Page 35 - ITU Journal, ICT Discoveries, Volume 3, No. 1, June 2020 Special issue: The future of video and immersive media

ITU Journal: ICT Discoveries, Vol. 3(1), June 2020

Accordingly, the content production part of the The project has focused on media delivery through
platform includes a set of (web-based) tools for the broadband Content Delivery Networks (CDNs), via
ingest of immersive VR360 content, the the Dynamic Adaptive Streaming over HTTP (DASH)
production/editing of access service content standard [19]. However, the platform is also
(including subtitles, audio description and sign prepared for the delivery of broadband content via
language videos), and their integration with the DASH, but as an enrichment of conventional
available VR360 content. These tools provide the broadcast Digital Video Broadcasting (DVB)
required metadata to signalize the properties of the services, by leveraging the features provided by the
authored media content. The supported features HbbTV standard [14].
are not detailed, but can be inferred from the In this context, ImAc has contributed with the
features provided by the developed VR360 player release of open-source software components and
[18] (described later). The access service editors open APIs to connect them with the content
are provided under a Software as a Service (SaaS) production tools. In addition, ImAc has explored the
distribution model.
specification of standard-compliant extensions to
In this context, the ImAc project has contributed to delivery technologies and signaling solutions. One
the specification of standard-compliant extensions example is the design of solutions to enable
to current technologies and formats. Two examples interactive and immersive multiscreen scenarios,
can be highlighted. First, the IMSC (Internet Media which can be relevant for the HbbTV standard.
Subtitles and Captions) subtitle format has been Another example is the extension of the DASH
extended to indicate where the speaker is in the 360° technology to signalize the availablity of all
space. IMSC is a subset of Timed Text Markup considered access services, beyond the classic and
Language (TTML) for distribution of subtitles, immersive media content elements. This can be
drawing the attention of, and being adopted by, relevant for the DASH technology specified by the
many standardization bodies, like the World Wide Moving Picture Experts Group (MPEG)
Web Consortium (W3C). Second, a new ad-hoc, but standardization body.
standard-compliant, solution has been defined to be 4.4 Content consumption
able to indicate the speaker’s name and position
together with the associated sign language video, as This part is mainly composed of a portal to select
well as to be able to dynamically show/hide the the desired content (see Fig. 2) and a web-based
video window based on the signer’s activity. player (see Fig. 3) for the personalized presentation
of the immersive (VR360 video and spatial audio)
4.2 Service provider
and access service (subtitles, audio subtitles, audio
This part of the platform includes different description and sign language) content. For visual
components for the management and cataloguing of elements, the player supports different
content, and triggering its publication, either by presentation modes such as:
associating it to scheduled (broadcast) TV
programs or by posting it on specific websites. One • User-reference: the visual elements
key component in this part is the Accessibility (e.g., subtitles, sign language, UI) are always
visible and follow the user’s viewing direction.
Content Manager (ACM), developed to enable the
upload of VR360 content (and optionally its related • Scene-reference: the visual elements are
assets, like personalized covers/thumbnails and attached to specific regions of the 360° space
existing access service content), to catalogue it, to (e.g., fixed angles, position of the speaker), so
link it with the editing tools, and finally to trigger they can be outside the user’s field of view
the publication of the immersive and accessibility during media consumption.
content for final consumption.
• Auto-positioning: the visual elements or the
4.3 Content preparation / distribution user’s field of view can be dynamically
positioned, based on predefined metadata
This part of the platform includes components for
preparing the available content for an appropriate generated at the production phase.
distribution. These components are mainly in
charge of (multi-quality) content encoding,
segmentation and signaling.

© International Telecommunication Union, 2020 13