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TV Video Overlay circuitry?

I need to produce a simple, very low cost product which is a TV set-top box to be connected inline with the TV signal cable that will generate simple preprogrammed animated overlays. The TV program image will not be affected, just overlaid.

I have Googled this but only find add-on graphics cards for PCs which cost several hundred dollars. I need something which can be mass produced cheaply.

Could this be manufactured cheaply (say under $10-$20)? What kind of circuitry/chips would I need? How do I program the animations? Where can I find out about this?

Could someone please point me in the right direction?

Thanks in advance.

Mitch

Reply to
mitch
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Hugely many thanks for your replies. As you can see, my knowledge in this area is minimal.

I don't intend to attempt this project myself, although I may program the animations if its not too tricky.

At this stage I'm simply trying to find out if its possible and what sort of costs might be involved, both for product development and manufactured unit cost.

Ideally I want this to work with broadcast TV anywhere in the developed world, but I recognise that the product would probably have to be made in market-specific (NTSC / PAL) versions. And then there's digital TV which presumably is different again?

The animations will be amorphous shapes, not text.

I was hoping to be able to use the antenna connector as it seems the simplest for the consumer to connect. My VCR/DVD recorder has the antenna cable going into it, and then coming out to the TV. I envisage a similar arrangement with my product receiving the cable from a VCR/DVD and then coming out to the TV. This presumably would then allow my product to work with live TV broadcasts as well as recorded material?

What unit costs might an RF receiver & re-modulator be in production? I have absolutely no idea?

Thanks

Mitch

Reply to
mitch

Which type of signal ? ( see below )

First off you need to determine if the set-top box is doing the overlay to an RF signal or simply a video signal. Or indeed demodulating a RF signal and supplying a video signal to the TV set.

There's 3 common ways to get a picture signal into a TV set.

  1. RF signal ( using an aerial / antenna connector )
  2. Composite video ( usually on an RCA jack )
  3. RGB input ( in Europe this would be on a SCART connector - dunno about USA - the mini-DIN 'SVHS connector' also does RGB )

All of these possibilites require differerent levels of complexity. RF in / out requires an RF receiver and re-modulator for example where as the other

2 don't.

If you need to ask these questions I seriously hope you don't plan to attempt the project yourself.

Graham

Reply to
Pooh Bear

Google for 'OSD' or On Screen Display, Character Generator and Genlock. These chips are usually used for Closed Captioning or Videotext, so they are limited to rendering text and simple block graphics, sometimes in color. The communications standard is serial protocol via i2c bus.

There are also projects out there using PIC's to generate video images. Using this technique for overlays would be possible, too. Google for "pic-pong".

Reply to
Matthias Melcher

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