Forums > Jitter

Multiple iSight Cameras

September 11, 2006 | 4:59 pm

Hi all,
I am attempting to correlate data from two obliquely angled iSight cameras in order to do 3D motion-tracking. However, when I plug in both cameras, my Mac just freaks out. The framerate fluctuates between 2000 and nearly 0, the images – if they exist – are distorted, and then Max hangs. If I look in system profiler, I can see both cameras along with two unknown devices. These two devices are apparently my root Firewire bus and the hub I’m using for the two cameras – at least that’s my best guess, since unplugging the external hub makes one of them disappear. I must admit I’m a Windows native, so I don’t know how to manually add and remove devices if the system isn’t detecting them properly. I’ve tried using the same two cameras without a hub as well, so the hub is not the issue. I have tried everything I can think of including manually resetting the Firewire bus as per instructions on the Apple support site – unplug the computer for 5 minutes, then try again. Both cameras work independently, but using them both causes problems.

The Compy:
Quad 2.5 Ghz G5
6.5 GB Ram
Running 10.4.7
Both cameras have the iSight 1.3 firmware update.

I’ve done a lot of searching on this, and what I can find seems to amount to many people having this problem and the few who don’t saying "mine works fine…" Any suggestions?

Cheers,
Mike



sm
September 11, 2006 | 9:14 pm

hm, i used that patch with 3 cam inputs on a g4 powerbook with a hub.

max v2;
#N vpatcher 241 123 1018 677;
#P toggle 370 28 15 0;
#P window setfont "Sans Serif" 9.;
#P newex 397 34 46 196617 metro 2;
#P window setfont "Sans Serif" 18.;
#P message 312 32 20 196626 4;
#B color 5;
#P message 281 35 20 196626 3;
#B color 5;
#P message 240 34 20 196626 2;
#B color 5;
#P message 202 34 28 196626 1;
#B color 5;
#P window setfont "Sans Serif" 9.;
#P number 84 34 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P newex 26 55 382 196617 gate 4;
#P message 643 127 45 196617 settings;
#P message 483 104 118 196617 open , input 1 , vdevice 0;
#P user jit.fpsgui 469 288 60 196617 0;
#P message 533 73 55 196617 getvdevice;
#P message 483 73 44 196617 getinput;
#P newex 469 133 95 196617 jit.qt.grab 160 120;
#P user jit.pwindow 468 160 162 122 0 1 0 0 1 0;
#P message 607 104 32 196617 close;
#P outlet 26 458 15 0;
#P message 236 113 118 196617 open , input 1 , vdevice 2;
#P user jit.fpsgui 222 297 60 196617 0;
#P message 286 82 55 196617 getvdevice;
#P message 236 82 44 196617 getinput;
#P newex 222 142 95 196617 jit.qt.grab 160 120;
#P user jit.pwindow 221 169 162 122 0 1 0 0 1 0;
#P message 360 113 32 196617 close;
#P message 40 113 118 196617 open , input 0 , vdevice 2;
#P user jit.fpsgui 26 297 60 196617 0;
#P message 90 82 55 196617 getvdevice;
#P message 40 82 44 196617 getinput;
#P newex 26 142 95 196617 jit.qt.grab 160 120;
#P user jit.pwindow 25 169 162 122 0 1 0 0 1 0;
#P message 164 113 32 196617 close;
#P connect 24 0 23 0;
#P connect 28 0 23 0;
#P fasten 4 0 2 0 95 105 31 105;
#P fasten 0 0 2 0 169 134 31 134;
#P fasten 6 0 2 0 45 134 31 134;
#P fasten 3 0 2 0 45 105 31 105;
#P connect 23 0 2 0;
#P connect 2 0 1 0;
#P connect 1 0 5 0;
#P hidden fasten 17 0 14 0 474 337 31 337;
#P hidden fasten 9 0 14 0 227 337 31 337;
#P hidden fasten 2 0 14 0 31 337 31 337;
#P hidden connect 25 0 24 0;
#P hidden connect 26 0 24 0;
#P hidden connect 27 0 24 0;
#P fasten 10 0 9 0 241 105 227 105;
#P fasten 13 0 9 0 241 134 227 134;
#P fasten 7 0 9 0 365 134 227 134;
#P fasten 11 0 9 0 291 105 227 105;
#P hidden connect 23 1 9 0;
#P connect 9 0 8 0;
#P connect 8 0 12 0;
#P connect 30 0 29 0;
#P connect 29 0 23 1;
#P fasten 19 0 17 0 538 96 474 96;
#P fasten 15 0 17 0 612 125 474 125;
#P fasten 21 0 17 0 488 125 474 125;
#P fasten 18 0 17 0 488 96 474 96;
#P connect 22 0 17 0;
#P hidden connect 23 2 17 0;
#P connect 17 0 16 0;
#P connect 16 0 20 0;
#P pop;


September 11, 2006 | 11:53 pm

Thanks for the help. That patch works for me as well, but unfortunately does not address my issue. I need to get video from both cameras simultaneously.

