Trick-play thumbnails

Give the item a storyboard VTT (the sprite-sheet format emitted by Mux, JW and Bitmovin tooling — cues pointing into sheet.jpg#xywh=x,y,w,h) and viewers get frame previews while scrubbing.

OGMediaItem.Builder(url)
    .setThumbnailTrack("https://example.com/storyboard.vtt")
    .build()

// engine access, e.g. for your own custom controls:
val bitmap = player.getThumbnail(positionMs)

var item = OGMediaItem(urlString: url)!
item.thumbnailTrack = URL(string: "https://example.com/storyboard.vtt")

let image = await player.getThumbnail(at: seconds)

player.load({
  url,
  thumbnailTrackUrl: "https://example.com/storyboard.vtt",
});

// engine access: sprite crop for a position
const frame = await player.getThumbnail(positionMs);
// { url, x, y, width, height }

With a storyboard attached, the built-in chrome shows the preview while scrubbing (hover previews too, on pointer devices). hasThumbnails tells you whether the current item carries one.