opencv2.1移植arm 出现找不到libcv.so not found (try using -rpath or -rpath-link) 及大量 undefined reference的解决

先介绍下环境:pc(虚拟机)+ubuntu11.10+qt4.8+arm6410（飞凌的），申明下解决onot found (try using -rpath or -rpath-link)的方法是换成了opencv2.0版本，待我慢慢道来！

自从移植完qt4.8后，就可以移植opencv，因为做视觉处理算法不移植不好搞啊！开始了蛋疼的opencv移植，参见我的救急帖子：http://topic.csdn.net/u/20120427/08/ae5d7b21-e58c-4b9a-8a79-a229e38195cc.html?seed=1445143701&r=78398534#r_78398534。为了后人少走弯路，我说下心得：

（1）不管移植不移植，在opencv没有和qt结合以前，大家要先写个小例子测试一下。新建test.c文件，代码如下：

#include <cv.h>
#include <highgui.h>
#include <stdio.h>
int main()
{
IplImage *img = cvLoadImage("/ayan/r3.jpeg",1);
cvNamedWindow( "Image", 1 );//创建窗口
cvShowImage( "Image", img );//显示图像
cvWaitKey(0); //等待按键
cvDestroyWindow( "Image" );//销毁窗口
cvReleaseImage(&img);

printf("OK!\n");

return 0;
}

如果出现大量undefined reference的错误，检查下编译器格式问题，正确的是：gcc test.c -o test -I/usr/include/opencv -L/usr/lib -lml -lcvaux -lhighgui -lcv -lcxcore ,这里先用pc机上测试下，注意这个include的目录和lib的目录是我linux 386系统安装的opencv，不是移植的arm版的。如果你写成：gcc -I/usr/include/opencv-L/usr/lib -lml -lcvaux -lhighgui -lcv -lcxcore-o test test.c，将会出现大量undefined reference的错误，错误提示如下，只摘录前几行：

/tmp/ccNgdhSo.o: In function `cvRound':

test.c:(.text+0x19): undefined reference to `lrint'
/tmp/ccNgdhSo.o: In function `cvDecRefData':
test.c:(.text+0xa5a): undefined reference to `cvFree_'
test.c:(.text+0xacb): undefined reference to `cvFree_'
/tmp/ccNgdhSo.o: In function `cvGetRow':
test.c:(.text+0xbc1): undefined reference to `cvGetRows'
/tmp/ccNgdhSo.o: In function `cvGetCol':
test.c:(.text+0xbec): undefined reference to `cvGetCols'
/tmp/ccNgdhSo.o: In function `cvReleaseMatND':
test.c:(.text+0xbff): undefined reference to `cvReleaseMat'
/tmp/ccNgdhSo.o: In function `cvSubS':
test.c:(.text+0xd1f): undefined reference to `cvAddS'
/tmp/ccNgdhSo.o: In function `cvCloneSeq':
test.c:(.text+0xd6d): undefined reference to `cvSeqSlice'
/tmp/ccNgdhSo.o: In function `cvSetNew':
test.c:(.text+0xdcc): undefined reference to `cvSetAdd'
/tmp/ccNgdhSo.o: In function `cvGetSetElem':
test.c:(.text+0xe5f): undefined reference to `cvGetSeqElem'
/tmp/ccNgdhSo.o: In function `cvEllipseBox':
test.c:(.text+0xf5f): undefined reference to `cvEllipse'
/tmp/ccNgdhSo.o: In function `cvFont':
test.c:(.text+0xfa9): undefined reference to `cvInitFont'
/tmp/ccNgdhSo.o: In function `cvReadIntByName':
test.c:(.text+0x1057): undefined reference to `cvGetFileNodeByName'
/tmp/ccNgdhSo.o: In function `cvReadRealByName':
test.c:(.text+0x10e8): undefined reference to `cvGetFileNodeByName'
/tmp/ccNgdhSo.o: In function `cvReadStringByName':
test.c:(.text+0x1142): undefined reference to `cvGetFileNodeByName'
/tmp/ccNgdhSo.o: In function `cvReadByName':
test.c:(.text+0x1172): undefined reference to `cvGetFileNodeByName'
test.c:(.text+0x1188): undefined reference to `cvRead'
/tmp/ccNgdhSo.o: In function `cvCreateSubdivDelaunay2D':
test.c:(.text+0x1287): undefined reference to `cvCreateSubdiv2D'
如果您出现了undefined reference 请首先排查这个错误！

