其中包含ffmpeg和v4l2。為什要要先裝這兩個套件呢？
因為opencv 在使用讀取影像檔案和相機擷取就需要以上兩個套件
如果沒安裝opencv在測試影片或者相機輸入會不能用。如果你覺得無所謂，那就跳過安裝ffmpeg和v4l2
以下是紀錄依照順序紀錄的，有些步驟在記錄的時候可能漏掉，請多包涵
注意安裝前需要先裝gcc, g++, autoconf, cmake, pkgconfig
可以使用
yum install gcc autoconf libtool make cmake automake gcc gcc-c++ yum install git nasm pkgconfig zlib-devel
!!pkgconfig 記得使用
export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
才會抓到/usr/local/lib下的.pc設定檔，很多lib預設安裝在/usr/local/lib下
開啟自動設定路徑
vim /etc/ld.so.conf
最後加入/usr/local/lib
/sbin/ldconfig
或者
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
1. Compile FFmpeg on CentOS 6.x
mkdir ~/ffmpeg_sources
建議一定要安裝x264，如果你要壓縮h264格式，x264需要yasm套件
Yasm
Yasm is an assembler used by x264 and FFmpeg.
cd ~/ffmpeg_sources curl -O http://www.tortall.net/projects/yasm/releases/yasm-1.2.0.tar.gz tar xzvf yasm-1.2.0.tar.gz cd yasm-1.2.0 ./configure make make install make distclean . ~/.bash_profile
x264
H.264 video encoder.
cd ~/ffmpeg_sources git clone --depth 1 git://git.videolan.org/x264 cd x264 ./configure --enable-static make make install make distclean
~~~~~~~~~~~~~~~~~~~~~~下面可选
libmp3lame
MP3 audio encoder.
Lame可有可無建議，都裝一裝，這是給mp3壓縮用的
cd ~/ffmpeg_sources curl -L -O http://downloads.sourceforge.net/project/lame/lame/3.99/lame-3.99.5.tar.gz tar xzvf lame-3.99.5.tar.gz cd lame-3.99.5 ./configure --disable-shared --enable-nasm make make install make distclean
libfdk_aac
AAC audio encoder.
cd ~/ffmpeg_sources git clone --depth 1 git://git.code.sf.net/p/opencore-amr/fdk-aac cd fdk-aac autoreconf -fiv ./configure --disable-shared make make install make distclean
libopus
Opus audio decoder and encoder.
cd ~/ffmpeg_sources curl -O http://downloads.xiph.org/releases/opus/opus-1.0.3.tar.gz tar xzvf opus-1.0.3.tar.gz cd opus-1.0.3 ./configure --disable-shared make make install make distclean
libogg
Ogg bitstream library. Required by libtheora and libvorbis.
cd ~/ffmpeg_sources curl -O http://downloads.xiph.org/releases/ogg/libogg-1.3.1.tar.gz tar xzvf libogg-1.3.1.tar.gz cd libogg-1.3.1 ./configure --disable-shared make make install make distclean
libvorbis
Vorbis audio encoder. Requires libogg.
cd ~/ffmpeg_sources curl -O http://downloads.xiph.org/releases/vorbis/libvorbis-1.3.3.tar.gz tar xzvf libvorbis-1.3.3.tar.gz cd libvorbis-1.3.3 ./configure --disable-shared make make install make distclean
libvpx
VP8/VP9 video encoder.
cd ~/ffmpeg_sources git clone --depth 1 http://git.chromium.org/webm/libvpx.git cd libvpx ./configure --disable-examples make make install make clean
~~~~~~~~~~~~~~~~~~~~
zlib開發套件一定要
yum install zlib-devel
如果要自己安裝要注意記得先用yum移除舊版，不然可能會跟舊版衝突
最後就是ffmpeg 預設安裝到/usr/local
如果不想要安裝到預設目錄記得在./configure 後加入 --prefix=[安裝目錄] （"$HOME/ffmpeg_build/“）
cd ~/ffmpeg_sources git clone --depth 1 git://source.ffmpeg.org/ffmpeg cd ffmpeg ./configure --extra-libs="-ldl" --enable-gpl --enable-nonfree --enable-libfdk_aac --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-shared -–disable-yasm make make install make distclean hash -r . ~/.bash_profile
最後透過yum安裝v4l2
yum install video4linux-devel
yum install libv4l-devel
這要安裝因為opencv會參考pkg-config，這個套件換安裝libv4l2.pc設定套件資訊
Additional Libraries
libfreetype
Font rendering library. Required for the drawtext video filter.
