I'm working on a project that ultimately needs to incorporate an analog video camera input, digitizing it and spitting it out a USB port as an MPEG stream. My general aim is for roughly a VGA resolution, so it's not super demanding in those terms.

While I've been digging quite a lot, I'm having a tough time finding ICs or example circuits that aren't either overkill or more focused on frame grabs rather than real-time streams.

Overkill examples are the enormous line of TI products that are aimed at home A/V receivers with multiple HDMI IO, for example.

I want this to essentially be a stand-alone module, but the larger project has a microcontroller and other elements that make me lean away from any SOC or FPGA or Linux-on-OMAP etc solutions, in favor of what I hope and would think could be a simpler circuit.

Can anyone here point me in the right direction? Or give me an appropriate kick-in-the-head, if I'm running off half-cocked in my thinking so far?

BTW - there is one cool, albeit dated design that I found here Homebrew digitizer: http://www.techmind.org/vd/vidmk2.html

  • \$\begingroup\$ Since I'm not really getting any feedback on this question - I'll update where things are and see if anyone can help me out... \$\endgroup\$ – ejoso Nov 2 '11 at 3:53
  • \$\begingroup\$ I'm going to try the TI ADS825e which is a CMOS ADC that spits out parallel 10bit signal at 40MHz. I'll use a TI SN74HC166AIDRQ1 PISO shift register to serialize my data stream, and will push that into a microcontroller (which I've not yet identified exactly.) I'm hoping I can push the serial input through the micro and out the USB of the microcontroller. \$\endgroup\$ – ejoso Nov 2 '11 at 3:58
  • \$\begingroup\$ I'd still love feedback though, if anyone here has any for me ;-) Thanks in advance! \$\endgroup\$ – ejoso Nov 2 '11 at 3:58
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    \$\begingroup\$ It turns out that doing stable NTSC recovery is a bit tricky; also decoding the phase-modulated color data will be non-trivial. Usually this is done in an ASIC, with or without the MPEG. I believe NTSC to USB (at least the version without the MPEG) is available off the shelf, connectorized, for about $40. Which really raises the question - do you want to get buried in a DIY effort for this particular sub-project, or do you want to solve the overall problem of which this is a part? \$\endgroup\$ – Chris Stratton Dec 8 '11 at 21:27
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    \$\begingroup\$ If you want to do it for the learning experience, you might learn a whole lot if you go the GnuRadio approach - the 10bit at 40MHz is enough to stick into USB 2.0 High Speed, with a microcontroller that can support it, you can get the PC to deal with stable NTSC recovery, phase demodulation etc.. a good winter project to learn about software defined radio :) \$\endgroup\$ – qdot Dec 18 '11 at 17:40

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