Designing an embedded Digital Video Recorder (DVR)

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.