stream-display  !License

A tiny Typescript wrapper around Screen Capture API getDisplayMedia that sends screen video feed as ImageData to your desired callback.

Installation

$3

``bash
npm install stream-display
`

and then

`javascript
import StreamDisplay from 'stream-display';
`

$3

You can take the dist/stream-display.js file or use a service like unpkg. Example:

`html


`

Usage

`javascript
const processImageData = imageData => {...};
const stream = new StreamDisplay(processImageData);

stream.startCapture();
// ...
stream.stopCapture();
`

$3

`javascript
new StreamDisplay(callback, options = {});
`

#### Arguments

- callback: (image: ImageData) => any - A function that takes one argument — image data from the screen capture feed
- options (optional) — a configuration object, currently can have only one option:
- scanInterval: number (ms) — interval between every callback invocation. Default value — 1000 . NB: when your tab enters background — most browsers will cap the setInterval at 1000ms maximum. Setting this value lower will not have any effect.

$3

`javascript
await stream.startCapture();
//...
stream.stopCapture();
`

startCapture() will trigger the screen capture modal and as soon as user accepts — start sending the ImageData. On error will return a rejected Promise with the error. A list of possible exceptions can be found on MDN.

stopCapture() — ends the capture session

$3

`JavaScript
stream.isCapturing // => boolean
`

Tests

This library is using tape as a test runner. Tests themselves are also written in typescript and launched using ts-node.

To run the tests simpy launch

`bash
npm run test
`

If you want to debug the tests, you can use the following configuration (VSCode):

`json
{
"type": "node",
"request": "launch",
"name": "Launch Program",
"args": [
"${workspaceRoot}/tests/StreamDisplay.test.ts"
],
"runtimeArgs": [
"-r",
"ts-node/register"
],
"cwd": "${workspaceRoot}",
"protocol": "inspector",
"internalConsoleOptions": "openOnSessionStart",
"env": {
"TS_NODE_IGNORE": "false"
}
}
`

Building

To build the library locally you need to

`bash
npm install
npm run build
`

A fresh build will be waiting for you in the /dist` folder.