（2）如果您还没移植opencv请看这里。参照网上若干文章，我最初移植的是opencv2.1，什么都搞好了，用上述在gcc编译器下证实的正确代码测试，总是出现/usr/local/arm/4.3.2/bin/../lib/gcc/arm-none-linux-gnueabi/4.3.2/../../../../arm-none-linux-gnueabi/bin/ld: warning: ../../lib/libcxcore.so, needed by /usr/local/arm/opencv-2.1/lib/libcv.so, not found (try using -rpath or -rpath-link)
/usr/local/arm/4.3.2/bin/../lib/gcc/arm-none-linux-gnueabi/4.3.2/../../../../arm-none-linux-gnueabi/bin/ld: warning: ../../lib/libcv.so, needed by /usr/local/arm/opencv-2.1/lib/libcvaux.so, not found (try using -rpath or -rpath-link)
/usr/local/arm/4.3.2/bin/../lib/gcc/arm-none-linux-gnueabi/4.3.2/../../../../arm-none-linux-gnueabi/bin/ld: warning: ../../lib/libhighgui.so, needed by /usr/local/arm/opencv-2.1/lib/libcvaux.so, not found (try using -rpath or -rpath-link)
/usr/local/arm/4.3.2/bin/../lib/gcc/arm-none-linux-gnueabi/4.3.2/../../../../arm-none-linux-gnueabi/bin/ld: warning: ../../lib/libml.so, needed by /usr/local/arm/opencv-2.1/lib/libcvaux.so, not found (try using -rpath or -rpath-link)

的蛋疼错误！在/etc/profile里也加export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/arm/opencv/lib这句话了，然后source /etc/profile. 不中后，gedit /etc/ld.so.conf也 include/usr/local/arm/opencv/include/opencv，然后 ldconfig依旧不中！最后找到了/usr/local/arm/qte-4.8.0/mkspec/default/qmake.conf，修改这个文件，添加：CPPFLAGS="-I /usr/local/arm/opencv/include/opencv"
LDFLAGS="-L /usr/local/arm/opencv/lib" 。。。。依旧不中！将这五个.so文件拷贝到交叉编译器的相关目录下依旧不中！ 最后想到修改MakeFile，将原始的

LIBS = $(SUBLIBS) -L/usr/local/arm/qte-4.8.0/lib /usr/local/arm/opencv/lib/libcv.so /usr/local/arm/opencv/lib/libcvaux.so /usr/local/arm/opencv/lib/libcxcore.so /usr/local/arm/opencv/lib/libhighgui.so /usr/local/arm/opencv/lib/libml.so -lQtGui -L/usr/local/arm/qte-4.8.0/lib -lQtNetwork -lQtCore -lpthread，以为这句话有问题，将其改成：

LIBS = $(SUBLIBS) -L/usr/local/arm/qte-4.8.0/lib -lQtGui -L/usr/local/arm/qte-4.8.0/lib -lQtNetwork -lQtCore -L/usr/local/arm/opencv/lib -lml -lcvaux -lhighgui -lcv -lcxcore -lpthread

以为这下格式可对了，依旧not found (try using -rpath or -rpath-link)！我日！！！最后参照http://blog.sina.com.cn/s/blog_602f87700100nyda.html

http://blog.sina.com.cn/s/blog_602f87700100fbm3.html 和http://www.cnblogs.com/s_agapo/archive/2011/11/24/2262346.html

，将makefile里添加：LFLAGS = -Wl,-O1 -Wl,-rpath,/usr/local/arm/qte-4.8.0/lib：-Wl,-O1 -Wl,-rpath,/usr/local/arm/opencv/lib以为这下可好了，谁知还是错！ 靠，惹火老子了！直接决定移植opencv2.0拉倒，参考http://blog.csdn.net/chennxi/article/details/6082039，我的配置为：./configure --host=arm-linux --without-gtk --without-carbon --without-quicktime --without-1394libs --without-ffmpeg --without-python --without-swig --enable-static --enable-shared --disable-apps CXX=arm-linux-g++ CPPFLAGS=-I/usr/local/arm/4.3.2/arm-none-linux-gnueabi/include LDFLAGS=-L/usr/local/arm/4.3.2/arm-none-linux-gnueabi/libc/lib --with-v4l2 --prefix=/usr/local/arm/opencv --libdir=/usr/local/arm/opencv/lib -includedir=/usr/local/arm/opencv/include

安装好后，首先在nfs测试的，编译上述的test.c文件，arm-linux-gcc test.c -o test-arm -I/usr/local/arm/opencv/include/opencv -L/usr/local/arm/opencv/lib -lml -lcvaux -lhighgui -lcv -lcxcore -lpthread -lrt编译通过，将可执行文件复制到板子里运行，会提示这不到libcv。so，记得要添加环境变量：

