thumbnail property with duration or temporal selector

[stephenwf]

With AV content, it's possible to provide a thumbnail, or a placeholder canvas to be shown before the content is displayed, but there is no way to provide thumbnails for time-stops.

It is supported by WebVTT: https://www.webtvsolutions.com/support.php?s=ws_webtv_docs&d=clips_video_thumbnails&lang=en with additional support for a spite-map style URLs.

Taking an example from the archive.org IIIF implementation of AV content, they have a list of thumbnails for the various time-stops that are used on the main site for previews while scrubbing.

For example: https://iiif.archive.org/iiif/3/APOLLO16MMLAUNCHVIEWS/manifest.json

Has the following thumbnails attached:

However, there no duration to tie them back to the canvas duration.

[azaroth42]

It's not a thumbnail property, but the use case is covered with the thumbnail-nav behavior:

Ranges that have this behavior may be used by the client to present an alternative navigation or overview based on thumbnails, such as regular keyframes along a timeline for a video, or sections of a long scroll.