@elah/core

Framework-agnostic video timeline engine. No React. No renderer. Just the pure logic layer — project state, playback, frame resolution, and media management.

Used internally by @elah/timeline and @elah/editor, but can be consumed directly for custom rendering pipelines or headless environments.

Install

npm install @elah/core

Bundle size: ~41 KiB gzipped (218 KiB raw, tsc ESM output). Runtime deps: immer (~9 KiB gz) + zustand (<1 KiB gz). No WASM, no bundled media toolchain.

What's inside

| Module | Description | |---|---| | TimelineEngine | Manages project state — tracks, clips, undo/redo | | PlaybackEngine | Frame-accurate playback clock | | resolveTimeline | Pure function — project → active scene at a given frame | | GpuRenderer | WebGL2 renderer for video, image, and text layers | | useTracksStore | Zustand mirror of project state for React | | usePlaybackStore | Zustand mirror of playback state for React | | useSelectionStore | Zustand mirror of selection state for React | | useMediaLibrary | Media asset library with thumbnail generation | | importFiles | Import local files into the media library | | exportVideo | Export the timeline to MP4 via a web worker |

Quick start

import { TimelineEngine, PlaybackEngine, createVideoClip } from '@elah/core'

const engine = new TimelineEngine({ fps: 30, stage: { width: 1920, height: 1080 } })
const playback = new PlaybackEngine(engine)

// Add a video clip
engine.addClip('track-1', createVideoClip({ src: 'video.mp4', startFrame: 0, durationFrames: 90 }))

// Resolve the scene at a given frame
import { resolveTimeline } from '@elah/core'
const scene = resolveTimeline(engine.getProject(), { currentFrame: 15 })

Clip factories

import { createVideoClip, createAudioClip, createTextClip, createImageClip } from '@elah/core'

Export

import { exportVideo } from '@elah/core'

const blob = await exportVideo(engine.getProject(), {
  videoBitrate: 8_000_000,
  onProgress: ({ frame, totalFrames }) => console.log(frame, '/', totalFrames),
})

Links

• Website
• GitHub
• Full SDK — @elah/editor
• License
• Commercial licensing