A photograph here is 189 KB of tufted yarn — high-frequency detail in every pixel, which is the worst
case for any lossy codec and not something a quality setting can fix. Re-encoding the same original
with ImageMagick at the same quality 82 gives 199 KB, so av-club is already slightly ahead of a
reference encoder. The 858 KB Lighthouse wants back is not available without softening the texture
the site exists to sell.
What was available was the wait. Each ladder now carries the picture at 16 pixels wide as a `data:`
URI inside its manifest — 300 to 500 bytes — and the site paints it as the image's own background. It
costs no request, which is the point: a placeholder you have to fetch is a smaller version of the
problem. When the real photograph arrives it paints over its own background and the placeholder is
gone, with no load handler, no class to remove and nothing to clean up if the script never ran. The
blur is the browser stretching 16 pixels across the box.
Videos take theirs from the poster still, before it is deleted — the same frame, so the two agree, and
sharp can read a JPEG where it cannot read an MP4.
── Existing directories are topped up, not rebuilt ──
The obvious move is to make `upToDate` insist on a placeholder, which turns all 62 ladders stale and
re-derives the library: minutes of CPU and 67 MB rewritten to add 400 bytes to each. Every rung in
them is already correct.
So `topUp` makes only the missing piece, and reads `320.webp` rather than the original — already
small, already browser-readable, already rotated. Going back to a 4000×6000 HEIC to produce a
16-pixel picture is the expensive half of a rebuild and precisely what this avoids. A directory with
no small rung is skipped rather than forced.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
pastilhasandClaude Opus 5
cd0d3fe09e