Say Cheese!

A minimal library for integrating webcam snapshots into your app.

Setup

Grab the JS, host it, and add it to your page. For example:

<script src='/assets/js/say-cheese.js'></script>

It also requires jQuery (for events), so make sure to include that before this.

Usage

Say Cheese exposes a minimal, event based API:

var sayCheese = new SayCheese('#element', { snapshots: true });

sayCheese.on('start', function() {
 // do something when started
 this.takeSnapshot();
});

sayCheese.on('error', function(evt, error) {
 // handle errors, such as when a user denies the request to use the webcam,
 // or when the getUserMedia API isn't supported
});

sayCheese.on('snapshot', function(evt, snapshot) {
  // do something with a snapshot canvas element, when taken
});

sayCheese.start();

Taking snapshots

You can take a snapshot at any time after initialisation, by calling takeSnapshot():

sayCheese.on('snapshot', function(evt, snapshot) {
  // do something with the snapshot
});

sayCheese.takeSnapshot();

I don't want snapshots; just give me the video!

No problem. Just disable it when you first create the instance:

var sayCheese = new SayCheese('#container-element', { snapshots: false });

Note that when you do this, takeSnapshot() will not do anything.

Stopping the show

There's also a function to stop the webcam after loading it up:

sayCheese.on('stop', function(evt) {
  // do something when it's stopped
});

sayCheese.stop();

Tests

Some basic tests cover the callback functionality. They were written to be run in a browser that supports the getUserMedia API. Due to the nature of that API, there is no automation for allowing or denying the request, so it has to be done manually for each one.

Compatibility

Tested and verified to work in:

Firefox Nightly and Aurora *§
Google Chrome
Opera

* The webcam functionality itself works in stable Firefox, however a bug in the browser prevents the snapshot feature from working correctly. The fix is now in the Beta channel.

§ Firefox on the stable channel also only supports a smaller webcam resolution, though this has been upped to 640x480 in Aurora and Nightly, to match Chrome and Opera.

Firefox caveats

A bug in the Firefox stable channel prevents the snapshot function from behaving correctly. This has been fixed upstream and, as of 21st November 2012, is now in the Beta channel.
The stable release of Firefox also supports a lower resolution compared to Opera and Chrome. This has been improved in Aurora and Nightly and may hopefully work its way into stable in the next version or two.

License

Copyright (C) 2012 Lee Machin

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

shobhit / say-cheese