Metadata standards, extensible ontology, vocabulary and API for multimedia track metadata, such as XMP, MPEG, Matroska and WebM, can provide enhanced viewing experiences and features based upon multimedia metadata. Describing multimedia tracks with metadata enhances the uses of tracks, of track-based data, and the portability of multimedia files. Web browsers and multimedia software can provide enhanced viewing experiences and features based upon multimedia metadata and including for multi-device scenarios as broached in: Argumentation Scenarios and Use Cases: Web and Television, Speeches, Presentations, Discussions and Debates.
A use case is that of multimedia presentations. Presentation scenarios are numerous, including digital education. Presentation videos might have a number of video tracks: (1) video of presenter, (2) video of a presentation surface, (3) video with cinematography between presenter and presentation surface. HTML5 supports synchronizing multiple media elements for simultaneous rendering such as video tracks (1) and (2). A fourth track, however, could be (4) side-by-side of tracks (1) and (2). Some of the combinations of presenters and presentation surfaces, as aforementioned, are referred to as enhanced video.
<video id="v1" poster="presenter.png" controls mediagroup="presentation"> <source type="video/mp4" src="video.mp4#track=v1&track=a1"> </video> <video id="v2" poster="presentation.png" controls mediagroup="presentation"> <source type="video/mp4" src="video.mp4#track=v2&track=a2"> </video>
The example multimedia object,
video.mp4 has four referenced tracks:
a2. Track metadata can be useful for programmatic uses of multimedia tracks, where track identifiers, such as
v2, are not indicative of the semantics of the track content, such as presenter and presentation. URI-based track metadata, from an extensible ontology and vocabulary, could indicate audio, video and data track contents for scenarios including enhanced video, multiple camera angle video, multiview video, free viewpoint video and 3D video and so as to increase the portability of the multimedia across web pages.
With URI-based track metadata, multimedia software could recognize multimedia track structure (see also:
VideoTrackList), such as tracks of presenters and presentations, and from URL’s such as to
video.mp4, to provide features, ergonomics and intuitive navigation.
Beyond features possible from XHTML transcripts, multimedia tracks can include: XML, RDF, temporal XML and RDF data, and other data pertaining to 3D geometry and animations (see also: http://ninsuna.elis.ugent.be/node/39) as well as data pertaining to multiple camera angles, multiview video, free viewpoint video and 3D video. Utilizing track metadata, selections of multimedia can provide data in multiple clipboarding formats.