologies where the definition of ‘game’ clearly evolves beyond the traditional one.

Face recognition across pose on video using eigen light-fields

We propose an approach to employ eigen light-fields for face recognition across pose on video. Faces of a subject are collected from video frames and combined based on the pose to obtain a set of probe light-fields. These probe data are then projected to the principal subspace of the eigen light-fields within which the classification takes place. We modify the original light-field projection and found that it is more robust in the proposed system. Evaluation on VidTIMIT dataset has demonstrated that the eigen light-fields method is able to take advantage of multiple observations contained in the video.

Modeling player-like behaviour for game Al design

The design of artificial intelligence in computer games is an important component of a player's game play experience. As games are becoming more life-like and interactive, the need for more realistic game AI will increase. This is particularly the case with respect to AI that simulates how human players act, behave and make decisions. The purpose of this research is to establish a model of player-like behavior that may be effectively used to inform the design of artificial intelligence to more accurately mimic a player's decision making process. The research uses a qualitative analysis of player opinions and reactions while playing a first person shooter video game, with recordings of their in game actions, speech and facial characteristics. The initial studies provide player data that has been used to design a model of how a player behaves.

Citizen Coombs Wins!

Citizen Coombs Wins! appears to be a standard arcade game placed within the gallery. Mortal Kombat is displayed on the screen inviting the viewer to press play. The ‘player’ selects their character and awaits the commencement of the game; at first move however, the player dies – sound and text informs them that ‘Citizen Coombs Wins!’. By altering the expected play of the game, this work exploring notions of play, control, the institution and expectation. This work seeks to invite, engage and repel the viewer in order to question, critique and play with the role of the artist and the viewer within the context of the institution. The work was included in the international group show 'Ceci n'est pas une Casino!', curated by Kevin Muhlen and Jo Kox for the Casino Luxembourg and later toured to Villa Merkel, Esslingen, Germany.

Developing and enhancing independent learning skills : using video tutorials as a means of helping students help themselves

Purpose – The purpose of this paper is to examine the use of short video tutorials in a post-graduate accounting subject, as a means of helping students develop and enhance independent learning skills. Design/methodology/approach – In total, five short (approximately five to 10 minutes) video tutorials were introduced in an effort to shift the reliance for learning from the lecturer to the student. Data on students’ usage of online video tutorials, and comments by students in university questionnaires were collated over three semesters from 2008 to 2009. Interviews with students were then conducted in late 2009 to more comprehensively evaluate the use and perceived benefits of video tutorials. Findings – Findings reveal preliminary but positive outcomes in terms of both more efficient and effective teaching and learning. Research limitations/implications – The shift towards more independent learning through the use of video tutorials has positive implications for educators, employers, and professional accounting bodies; each of whom has identified the need for this skill in accounting graduates. Practical implications – The use of video tutorials has the potential for more rewarding teaching and more effective learning. Originality/value – This study is one of the first to examine the use and benefits of video tutorials as a means of developing independent learning skills in accountancy students – addressing a key concern within the profession.

Dancelines series

Dancelines was a body of work commissioned by Bangarra Dance Company and The Arts Centre, Melbourne. The artist was invited to produce a body of work that responded to the dance company's production of 'Boomerang'. The result was a body of photographs that applied the artist's interest in layering as a photographic technique and her interest in indigenous subjectivity and sprituality. The works drew correspondences between Rheannan Port, the subject's, own biography and character and the artist's voluminous archive of iamges of the natural world. The result complemented and formalised the collaborative processes that the artist had previously only explored in the video medium. The work was shown at the George Adams Gallery of the Arts Centre as part of Melbourne 2006 Commonwealth Games Arts Festival. 'Rheannan Port, #1' was selected for the 2006 Archibald Photographic Portrait Prize, at the Art Gallery of New South Wales. The work was reviewed in The Age newspaper.

Proximity-to-goal as a constraint on patterns of behaviour in attacker–defender dyads in team games

The aim of this study was to determine whether spatiotemporal interactions between footballers and the ball in 1 vs. 1 sub-phases are influenced by their proximity to the goal area. Twelve participants (age 15.3 ± 0.5 years) performed as attackers and defenders in 1 vs. 1 dyads across three field positions: (a) attacking the goal, (b) in midfield, and (c) advancing away from the goal area. In each position, the dribbler was required to move beyond an immediate defender with the ball towards the opposition goal. Interactions of attacker-defender dyads were filmed with player and ball displacement trajectories digitized using manual tracking software. One-way repeated measures analysis of variance was used to examine differences in mean defender-to-ball distance after this value had stabilized. Maximum attacker-to-ball distance was also compared as a function of proximity-to-goal. Significant differences were observed for defender-to-ball distance between locations (a) and (c) at the moment when the defender-to-ball distance had stabilized (a: 1.69 ± 0.64 m; c: 1.15 ± 0.59 m; P < 0.05). Findings indicate that proximity-to-goal influenced the performance of players, particularly when attacking or advancing away from goal areas, providing implications for training design in football. In this study, the task constraints of football revealed subtly different player interactions than observed in previous studies of dyadic systems in basketball and rugby union.

