1. installing FFMPEG dependencies
   sudo apt-get install build-essential checkinstall libfaac-dev libjack-jackd2-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libsdl1.2-dev libtheora-dev libva-dev libvdpau-dev libvorbis-dev libx11-dev libxfixes-dev libxvidcore-dev texi2html yasm zlib1g-dev libsdl1.2-dev libvpx-dev

2. Installing Gstreamer
   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

有人说还有安装 gstreamer0.10-plugins-ugly gstreamer0.10-plugins-bad gstreamer0.10-ffmpeg， 但是，在ubuntu16.04上，没有这三个库，不安装这三个库，也可以成功

2。 Installing libgtk2
sudo apt-get install libgtk2.0-0 libgtk2.0-dev

安装完成后，提示需要 运行sudo apt autoremove， 千万不能运行，否则，会删掉cuda, boost相关的库

3。 Installing libjpeg
sudo apt-get install libjpeg8 libjpeg8-dev

4。 Compile required libraries
Create a folder with the source code of all required packages:
mkdir ~/source
mkdir ~/source/v4l
mkdir ~/source/ffmpeg

• Compile X264

  https://www.videolan.org/developers/x264.html 下载: git clone http://git.videolan.org/git/x264.git
  ./configure --disable-asm
  make
  sudo make install

  • Compile ffmpeg
    cd ..
    https://www.ffmpeg.org/download.html 下载: git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg
    cd ~/source/ffmpeg
    ./configure --enable-gpl --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libxvid --enable-nonfree --enable-version3 --enable-shared --enable-libvpx --enable-pic
    make -j4
    sudo make install

• Compile v4l

下载，解压
cd ~/source/v4l
https://www.linuxtv.org/downloads/v4l-utils/
找最新版本下载
configure
make
sudo make install

最后从github上下载opencv 和opencv-contrib:
git clone https://github.com/opencv/opencv.git
git clone https://github.com/opencv/opencv_contrib.git

通过cmake-gui配置、编译和安装
在配置cmake时注意：
OPENCV_EXTRA_MODULES_PATH ->opencv_contrib-master/modules

PYTHON2_EXECUTABLE--->venv/py27/bin/python2.7
PYTHON2_INCLUDE_DIR--->venv/py27/include/python2.7
PYTHON2_LIBRARY ---->/usr/lib/x86_64-linux-gnu/libpython2.7.so
PYTHON2_NUMPY_INCLUDE_DIRS-->venv/py27/lib/python2.7/site-packages/numpy/core/include
PYTHON2_PACKAGES_PATH--->lib/python2.7/dist-packages

PYTHON3_EXECUTABLE--->venv/py36/bin/python3.6
PYTHON3_INCLUDE_DIR--->venv/py36/include/python3.6m
PYTHON3_LIBRARY--->/usr/lib/x86_64-linux-gnu/libpython3.6m.so
PYTHON3_NUMPY_INCLUDE_DIRS--->venv/py36/lib/python3.6/site-packages/numpy/core/include
PYTHON3_PACKAGES_PATH--->lib/python3.6/dist-packages

编译和安装成功后：
cd /usr/local/lib/python2.7/dist-packages
sudo chmod +x ./cv2.so
cp ./cv2.so ~/venv/py27/lib/python2.7/site-packages/

cd /usr/local/lib/python3.6/dist-packages
sudo mv ./cv2.cpython-36m-x86_64-linux-gnu.so ./cv2.so
sudo chmod +x ./cv2.so
cp ./cv2.so ~/venv/py36/lib/python3.6/site-packages/

测试：
进入python虚拟环境，启动python
import cv2