web-gphoto2-npm-test

Web-gPhoto2

A gPhoto2 implementation using WebAssembly to control DSLR cameras from the browser.

Powered by a custom fork of libgphoto2, the WebUSB backend of libusb, and WebAssembly via Emscripten.

NPM

Installation

npm install web-gphoto2
// or
yarn add web-gphoto2

Usage

A short example on how to use this package:

import { Camera } from "web-gphoto2";

let camera = new Camera();

async function connectCamera() {
  await camera.showCameraPicker();
  await camera.connect();
}

async function getSupportedOps() {
  const ops = await camera.getSupportedOps();
  console.log("Supported Ops:", ops);
}

async function getCameraConfig() {
  const config = await camera.getConfig();
  console.log("Config:", config);
}

async function updateConfig() {
  await camera.setConfigValue("iso", "800");
}

async function capturePreviewAsBlob() {
  // Capture a frame while in live view mode
  const blob = await camera.capturePreviewAsBlob();
  imageUrl = URL.createObjectURL(blob);
  // Set the imageUrl as the src of an image element in your HTML
}

async function captureImageAsFile() {
  // Capture an image
  const file = await camera.captureImageAsFile();
  imageUrl = URL.createObjectURL(file);
  // Set the imageUrl as the src of an image element in your HTML
}

Demo

This repository also contains a demo app running gPhoto2 on the Web:

For the detailed technical write-up, see the official blog post. To see the demo in action, visit the hosted version here (but make sure to read the cross-platform compatibility notes first).

If you don't have a DSLR, you can check out a recording of the demo below:

https://user-images.githubusercontent.com/557590/152155035-a1664656-a7d9-411f-8cb3-5f04320f1391.mp4

Building

To build, you'll need Docker. Then:

./build.sh # runs build in Docker
npx serve examples/preact # starts a local server with COOP/COEP

Then, navigate to http://localhost:3000/ in Chrome.

Common Issues

SharedArrayBuffer can not be found

SharedArrayBuffer has been disabled across all browsers due to the Spectre vulnerability. This package uses SharedArrayBuffer to communicate with the WebAssembly module. To work around this issue, you need to set two response headers for your document:

Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp

Information from Stackoverflow

Error: Not found: /node_modules/.vite/deps/libapi.wasm

Vite tries to optimize the dependencies by default. This causes the WebAssembly module to be moved to a different location. To prevent this, you need to exclude the web-gphoto2 package from the optimization.

In vite, both of the above mentioned issues are solved by adding the following to your vite.config.js:

import { sveltekit } from "@sveltejs/kit/vite";
import { defineConfig } from "vite";

/** @type {import('vite').Plugin} */
const viteServerConfig = {
  name: "add headers",
  configureServer: (server) => {
    server.middlewares.use((req, res, next) => {
      res.setHeader("Cross-Origin-Opener-Policy", "same-origin");
      res.setHeader("Cross-Origin-Embedder-Policy", "require-corp");
      next();
    });
  },
};

export default defineConfig({
  plugins: [sveltekit(), viteServerConfig],
  optimizeDeps: {
    exclude: ["web-gphoto2"],
  },
});

See also

RReverser/eos-remote-web - my other project for controlling Canon cameras over Web Bluetooth.

License

Like the dependencies, this demo is licensed under LGPL v2.1.