rvfc-legacy-polyfill

Legacy HTMLVideoElement.requestVideoFrameCallback polyfill using requestAnimationFrame + video.currentTime.

What it does

• Adds requestVideoFrameCallback / cancelVideoFrameCallback only if the browser does not provide native RVFC.
• Uses frame counters when available (getVideoPlaybackQuality, webkitDecodedFrameCount, mozPresentedFrames/mozPaintedFrames) to detect new presented frames more reliably.
• Falls back to currentTime changes when counters are not available.
• Reports mediaTime as video.currentTime (no RAF-based drift correction).

Install

npm i rvfc-legacy-polyfill

Usage

Import once at startup (side-effect import):

import "rvfc-legacy-polyfill";

Or in CommonJS:

require("rvfc-legacy-polyfill");

Notes / Accuracy

This polyfill runs on requestAnimationFrame, so timestamps are window-framerate-bound and not decoder-accurate. It may:

• introduce jitter,
• miss frames when video FPS > display FPS,
• report renderer-aligned timestamps (not true decode timestamps).

Compatibility

This package ships as plain JS (no build step). If your target browser requires transpilation/polyfills, your app/bundler must provide them.

License

Apache-2.0