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/arm/opencv/lib，运行./test-arm会提示 什么highgui的函数不支持，gtk之类的！这就对了！

提示： 在pc linux上交叉编译时，一定要指定-I/usr/local/arm/opencv/include/opencv -L/usr/local/arm/opencv/lib -lml -lcvaux -lhighgui -lcv -lcxcore，即便你设置了LD_LIBRARY_PATH，如果不加这个-I 和-L 依旧会出错。反之，如果不设LD_LIBRARY_PATH，只需指定-I和-L也是可以的！！！

（3）如果不用nfs，要将opencv下的lib和include拷贝到相同目录下。在拷贝时，会出现找不到.so,这是因为用cp命令拷贝时找不到 快捷方式所致的，解决办法有两种，1，直接给.so文件改名字，比如提示找不到libcv.so，你到板子里发现就是没有libcv.so，只有libcv.so.4.0，你再到pc机上查看发现有libcv.so libcv.so.4 和lib.so.4.0三个文件，前两个都是快捷方式，用ls -al 命令，会看到libcv.so 指向libcv.so.4.0，在板子里连的超级终端,cd到lib的目录， 用ln -s libcv.so.4.0(老名字) libcv.so（新名字，快捷方式）

即可！2，直接mv libcv.so.4.0 libcv.so 就是直接改名字的意思！

（4）至此，我们回顾为什么会not found (try using -rpath or -rpath-link），只能一种解释，cmake2.8.5下make出来的.so 文件 arm-linux-gcc-4.3.2不识别！参照http://blog.sina.com.cn/s/blog_602f87700100nyda.html这篇文章，即便需要用到动态链接库，只需在LFLAGS中添加了：-Wl,-rpath-link -Wl,/。。、。。。/.....（lib的目录）就可以了！

（5）qmake生成的makefile的正确格式，就是LIBS = $(SUBLIBS) -L/usr/local/arm/qte-4.8.0/lib /usr/local/arm/opencv/lib/libcv.so /usr/local/arm/opencv/lib/libcvaux.so /usr/local/arm/opencv/lib/libcxcore.so /usr/local/arm/opencv/lib/libhighgui.so /usr/local/arm/opencv/lib/libml.so -lQtGui -L/usr/local/arm/qte-4.8.0/lib -lQtNetwork -lQtCore -lpthread这样的！ 这是没问题的！ 只需在.pro文件里添加：

INCLUDEPATH += /usr/local/arm/opencv/include/opencv
LIBS += /usr/local/arm/opencv/lib/libcv.so \
/usr/local/arm/opencv/lib/libcvaux.so \
/usr/local/arm/opencv/lib/libcxcore.so \
/usr/local/arm/opencv/lib/libhighgui.so \
/usr/local/arm/opencv/lib/libml.so

就可以了！另外在设置export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/arm/opencv/lib,如果你opencv编译正确的话只需这两个额外的设置，qt就可以用opencv了！ 其他的一律多余！

（6）网上至今没有qt下的用opencv的测试程序，我这里提供一个代码，利用cvLoadImage 读一个函数，将IplImage格式转成Qimage格式，并显示出来。图片的路径是/ayan/r3.jpeg。鄙人姓晏，呵呵，在根目录下建文件夹ayan，然后把r3.jpeg拷贝到文件夹下。 在arm板子上也做如下操作。运行前设置export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/arm/opencv/lib就可以了！下载地址我会上传。。。。。

一点疑惑：

1，我在移植qt的时候设置了环境变量export QTDIR=/usr/local/arm/qte-4.8.0


export LD_LIBRARY_PATH=$QTDIR/lib:/usr/local/arm/opencv-2.1/lib:$LD_LIBRARY_PATH
export QT_QWS_FONTDIR=/usr/local/arm/qte-4.8.0/lib/fonts
export QWS_DISPLAY='LinuxFb:mmWidth76:mmHeight44:1'

但在后来的qt测试程序中，我没有设置这些环境变量程序照样运行了！我用env命令查看的确没有这些变量的设置。但用到opencv时 ，就必须设置opencv的lib目录！这是为何？？？

（2）arm板子上 用opencv预览视频，虽然在pc机上跑通了，但在板子上出现了错误，蛋疼啊！段错误！我用的是飞凌的6410上面已经可以播放视频了，请问还需要移植xvid、ffmpeg这些东西吗？？

（3）gtk这个玩意究竟能移植到arm6410上吗？？