Files
Miguel Ángel 4e6fcdb3a9 fix(core): a caption line shows again after the playhead jumps back over it (#5690)
* fix(core): a caption line shows again after the playhead jumps back over it

The runtime hides an off-screen clip with an inline visibility:hidden that its
children inherit. A seek that jumps over a clip renders that clip's GSAP tweens
for the first time while it is hidden, so a set or autoAlpha tween records the
inherited "hidden" as the value to restore. Seeking back then writes it back,
and the element stays hidden for the rest of the session.

Interactive seeks now render GSAP with hidden clips shown, so first reads see
the authored style. Play ticks and render captures move forward and are
unchanged.

* fix(core): keep the files' comment share where it was

* fix(core): show hidden clips for any seek that jumps past what has rendered

Clicks and scrubs were covered, but render seeks jump too (hover frames,
thumbnails, stills at several times). The decision now lives in the seek
itself: a seek more than a frame and a half from the last one, to a time the
timelines have not rendered through yet, renders GSAP with hidden clips shown.
Frame-by-frame renders, play ticks and scrubs over already-rendered time pay
nothing.
2026-10-16 10:54:31 +00:00
..
2026-10-16 08:42:19 +00:00

@hyperframes/core

Types, parsers, generators, compiler, linter, runtime, and frame adapters for the Hyperframes video framework.

Install

npm install @hyperframes/core

Most users don't need to install core directly — the CLI, producer, and studio packages depend on it internally.

What's inside

Module Description
Types TimelineElement, CompositionSpec, Asset, canvas dimensions, defaults
Parsers parseHtml — extract timeline elements from HTML; parseGsapScript — parse GSAP animations
Generators generateHyperframesHtml — produce valid Hyperframes HTML from a composition spec
Compiler compileTimingAttrs — resolve data-start / data-duration into absolute times
Linter lintHyperframeHtml — validate Hyperframes HTML (missing attributes, overlapping tracks, etc.)
Runtime IIFE script injected into the browser — manages seek, media playback, and the window.__hf protocol
Frame Adapters Pluggable animation drivers (GSAP, Lottie, CSS, or custom)

Generated composition trust

Composition generators require trusted authors for code-bearing inputs. styles and generateHyperframesStyles preserve authored CSS, which can load external resources. animations may contain __raw: values that are emitted as JavaScript; includeScripts: true includes executable timeline code. serializeGsapAnimations also accepts raw preamble, postamble, and a code-bearing timelineVar. Never fill these inputs with untrusted data. Attribute encoding and closing-tag containment are not a sandbox; render untrusted compositions in an appropriately isolated execution environment and never serve them on a privileged origin.

Text content retains the supported inline-formatting sanitizer contract. The clip parser intentionally flattens inner formatting to text, so parse/generate is not a lossless replacement for editing the source HTML.

Frame Adapters

A frame adapter tells the engine how to seek your animation to a specific frame:

import { createGSAPFrameAdapter } from "@hyperframes/core";

const adapter = createGSAPFrameAdapter({
  getTimeline: () => gsap.timeline(),
  compositionId: "my-video",
});

Implement FrameAdapter for custom animation runtimes:

import type { FrameAdapter } from "@hyperframes/core";

const myAdapter: FrameAdapter = {
  id: "my-adapter",
  getDurationFrames: () => 300,
  seekFrame: (frame) => {
    /* seek your animation */
  },
};

Parsing and generating HTML

import { parseHtml, generateHyperframesHtml } from "@hyperframes/core";

const { elements, metadata } = parseHtml(htmlString);
const html = generateHyperframesHtml(spec);

Linting

import { lintHyperframeHtml } from "@hyperframes/core/lint";

const result = lintHyperframeHtml(htmlString);
// result.findings: { severity, message, elementId }[]

Documentation

Full documentation: hyperframes.heygen.com/packages/core