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talonsoalbi · 2015-05-26, 20:30

Hi All,

Many of us use Kodi with a projector on a 2m screen. I've been thinking about constructing an ambilight system but it is a little mess with such large screen size. I wonder if it is technically possible to add an ambilight video mode (in addition to the 2d and 3d video modes) that would play a movie with the image scaled down a little bit (some configurable fraction of the screen), and using the generated borders to apply the ambilight effect without any third party tool.

Its just an idea, I assume there are other priorities in this great project.
Regards

**Memphiz** · 2015-05-26, 20:42

Could you rephrase or clarify your request? I don't understand really. Thats what the boblight addon is ment to be used for imo.

talonsoalbi · 2015-05-26, 21:13

Sorry. If I'm right boblight is an external program and the kodi addon uses it to control the leds of an ambilight system. What I mean is to use only kodi with no leds or external programs, simply by scaling down the video (which is already possible) and 'decorating' the resulting borders of the screen around the video with the adequate colors, instead of sending them as commands to boblight. I suppose the effect will not be the same, but close.

**Memphiz** · 2015-05-27, 11:36

I still miss the key fact here. If you don't use leds. What do you do to show the border colors then instead?

**da-anda** · (This post was last modified: 2015-05-27, 11:46 by da-anda.)

he want's the main movie scaled down and the resulting empty space of the screen filled with colour in an ambilight way, so that he can make his projector not only cover the canvas but go beyond, while the main movie will still be limited (scaled down) to the canvas size.

**Memphiz** · (This post was last modified: 2015-05-27, 13:33 by Memphiz.)

ahh ok. Sounds like this is not easily doable (because the whole rendering assumes that the canvas is where we want to see the movie. There is no inner and outer border or something strange like that). Also this would involve "drawing" on the texture while normal video playback just uploads a frame/image and binds it to a texture.

All in all a nice idea for a very limited userbase and only 2 or 3 people in our team which would have the skills to accomplish it i think.

~~Ned Scott~~ · 2015-05-27, 20:02

Could be neat for projection systems, but yeah, sounds like a lot of work.

**sualfred** · 2015-05-28, 13:18

One of the main ideas of ambilight is to visually "extend" the screen. I don't really see a logical scenario to scale down the screen just to extend it again with a "blurry border" O_o

I still would prefer adding LEDs behind the white screen, it looks incredible:

**da-anda** · 2015-05-28, 14:19

@sualfred - he would adjust the projector to extend the canvas while having the scaled down UI fill the entire canvas

**sualfred** · 2015-05-28, 14:20

Ah now I get it. Sry, missunderstood the request.

talonsoalbi · 2015-05-28, 16:16

Thanks to all for your relatively good reception of the idea. I have done a little experiment implementing it. You can find some images at

http://conga.oan.es/~alonso/ambilightExperiment/

I include the code in Java for the program. It uses an external library I have for all things, but I think you can follow the idea easily. One advantage is that I can create a custom black border to separate the outer lights from the video itself, and even add some 'resolution' to the borders so that they are not just lights, but includes some structure. In this case by fliping the borders adequately I can simulation some kind of 'mirror effect' quite visible in the right corner of image 2 (green color). It is not perfect, specially the corners, but seems just fine for a start.

In another time I will do a real test with a movie and I will post the video to the same url. I expect the effect to be good enough in a projector since the screen is partially reflective compared to a LCD monitor.

omriamos · 2015-05-28, 18:18

(2015-05-28, 13:18)sualfred Wrote: One of the main ideas of ambilight is to visually "extend" the screen. I don't really see a logical scenario to scale down the screen just to extend it again with a "blurry border" O_o

I still would prefer adding LEDs behind the white screen, it looks incredible:

OMG THIS IS SO COOL !!

talonsoalbi · 2015-06-07, 13:00

I have uppload two example videos to http://conga.oan.es/~alonso/ambilightExperiment/. The result is quite nice for a first test, although I can say nothing about how it compares with an ambilight system consisting on leds. The effect is based on the Java program I mentioned above, which can obviously be improved since in some cases there is too much 'white' light in the borders.