07-14-2012 11:11 AM
I will try not to be unnecessarily long winded, but here is what I'm trying to accomplish:
My Project: Build a circuit that will capture a digital camera's NTSC video signal via a 8-10 bit NTSC decoder with a clocked output at 27MHz. Store this raw video data in memory (1-2GB DDR/2/3 or whatever) and after a certain amount of time has passed (the delay), encode the video data stored in memory back to NTSC and send it back out to a television.
This is basically a NTSC video delay system that needs to delay the signal for 60-120 seconds.
[NTSC VIDEO IN] >> NTSC Decoder >> FPGA >> MEMORY
MEMORY >> FPGA >> NTSC Encoder >> [NTSC VIDEO OUT]
My Problem: I currently have no FPGA development hardware and am doing this project for fun. I don't mind spending a bit of money on the more inexpensive dev kits ($100-$300), but really don't want to spend a lot more than that if I don't need to.
1. Are there any dev kits out there that will allow me to get something like this running? I understand that the dev kits are not likely to have 1-2GBs of memory and that's fine. I can work with a much smaller amount of memory (and video delay) if necessary until I have a better understanding of how everything works together. Then I will begin working on a custom design.
2. What is the appropriate device for a project like this? Even if it's considered a legacy device, I'm fine with that. I don't want to get something unnecessarily expensive with all the bells and whistles if I am not going to need all those bells and whistles. I want to get something sufficient with some performance/spec buffer for unexpected design considerations.
3. Is there something I'm missing or not considering? Any feedback will help.
The primary goal of this project for me is to learn. I have allotted a fair amount of time to complete it since it is such a big undertaking considering my experience with many of the things above (NTSC, FPGAs, Memory, etc.) ...which is minimal.
07-14-2012 11:59 AM
3. Is there something I'm missing or not considering?
NTSC Video is on its way out. And with it, most of the popular video decoder chips
like the SAA711x series have become obsolete. A quick check at DigiKey turned
up no in-stock video decoders for NTSC. So unless you already have your video
decoder chips, you may want to look around for what's still available before designing
07-14-2012 12:06 PM
Am I missing something?
07-14-2012 12:37 PM
No - I'm having a bad search day :-) I was looking under Video processing IC's.
The TI TVP5150AM1 is a good part. I've used it. It's not quite as easy to set up as
the old Philips SAA711x parts, though. i.e. it doesn't come up in a reasonable
state where it can just capture video. You need to program some registers first.
I think your best bet is to look for a kit with plenty of external SDRAM. The bandwidth
for NTSC is low enough that you don't need to be concerned about the width or
frequency of the attached memory. Spartan 3A or 3E is fast and big enough to
do what you need. Spartan 6 would be a good choice except for the single-chip
limit on its built-in memory controller. Any Virtex part is good, but pricey unless you
can find a University version. If you don't see what you want at Avnet or Digilent,
you could also look into Enterpoint for more options.