Play live webcam feed in Max MSP / Jitter

jit.qt.grab, you have to click "open" to start the camera, and it shows frames once per bang. Does this work in the help file? In my experience, if the OS sees it (like iMovie works fine) then Jitter will see it. Probably it's not hot-pluggable though. (?)

For tracking motion look into cv.jit (3rd party), this works quite well once you get the settings tweaked right. For sampling individual colors you can use getcell on the matrix, or the suckah object over the video, then depending on where the color is in the video (test with some XY comparators) you can determine what to do with it.

--CJ

Thank you so much for your response, I'm just trying it now.
I really appreciate your help and will let you know how it goes!

(Don't think webcam is hot-pluggable - you need to have a little thing called "monitor" running in order to see the picture) I can't get the webcam to work into iMovie though unless I record the webcam feed and then import it to iMovie after... I'm not that accomplished with iMovie - I'm usually "all about sound"!

Will investigate further for now.

Well, slight progress in that getdevlist brings up a list which includes the webcam I use, however no amount of selecting "open" or fiddling with settings will make that little black screen show the picture. An exported jpeg comes up with black screen also.
I get this in log (don't know if that gives any clues?):

print: open -1 0
print: exportimage first try.jpg 1
? error: jit.qt.grab: could not create video channel -9405
? error: jit.qt.grab: error opening device for grab.
print: open -1 0

if you get those messages then the OS isn't seeing the camera, not sure what's up. AFAIK whenever the cam works in something like iMovie (testing there is good) then Max will see it too. "open -1" means no go :(

That's weird. The cam definitely works on the commputer because I can see myself on it! It def doesn't work in iMovie because it says "no camera attached" but I thought it was looking for a videocamera. When i do the getdevlist though, "VideoCamEye" comes up and allows itself to be selected - that's the name of my webcam, so the OS must accept it. That's so strange. I'll keep looking in to it. Basically it's for a uni project I have an extension for and my lecturers have dissappeared off the face of the planet. So I'm using a programme I'm inexperienced in, with no lecturer help, for my final project! Woohoo! Might try and find another webcam, although few of the cheap ones are Mac-happy.
Will post up how I get on, if I get anywhere I'll attach the patch.
Cheers.

For anyone who is looking to do the same thing. I have found a work around. Most webcams have a "monitor" function in which you can open a window and see what your webcam is filming. If you use the "jit.desktop" object, and set the coordinates to whereabouts on the screen the "monitor" window is, it display it in Max / Jitter, in a matrix.

Thanks SeeJay for trying to help, I think I just had an awkward webcam and this is a good workaround. Also handy as you don't even really need to have a webcam - you can just move your mouse around the coordinates for jitter to sense the movement.

Hope this helps anyone who is trawling the forums for the same sort of thing.

Hi,

Sorry for the (probably too) late comment
I've had similar problems with web cams on mac and ended up buying an
external isight. You've probably tried this but I had some success by
installing maccam available at http://webcam-osx.sourceforge.net/ and using
it as the driver. Max seems to find cams installed this way.

Hope this helps

2008/7/15 Lol :

>
> For anyone who is looking to do the same thing. I have found a work around.
> Most webcams have a "monitor" function in which you can open a window and
> see what your webcam is filming. If you use the "jit.desktop" object, and
> set the coordinates to whereabouts on the screen the "monitor" window is, it
> display it in Max / Jitter, in a matrix.
>
> Thanks SeeJay for trying to help, I think I just had an awkward webcam and
> this is a good workaround. Also handy as you don't even really need to have
> a webcam - you can just move your mouse around the coordinates for jitter to
> sense the movement.
>
> Hope this helps anyone who is trawling the forums for the same sort of
> thing.
>
>
>

yea, dunno when your project gotta be in by but am working on one very similiar. jit.scissors and jit.glue will split the matrix from the grab object up as required and put it back together if need be. There is a tutorial on the Max website called Hold still that will measure movement in any one of these grid sections and this movement can be used to trigger bangs that cause events, (make sure you reference if you use it, cause your tutor probably reads this forum too). Bit of a long way round though, if anyone has any better ideas would love to hear it.

By the way, when using jit.scissors on a jit.qt.grab in my patch, the live feed is only recognised about half of the time in Max 5, worked fine in Max 4 though, anyone else had this problem . B

Project has to be in really really soon - less than a week. I've got no further on this. I can't find anyone who can tell me how to get an output from jit.desktop that will change when what is on the desktop changes and I just don't know where else I can go with my patch to make it worthwhile. I've spent hours poring over forums and looking at patches and tutorials so it's not a case of wanting a quick fix I'm just really up sh*t creek without a paddle, it would seem.

A few people have downloaded my patch from my other thread but no one has come up with a solution yet I'm finding it all pretty frustrating. (Not that I'm expecting anyone to do the patch for me, I wish I could do it on my own!)

The HoldStill tutorial works with jit.qt and I tried to use some of the elements they used but they didn't work with desktop or seem to be there for the functions I needed them for. Thanks for the heads up on it though.