@kitsra/kavio-render

Concrete local render execution for Kavio: browser frame capture plus FFmpeg encoding.

Install

corepack pnpm add @kitsra/kavio-render

Render Binaries

Kavio resolves FFmpeg in this order:

1. The executable file named by KAVIO_FFMPEG_PATH.
2. A system ffmpeg on PATH.
3. The optional ffmpeg-static package.

An invalid KAVIO_FFMPEG_PATH is reported instead of silently selecting a different binary. To run with FFmpeg 8, install it on the host or point KAVIO_FFMPEG_PATH at it; ffmpeg-static is only a compatibility fallback and is not represented as FFmpeg 8.

Call resolveFfmpegDiagnostics() to confirm the exact path, resolution source, and version that Kavio will use. This value can also be recorded alongside render metadata:

import { resolveFfmpegDiagnostics } from "@kitsra/kavio-render";

console.log(await resolveFfmpegDiagnostics());
// { path: "/opt/homebrew/bin/ffmpeg", source: "system", version: "8.0.1" }

@kitsra/kavio-render also declares playwright as an optional dependency. Projects using the ffmpeg-static fallback or browser rendering should provision those binaries after install:

corepack pnpm rebuild ffmpeg-static
corepack pnpm exec playwright install chromium

No dependency upgrade is required for FFmpeg 8 support: the FFmpeg runtime is supplied explicitly by the caller or host, avoiding lockfile churn and avoiding any false claim that the pinned ffmpeg-static package provides FFmpeg 8.

What It Does

• Provides PlaywrightDriver for browser frame capture.
• Supports deterministic custom HTML frame callbacks, used by @kitsra/kavio-react for opt-in component rendering.
• Encodes opaque graphics-only Kavio stage captures as the primary video stream so live browser transitions are not dropped by FFmpeg framesync.
• Resolves FFmpeg binaries.
• Assembles render commands.
• Maps linear full-frame image transition tracks to FFmpeg-direct fade, directional wipe/slide/push, circular iris, clock-wipe, zoom, blur, squeeze, letterbox, and constrained black/white color filters.
• Renders a single composition/export.
• Streams png-sequence captures to deterministic frame-%05d.png files in a new output directory without invoking FFmpeg.
• Expands and renders batch jobs, retaining worker-local Chromium processes across compatible browser-overlay jobs while isolating each job in a fresh browser context and harness.

Links

• Repository: https://github.com/kitsra/kavio
• Rendering docs: https://github.com/kitsra/kavio/blob/main/docs/rendering.md
• Render pipeline docs: https://github.com/kitsra/kavio/blob/main/docs/render-pipeline.md
• License: Elastic-2.0