opencv highgui error [closed]

asked 2013-03-09 02:52:37 -0500

mrpiccolo gravatar image

updated 2014-01-28 17:15:36 -0500

ngrennan gravatar image

I wrote a ros node that takes a video from a webcam and publish its frame and it works.
Yesterday I installed the driver for video capture "media_build" to take a video from a video grabber, but the same program doesn't work, while if I open "video for linux 2" on VLC it works.

This is the error:

libv4l2: error set_fmt gave us a different result then try_fmt! HIGHGUI ERROR: libv4l unable convert to requested pixfmt
HIGHGUI ERROR: V4L: device /dev/video0: Unable to query number of channels
ERROR: capture is NULL

The instruction is:

CvCapture* capture = cvCaptureFromCAM( CV_CAP_ANY );
if ( !capture ) {
fprintf( stderr, "ERROR: capture is NULL \n" );
return -1;

any suggestion? (P.S. I have ros fuerte in my ubuntu pc)

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Closed for the following reason OpenCV Question: THe OpenCV community prefers to answer questions at: by tfoote
close date 2015-10-30 17:57:42.079221