ubuntu16.04下利用wigwam安装mpegflow

最近想从264视频中提取运动向量（motion vector),ffmpeg的ffplay是可以显示运动向量在播放画面中的，但是具体怎么样将运动向量提取到文件中似乎没有给出解决办法，自己Google了半天才发现一个github的项目，发现其可以提取运动向量到文件中，也可以显示运动向量在播放的画面当中。具体的主页是：

https://github.com/vadimkantorov/mpegflow

其主要的功能也是十分简单：

./mpegflow examples/mpi_sintel_final_alley_1.avi > examples/alley_1.txt

还有一下几种模式可供选择：

在此不多解释。

然后主要是这个项目的编译，自己在windows下面编译似乎是通过了，但是在实际运用的过程中似乎存在问题，只能使用一种模式提取运动向量(--raw模式)，其他的几种模式似乎都没有成功，所以索性放弃，在Ubuntu16.04下进行编译。

查看其编译说明是依赖于FFmpeg软件包的,所以在编译之前是要安装ffmpeg的，ffmpeg其官网上已经有源代码可供Linux编译，具体我也是没怎么去试，看到作者推荐使用他自己的另一个项目wigwam安装ffmpeg，也就没有多想，直接安装wigwam

wigwam的主页是：

http://wigwam.in/

在其主页上也很详细地写明了安装方法。

第一：

在～/.bashrc文件中末尾添加以下内容：

alias wigwam='python2.7 <($([ -z "$(which curl)" ] && echo "wget -nv -O -" || echo "curl -sS") https://raw.githubusercontent.com/vadimkantorov/wigwam/master/wigwam.py) --repo https://github.com/vadimkantorov/wigwam/tree/master/wigs'

sudo vim ～/.bashrc

修改后保存退出，然后reload一下：

source ～/.bashrc

然后就是进行ffmpeg的安装：
wigwam init

wigwam install ffmpeg

其中安装ffmpeg的过程稍微久一点，十分钟左右。

安装完后进行mpegflow的编译，首先得让make发现你的ffmpeg在什么地方：

wigwam in 

切换到mpegflow的目录编译：

make

有一些warning可以忽略，编译成功后会生成可执行文件mpegflow

最后可以在example文件夹下面验证以下mpegflow，切换到mpegflow文件夹下面运行bash脚本文件：

$ /\ $ bash extract_mpeg_flow.sh

然后就会生成4个txt文件，具体的命令可以查看extract_mpeg_flow.sh

注意：因为mpegflow是依赖于FFmpeg的，所以一定要在使用wigwam in命令进入wigwam环境后才能正常运行，不然会提示找不到

一些库：
../mpegflow: error while loading shared libraries: libavformat.so.57: cannot open shared object file: No such file or directory
../mpegflow: error while loading shared libraries: libavformat.so.57: cannot open shared object file: No such file or directory
../mpegflow: error while loading shared libraries: libavformat.so.57: cannot open shared object file: No such file or directory
../mpegflow: error while loading shared libraries: libavformat.so.57: cannot open shared object file: No such file or directory

终端输入exit可以退出wigwam环境。

2017/10/14补充：

使用这种方法每次都必须进入wigwam环境才能够正常使用，所以在正常安装ffmpeg之后，可以直接进行编译，关于Ubuntu下安装FFmpeg的具体方法可以参考我的另一篇博文，在安装好FFmpeg之后，即可进行mpegflow的编译：

直接make

这个过程中会出现报错：

/usr/bin/ld: cannot find -lbz2
collect2: error: ld returned 1 exit status
Makefile:6: recipe for target 'mpegflow' failed
make: *** [mpegflow] Error 1
根据提示是因为缺少bz2的库，所以进行安装：

$ sudo apt-get install libbz2-devReading package lists... DoneBuilding dependency tree       Reading state information... DoneThe following additional packages will be installed:  bzip2-docThe following NEW packages will be installed:  bzip2-doc libbz2-dev0 upgraded, 2 newly installed, 0 to remove and 186 not upgraded.Need to get 324 kB of archives.After this operation, 556 kB of additional disk space will be used.Do you want to continue? [Y/n] 

安装之后重新make,又会出现一系列错误：

undefined reference to `dlclose'

undefined reference to `dlsym'

undefined reference to `dlclose'

