Study Mission on Object-Based Media

Introduction

Inspired by trials and service launches worldwide, The DVB Project is undertaking a study mission to gain insight and collect use cases for Object-Based Media (OBM). The term object-based media is used to describe an approach to producing, distributing and consuming media content that uses separate media assets, known as ‘objects’. An object consists of essence and its associated metadata, which describes the essence.

For example, a viewer watching a football match might choose to hear commentary from a pundit who is a supporter of their team, instead of the standard broadcast commentary. By producing three audio objects, one for each team and one standard broadcast, alongside the video object, this choice can be offered to the viewer. Interaction by the user can occur explicitly, through user controls. The content may also be automatically adapted based on user preferences or device characteristics. As well as offering new opportunities to adapt the narrative experience, object based media also offers opportunities to optimise the presentation of content for the device being used or the environment in which the content is being consumed.

Where object-based media presentations are used, some objects are considered essential to the default content, such as the standard audio or video, while other objects might be additions, such as an alternative language.

The situation today

Most standard programmes today contain at least two additional media tracks (e.g., audio description, subtitles) but many contain several more (such as visual signing, director’s commentary, additional graphics, EPG links, trailers and references to online information).
These can and sometimes are considered to be objects, and can sometimes be combined to offer several experiences.

Although these tracks exist today, they are not currently considered as object-based media as each one is a stand-alone service which can be enabled or disabled and has limited metadata, and they rarely have the metadata that describes how they can be combined to form an object-based presentation.
Recently however, it has become possible to create and deliver more sophisticated object based media, such as branching narratives, personalised presentations, which offer totally new viewing experiences. Many of the underlying media types are delivered in existing standardised ways, but today the methods used identify them and link them to the primary programme or to each other often rely on proprietary or app specific data.

In current DVB systems there are specifications for carrying the most common types of media essences, e.g., subtitles or alternate audio tracks, but these specifications are designed for that specific purpose and a common method to label, identify and carry metadata for multiple objects is not available.

Preparing for the future

As media and media delivery systems evolve, the number of elements associated with the content increases. Social media posts, trailers, promotional web content, photos, sound clips and a host of other assets are now associated with media. All these elements have traditionally been managed in an ad-hoc way and the media archive for many programmes in the past, merely consisted of a master copy of the programme itself, with a short filename, or label on the tape or storage media.

In addition, the media may be composed dynamically from separate digital media assets, and can be made responsive to user preferences or interaction, and rendered dynamically by the client device or by a cloud service.

The group is examining how “objects” consisting of media elements with metadata are being used in the industry and determining how well existing specifications cover the carriage of multiple objects, and whether