Device or resource busy

asked 2014-10-11 00:16:34 -0500

maxdoom gravatar image

updated 2014-10-11 03:00:25 -0500

Hi there,

I'm trying to write a program that uses 2 cameras. In the first step I open the cameras on by one for configuration (which is left, right, not to use and so on). After that I open the left and right camera each in on thread. I close the configuration with:



The Problem is after the configuration I get the following massage when I try to open the capturing:

    VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV
    VIDIOC_REQBUFS: Device or resource busy
    VIDIOC_G_FMT: Bad file descriptor
    Unable to stop the stream.: Device or resource busy
    VIDIOC_G_FMT: Bad file descriptor

Another thing thats happening is that the camera window stays open for much to long. I put a sleep(60) after closing the video feed and the window stays open until the sleep is over. It's like the command is not even executed when the command is given.

Edit: Full Code in here: The important part is the main function and the registerCameras function.

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please show more code. (impossible to guess, what you're doing now)

berak gravatar imageberak ( 2014-10-11 02:35:30 -0500 )edit

It's done, pastbin link is up.

maxdoom gravatar imagemaxdoom ( 2014-10-11 02:52:24 -0500 )edit

the capture is already running in a thread of its own. (it's all async)

does it get better, if you skip the registerCameras() function ? (i don't see the reason for this anyway)

berak gravatar imageberak ( 2014-10-11 03:23:41 -0500 )edit

The 2 threads run fine if I don't use registerCameras(). I need to register them because I have 3 cameras and need to know which one is left or right.

maxdoom gravatar imagemaxdoom ( 2014-10-11 03:34:00 -0500 )edit

again, the main code won't wait until your captures(from registerCameras()) properly close.

berak gravatar imageberak ( 2014-10-11 04:00:23 -0500 )edit

Yeah I thought so, but how do I close it properly?

maxdoom gravatar imagemaxdoom ( 2014-10-11 04:11:36 -0500 )edit

it will get even worse, once you try to port to a different machine/os/capture_type.

berak gravatar imageberak ( 2014-10-11 04:26:12 -0500 )edit

And what do you suggest I do? No Threads? How do I properly close the video stream?

maxdoom gravatar imagemaxdoom ( 2014-10-11 04:41:32 -0500 )edit

maybe: while( cap.isOpened() ) waitKey(20);

berak gravatar imageberak ( 2014-10-11 04:44:57 -0500 )edit

the complete VideoCapture interface is quite unable to handle multiple cameras effectively. This is a known issue but adapting the complete interface will indeed be one hell of a job.

StevenPuttemans gravatar imageStevenPuttemans ( 2014-10-12 07:38:03 -0500 )edit