Hello!

I'm trying to record 4 video streams real time on a mobile platform. The off-the-shelf solution would be to use a couple of Hauppauge PVR500 cards ($150 each), and use a motherboard with 2 PCI slots. However, I was wondering if it would be possible to build a standalone encoder/compression device that would grab the video/audio stream, encode it, and output it in a ~1-2Mbits/s stream via USB (for example) to a small form-factor PC (eg mini-ITX). This would also allow a more modular selection of the number of channels (ie, instead of 2, or 4, I could build as many encoders as necessary).

I could either use an encoding chip (eg CX23416) managed by a 16bit AVR/PIC, or have a Blackfin/ARM/AVR32 do the encoding/compression/streaming.

Any suggestions on how to get this done??

Alex

I don't have any experience with video encoding. But, I don't suspect that it would be too challenging if I had a reason to do so.

The first priority should be to pick an architecture that you are comfortable working with. If you are comfortable programming 32-bit micros or 8-bit AVRs or PICs, great-- pick it as your starting point, so that your supervisory tasks will be straightforward. Whether or not that chip itself can do the processing that you need to should be a secondary consideration.
If you are *not* already comfortable programming a micro, you probably should stick to the off-the-shelf solution and separately get comfortable with microcontrollers on a smaller scale first.

A significant amount of computing horsepower is necessary to perform the tasks that you want to; I do not know whether a single ARM/Blackfin/AVR32 or CX23416 has the speed to do your video processing in real time-- you will have to investigate that as a separate question. Whichever chip you use to do that will either be easy, e.g., a dedicated video chip managed by the supervisor micro, or a heck of a lot of programming if you write it yourself on a 32-bit micro. Again, it really depends most on what you are comfortable doing. (Note: the CX23416 is not obviously available from any of the top 20 electronics distributors; you should make sure you can actually get your hands on some before proceeding down that road.)

One other thing to note: it's not obvious to me that managing several simultaneous 1-2 Mbit/s USB streams is easy; you may want to consider some other interface.