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Possible Solution to the Multiple Camera Problem
Posted: 01 December 2008 09:33 AM   [ Ignore ]
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After an Epic Googling session last night, I came across this…

http://www.medialooks.com/products/directshow_filters/videomixer.html

Its a DirectShow Filter that effectively allows you to stitch multiple webcams together and even lets you do perspective correction on each webcam individually. Its not free, but there is a free demo and it looks like it only has a demo warning scrolling across the bottom of the final output which shouldn’t be too much of a problem if we can tell our blob tracker code to ignore the bottom part of the image.

I bought a second PS3 eye today and I will be testing it out when I get home, I will post some images of my results.

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Posted: 01 December 2008 11:10 AM   [ Ignore ]   [ # 1 ]
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Sounds Great! Only problem I could see is if you were running too many USB cameras that you would be running too much data through your USB host controller and it would barf. But as long as you kept it to less than 5 (fairly random number) I think you would be fine. Do you have any idea what kind of processor overhead it takes to run this directshow filter?

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Posted: 01 December 2008 11:56 AM   [ Ignore ]   [ # 2 ]
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I’m going to be testing it with 2 PS3 Eyes @ 640x480 60FPS. I will let you know how I get on tonight. smile

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Posted: 01 December 2008 12:21 PM   [ Ignore ]   [ # 3 ]
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why would mutiple cameras be necassary?

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Posted: 01 December 2008 12:36 PM   [ Ignore ]   [ # 4 ]
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Because I’m using a short throw projector and a single camera cant see the whole image, also the projector is in the way, so I’m using 2 angled webcams, one from each side.

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Posted: 01 December 2008 02:29 PM   [ Ignore ]   [ # 5 ]
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can’t wait to read your results for this so awaited solution !

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Posted: 01 December 2008 02:51 PM   [ Ignore ]   [ # 6 ]
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Ok guys, Ive hit a bit of a snag, I cant seem to use 2 PS3 eyes with Alex’s DirectShow Filter and it also only lets me use 30 fps, im not sure if this is a restriction in the PS3 eye filter of the VideoMixer filter. I’m going to keep trying to get both cams working, I will let you guys know if I get it to work.

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Posted: 01 December 2008 02:59 PM   [ Ignore ]   [ # 7 ]
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Pleh, one thing I saw Alex mention before is that you’re probably not going to be able to run more than one ps3 cam on the same usb controller at high framerates. One ps3 cam alone is taking most of the bandwidth the controller needs to run it. So running two ps3 cams at @ 60fps at the higher res doesn’t seem like it’ll work.

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Posted: 01 December 2008 03:17 PM   [ Ignore ]   [ # 8 ]
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It should work if I use 2 USB Controllers tho shouldn’t it?

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Posted: 01 December 2008 10:37 PM   [ Ignore ]   [ # 9 ]
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Maybe. If you wanna check; http://duartes.org/gustavo/blog/post/what-your-computer-does-while-you-wait that will show you the amount of bandwidth you can push through stuff. I think that at 60 FPS the sony PS3 eye cam uses about 30-60 MB/s so its gonna soak up most of the USB data-rate right there.

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Posted: 02 December 2008 05:45 AM   [ Ignore ]   [ # 10 ]
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Just found another filter that may work faster and there is a free version…

http://www.roguestream.com/3D_video_mixer_filter.html

Still having problems using 2 PS3 Eyes at once tho, I’m going to try the other drivers tonight, but I hear they aren’t as fast as Alex’s ones. It looks like Alex’s PS3 Eye SDK doesn’t support multiple came either, so it may be a driver limitation rather than a directshow filter limitation :(

*EDIT*
Just tested the RogueStream one and it seems alot faster and easier to use. If I ever get both eyes working this is the filter I will probably end up using.

*EDIT2*
Just tried the other drivers, they let you use more than one cam, but are capped at 30fps and are extremely unstable, they will have to do for now until Alex sorts his out smile

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Posted: 07 December 2008 07:07 AM   [ Ignore ]   [ # 11 ]
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I’ve been doing some testing and have a prototype working…

?ACT=28&fid=34&aid=2115_s7WAXTveTQEo1lYLpt2A

It seems to use up alot of CPU tho (40-50%) so I’m not sure how well its going to work once I add blob tracking over the top.

I will keep you all posted.

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Multi Camera Test.PNG
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Posted: 20 December 2008 01:51 PM   [ Ignore ]   [ # 12 ]
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hi Pleh,
have you tested your prototype with an active blob tracking software (tbeta/touchlib) yet?
can it be used?

thx

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Posted: 21 December 2008 12:42 PM   [ Ignore ]   [ # 13 ]
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I have tried it with vcam, which lets you use any direct show filter as a virtual camera, and that worked with tbeta, but using vcam adds a bit of a delay. So im gonna write a touchlib source filter which should work nicely. Untill they release the source of tbeta, then I will write a source filter for that instead.

I have 2 ps3 eyes running at 320x240@60fps smoothly at the moment with the omnivision drivers (waiting for Alex to add multiple camera support)

I will post some screenshots and videos of it in action once I have written a touchlib source filter.

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Posted: 29 December 2008 08:21 PM   [ Ignore ]   [ # 14 ]
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I suggest you use 2 PC to do this job, one connect with 2 ps3eyes, it is in charge of that capture image and analyse the blobs, send the point data to another pc. Another one is in charge of screen show.

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Posted: 18 January 2009 06:18 PM   [ Ignore ]   [ # 15 ]
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what’s up , PLeh , any update of your project ?

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