Just like title says its using the methods in Microsoft.Phone.Media.Extended to access the raw camera feed and process some augmented reality markers. FYI, the video sucks. I took longer to record this than I did to get everything working. It does actually work much better when Im not trying to line up a web cam filming a phone showing video of a piece of paper in front of a monitor.
Thanx to this thread, @ChrisWalshie and the SLARToolkit for doing 97.5% of the work. I tried invoking the non-public and native dlls awhile back but who knew you needed this empty WPInteropManifest.xml file? After seeing Chriss tweets it gave me some motivation to try getting the camera and compass to work. Ideally this would be accessible to everyone somewhere between now and really soon. Sometimes I think Microsoft doesnt want developers to have fun on this platform.
And why does LG get access to this, but no one else does officially? Raw camera access and the compass are two of the 4-5*things you need to make some awesome phone apps like video chat, Facebook augmented reality view of places/friends, shiba inu mobile puppy cams, etc. Instead all we get is LG Scan Search? Come on now, thats ridiculous. LG should be on double secret app certification probation until they can build a phone that goes over 50fps** and renders colors within several shades of the hex values you specify.
Seriously, everyone needs to write a letter to their local Microsoft representative and demand some access to all he cool APIs blocked for 3rd party apps. That or whine about it on Twitter.
*coffee and cigarettes are right up there in the top 3
**For real. Check it yourself. No way you will ever hit 60fps like windows phones are supposed to on a LG unless you solder on another GPU.