music-video-gen/flow-state/filmstrip.html
Dejvino 3a0cf26e6c The filmstrip fills in as it renders
A full build is a couple of minutes of GPU work, and the page spent all of it
showing an empty screen and then everything at once. The interesting failure —
a strip whose frames could be shuffled without anyone noticing — is visible in
the first row, so waiting for the seventeenth to look at the first is a
needlessly slow way to find it out.

Rows are appended as they land, in bank order, and re-sorted once at the end
when there is finally something to sort by. One row renderer handles both raw
pixels, which is what exists mid-build, and the compressed blobs the cache
holds afterwards, so what you watch appear is what you keep.

The song is announced BEFORE its render rather than only after it, too:
synthesising and rendering one is tens of seconds, and a page that says nothing
until the first one lands looks broken for exactly as long as that takes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-20 09:02:10 +02:00

280 lines
12 KiB
HTML

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>flow-state · filmstrip</title>
<style>
:root { color-scheme: dark; }
body {
margin: 0; padding: 20px 24px 60px;
background: #0b0d12; color: #d6dae3;
font: 13px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
}
h1 { font-size: 15px; letter-spacing: .12em; text-transform: uppercase; color: #7d8698; margin: 0 0 4px; }
a { color: #7dd3fc; }
.lede { color: #8b94a7; max-width: 84ch; margin: 0 0 14px; }
.bar { position: sticky; top: 0; z-index: 5; background: #0b0d12; padding: 10px 0 12px; border-bottom: 1px solid #1c2030; margin-bottom: 16px; }
button, select {
background: #171b24; color: #d6dae3; border: 1px solid #2a3040;
padding: 5px 10px; font: inherit; border-radius: 3px; cursor: pointer;
}
button:hover:not(:disabled) { border-color: #4a5468; }
button:disabled { opacity: .5; cursor: default; }
#status { color: #8b94a7; margin-left: 10px; }
#status.cached { color: #4ade80; }
.spinner {
display: none; width: 13px; height: 13px; vertical-align: -2px;
border: 2px solid #2a3040; border-top-color: #7dd3fc; border-radius: 50%;
animation: spin .8s linear infinite; margin-right: 6px;
}
.building .spinner { display: inline-block; }
@keyframes spin { to { transform: rotate(360deg); } }
#progress { height: 2px; background: #1a1e28; margin-top: 8px; border-radius: 2px; overflow: hidden; display: none; }
.building #progress { display: block; }
#progress i { display: block; height: 100%; width: 0; background: #7dd3fc; transition: width .2s; }
.row { margin-bottom: 22px; border-left: 3px solid #232838; padding-left: 12px; }
.row.static { border-color: #ef4444; }
.row.churn { border-color: #eab308; }
.row.arc { border-color: #22c55e; }
.row.broken { border-color: #a855f7; background: #150e1c; }
.head { display: flex; align-items: baseline; gap: 12px; margin-bottom: 6px; flex-wrap: wrap; }
.name { font-size: 14px; color: #e6eaf2; }
.meta { color: #6b7280; font-size: 11px; }
.num { color: #9aa3b5; }
.num b { color: #d6dae3; font-weight: normal; }
.story { color: #a5b4fc; font-size: 11px; }
.watch { font-size: 11px; text-decoration: none; }
.watch:hover { text-decoration: underline; }
.err { color: #f87171; }
/* The strip scrolls sideways rather than wrapping: a filmstrip that wraps
stops being a filmstrip, and reading it left to right IS the measurement. */
.strip { display: flex; gap: 4px; overflow-x: auto; padding-bottom: 6px; }
.strip figure { margin: 0; flex: 0 0 auto; width: 168px; }
.strip canvas { width: 100%; display: block; background: #05070a; border-radius: 2px; aspect-ratio: 16 / 9; }
.strip figcaption { font-size: 10px; color: #565f70; margin-top: 3px; line-height: 1.35; }
.strip .t { color: #8b94a7; }
.strip .sc { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.moment { color: #fbbf24; }
/* The climax is the one frame worth finding at a glance. */
figure.climax canvas { outline: 2px solid #fbbf24; outline-offset: -2px; }
</style>
</head>
<body>
<h1>flow-state · filmstrip</h1>
<p class="lede">
Every song in the bank, one frame every <span id="everyLabel">30</span> seconds,
left to right. The gallery asks whether a scene looks the same in every song;
this asks whether a song looks the same as <em>itself</em> four minutes later.
