Video Quality Evaluation for Tile-Based Spatial Adaptation

The demand for very high-resolution video content in entertainment services (4K, 8K, panoramic, 360 VR) puts an increasing load on the distribution network. In order to reduce the network usage in existing delivery infrastructure for such services while keeping a good quality of experience, dynamic spatial video adaptation at the client side is seen as a key feature, and is actively investigated by academics and industrials. However, the impact of spatial adaptation on quality perception is not clear. In this paper, we propose a methodology for the evaluation of such adapted content, conduct a series of perceived quality measurements and discuss results showing potential benefits and drawbacks of the technique. Based on our results, we also propose a signaling mechanism in MPEGDASH to assist the client in its spatial adaptation log

An HTTP/2-based adaptive streaming framework for 360° virtual reality videos

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Video processing for panoramic streaming using HEVC and its scalable extensions

Panoramic streaming is a particular way of video streaming where an arbitrary Region-of-Interest (RoI) is transmitted from a high-spatial resolution video, i.e. a video covering a very “wide-angle” (much larger than the human field-of-view – e.g. 360°). Some transport schemes for panoramic video delivery have been proposed and demonstrated within the past decade, which allow users to navigate interactively within the high-resolution videos. With the recent advances of head mounted displays, consumers may soon have immersive and sufficiently convenient end devices at reach, which could lead to an increasing demand for panoramic video experiences. The solution proposed within this paper is built upon tile-based panoramic streaming, where users receive a set of tiles that match their RoI, and consists in a low-complexity compressed domain video processing technique for using H.265/HEVC and its scalable extensions (H.265/SHVC and H.265/MV-HEVC). The proposed technique generates a single video bitstream out of the selected tiles so that a single hardware decoder can be used. It overcomes the scalability issue of previous solutions not using tiles and the battery consumption issue inherent of tile-based panorama streaming, where multiple parallel software decoders are used. In addition, the described technique is capable of reducing peak streaming bitrate during changes of the RoI, which is crucial for allowing a truly immersive and low latency video experience. Besides, it makes it possible to use Open GOP structures without incurring any playback interruption at switching events, which provides a better compression efficiency compared to closed GOP structures

Improving virtual reality streaming using HTTP/2

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Streaming and User Behaviour in Omnidirectional Videos

Omnidirectional videos (ODVs) have gone beyond the passive paradigm of traditional video, offering higher degrees of immersion and interaction. The revolutionary novelty of this technology is the possibility for users to interact with the surrounding environment, and to feel a sense of engagement and presence in a virtual space. Users are clearly the main driving force of immersive applications and consequentially the services need to be properly tailored to them. In this context, this chapter highlights the importance of the new role of users in ODV streaming applications, and thus the need for understanding their behaviour while navigating within ODVs. A comprehensive overview of the research efforts aimed at advancing ODV streaming systems is also presented. In particular, the state-of-the-art solutions under examination in this chapter are distinguished in terms of system-centric and user-centric streaming approaches: the former approach comes from a quite straightforward extension of well-established solutions for the 2D video pipeline while the latter one takes the benefit of understanding users’ behaviour and enable more personalised ODV streaming

Enhancing the broadcasted TV consumption experience with broadband omnidirectional video content

[EN] The current wide range of heterogeneous consumption devices and delivery technologies, offers the opportunity to provide related contents in order to enhance and enrich the TV consumption experience. This paper describes a solution to handle the delivery and synchronous consumption of traditional broadcast TV content and related broadband omnidirectional video content. The solution is intended to support both hybrid (broadcast/broadband) delivery technologies and has been designed to be compatible with the Hybrid Broadcast Broadband TV (HbbTV) standard. In particular, some specifications of HbbTV, such as the use of global timestamps or discovery mechanisms, have been adopted. However, additional functionalities have been designed to achieve accurate synchronization and to support the playout of omnidirectional video content in current consumption devices. In order to prove that commercial hybrid environments could be immediately enhanced with this type of content, the proposed solution has been included in a testbed, and objectively and subjectively evaluated. Regarding the omnidirectional video content, the two most common types of projections are supported: equirectangular and cube map. The results of the objective assessment show that the playout of broadband delivered omnidirectional video content in companion devices can be accurately synchronized with the playout on TV of traditional broadcast 2D content. The results of the subjective assessment show the high interest of users in this type of new enriched and immersive experience that contributes to enhance their Quality of Experience (QoE) and engagement.This work was supported by the Generalitat Valenciana, Investigacion Competitiva Proyectos, through the Research and Development Program Grants for Research Groups to be Consolidated, under Grant AICO/2017/059 and Grant AICO/2017Marfil-Reguero, D.; Boronat, F.; López, J.; Vidal Meló, A. (2019). Enhancing the broadcasted TV consumption experience with broadband omnidirectional video content. IEEE Access. 7:171864-171883. https://doi.org/10.1109/ACCESS.2019.2956084S171864171883