Install the package and ffmpeg, encode your first file, and preview the result.
Install
Requires Node 18.17+ or Bun and ffmpeg/ffprobe on the encoding machine. Install sharp only for image previews and the AWS SDK only for S3/R2.
Bash
npm install seamtranscode
brew install ffmpeg
# Debian / Ubuntu: sudo apt-get install ffmpegEncode and preview
The CLI writes HLS and seamtranscode.json. Preview binds to localhost and loads seamplayer from a CDN, so it needs internet. Progress goes to stderr; --json prints the result to stdout.
Bash
npx seamtranscode film.mp4 -o ./film
npx seamtranscode preview ./film
npx seamtranscode film.mp4 --renditions 360,720 --no-scrub --json
npx seamtranscode --helpImages and previews only
Video previews work with ffmpeg. Image and SVG previews need sharp. EXIF orientation and transparency are preserved; external SVG resources are rejected.
TypeScript
import { previews } from "seamtranscode";
await previews({ input: "film.mp4", output: "out/previews" });