VideoCapture is not working in OpenCV 2.4.2
So, I realized there was some problem with ffmpeg. and I rebuilt and installed ffmpeg and then changed flags for cmake to make opencv.
For ffmpeg,
./configure --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-nonfree --enable-postproc --enable-version3 --enable-x11grab
make
sudo make install
For OpenCV,
cmake -D CMAKE_BUILD_TYPE=RELEASE ..
make
sudo make install
Here's the complete script to install OpenCV 2.4.2 https://github.com/jayrambhia/Install-OpenCV/blob/master/Ubuntu/2.4/opencv2_4_2.sh
and here's my blogpost about OpenCV 2.4.2 installation in detail http://jayrambhia.com/blog/install-opencv-2-4-in-ubuntu-12-04-precise-pangolin/
Froyo
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Updated on July 05, 2022Comments
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Froyo almost 2 years
I recently installed OpenCV 2.4.2 in Ubuntu 12.04.
cap = VideoCapture(0)
is working. but I can't grab frames from some video source.
cap = VideoCapture("input.avi") img = cap.read()
gives me a numpy with all zero elements.
I have also installed ffmpeg 0.11, Latest snapshot of x264, v4l-0.8.8 (All are latest stable versions)
cmake -D WITH_QT=ON -D WITH_FFMPEG=ON -D WITH_OPENGL=ON -D WITH_TBB=ON -D BUILD_EXAMPLES=OFF WITH_V4L=ON .. make sudo make install
When I do cmake, I get this
-- Detected version of GNU GCC: 46 (406)
-- Found OpenEXR: /usr/lib/libIlmImf.so
-- Looking for linux/videodev.h
-- Looking for linux/videodev.h - not found
-- Looking for linux/videodev2.h
-- Looking for linux/videodev2.h - found
-- Looking for libavformat/avformat.h
-- Looking for libavformat/avformat.h - found
-- Looking for ffmpeg/avformat.h
-- Looking for ffmpeg/avformat.h - not found
-- checking for module 'tbb'
-- package 'tbb' not foundAnd
-- Video I/O: -- DC1394 1.x: NO -- DC1394 2.x: YES (ver 2.2.0) -- FFMPEG: YES -- codec: YES (ver 54.23.100) -- format: YES (ver 54.6.100) -- util: YES (ver 51.54.100) -- swscale: YES (ver 2.1.100) -- gentoo-style: YES -- GStreamer: -- base: YES (ver 0.10.36) -- app: YES (ver 0.10.36) -- video: YES (ver 0.10.36) -- OpenNI: NO -- OpenNI PrimeSensor Modules: NO -- PvAPI: NO -- UniCap: NO -- UniCap ucil: NO -- V4L/V4L2: Using libv4l (ver 0.8.8) -- XIMEA: NO -- Xine: NO
I looked for videodev.h, etc
- /usr/include/linux/videodev2.h exists
- /usr/include/libavformat/avformat.h exists
- /usr/local/include/libavformat/avformat.h exists
But I couldn't find
ffmpeg/avformat.h
What's the problem here?