Ubuntu compiler Ffmpeg+sdl+ffplay Extract motion vectors

Compile FFmpeg: The first step:

从官网http://ffmpeg.org/下载最新版本.解压tar -xjvf ffmpeg-3.3.1.tar.bz2进入目录cd ffmpeg-3.3.1

Step Two:

从http://yasm.tortall.net/Download.html下载yasmtar -xvzf yasm-1.3.0.tar.gzcd yasm-1.3.0/./configuremakemake install

Step Three:

回到ffmpeg目录中./configure --enable-shared --prefix=/你想让他编译以后在哪里/ffmpegmakemake install编译为动态库时的问题：/usr/bin/ld: /usr/local/lib/libavcodec.a(avpacket.o): relocation R_X86_64_32S against `av_destruct_packet‘ can not be used when making a shared object; recompile with -fPIC修改方法：./configure --enable-pic && make[默认编译安装在/usr/local/下

Test: 1. Enter/usr/local/ffmpeg/bin./ffmpeg View installation 2. Compile the C file with FFmpeg:

  gcc -o 可执行文件名 待编译文件名.c -L../lib/ -lavcodec -lavdevice -lavfilter -lavformat -lavutil

Compilation uses FFmpeg to extract motion Vector1. Compile and install ffmpeg;2. Use Pkg-config--cflags--libs OpenCV to find the OPENCV link library required for compiling files, Modify the Objects.mk and subdir.mk files, then make, 3. Or compile with the cmakefile of OpenCV:

具体内容：[注意每行之间不能有空格，直接回车]PROJECT(mpegflow)CMAKE_MINIMUM_REQUIRED(VERSION 2.8)if(COMMAND cmake_policy)cmake_policy(SET CMP0003 NEW)endif(COMMAND cmake_policy)FIND_PACKAGE( OpenCV REQUIRED )# Declare the target (an executable)ADD_EXECUTABLE(mpegflow  draw_flow.cpp)TARGET_LINK_LIBRARIES(mpegflow ${OpenCV_LIBS})  然后cmake.,再执行make即可。

4. Compile the Extract_mvs file using the FFmpeg library:

  gcc -o extract_mvs /ffmpeg-2.8/doc/samples/extract_mvs.c -L../lib/ -lavcodec -lavdevice -lavfilter -lavformat -lavutil

Install FFmpeg load SDL, compile run ffplay1. Install the FFMPEG2. Install SDL:

sudo apt-get install libsdl1.2-dev libsdl-image1.2-dev libsdl-ttf2.0-dev libsdl-mixer1.2-dev libsdl-net1.2-dev libsdl-sound1.2-dev

Detects that the SDL is loaded without: Sdl-config--exec-prefix--version--cflag]ffplay for motion vector visualization:

ffplay -debug vis_mb_type test.mp4 ffplay -vismv pf test.mp4

Ubuntu compiler Ffmpeg+sdl+ffplay Extract motion vectors