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sheesh-kebab

software-based diversity receiver?

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Anyone know of any software that would perform functions similar to the diverisity video receiver?

I know blacwidowav.com sells a hardware solution - "Diversity 2.4 Receiver" - but I thought that technically it should be possible to hookup a couple of vanilla video receivers to a laptop in the field (via say 2 PCMCIA TV cards) and achieve a cleaner picture using some form of software video muxer. Then the clean picture could be fed via s-video/composite video out to VR goggles or recorded directly on the laptop.

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With a PC-based solution the main problem is that you usually will have a delay in the processing line. Also, the lack of RSSI signal used in a hardware solution would mean complex image processing to determine which one is the best.

Keep in mind that real-time image processing uses a lot of computing power. Recording one stream in decent quality MPEG-2 used ~80% of processor power on my 1.5GHz centrino. You'd need a brand new dual core hardware to handle 2 recordings, not speaking of the image processing yet.

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well, MPEG video encoding/compression is definitely something that is very resource intensive. However, I'm not really sure whether the performance hit would be that dramatic if the video "clean-up" happened on the raw audio/video input, with the follow on direct "pass through" to playback, bypassing MPEG all together..

I wonder whether there is any software capable of doing something like this to try it out...

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I have never heard of software to do what you want and personally I like to keep computers out of the link as much as possible. It makes much more sense to do the job directly and keep wires and therefor potetial problems to a minimum. Why run a large computer with complicated software if it can be done with a few lines on a PIC ?

Terry

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being a software engineer, to me it's actually simpler to handle computer based stuff than dealing with custom electronic modules and equipment.

Plus I think it might be not such a bad idea anyway since (theoretically I guess) one could build up a very low cost n-diversity receiver limited only by the power of cpu on a laptop and the bandwidth of the input/output bus. Not too mention that anyone else who has a laptop and basic computer skills (most of the folks currently) could do the same...

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OK, well thats the great thing about this hobby, you can try anything you believe will work. You may well be on to something who knows, I will be interested in your results if you try it. Its good to hear other peoples opinions, it helps us keep an open mind.

Terry

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It can be done, you just need a device to convert the RSSI into usable data that the computer can compare. A uC with rs232 interface and a com port enabled PC and you should be able to figure out the rest.

So, you still need some hardware. And then you'd need 2 or more video capture cards.

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Or get one of those multi-input capture cards that are made for security recording. Some have 4, 8 or even 16 video inputs and do all the encoding by hardware up to a few hundred frames per second.

But here's the problem: hardware encoders usually use buffers, thus introduce a delay. For FPV flight you couldn't allow more than 2 frames lag.

Edited by Kilrah

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yeah, something like that - I found some el cheapo ($99) Adaptec dual channel pvr box (http://www.buy.com/retail/product.asp?sku=201962145&loc=101&sp=1)

- it has 2 A/V inputs, hardware encoding and USB2.0 interface. The thing to try now is to find/write a filter program that would merge 2 feeds and either play the merged feed back and/or record it...

If not for VR flying, this thing could be used for recording higher quality videos...

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If you just want higher quality videos then you can use a micro recorder on board, no dropouts !

I you just want to try it to see if it can work thats another matter. ;)

Terry

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