Video Multiplier

Hallicks

I'm doing a project that uses the propeller to generate a·strap of video over the lower third of the screen. I have a GT4123A video multiplier and an LM1881 sync separator.·My external video source comes from a PAL test signal generator.· I have a feeling it's quite similar in nature to Bean's Video Overlay which is in the object exchange.· I can see how the syncs are taken in by the propeller, but I'm really struggling to tell what the propeller to do with this information.·I'll need to count the syncs (I swear I saw a basic counter in the object exchange, now I can't find it), then I'll need to generate video for a certain number of lines.

Sadly despite going through the tutorial, I'm still a total novice with the programming. If anyone could help or guide me, I'd be eternally grateful. Thanks

Hallicks

Mike Green

Video generation is one of the most demanding tasks the Propeller does because of the timing constraints involved. I don't recommend starting with that as a novice. If you must, start with Bean's video overlay program since that's very close to what you want to do and modify that. If you can't at least understand what he's doing, you are not likely to be able to do something similar.

There's a pretty good application note on the cog counters (AN001) in the Downloads section of the main Propeller web page. Also have a look at the tutorials developed for the Propeller Education Kit. (www.parallax.com/propeller/downloads.asp)