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Topic: Help coming up with Anti-BLUESCREEN device (Read 4 times) previous topic - next topic

Grumpy_Mike

If you don't use the idea of switching video sources you need to syncronise the blank video source with the real video source. That is the sync pulses must be exactly in phase. This is a difficult thing to do and impossible on an arduino because these pulses must remain in phase even when the signal that syncronised them is gone. This would involve a complex phase locked loop and is not something that could be simply described in a forum post. It would be quite an involved design. Google the term genlock this reffers to a circuit that locks video sources together but requires your video source to be able to accept a syncronising oscillator input.
What form is this video in? Composite or RGBS or som other form. This is important for any solution.

MatCat

I can't take not possible as an answer because there are devices that already do so, granted they are processing the video before output and if that is how it can be done then there must be a way to do it!

funkyguy4000

He didn't say it was flat out impossible.  I said it was impossible on the arduino.  The other platforms probably aren't using the arduino as the brains. 



What form is this video in? Composite or RGBS or som other form. This is important for any solution.
Accelerate to 88 miles per hour.

kg4wsv

#18
Sep 20, 2012, 04:55 pm Last Edit: Sep 20, 2012, 04:57 pm by kg4wsv Reason: 1
The MAX7456 video overlay IC can generate a sync signal - I've used it as a display driver, with no input at all.  It has some modes for detecting sync in the input, too. Of course, it's for NTSC/PAL, not sure what resolution you are using.

As others have pointed out, it won't magically make a weak signal appear.  Sounds like you need better gain at the receive station; maybe an amplifier or directional antenna.

-j

Docedison

The problem with Genlock is that it requires the original information's synch signal and there is no (to the best of my knowledge as I date from the tube and early non digital systems information contained withing a video line to regenerate the synch information when it is lost and the data it was encoded with unless you can store a lot of lines of video or count them to try and detirmine the frame synch that way, either way it does exceed the limitations of this forum because of the nature of the task and it's inherent complexity... IMO

Doc
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