Install
That writes one file:compositions/yt-vertical-fill.html.
Add it to your video
It runs for 8 seconds at 1920×1080. Paste this into your composition:index.html
<div
data-composition-id="yt-vertical-fill"
data-composition-src="compositions/yt-vertical-fill.html"
data-start="0"
data-duration="8"
data-track-index="1"
data-width="1920"
data-height="1080"
></div>
data-start. Put it on a different timeline row with
data-track-index. See data attributes for the rest.
Source
yt-vertical-fill.html
yt-vertical-fill.html
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8" />
<script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
<style>
*,
*::before,
*::after {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
background: transparent;
overflow: hidden;
}
#yt-vf-root {
/* ---- yt tokens ---- */
--yt-font: "Inter", -apple-system, sans-serif;
--yt-grid-size: 28px;
--yt-grid-alpha: 0.05;
--yt-stage: #101012;
--yt-scrim: rgba(8, 8, 10, 0.28);
--yt-cyan: #35c8d9;
--yt-prism-b: #2a7fff;
--yt-violet: #7d5cff;
position: relative;
width: 1920px;
height: 1080px;
overflow: hidden;
background: var(--yt-stage);
font-family: var(--yt-font);
}
.yt-vf-media {
position: absolute;
overflow: hidden;
}
.yt-vf-media img,
.yt-vf-media .yt-vf-fill {
width: 100%;
height: 100%;
object-fit: cover;
}
#yt-vf-bg {
inset: -60px;
filter: blur(42px) brightness(0.75);
}
.yt-vf-side {
top: 0;
bottom: 0;
width: 656px;
}
#yt-vf-scrim {
position: absolute;
inset: 0;
background: var(--yt-scrim);
}
#yt-vf-grid {
position: absolute;
inset: 0;
background:
repeating-linear-gradient(
0deg,
rgba(255, 255, 255, var(--yt-grid-alpha)) 0 1px,
transparent 1px var(--yt-grid-size)
),
repeating-linear-gradient(
90deg,
rgba(255, 255, 255, var(--yt-grid-alpha)) 0 1px,
transparent 1px var(--yt-grid-size)
);
}
#yt-vf-fg {
top: 0;
bottom: 0;
left: 656px;
width: 608px;
box-shadow: 0 0 90px rgba(0, 0, 0, 0.55);
}
/* stand-in portrait when no media is configured (self-demo) */
.yt-vf-fill {
display: flex;
align-items: center;
justify-content: center;
font-weight: 700;
font-size: 120px;
color: rgba(255, 255, 255, 0.9);
background: linear-gradient(
160deg,
var(--yt-cyan) 0%,
var(--yt-prism-b) 50%,
var(--yt-violet) 100%
);
}
</style>
</head>
<body>
<div
id="yt-vf-root"
data-composition-id="yt-vertical-fill"
data-start="0"
data-duration="8"
data-width="1920"
data-height="1080"
>
<div class="yt-vf-media" id="yt-vf-bg" data-layout-allow-overflow></div>
<div class="yt-vf-media yt-vf-side" id="yt-vf-side-l" style="left: 0"></div>
<div class="yt-vf-media yt-vf-side" id="yt-vf-side-r" style="right: 0"></div>
<div id="yt-vf-scrim"></div>
<div id="yt-vf-grid"></div>
<div class="yt-vf-media" id="yt-vf-fg"></div>
<div
id="yt-vf-drv"
class="clip"
data-start="0"
data-duration="8"
data-track-index="0"
style="position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none"
></div>
</div>
<script>
(function () {
window.__timelines = window.__timelines || {};
/* ---- published parameters ----
Vertical media filling a 16:9 frame — three fill modes:
mode "scale" (big blurred copy behind), "mirror" (flanking
mirrored copies), "copy" (flanking straight copies).
IMAGES ONLY inside this block: the runtime never seeks media
elements inside a sub-composition (renders black). For live
vertical FOOTAGE, keep the media element in the HOST root
positioned over the fg slot (left:656px width:608px) and feed
this block a representative still for the fill layers. */
var CONFIG = {
src: null, // portrait IMAGE path; null -> stand-in gradient (demo)
mode: "scale", // "scale" | "mirror" | "copy"
fgContrast: 1.06,
fgBrightness: 1.03,
fgSaturation: 1.08,
grid: { enabled: true },
kenBurns: true,
animationIn: true,
animationOut: true,
};
var DUR = 8;
function clamp(v, lo, hi) {
return Math.min(hi, Math.max(lo, v));
}
var IN = clamp(DUR * 0.08, 0.3, 0.8);
var OUT = clamp(DUR * 0.06, 0.25, 0.6);
var root = document.getElementById("yt-vf-root");
var bg = document.getElementById("yt-vf-bg");
var sideL = document.getElementById("yt-vf-side-l");
var sideR = document.getElementById("yt-vf-side-r");
var fg = document.getElementById("yt-vf-fg");
var grid = document.getElementById("yt-vf-grid");
if (!CONFIG.grid.enabled) grid.style.display = "none";
function media(id) {
if (!CONFIG.src) {
var d = document.createElement("div");
d.className = "yt-vf-fill";
d.textContent = "9:16";
return d;
}
var img = document.createElement("img");
img.src = CONFIG.src;
img.id = id;
return img;
}
fg.appendChild(media("yt-vf-m-fg"));
fg.style.filter =
"contrast(" +
CONFIG.fgContrast +
") brightness(" +
CONFIG.fgBrightness +
") saturate(" +
CONFIG.fgSaturation +
")";
if (CONFIG.mode === "scale") {
bg.appendChild(media("yt-vf-m-bg"));
sideL.style.display = "none";
sideR.style.display = "none";
} else {
bg.style.display = "none";
sideL.appendChild(media("yt-vf-m-l"));
sideR.appendChild(media("yt-vf-m-r"));
if (CONFIG.mode === "mirror") {
sideL.firstChild.style.transform = "scaleX(-1)";
sideR.firstChild.style.transform = "scaleX(-1)";
}
sideL.style.filter = "blur(6px) brightness(0.72)";
sideR.style.filter = "blur(6px) brightness(0.72)";
}
var tl = gsap.timeline({ paused: true });
if (CONFIG.animationIn) {
tl.from(root, { opacity: 0, duration: IN, ease: "power2.out" }, 0);
gsap.set(fg, { y: 34, opacity: 0 });
tl.to(fg, { y: 0, opacity: 1, duration: IN * 1.6, ease: "power3.out" }, IN * 0.5);
}
if (CONFIG.kenBurns) {
tl.fromTo(
fg.firstChild,
{ scale: 1.05 },
{ scale: 1, duration: DUR - 1, ease: "sine.out" },
0.4,
);
}
if (CONFIG.animationOut) {
tl.to(root, { opacity: 0, duration: OUT, ease: "power2.in" }, DUR - OUT - 0.05);
}
tl.set(root, { visibility: "hidden" }, DUR - 0.02);
window.__timelines["yt-vertical-fill"] = tl;
})();
</script>
</body>
</html>
placeholder vertical media.