Embedded Video Device

Can someone give me an idea on what it would take to make this...

A simple (?) embedded device that crops video. Basicly it would have a video input and output and would process a matte over the video that would give the output a widescreen look. The matte opening that the video shows through would need to be resizable.

I really have no idea on where to start with this. Help is appreciated.

Reply to
Chris
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sounds like two pieces of cardboard would do the trick.

Reply to
BE

"BE" wrote in news:a5gmb.17034$ snipped-for-privacy@news4.srv.hcvlny.cv.net:

That would work great if I could get to the camera. I'm doing video assist work for film. I want to mimic whatever aspect ratio they are working in. The video would still be 4x3 but the matte would black out the appropriate aspect ratio.

Ideas?

Reply to
Chris

Should be really very simple. Get a sync separator (National LM1881 say), after the vblank keep the signal black for however many lines you want to blank at the top - then switch back to the incoming video count more lines untill you want to start blanking again (for the bottom border).

Job done!

using a simple cpld you could even do move in and out of your borders and other interesting patterns if you felt so inclined.

Ralph

Reply to
Ralph Mason

Philips video decoder --> Averlogic digital FIFO or Dual port RAM -->

Philips Encoder

All controlled buy a simple 80c51 micro.

Philips Decoders SAA711x

Philips Encoders SAA712x

Averlogic dual port RAM

formatting link

Philips

formatting link

Regards Joseph Goldburg

would

shows

Reply to
Joseph Goldburg

There is one nasty bit.

You must let through the horizontal synch and colour burst during the blanked lines, so you also need a horizontal blanking signal. Any processor with a few digital inputs and capable of counting the horizontal pulses every 64 us should be sufficient. One digital output is needed to control the external video switch.

Paul

Reply to
Paul Keinanen

would

shows

Sounds like something that I made to cut a rectangular hole in a video signal. The idea was to put a rectangle over the "DOG" and drop the contrast so that it wouldn't burn into those expensive plasma screens.

It used 3 chips:

1) PIC chip. 2) Horizontal Genlock. 3) Dual monostable.

The horizontal genlock got me the sync pulses, the PIC chip counted lines, and the monostables blanked the hole that you wanted. Hmm, maybe there was a sync separator in there too?

There were four buttons read by the PIC to select the upper and lower limit of lines that you wanted to blank out and two analogue pots to set the horizontal start and width of the hole. A transistor fuzzed up the image in my case but you would want to invert the matte and pull the image down to black instead.

My actual design was lost long ago but it's pretty trivial to do again. If you don't want to get the soldering iron out then a cheap vision mixer would do the job too.

Peter

Reply to
moocowmoo

In a flurry of electrons Chris spake thus:

As others have said...

Sync Seperator = LM1881 or EL1881 or similar Small CPU with H and V sync fed into external interrupts Video Clamp and black inserter = one op-amp and a CMOS analogue switch User interface to CPU = a few LEDs and a couple of buttons.

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Brian Fairchild
B dot Fairchild at Dial dot Pipex dot Com
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Brian Fairchild

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