解决方法参考了：http://www.xuebuyuan.com/220857.html

$ vim ./Makefile

在LDFLAGS一行的后面加上 -ldl
最后进行make,编译通过，在此记录一下warning：

mpegflow.cpp: In function ‘void ffmpeg_init()’:mpegflow.cpp:75:56: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]   AVCodecContext *enc = ffmpeg_pFormatCtx->streams[i]->codec;                                                        ^In file included from mpegflow.cpp:10:0:/usr/local/include/libavformat/avformat.h:893:21: note: declared here     AVCodecContext *codec;                     ^mpegflow.cpp:75:56: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]   AVCodecContext *enc = ffmpeg_pFormatCtx->streams[i]->codec;                                                        ^In file included from mpegflow.cpp:10:0:/usr/local/include/libavformat/avformat.h:893:21: note: declared here     AVCodecContext *codec;                     ^mpegflow.cpp:75:56: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]   AVCodecContext *enc = ffmpeg_pFormatCtx->streams[i]->codec;                                                        ^In file included from mpegflow.cpp:10:0:/usr/local/include/libavformat/avformat.h:893:21: note: declared here     AVCodecContext *codec;                     ^mpegflow.cpp: In function ‘bool process_frame(AVPacket*)’:mpegflow.cpp:102:12: warning: ‘int avcodec_decode_video2(AVCodecContext*, AVFrame*, int*, const AVPacket*)’ is deprecated [-Wdeprecated-declarations]  int ret = avcodec_decode_video2(ffmpeg_pVideoStream->codec, ffmpeg_pFrame, &got_frame, pkt);            ^In file included from mpegflow.cpp:9:0:/usr/local/include/libavcodec/avcodec.h:4901:5: note: declared here int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,     ^mpegflow.cpp:102:12: warning: ‘int avcodec_decode_video2(AVCodecContext*, AVFrame*, int*, const AVPacket*)’ is deprecated [-Wdeprecated-declarations]  int ret = avcodec_decode_video2(ffmpeg_pVideoStream->codec, ffmpeg_pFrame, &got_frame, pkt);            ^In file included from mpegflow.cpp:9:0:/usr/local/include/libavcodec/avcodec.h:4901:5: note: declared here int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,     ^mpegflow.cpp:102:55: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]  int ret = avcodec_decode_video2(ffmpeg_pVideoStream->codec, ffmpeg_pFrame, &got_frame, pkt);                                                       ^In file included from mpegflow.cpp:10:0:/usr/local/include/libavformat/avformat.h:893:21: note: declared here     AVCodecContext *codec;                     ^mpegflow.cpp:102:55: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]  int ret = avcodec_decode_video2(ffmpeg_pVideoStream->codec, ffmpeg_pFrame, &got_frame, pkt);                                                       ^In file included from mpegflow.cpp:10:0:/usr/local/include/libavformat/avformat.h:893:21: note: declared here     AVCodecContext *codec;                     ^mpegflow.cpp:102:55: warning: ‘AVStream::codec’ is deprecated [-Wdeprecated-declarations]  int ret = avcodec_decode_video2(ffmpeg_pVideoStream->codec, ffmpeg_pFrame, &got_frame, pkt);                                                       ^In file included from mpegflow.cpp:10:0:/usr/local/include/libavformat/avformat.h:893:21: note: declared here     AVCodecContext *codec;                     ^mpegflow.cpp:102:92: warning: ‘int avcodec_decode_video2(AVCodecContext*, AVFrame*, int*, const AVPacket*)’ is deprecated [-Wdeprecated-declarations]  int ret = avcodec_decode_video2(ffmpeg_pVideoStream->codec, ffmpeg_pFrame, &got_frame, pkt);                                                                                            ^In file included from mpegflow.cpp:9:0:/usr/local/include/libavcodec/avcodec.h:4901:5: note: declared here int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,     ^mpegflow.cpp: In function ‘bool read_frame(int64_t&, char&, std::vector<AVMotionVector>&)’:mpegflow.cpp:154:23: warning: ‘AVFrame::pkt_pts’ is deprecated [-Wdeprecated-declarations]  pts = ffmpeg_pFrame->pkt_pts != AV_NOPTS_VALUE ? ffmpeg_pFrame->pkt_pts : (ffmpeg_pFrame->pkt_dts                       ^In file included from /usr/local/include/libavcodec/avcodec.h:38:0,                 from mpegflow.cpp:9:/usr/local/include/libavutil/frame.h:279:13: note: declared here     int64_t pkt_pts;             ^mpegflow.cpp:154:23: warning: ‘AVFrame::pkt_pts’ is deprecated [-Wdeprecated-declarations]  pts = ffmpeg_pFrame->pkt_pts != AV_NOPTS_VALUE ? ffmpeg_pFrame->pkt_pts : (ffmpeg_pFrame->pkt_dts                       ^In file included from /usr/local/include/libavcodec/avcodec.h:38:0,                 from mpegflow.cpp:9:/usr/local/include/libavutil/frame.h:279:13: note: declared here     int64_t pkt_pts;             ^mpegflow.cpp:154:23: warning: ‘AVFrame::pkt_pts’ is deprecated [-Wdeprecated-declarations]  pts = ffmpeg_pFrame->pkt_pts != AV_NOPTS_VALUE ? ffmpeg_pFrame->pkt_pts : (ffmpeg_pFrame->pkt_dts                       ^In file included from /usr/local/include/libavcodec/avcodec.h:38:0,                 from mpegflow.cpp:9:/usr/local/include/libavutil/frame.h:279:13: note: declared here     int64_t pkt_pts;             ^mpegflow.cpp:154:66: warning: ‘AVFrame::pkt_pts’ is deprecated [-Wdeprecated-declarations]  pts = ffmpeg_pFrame->pkt_pts != AV_NOPTS_VALUE ? ffmpeg_pFrame->pkt_pts : (ffmpeg_pFrame->pkt_dts                                                                  ^In file included from /usr/local/include/libavcodec/avcodec.h:38:0,                 from mpegflow.cpp:9:/usr/local/include/libavutil/frame.h:279:13: note: declared here     int64_t pkt_pts;             ^mpegflow.cpp:154:66: warning: ‘AVFrame::pkt_pts’ is deprecated [-Wdeprecated-declarations]  pts = ffmpeg_pFrame->pkt_pts != AV_NOPTS_VALUE ? ffmpeg_pFrame->pkt_pts : (ffmpeg_pFrame->pkt_dts                                                                  ^In file included from /usr/local/include/libavcodec/avcodec.h:38:0,                 from mpegflow.cpp:9:/usr/local/include/libavutil/frame.h:279:13: note: declared here     int64_t pkt_pts;             ^mpegflow.cpp:154:66: warning: ‘AVFrame::pkt_pts’ is deprecated [-Wdeprecated-declarations]  pts = ffmpeg_pFrame->pkt_pts != AV_NOPTS_VALUE ? ffmpeg_pFrame->pkt_pts : (ffmpeg_pFrame->pkt_dts                                                                  ^In file included from /usr/local/include/libavcodec/avcodec.h:38:0,                 from mpegflow.cpp:9:/usr/local/include/libavutil/frame.h:279:13: note: declared here     int64_t pkt_pts;