Understanding user experience of mobile video : framework, measurement, and optimization

Since users have become the focus of product/service design in last decade, the term User eXperience (UX) has been frequently used in the field of Human-Computer-Interaction (HCI). Research on UX facilitates a better understanding of the various aspects of the user’s interaction with the product or service. Mobile video, as a new and promising service and research field, has attracted great attention. Due to the significance of UX in the success of mobile video (Jordan, 2002), many researchers have centered on this area, examining users’ expectations, motivations, requirements, and usage context. As a result, many influencing factors have been explored (Buchinger, Kriglstein, Brandt & Hlavacs, 2011; Buchinger, Kriglstein & Hlavacs, 2009). However, a general framework for specific mobile video service is lacking for structuring such a great number of factors. To measure user experience of multimedia services such as mobile video, quality of experience (QoE) has recently become a prominent concept. In contrast to the traditionally used concept quality of service (QoS), QoE not only involves objectively measuring the delivered service but also takes into account user’s needs and desires when using the service, emphasizing the user’s overall acceptability on the service. Many QoE metrics are able to estimate the user perceived quality or acceptability of mobile video, but may be not enough accurate for the overall UX prediction due to the complexity of UX. Only a few frameworks of QoE have addressed more aspects of UX for mobile multimedia applications but need be transformed into practical measures. The challenge of optimizing UX remains adaptations to the resource constrains (e.g., network conditions, mobile device capabilities, and heterogeneous usage contexts) as well as meeting complicated user requirements (e.g., usage purposes and personal preferences). In this chapter, we investigate the existing important UX frameworks, compare their similarities and discuss some important features that fit in the mobile video service. Based on the previous research, we propose a simple UX framework for mobile video application by mapping a variety of influencing factors of UX upon a typical mobile video delivery system. Each component and its factors are explored with comprehensive literature reviews. The proposed framework may benefit in user-centred design of mobile video through taking a complete consideration of UX influences and in improvement of mobile videoservice quality by adjusting the values of certain factors to produce a positive user experience. It may also facilitate relative research in the way of locating important issues to study, clarifying research scopes, and setting up proper study procedures. We then review a great deal of research on UX measurement, including QoE metrics and QoE frameworks of mobile multimedia. Finally, we discuss how to achieve an optimal quality of user experience by focusing on the issues of various aspects of UX of mobile video. In the conclusion, we suggest some open issues for future study.

Enlightenment out of chaos : power, politics and The Chaser’s War on Everything

This paper focuses on the satirical Australian television show The Chaser’s War on Everything, and uses it to critically explore the potential ramifications of what McNair (2006) has called ‘cultural chaos’. Through an analysis of several examples from this particular program, alongside interviews with its production team and qualitative audience research, this paper argues that this TV show’s engagement with political issues in a creative, entertaining way that departs from the conventions of traditional journalism, allows it to present a perhaps more authentic image of political agents than is often cultivated in the mainstream news media. This paper therefore provides clear evidence that the shift from homogeneity to heterogeneity in the news media presents a significant challenge to those who wish to heavily control public opinion. It also provides further support for an optimistic re-appraisal of entertainment which emphasises its central (not merely periphery) role in political discourse.

Measuring bitrate and quality trade-off in a fast region-of-interest based video coding

Prevailing video adaptation solutions change the quality of the video uniformly throughout the whole frame in the bitrate adjustment process; while region-of-interest (ROI)-based solutions selectively retains the quality in the areas of the frame where the viewers are more likely to pay more attention to. ROI-based coding can improve perceptual quality and viewer satisfaction while trading off some bandwidth. However, there has been no comprehensive study to measure the bitrate vs. perceptual quality trade-off so far. The paper proposes an ROI detection scheme for videos, which is characterized with low computational complexity and robustness, and measures the bitrate vs. quality trade-off for ROI-based encoding using a state-of-the-art H.264/AVC encoder to justify the viability of this type of encoding method. The results from the subjective quality test reveal that ROI-based encoding achieves a significant perceptual quality improvement over the encoding with uniform quality at the cost of slightly more bits. Based on the bitrate measurements and subjective quality assessments, the bitrate and the perceptual quality estimation models for non-scalable ROI-based video coding (AVC) are developed, which are found to be similar to the models for scalable video coding (SVC).

Engaging bodily with video in design

Video is commonly used as a method for recording embodied interaction for purposes of analysis and design and has been proposed as a useful ‘material’ for interaction designers to engage with. But video is not a straight forward reproduction of embodied activity – in themselves video recordings ‘flatten’ the space of embodied interaction, they impose a perspective on unfolding action, and remove the embodied spatial and social context within which embodied interaction unfolds. This does not mean that video is not a useful medium with which to engage as part of a process of investigating and designing for embodied interaction – but crucially, it requires that as people attempting to engage with video, designers own bodies and bodily understandings must be engaged with and brought into play. This paper describes and reflects upon our experiences of engaging with video in two different activities as part of a larger research project investigating the design of gestural interfaces for a dental surgery context.

The market structure and characteristics of electronic games

A multi-billion dollar industry, electronic games have been experiencing strong and rapid growth in recent times. The world of games is not only exciting due to the magnificent growth of the industry however, but due to a host of other factors. This chapter explores electronic games, providing an analysis of the industry, key motivators for game play, the game medium and academic research concerning the effects of play. It also reviews the emerging relationship games share with sport, recognizing that they can replicate sports, facilitate sports participation and be played as a sport. These are complex relationships that have not yet been comprehensively studied. The current chapter serves to draw academic attention to the area and presents ideas for future research.

Probabilistic matching of image sets for video-based face recognition

We address the problem of face recognition on video by employing the recently proposed probabilistic linear discrimi-nant analysis (PLDA). The PLDA has been shown to be robust against pose and expression in image-based face recognition. In this research, the method is extended and applied to video where image set to image set matching is performed. We investigate two approaches of computing similarities between image sets using the PLDA: the closest pair approach and the holistic sets approach. To better model face appearances in video, we also propose the heteroscedastic version of the PLDA which learns the within-class covariance of each individual separately. Our experi-ments on the VidTIMIT and Honda datasets show that the combination of the heteroscedastic PLDA and the closest pair approach achieves the best performance.