[ros-users] camera1394 - failure to start cameras

[Jack O'Quin]

On Sat, Jul 10, 2010 at 11:32 PM, Kim Houck <kim_houck at yahoo.com> wrote:
> I was wondering if anyone else has seen issues with camera1394 throwing
> an exception after failing to start the camera.  I have been dealing
> with an older firewire camera(dc1394 A) that often fails to start on the
> first try(this also occurs using the camera with opencv or the dc1394
> interface directly).

What make and model of camera do you have?

Which version of ROS and camera1394 are you running?

With the cturtle version of the camera1394 driver, the expected
behavior when the camera open fails is to print an exception message,
but the driver node should continue running. The intent is to give
users the opportunity to change camera parameters with dynamic
reconfigure. When a parameter changes, the driver will attempt to open
the camera again (using the new values).

> hen the camera fails to start properly the camera1394 node needs to be
> restarted to get get the camera to work, which isn't a problem for a
> stand alone node but gets aggravating when using launch files.  I made a
> change to openCamera in camera1394.cpp to have it try again to open the
> camera if it fails the first time and only give up and throw an
> exception if it fails twice.  I was wondering if anyone else has
> encountered this problem and if so if have they found a better solution
> for it?

Did the driver keep running after the open failed?

So, you are saying that this device fails to open on the first try,
but succeeds on a second attempt using the same parameters?

> I'm not sure if this constitutes a bug/change request for camera1394,
> since it may be limited to a very small subset of hardware and I'm not
> sure if fixing this would cause problems for other camera hardware.

I have not personally seen any cameras that behave as you describe,
but the range of behavior exhibited by IIDC cameras never ceases to
amaze. I am very curious exactly what device this is.
-- 
 joq