V412 Grabber Hyperion supports the v412 Grabber which is the most common used for grabbing Ambilight signals. This currently does not work with Openelec because it doesnt have the drivers in it. Some users did it on their own. With this built in method there is no need to struggle around with mplayer!

Hardware:

You need a grabber with a special chipset. Known, working grabbers are: mumbi video grabber Dazzle DVR

Not working grabbers are: Logilink

Setup

For normal wheezy you need to plug in your grabber, connect a video signal to it and start Hyperion.

First we try to get a Screenshot from the grabber.

sudo hyperion-v4l2 --width 320 --height 180 --screenshot

The screenshot will be saved in the current directory. It can have green parts or weird quality. Thats no problem, try to get a clean picture. Then open the picture in a graphic editor and measure the black blanks around. Note this for every side.

You can test your setup like this:

sudo hyperion-v4l2 --width 640 --height 480 --screenshot --frame-decimator 2 --size-decimator 8 --crop-left 26 --crop-right 27 --crop-top 20 --crop-bottom 20

To permanently add your Grabber you can do:

	/// Configuration for the embedded V4L2 grabber
	///  * device          : V4L2 Device to use [default="/dev/video0"]
	///  * input           : V4L2 input to use [default=0]
	///  * standard        : Video standard (no-change/PAL/NTSC) [default="no-change"]
	///  * width                : V4L2 width to set [default=-1]
	///  * height               : V4L2 height to set [default=-1]
	///  * frameDecimation      : Frame decimation factor [default=2]
	///  * sizeDecimation       : Size decimation factor [default=8]
	///  * priority             : Hyperion priority channel [default=800]
	///  * mode                 : 3D mode to use 2D/3DSBS/3DTAB (note: no autodetection) [default="2D"]
	///  * cropLeft             : Cropping from the left [default=0]
	///  * cropRight            : Cropping from the right [default=0]
	///  * cropTop              : Cropping from the top [default=0]
	///  * cropBottom           : Cropping from the bottom [default=0]
	///  * redSignalThreshold   : Signal threshold for the red channel between 0.0 and 1.0 [default=0.0]
	///  * greenSignalThreshold : Signal threshold for the green channel between 0.0 and 1.0 [default=0.0]
	///  * blueSignalThreshold  : Signal threshold for the blue channel between 0.0 and 1.0 [default=0.0]
	"grabber-v4l2" :
	{
		"device" : "/dev/video0",
		"input" : 0,
		"standard" : "PAL",
		"width" : 640,
		"height" : 480,
		"frameDecimation" : 2,
		"sizeDecimation" : 8,
		"priority" : 1000,
		"mode" : "2D",
		"cropLeft" : 26,
		"cropRight" : 27,
		"cropTop" : 20,
		"cropBottom" : 20,
		"redSignalThreshold" : 0.1,
		"greenSignalThreshold" : 0.1,
		"blueSignalThreshold" : 0.1
	},

Frame decimation will clean out all green and blury stuff. I dont know exactly how it works, but then every green should be gone. Frame decimation shrinks your grabbed picture to get more fps. These values are default and should suit very well to every grabber.

Some other notes:

Driver info:

-v4l2-ctl --all

Be sure you remove any "framegrabber" section if you want to use the "grabber-v4l2" othewise you may encounter blinking leds.