A poster was one file at the video's full size — 1280x720 for a hero displayed 412 CSS pixels wide.
Three times the pixels a phone can show, on the element that IS the page's Largest Contentful Paint,
which is the most expensive place on the site to be careless.
384, 512, 768, 1024, plus poster.webp as the widest rung. Those are viewport widths times the density
behind them: 412 at 1.75 wants 768, a tablet wants 768, a desktop wants 1280.
Cut from the still rather than from poster.webp, so each rung is scaled once from the original frame
instead of being a re-encode of an encode. poster.webp keeps its name — the placeholder is cut from
it, the site falls back to it, and a directory built before this has only that one.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
pastilhasandClaude Opus 5
931807f3a5