{
  "name": "my-film",
  "private": true,
  "type": "module",
  "allowScripts": {
    "skia-canvas": true,
    "sharp": false,
    "webgpu": false,
    "onnxruntime-node": false,
    "node-av": false,
    "esbuild": false
  },
  "pnpm": {
    "onlyBuiltDependencies": ["skia-canvas"],
    "ignoredBuiltDependencies": ["sharp", "webgpu", "onnxruntime-node", "node-av", "esbuild"]
  },
  "trustedDependencies": ["skia-canvas"]
}

npm install gitframes
npm install --save-dev tsx typescript @types/node

{
  "compilerOptions": {
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "target": "ES2022",
    "strict": true,
    "skipLibCheck": true,
    "noEmit": true,
    "types": ["node"]
  },
  "include": ["src/**/*"]
}

src/
  theme.ts    # canvas size, fps, colors, fonts: the only place for magic numbers
  film.ts     # buildFilm(): assembles the Composition
  render.ts   # renders frames for review, a live preview, or the full video
assets/
  fonts/      # .ttf / .otf files the film uses
output/       # renders (add to .gitignore)

// src/theme.ts
import { FontManager } from "gitframes";

export const W = 1920;
export const H = 1080;
export const FPS = 30;
export const INK = "#0E0D0C";
export const PAPER = "#EEE9E0";
export const SANS = "Inter";

export async function registerFonts(): Promise<void> {
  await FontManager.register({ family: SANS, source: "assets/fonts/Inter.ttf" });
}

// src/film.ts
import { Composition, Layer, LayerAnimation } from "gitframes";
import { FPS, H, INK, PAPER, registerFonts, SANS, W } from "./theme.js";

const DURATION = 3 * FPS; // frames

export async function buildFilm(): Promise<Composition> {
  // Fonts must be registered before any text layer is built.
  await registerFonts();

  const film = new Composition({
    width: W,
    height: H,
    fps: FPS,
    durationMs: (DURATION / FPS) * 1000,
    backgroundColor: INK,
  });

  film.add(
    Layer.text("Hello, gitframes", {
      id: "title",
      position: "absolute",
      x: 0,
      y: H / 2 - 60,
      width: W,
      height: 120,
      fontFamily: SANS,
      fontSize: 96,
      fontWeight: 700,
      fill: PAPER,
      align: "center",
    }).animate(
      LayerAnimation.create()
        .fadeIn(0, 20, "power2.out")
        .fromTo("y", H / 2 - 20, H / 2 - 60, { start: 0, end: 30, ease: "expo.out" }),
    ),
  );

  return film;
}

// src/render.ts
import fs from "node:fs/promises";
import path from "node:path";
import { HeadlessMediaRenderer, startPreview } from "gitframes";
import { buildFilm } from "./film.js";

const OUT = path.resolve(import.meta.dirname, "../output");
const [mode = "video", ...args] = process.argv.slice(2);

if (mode === "preview") {
  // The page runs film.ts itself and renders it with WebGPU in the browser.
  const session = await startPreview({ entry: new URL("./film.ts", import.meta.url), export: "buildFilm" });
  console.log(`Preview at ${session.url}`);
  await session.closed; // until its tab closes or the next preview replaces it
  process.exit(0);
}

const film = await buildFilm();
await fs.mkdir(OUT, { recursive: true });

if (mode === "frames") {
  const renderer = new HeadlessMediaRenderer();
  for (const frame of args.map(Number)) {
    const png = await film.renderFrame({ frame, renderer });
    await fs.writeFile(path.join(OUT, `f${String(frame).padStart(4, "0")}.png`), png);
  }
} else if (mode === "grid") {
  const png = await film.renderFrameGrid({
    frames: args.length ? args.map(Number) : [0, 10, 20, 30, 45, 60, 75, 89],
    columns: 4,
    cellWidth: 480,
    showLabels: true,
  });
  await fs.writeFile(path.join(OUT, "grid.png"), png);
} else {
  const result = await film.renderVideo({
    outputPath: path.join(OUT, "output.mp4"),
    quality: "high",
  });
  await result.cleanup?.();
  console.log(`Exported ${result.filePath}`);
}

// Native GPU and encoder threads keep Node alive; always exit explicitly.
process.exit(0);

"scripts": {
  "typecheck": "tsc --noEmit -p .",
  "frames": "tsx src/render.ts frames",
  "grid": "tsx src/render.ts grid",
  "preview": "tsx src/render.ts preview",
  "render": "tsx src/render.ts"
}