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Designing an embedded Digital Video Recorder (DVR)

Started by Miem August 12, 2007
Hi,

I wonder if someone tell me how to digitize and save/record composite
color video data (and optionally audio) from a low-cost camera into
compact flash or SD memory without using a PC.

Following URL (http://www.circuitcellar.com/avr2006/winners/
AT3267.htm ) points an interesting AVR based image/video capture
circuit in which designer use an OV528 (www.ovt.com) which is a JPEG
compression chip designed for mobile phones and PDA's. My
understanding is that it requires OVT's digital camera chips.

However I want to be able to digitize/capture composite video signal
from any ordinary video source such as low-cost cameras, VCR, etc.

Do you know also any other circuit which can digitize composite video
signals without needing a PC?

I know I can purchase COTS units like
http://nservices.com/wireless3.htm
http://www.brickhousesecurity.com/memory-card-dvr-video-recorders.html
http://www.startechoutlet.com/product_404_detailed.htm
http://www.pimall.com/nais/ultraminidvr.html
http://www.eyespyli.com/dvr9800.htm

But, I want to learn how to digitize and record composite video (as a
hobby) with an AVR (and/or a PIC) or some other simple
microcontroller.

Thx

Miem

On Aug 12, 5:27 pm, Miem <MiemC...@gmail.com> wrote:
> Hi, > > I wonder if someone tell me how to digitize and save/record composite > color video data (and optionally audio) from a low-cost camera into > compact flash or SD memory without using a PC. > > ... > But, I want to learn how to digitize and record composite video (as a > hobby) with an AVR (and/or a PIC) or some other simple > microcontroller.
Didn't I answere this question somewhere, sometime? You cannot do video capture with PIC/AVR alone. You can do the easy way with a chip like SAA71XX or the hard way with FPGA, flash A2D and local RAM. Of course, you can do the whole thing in a single chip ASIC.
linnix wrote:
> On Aug 12, 5:27 pm, Miem <MiemC...@gmail.com> wrote: > >>Hi, >> >>I wonder if someone tell me how to digitize and save/record composite >>color video data (and optionally audio) from a low-cost camera into >>compact flash or SD memory without using a PC. >> >>... >>But, I want to learn how to digitize and record composite video (as a >>hobby) with an AVR (and/or a PIC) or some other simple >>microcontroller. > > > Didn't I answere this question somewhere, sometime? You cannot do > video capture with PIC/AVR alone. You can do the easy way with a chip > like SAA71XX or the hard way with FPGA, flash A2D and local RAM. Of > course, you can do the whole thing in a single chip ASIC. > >
I think the OP needs to understand what it will take to digitize video. Once he understands that, he will be ready to understand your (linnix) response. Good Luck to Miem, I hope he will take the time to learn something new. donald
Miem wrote:
> I wonder if someone tell me how to digitize and save/record composite > color video data (and optionally audio) from a low-cost camera into > compact flash or SD memory without using a PC.
That depends entirely on where you drawn the line beyond which you call things a "PC". Generally, a system capable of pulling off that job will most likely end up more expensive than your average PC.
> But, I want to learn how to digitize and record composite video (as a > hobby) with an AVR (and/or a PIC) or some other simple > microcontroller.
Let me put it bluntly: no way is that going to work as advertized. The most an AVR or PIC could do for you in such a system is house-keeping and control for several specialized chips that do the actual work. Those controllers are nowhere near fast enough for realtime video processing on their own.