@webcam/core

📸 Webcam Core

Ultimate tool for working with media stream

References

• Demo
• Web API
• Browser Сompatibility

Installation

Install with npm or yarn

npm i @webcam/core

# or
yarn add @webcam/core

🦉 Philosophy

📸 Webcam Core is a package that includes ready-made solutions for common cases of setting up and using a media stream from your webcam using Web API. Our goal is to create simple and flexible tools that allow users to create, test and maintain their products.

Features

• TypeScript support out of the box - full typed package
• Webcam Snapshots - creating an image from a video stream
• Media Stream Handling - request, errors, update, stop, etc
• Advanced Video Settings - selecting camera type and resolution
• Legacy API Support - outdated implementations for each browser

Usage

import {
  applyMediaStreamConstraints,
  getMediaStream,
  getMediaStreamConstraints,
  stopMediaStream
} from '@webcam/core';

let runningStream: MediaStream | undefined;

const requestStream = async (params: GetMediaStreamConstraintsParams) => {
  try {
    runningStream = await getMediaStream(params, 5000);
  } catch (error) {
    console.error(error);
  }
};

const updateConstraints = async (params: GetMediaStreamConstraintsParams) => {
  try {
    const constraints = await getMediaStreamConstraints(params);

    applyMediaStreamConstraints(runningStream, constraints)
  } catch {
    requestMediaStream(params);
  }
};

const stopStream = () => stopMediaStream(runningStream);

requestStream({ mainCamera: true }, { width: 1920, height: 1080 });

API

getUserMedia

Adds extra error handling and support for legacy getUserMedia implementation.

NOTE: The function can only be used in a secure context. For example, when a page is loaded using HTTPS or a page loaded from localhost. Otherwise the function will throw an error.

getMediaStream

Accepts custom parameters and uses getUserMedia to get an instance of the MediaStream.

• params?: {GetMediaStreamConstraintsParams} - Parameters passed to getMediaStreamConstraints function
• timeLimitMs?: {number} - Time limit for MediaStream request execution

getMediaStreamConstraints

Generates and returns media stream constraints by passed options.

• constraints?: {MediaStreamConstraints} - External primary constraints (override output)
• options?: {MediaTrackConstraintsOptions} - Options for constraints generating
  • muted?: {boolean} - Excludes audio constraints from the MediaStream request
  • ... {VideoTrackConstraintsOptions} - Options passed to getVideoTrackConstraints function

getVideoTrackConstraints

Generates and returns video track constraints by passed options.

• frontCamera? {boolean} - Should use a front camera (MediaTrackConstraints['facingFront'] === 'user')
• mainCamera? {boolean | GetMainCameraParams} - Should find and use the main camera by default/passed label patterns
• cameraResolutionType? {CameraResolutionType} - Video track resolution size (width x height)
  • HD - 1280 x 720
  • FHD - 1920 x 1080
  • QHD - 2560 x 1440
  • UHD - 3840 x 2160
• cameraResolutionMode? {keyof ConstrainULongRange} - Video track resolution mode
  • min - Value is the smallest permissible. If the value cannot remain equal to or greater than this value, matching will fail.
  • max - Value is the largest permissible. If the value cannot remain equal to or less than this value, matching will fail.
  • exact - Value is specific and required. If the value cannot be considered acceptable, the match will fail.
  • ideal - If possible, a value will be used, but if it's not possible, the user agent will use the closest possible match.

getMainCamera

Returns main camera info in accordance with the default or passed parameters.

NOTE: Requires browser support for Navigator.MediaDevices.enumerateDevices to work.

• params? {GetMainCameraParams} - Pattern for searching the main camera device info by its label
  • {RegExp} - General default pattern
  • {Object} - Patterns for front and main cameras
    • back? {RegExp} - Value (?=.*\bback\b)(?=.*\b0\b) is using as default
    • front? {RegExp} - Value \bfront\b is using as default
• isFrontCamera? {boolean} - Should the front camera be searched (back camera as default)

applyMediaStreamConstraints

Applies a set of audio and video constraints to the corresponding media stream tracks.

NOTE: New constraints apply only within the previously used source.

• stream {MediaStream} - Media stream instance
• constraints {MediaStreamConstraints} - Constraints to be applied

stopMediaStream

Stops and removes audio and video tracks from the stream.

• stream? {MediaStream | MediaStreamTrack} - Media stream or its track instance

hasGetUserMedia

Checks for the presence of getUserMedia in mediaDevices.

canGetUserMedia

Checks the possibility of using any implementation of getUserMedia.

getWebcamSnapshot

Returns a base64 encoded string of the current video stream frame in the specified format and quality.

• source {HTMLVideoElement} - Video element instance with provided media stream
• options? {GetWebcamSnapshotOptions} - Options for getting webcam snapshot
  • format? - {image/webp | image/png | image/jpeg} - A string indicating the image format (default === image/jpeg)
  • quality? - {number} - A number between 0 and 1 indicating the image quality (only for image/jpeg or image/webp)
  • ... {GetVideoFrameCanvasOptions} - Options passed to getVideoFrameCanvas function

getVideoFrameCanvas

Returns a canvas with a drawn image of the current video stream frame in accordance with the passed options.

• source {HTMLVideoElement} - Video element instance with provided media stream
• options? {GetVideoFrameCanvasOptions} - Options for getting video frame canvas
  • width? {number} - Width of the canvas on which the image will be drawn
  • height? {number} - Height of the canvas on which the image will be drawn
  • mirrored? {boolean} - Should the drawing image be mirrored horizontally
  • imageSmoothingEnabled? {boolean} - Should smooth scaled image or not (default === true)

✨ Contributors

🌶️ michael-mir

🧊 debabin

🐘 RiceWithMeat