Can't open video using opencv

Question

The opencv works fine when doing other things. It can open images and show images. But it can\'t open a video.

The code I\'m using to open a video is as below

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Answer 1

for ubuntu 14.04, this is how i fixed it.

install the dependencies required for OpenCV"

sudo apt-get remove ffmpeg x264 libx264-dev

sudo apt-get update

sudo apt-get install libgstreamer0.10-0 libgstreamer0.10-dev gstreamer0.10-tools gstreamer0.10-plugins-base libgstreamer-plugins-base0.10-dev gstreamer0.10-plugins-good gstreamer0.10-plugins-ugly gstreamer0.10-plugins-bad gstreamer0.10-ffmpeg

sudo apt-get -y install libopencv-dev build-essential cmake git libgtk2.0-dev pkg-config python-dev python-numpy libdc1394-22 libdc1394-22-dev libjpeg-dev libpng12-dev libtiff4-dev libjasper-dev libavcodec-dev libavformat-dev libswscale-dev libxine-dev libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev libv4l-dev libtbb-dev libqt4-dev libfaac-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libtheora-dev libvorbis-dev libxvidcore-dev x264 v4l-utils unzip

sudo add-apt-repository ppa:mc3man/gstffmpeg-keep

sudo apt-get update

sudo apt-get install gstreamer0.10-ffmpeg

sudo apt-get install gstreamer0.10-plugins-bad

sudo apt-get update

Install ffmpeg inside anaconda3"

conda install -c menpo ffmpeg=2.7.0

Dowload Opencv 3.1.0"

wget https://github.com/Itseez/opencv/archive/3.1.0.zip unzip 3.1.0.zip

mkdir build

cd build

cmake -DBUILD_TIFF=ON -DBUILD_opencv_java=OFF -DWITH_CUDA=OFF -DWITH_FFMPEG=OFF -DENABLE_AVX=ON -DWITH_OPENGL=ON -DWITH_OPENCL=ON -DWITH_IPP=ON -DWITH_TBB=ON -DWITH_EIGEN=ON -DWITH_V4L=ON -DBUILD_TESTS=OFF -DBUILD_PERF_TESTS=OFF -DCMAKE_BUILD_TYPE=RELEASE -DCMAKE_INSTALL_PREFIX=$(python3 -c "import sys; print(sys.prefix)") -DPYTHON3_EXECUTABLE=$(which python3.5) -DPYTHON3_INCLUDE_DIR=$(python3 -c "from distutils.sysconfig import get_python_inc; print(get_python_inc())") -DPYTHON3_PACKAGES_PATH=$(python3 -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())") ..

make

sudo make install