A strip whose frames could be shuffled without anyone noticing is a video with
no arc, however busy it is.
<strong>drift</strong> is how far the video gets from itself and
<strong>direction</strong> is whether that distance grows with time — churn
scores the first and not the second. The climax frame is outlined.
<a href="/debug.html">← all debug tools</a>
</p>
<div class="bar" id="bar">
<span class="spinner"></span>
<button id="rebuild">rebuild</button>
<select id="sort">
<option value="direction">sort: least direction first</option>
<option value="drift">sort: least drift first</option>
<option value="name">sort: bank order</option>
<option value="plot">sort: by plot</option>
</select>
<span id="status">checking cache…</span>
<div id="progress"><i></i></div>
</div>
<div id="out"></div>
<script type="module">
import { buildFilmstrip, songNames, STRIP, DEFAULT_EVERY, DEFAULT_DURATION } from '/src/checks/filmstrip.js';
import { blit } from '/src/checks/blit.js';
import { hashString } from '/src/engine/rng.js';
import {
sourceFingerprint, loadGallery, saveGallery,
pixelsToBlob, blobToCanvas,
} from '/src/checks/gallery-cache.js';
const params = new URLSearchParams(location.search);
const every = Number(params.get('every')) || DEFAULT_EVERY;
const duration = Number(params.get('duration')) || DEFAULT_DURATION;
const only = params.get('song') ? params.get('song').split(',') : null;
document.getElementById('everyLabel').textContent = every;
const bar = document.getElementById('bar');
const out = document.getElementById('out');
const status = document.getElementById('status');
const sortSel = document.getElementById('sort');
const progress = document.querySelector('#progress i');
const rebuildBtn = document.getElementById('rebuild');
let rows = [];
// Read against the arcless reference the variety report prints: around zero is
// a video that is as unlike itself after ten seconds as after four minutes.
const grade = (row) => (row.error ? 'broken'
: row.direction < 0.15 ? 'static'
: row.direction < 0.45 ? 'churn' : 'arc');
// Nine stills are an argument about a video, and the only reply to them is the
// video. The app takes the bank's wav straight from `?song=`, and the seed is
// the one renderSong() uses — hashed off the name — so what plays is the take
// the strip measured rather than a fresh draw that happens to share a title.
const watchLink = (name) =>
`/?song=${encodeURIComponent(name)}&seed=${hashString(name)}`;
/**
* One song's row.
*
* Shots arrive as raw pixels while the build is running and as compressed blobs
* once it has finished (and on every later sort, out of the cache). Both are
* drawn here rather than in two places, because the whole point of painting
* during the build is that what you see then is what you keep.
*/
function renderRow(row) {
const el = document.createElement('div');
el.className = `row ${grade(row)}`;
el.innerHTML = `
<div class="head">
<span class="name">${row.name}</span>
<a class="watch" href="${watchLink(row.name)}" target="_blank"
title="play this song in the app, on the seed this strip was rendered with">watch ▸</a>
<span class="meta">${row.bpm ?? '?'} bpm · ${row.sections ?? '?'} sections · ${row.director || ''}</span>
<span class="num">direction <b>${(row.direction ?? 0).toFixed(2)}</b> · drift <b>${(row.drift ?? 0).toFixed(3)}</b></span>
<span class="story">${row.error ? `<span class="err">${row.error}</span>` : (row.storyLine || '')}</span>
</div>
<div class="strip"></div>`;
const strip = el.querySelector('.strip');
for (const shot of row.shots || row.frames || []) {
const fig = document.createElement('figure');
if (shot.moment === 'climax') fig.className = 'climax';
const canvas = document.createElement('canvas');
fig.appendChild(canvas);
const cap = document.createElement('figcaption');
const mm = Math.floor(shot.time / 60);
const ss = String(Math.round(shot.time % 60)).padStart(2, '0');
cap.innerHTML =
`<span class="t">${mm}:${ss}</span> ${shot.kind}` +
(shot.moment ? ` <span class="moment">${shot.moment}</span>` : '') +
`<span class="sc">${shot.scene}</span>` +
`<span class="sc">j ${shot.journey.toFixed(2)} · t ${shot.tension.toFixed(2)}</span>`;
fig.appendChild(cap);
strip.appendChild(fig);
if (shot.pixels) {
// Straight from the render, mid-build. Synchronous and cheap — it is
// one song's nine frames, not the whole bank's.
