Embedded Video Device

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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.

Re: Embedded Video Device

sounds like two pieces of cardboard would do the trick.

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Re: Embedded Video Device

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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.


Re: Embedded Video Device
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   www.averlogic.com

Philips  www.semiconductors.com

Joseph Goldburg

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Re: Embedded Video Device

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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.


Re: Embedded Video Device

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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.


Re: Embedded Video Device
On Sat, 25 Oct 2003 14:43:41 +1300, "Ralph Mason"

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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.


Re: Embedded Video Device
In a flurry of electrons Chris spake thus:

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

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