# yum install freetype-devel
Add --enable-libfreetype to your ffmpeg ./configure.
libspeex
Speex audio decoder and encoder.
# yum install speex-devel
Add --enable-libspeex to your ffmpeg ./configure.
libtheora
Theora video encoder. Requires libogg.
cd ~/ffmpeg_sources curl -O http://downloads.xiph.org/releases/theora/libtheora-1.1.1.tar.gz tar xzvf libtheora-1.1.1.tar.gz cd libtheora-1.1.1 ./configure --disable-examples --disable-shared --disable-sdltest --disable-vorbistest make make install make distclean
Add --enable-libtheora to your ffmpeg ./configure.
2. OpenCV Installation Guide
現在準備安裝opencv
這邊需要幾個套件
yum install swig sip
gtk2.0 用來cvNameWindows顯示用
yum install gtk2-devel
centos 5內建的python版本太舊建議安裝至少2.6
不過安裝不太容易
我是參考 >> HostUcan <<
wget http://www.python.org/ftp/python/2.6.7/Python-2.6.7.tgz tar xzvf Python-2.6.7.tgz ./configure --prefix=/opt/python2.6 --with-threads --enable-shared --with-zlib=/usr/include --prefix=/opt/python2.6不見得要要的話下面指令要修改 make make install
/python2.6不見得要要的話下面指令要修改
make
make install
如果你照上面 --prefix=/opt/python2.6打則
sudo ln -s /opt/python2.6/lib/libpython2.6.so /usr/lib sudo ln -s /opt/python2.6/lib/libpython2.6.so.1.0 /usr/lib
如果沒打則
sudo ln -s /usr/local/lib/libpython2.6.so /usr/lib sudo ln -s /usr/local/lib/libpython2.6.so.1.0 /usr/lib
# Create necessary links and cache
sudo /sbin/ldconfig -v
記得重新登入
現在來開始安裝opencv
我是參考 OpenCV Installation Guide
tar jxvf opencv-2.4.7.tar.bz2 cd opencv-2.4.7 mkdir build cd build cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D BUILD_PYTHON_SUPPORT=ON ..
你應該要看到ffmpeg和v4l2是On如果沒看到，請檢查上面有沒有步驟少了
然後最後會產生Makefile檔。如果沒看到Makefile檔產生訊息也是錯了
make
make install
恭喜你安裝成功
你打pkg-config --cflags --libs opencv
你應該看到
-I/usr/local/include/opencv -I/usr/local/include /usr/local/lib/libopencv_calib3d.so /usr/local/lib/libopencv_contrib.so /usr/local/lib/libopencv_core.so /usr/local/lib/libopencv_features2d.so /usr/local/lib/libopencv_flann.so /usr/local/lib/libopencv_gpu.so /usr/local/lib/libopencv_highgui.so /usr/local/lib/libopencv_imgproc.so /usr/local/lib/libopencv_legacy.so /usr/local/lib/libopencv_ml.so /usr/local/lib/libopencv_nonfree.so /usr/local/lib/libopencv_objdetect.so /usr/local/lib/libopencv_photo.so /usr/local/lib/libopencv_stitching.so /usr/local/lib/libopencv_ts.so /usr/local/lib/libopencv_video.so /usr/local/lib/libopencv_videostab.so
編譯程式可以直接在gcc後面加入 `pkg-config --cflags opencv`
e.g.
gcc -c test `pkg-config --cflags opencv` -o test.o
gcc test.o -o foo `pkg-config --libs opencv`
注意`是在鍵盤上esc下面那個，不是冒號右邊那個
在`XXXX`表示執行shell指令後回傳的值，它會自動替換掉上面剛剛一大串的指令執行結果
cmake -DBUILD_TIFF=ON -DBUILD_opencv_java=OFF -DWITH_CUDA=OFF -DWITH_IPP=ON -DWITH_TBB=ON -DWITH_EIGEN=ON -DWITH_GStreamer=OFF -DWITH_V4L=ON -DBUILD_TESTS=OFF -DBUILD_PERF_TESTS=OFF -DCMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/home/yaodezhong/env/local/ ..