blit(canvas, shot.pixels, STRIP.width, STRIP.height);
} else {
// Decoded lazily: seventeen songs of nine frames is 150 images and
// decoding them synchronously stalls the page.
blobToCanvas(canvas, shot.blob);
}
}
return el;
}
function draw() {
const mode = sortSel.value;
const order = songNames();
const sorted = rows.slice().sort((a, b) => (
mode === 'name' ? order.indexOf(a.name) - order.indexOf(b.name)
: mode === 'drift' ? a.drift - b.drift
: mode === 'plot' ? ((a.story?.plot || '').localeCompare(b.story?.plot || '') || a.direction - b.direction)
: a.direction - b.direction));
out.innerHTML = '';
for (const row of sorted) out.appendChild(renderRow(row));
}
sortSel.addEventListener('change', draw);
function summarise(built) {
const flat = rows.filter((r) => !r.error && r.direction < 0.15).length;
const meanDir = rows.length
? rows.reduce((a, r) => a + (r.direction || 0), 0) / rows.length : 0;
return `${rows.length} songs · every ${every}s of ${duration}s · ` +
`mean direction ${meanDir.toFixed(2)} · ${flat} with no direction` +
(built ? ` · built ${new Date(built).toLocaleString()}` : '');
}
// The cache key carries the sampling parameters as well as the source, so
// changing `?every=` does not silently show you the previous spacing's pixels.
const cacheKey = () => `filmstrip:${every}:${duration}:${only ? only.join(',') : 'all'}:${sourceFingerprint()}`;
async function build() {
bar.classList.add('building');
rebuildBtn.disabled = true;
rows = [];
out.innerHTML = '';
const total = (only || songNames()).length;
const built = await buildFilmstrip({
duration, every, names: only,
// Painted as they land, in bank order, rather than after the whole run.
// A full build is a couple of minutes of GPU work and the interesting
// failure — a strip whose frames could be shuffled — is visible in the
// first row. Waiting for the seventeenth to look at the first is a
// needlessly slow way to find that out. Re-sorted once at the end, when
// there is finally something to sort by.
onSongStart: (done, of, name) => {
status.textContent = `rendering ${name}… (${done}/${of})`;
progress.style.width = `${((done - 1) / of) * 100}%`;
},
onSong: (done, of, row) => {
progress.style.width = `${(done / of) * 100}%`;
out.appendChild(renderRow(row));
},
});
// Compress once, here, rather than holding 150 raw frames: the strips are
// stored and redrawn from these blobs on every sort.
for (const row of built) {
rows.push({
...row,
frames: undefined,
shots: await Promise.all((row.frames || []).map(async (f) => ({
time: f.time, kind: f.kind, scene: f.scene, act: f.act,
tension: f.tension, journey: f.journey, moment: f.moment,
blob: await pixelsToBlob(f.pixels, STRIP.width, STRIP.height),
}))),
});
}
bar.classList.remove('building');
rebuildBtn.disabled = false;
const stamp = Date.now();
status.textContent = summarise(stamp);
status.className = '';
draw();
await saveGallery(cacheKey(), { built: stamp, rows });
return total;
}
async function load() {
const cached = await loadGallery(cacheKey());
if (cached && cached.rows && cached.rows.length) {
rows = cached.rows;
status.textContent = summarise(cached.built);
status.className = 'cached';
draw();
return;
}
await build();
}
rebuildBtn.addEventListener('click', () => build());
// Dev handle, so a headless run can wait for the build and read the numbers
// without scraping the DOM.
window.__FILMSTRIP__ = { get rows() { return rows; } };
load().then(() => { window.__FILMSTRIP_DONE__ = true; });
</script>
</body>
</html>