2 replies to this topic

[Dean]

Available antilogo plugin overlays a black rectangle over the logo. I am wondering about the possibility of writing a plugin similar to virtualdub's and ffdshow's logoaway filter that will mask the logo with surrounding pixels (similar to spot removal tool in image editors). The purpose of this would be to avoid image retention and burn-in on TVs that are susceptible to it.

 

Take a look at this video:

 

 

In Windows this works perfectly even on live television thanks to ffdshow's directx logoaway filter which does the same thing. It works in any player or DVB program that uses directshow filters (pretty much all of them).

 

Since I have never programmed for dreambox before I am wondering about the following:

 

1) Would it even be possible to write a plugin like this? Are there functions in the plugin API that can inspect individual pixels and draw over them on a frame by frame basis efficiently (preferably after deinterlacing and other image processing was done)?

2) Is processing power of 400Mhz dreambox sufficient to do this for live HD TV without frame drops while making it look as good as it does in the youtube video above? For SD?

 

If processing power is currently insufficient but API makes it possible algorithm could be simplified. It does not have to look as good as in the video above to be functional.

 

For example one could overlay entire row of the logo or entire logo with a single color (the average color of the N pixels surrounding the logo). This would be sufficient for starters and would serve the purpose of the plugin. As long as the color of the rectangle constantly changes with the video image retention will be avoided.

 

What are your thoughts? Any input is appreciated.

Edited by Dean, 21 December 2015 - 12:20.

[malakudi]

Not possible, video decoding is done in hardware and the resulting frames are not accessible AFAIK. You can grab the framebuffer, but not realtime, maybe 1-2 frames per second at maximum. However you cannot modify the output frames, you can only overlay images on top of them - and that's how the plugin you mention is doing it.

Edited by malakudi, 21 December 2015 - 20:43.

[Dean]

Hi malakudi,

 

Not possible, video decoding is done in hardware and the resulting frames are not accessible AFAIK. You can grab the framebuffer, but not realtime, maybe 1-2 frames per second at maximum.

 

I did more research since asking the question and there seems to be a way to capture current frame far faster than just 2 times per second. Enigmalight plugin looks extremely smooth.

 

 

https://github.com/S...985/enigmalight

 

Relevant code (or part of it at least) is in here.

 

https://github.com/S...ild/src/Grabber

 

From what it says on their site they have taken code from aiograb and then likely improved it.

  

However you cannot modify the output frames, you can only overlay images on top of them - and that's how the plugin you mention is doing it.

 

How many times per second can I update overlay image?