Could not connect to the image acquisition device. Device may be in use.

Question

Sergey Stepanov 2011-9-13

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/15775-could-not-connect-to-the-image-acquisition-device-device-may-be-in-use

Hello there,

I was trying to get a video stream from my web camera genius gf112 under linux OS. I use 64-bit Gentoo and Matlab 7.12.0(R2011a). I used the following command line:

LD_PRELOAD=/usr/lib/libv4l/v4l2convert.so ./matlab

to run Matlab. After that I got a vid object using videoinput() function like shown here:

   vid = videoinput('linuxvideo', 1, 'RGB3_352x288')
Summary of Video Input Object Using 'CIF Single Chip     '.
     Acquisition Source(s):  pac207 is available.
    Acquisition Parameters:  'pac207' is the current selected source.
                             10 frames per trigger using the selected source.
                             'RGB3_352x288' video data to be logged upon START.
                             Grabbing first of every 1 frame(s).
                             Log data to 'memory' on trigger.
        Trigger Parameters:  1 'immediate' trigger(s) on START.
                    Status:  Waiting for START.
                             0 frames acquired since starting.
                             0 frames available for GETDATA.

But when I tried to preview or start getting a stream from the camera

start(vid)
preview(vid)

I received the following error:

Warning: Unable to reset the crop area.  Perhaps the device is
in use. 
??? Error using ==> imaqdevice.preview at 181
Could not connect to the image acquisition device.  Device may
be in use.