Compile OpenCV (and ffmpeg) on Ubuntu Linux

This post is about the experience to compile OpenCV on Ubuntu 14.04. It was quite hard to find the correct information and dependencies to make the project, and the following error might be happened: /usr/bin/ld.bfd.real: /usr/local/lib/libavcodec.a(avpacket.o): relocation R_X86_64_32 against `.rodata.str1.1′ can not be used when making a shared object; recompile with -fPIC /usr/local/lib/libavcodec.a: error adding symbols: Bad value collec

Setting permissions for one file/directory to multiple groups in Linux

This post is a summary of (workaround) methods to have a file/directory owned by multiple Linux groups with traditional Unix permissions. Access Control Lists (ACL) Each file or directory can only have one group as owner, but permissions can be defined for other groups using ACL. If your system hasn’t ACL installed, install the command line tools which are in the acl package with: sudo apt-get install acl Then with getfacl you can read the