Cheers,
Mike


September 12, 2006 | 5:37 am

I m sorry to say, but you won’t be able to acheive that.
as far as I can remember, the iSight driver only accepts on cam at a time.

//yac
>
> Thanks for the help. That patch works for me as well, but unfortunately does not address my
> issue. I need to get video from both cameras simultaneously.
>
> Cheers,
> Mike
>



sm
September 12, 2006 | 11:12 am

but the patch has the cams running simultaneously. the gate just
decides which jit.grab gets the bangs.
if it is too much for the computer, you could switch between the
grabbers in an 20 ms interval -> since the camera would provide you
with a new image every 40 ms anyway.
maybe you could post the grabber part of your patch.

On Sep 12, 2006, at 1:53 AM, Mike Sayre wrote:

>
> Thanks for the help. That patch works for me as well, but
> unfortunately does not address my issue. I need to get video from
> both cameras simultaneously.
>
> Cheers,
> Mike
>


September 12, 2006 | 2:54 pm

Hmm, would it be possible to do some sort of hack that had two instances of the driver running, or some such wizardry? I will let ‘you know how the alternating thing works out.

Many Thanks,
Mike Sayre


September 14, 2006 | 2:57 am

The alternating idea didn’t work. It just froze like before. It seems that the problem must be with the camera driver. I wonder if it might be possible to kludge a driver using the cvcam component of OpenCV. Anyone ever try doing something like that?


September 14, 2006 | 9:29 am

> The alternating idea didn’t work. It just froze like before. It seems that the problem must be
> with the camera driver. I wonder if it might be possible to kludge a driver using the cvcam
> component of OpenCV. Anyone ever try doing something like that?

just to say, if you don’t find your way with iSights, Unibrain Fire-i do accept chaining:
http://www.unibrain.com/Products/VisionImg/Fire_i_DC.htm
and it’s cheap:

http://www.firewire-1394.com/fire-i-webcam-unibrain.htm

//yac


September 14, 2006 | 11:32 am

i think i posted this a while back, it uses 6 the unibrain cameras no a mac
for 360 panorama
http://www.vrhotwires.com/InexpensivePanoramicVideo.html
2006/9/14, Yacine Sebti :
>
> > The alternating idea didn’t work. It just froze like before. It seems
> that the problem must be
> > with the camera driver. I wonder if it might be possible to kludge a
> driver using the cvcam
> > component of OpenCV. Anyone ever try doing something like that?
>
> just to say, if you don’t find your way with iSights, Unibrain Fire-i do
> accept chaining:
> http://www.unibrain.com/Products/VisionImg/Fire_i_DC.htm
> and it’s cheap:
> http://www.firewire-1394.com/fire-i-webcam-unibrain.htm
>
> //yac
>


September 21, 2006 | 10:12 am

I don’t have 2 iSights to test with, but a little searching around
the web (links below) indicates that the iSights (depending on
resolution) are pumping out too much data to work simultaneously on a
single bus. I would argue that Max shouldn’t freak out in this
manner, but until such time as I can test this myself, I don’t have a
fix for that. Sale of iSights is now prohibited in Europe (lead is
used somewhere within the thing), so it won’t be anytime soon.

You might try the Quartz Composer patch mentioned in the 2nd link and
let me know how that works, too.

jb

http://lists.apple.com/archives/QuickTime-API/2004/Oct/msg00161.html
http://lists.apple.com/archives/quartzcomposer-dev//2006/Feb/
msg00015.html

Am 11.09.2006 um 19:00 schrieb Mike Sayre:

>
> Hi all,
> I am attempting to correlate data from two obliquely angled
> iSight cameras in order to do 3D motion-tracking. However, when I
> plug in both cameras, my Mac just freaks out. The framerate
> fluctuates between 2000 and nearly 0, the images – if they exist –
> are distorted, and then Max hangs. If I look in system profiler, I
> can see both cameras along with two unknown devices. These two
> devices are apparently my root Firewire bus and the hub I’m using
> for the two cameras – at least that’s my best guess, since
> unplugging the external hub makes one of them disappear. I must
> admit I’m a Windows native, so I don’t know how to manually add and
> remove devices if the system isn’t detecting them properly. I’ve
> tried using the same two cameras without a hub as well, so the hub
> is not the issue. I have tried everything I can think of including
> manually resetting the Firewire bus as per instructions on the
> Apple support site – unplug the computer for 5 minutes, then try
> again. Both!
> cameras work independently, but using them both causes problems.
>
> The Compy:
> Quad 2.5 Ghz G5
> 6.5 GB Ram
> Running 10.4.7
> Both cameras have the iSight 1.3 firmware update.
>
> I’ve done a lot of searching on this, and what I can find seems
> to amount to many people having this problem and the few who don’t
> saying "mine works fine…" Any suggestions?
>
> Cheers,
> Mike


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