OpenPose Library - build release issue - linux

Question

We are trying to install and run a demo for OpenPose Library available on Github :
https://github.com/CMU-Perceptual-Computing-Lab/openpose/blob/master/doc/installation.md#manual-compilation
Done with installing Caffe and all prerequisites, but while performing install command we are getting following errror :
CXX examples/tutorial_wrapper/2_user_synchronous.cpp
AR -o .build_release/lib/libopenpose.a
LD -o .build_release/lib/libopenpose.so.1.0.0-rc3
CXX/LD -o .build_release/examples/tutorial_pose/2_extract_pose_or_heatmat_from_image.bin
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::VideoCapture(cv::String const&)'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::set(int, double)'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::release()'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::operator>>(cv::Mat&)'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoWriter::VideoWriter(cv::String const&, int, double, cv::Size_<int>, bool)'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::isOpened() const'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::get(int) const'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::VideoCapture(int)'
.build_release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::~VideoCapture()'
.build_release/lib/libopenpose.so: undefined reference to `vtable for cv::VideoWriter'
collect2: error: ld returned 1 exit status
Makefile:492: recipe for target '.build_release/examples/tutorial_pose/2_extract_pose_or_heatmat_from_image.bin' failed
make: *** [.build_release/examples/tutorial_pose/2_extract_pose_or_heatmat_from_image.bin] Error 1
make: *** Waiting for unfinished jobs....
------------------------- -------------------------
Errors detected. Exiting script. The software might have not been successfully installed.
------------------------- -------------------------
Please help me get rid of this.
Thanks

Answer 1

This could be because libopencv_video and/or libopencv_videoio has not been added to the project. If you build opencv from source, do check whether these libraries have been built.

Answer 2

It looks like you did not check the OpenCV3 flag in both the OpenPose and Caffe makefiles.config files.
E.g., if you are using manual compilation as you indicated, assume you have Ubuntu 16 and CUDA 8. So you need to modify both these files:
https://github.com/CMU-Perceptual-Computing-Lab/openpose/blob/master/Makefile.config.Ubuntu16.example
https://github.com/CMU-Perceptual-Computing-Lab/openpose/blob/master/3rdparty/caffe/Makefile.config.Ubuntu16.example
By uncommenting # OPENCV_VERSION := 3 in both of them.
After that simply run again the command they specify: cp Makefile.config.Ubuntu16.example Makefile.config
And make clean in both OpenPose and Caffe and re-build it again.