Support MPEG-DASH native in-manifest thumbnails

[filiptronicek]

Related Problem:

Arguably, the best way to supply thumbnails of a video today is through the use of specifying the thumbnails prop of the player to link to some .vtt file. It has recently come to my attention that .mpd (MPEG-DASH) manifests have native support of these thumbnails within them, without the need to store another source of truth about thumbnails somewhere else.

Related links

• Guidelines for Implementation: DASH-IF Interoperability Points (see section 6.2.6)
• Reference player implementation demo: https://reference.dashif.org/dash.js/latest/samples/thumbnails/thumbnails.html
• A Stackblitz demonstrating this isn't working as of today: https://stackblitz.com/edit/vidstack-examples-w7luumku?file=src%2Fplayer.tsx

Describe:

I'd love for thumbnails to be inferred from the .mpd manifest if no other explicit source is given.

Alternatives:

I've considered parsing the manifest myself and somehow translating that into the object structure Vidstack expects. Although I think that might work, it feels error-prone and expensive to introduce manifest parsing into a project just for this.