Hi all,
I'm trying to do some video processing with OpenCV (mainly python) on Fedora. My main machine runs Fedora 17 with OpenCV 2.3.1 installed from the Fedora repositories. Basic video reading and playback using cv2.VideoCapture works fine, but when I read the file's framerate info, it invariably returns 0, and when I try to search frame positions using CV_CAP_PROP_POS_FRAMES (or _MSEC or _AVI_RATIO), the set function returns False, and positions aren't set. This makes seeking/rewind/replay etc. functionality impossible. To find where the problem originated, I compiled a basic c++ video player, which also failed during these operations. Lastly, I tried both approaches (python and c++) on a different machine on our network with Fedora 19 and OpenCV 2.4.6 installed. Same problem, but with an error message shedding some light on the problem:
warning: GStreamer: unable to seek (/builddir/build/BUILD/opencv-2.4.6.1/modules/highgui/src/cap_gstreamer.cpp:718)
warning: GStreamer: unable to query position of stream (/builddir/build/BUILD/opencv-2.4.6.1/modules/highgui/src/cap_gstreamer.cpp:634)
So apparently the problem is caused by a faulty gstreamer implementation. Any suggestions on how to solve this?