Ability to know user's cam aspect ratio about webcamjs

[jhuckaby]

Unfortunately I don't know of a native way to do this. There doesn't appear to be an API to get the camera dimensions in either getUserMedia (HTML5) or in Adobe Flash. The best way I've found to deal with this is to always capture in 4:3 aspect ratio, and then crop your desired rectangle/square out of the center of the image after capture (using HTML5 Canvas, or on the server using GD or ImageMagick).

I may add an API to do this for you, in an upcoming version of WebcamJS.

[mfkp]

There's videoHeight and videoWidth attributes on a video element, which you can use to calculate the aspect ratio.

[Krakabek]

mfkp, thanks.
I found, how to do it, but the only problem is that I can't calculate it before I attach the camera and start streaming.

[mfkp]

You might need to start it up, get the video element, calculate the aspect ratio, then do Webcam.reset() and initialize it again with the new values.

Could be a better way to do it, but nothing is coming to mind right now.

[Krakabek]

A bit weird way, but it's the only thing came to my ming too.
For my purpose I've saved videoH and videoW, and after making a snapshot do some math to resize taken image to proportional size
(By the way, about resize() method - Look at the issue #25
There are some troubles and I solved it, but I can't commit changes)

[jhuckaby]

Looks like videoWidth / videoHeight are only available with getUserMedia (Chrome & Firefox only). I don't see a way to do it with the Flash fallback (Safari / IE). For now, I'm going to try my "post-crop" idea, and will continue to look at a universal way to support this. Thanks guys.

[jhuckaby]

Hey guys, I have implemented an automatic "crop" feature which can be used if you want to capture a square image. The idea is, the engine will capture at 4:3 aspect ratio (as 99.99999% of all webcams support that), but then it'll crop a square (or any rectangle shape) out of the center for you, all handled automatically in the background, and reflected in the live preview as well.

Live Demo: http://pixlcore.com/demos/webcamjs/demos/crop.html

[Zireael07]

Live demo shows an error :(