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mysteryli

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注册时间： 2020-03-05

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opencv链接库顺序问题

在qtcreator中引入qt库，头文件引入成功，pro文件添加库文件时候遇到错误
编译器是arm-linux-gnueabihf V6.3.1
编译的时候提示很多未定义的引用，猜测是库的问题，已经包含了-lz -ldl
后来百度发现说库的顺序也有要求，但是opencv那么多库，我没法排列组合的尝试啊，不知道有没有固定的顺序去链接？

mysteryli

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已发帖子： 485

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Re: opencv链接库顺序问题

报错截图及pro文件，代码如下

pro文件

#-------------------------------------------------
#
# Project created by QtCreator 2021-03-28T16:31:53
#
#-------------------------------------------------

QT       += core gui
QT       +=  network
QT       += multimedia
QT       += multimediawidgets

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = untitled
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0


SOURCES += main.cpp\
        widget.cpp

HEADERS  += widget.h

FORMS    += widget.ui

INCLUDEPATH +=  /opt/opencv/include \
                /opt/opencv/include/opencv \
                /opt/opencv/include/opencv2

LIBS    +=  -L/opt/opencv/lib   -lopencv_calib3d    -lopencv_core   -lopencv_dnn    -lopencv_features2d \
                                -lopencv_flann  -lopencv_highgui    -lopencv_imgcodecs  -lopencv_imgproc    \
                                -lopencv_ml -lopencv_objdetect  -lopencv_photo  -lopencv_shape  -lopencv_stitching  \
                                -lopencv_superres   -lopencv_video  -lopencv_videoio    -lopencv_videostab  \
                                -lopencv_videoio -lopencv_video  -lopencv_superres   -lopencv_stitching  \
                                -lopencv_shape  -lopencv_photo  -lopencv_objdetect  -lopencv_ml -lopencv_imgproc    \
                                -lopencv_imgcodecs  -lopencv_highgui    -lopencv_flann  -lopencv_features2d \
                                -lopencv_dnn    -lopencv_core   -lopencv_calib3d    -ldl
LIBS    +=  -L/opt/zlib/lib -lz
#LIBS    +=  /opt/opencv/lib/libopencv_core.a \
#            /opt/opencv/lib/libopencv_imgproc.a \
#            /opt/opencv/lib/libopencv_imgcodecs.a \
#            /opt/opencv/lib/libopencv_flann.a \
#            /opt/opencv/lib/libopencv_highgui.a \
#            /opt/opencv/lib/libopencv_calib3d.a \
#            /opt/opencv/lib/libopencv_ml.a \
#            /opt/opencv/lib/libopencv_objdetect.a \
#            /opt/opencv/lib/libopencv_photo.a \
#            /opt/opencv/lib/libopencv_ml.a \
#            /opt/opencv/lib/libopencv_features2d.a \
#            /opt/opencv/lib/libopencv_superres.a \
#            /opt/opencv/lib/libopencv_videoio.a \
#            /opt/opencv/lib/libopencv_video.a \
#            /opt/opencv/lib/libopencv_videostab.a \
#            /opt/opencv/lib/libopencv_imgproc.a \
#            /opt/opencv/lib/libopencv_calib3d.a \
#            /opt/opencv/lib/libopencv_core.a \

void Widget::on_CamTest_clicked()
{
    cout << "cam test is clicked" << endl;
    cout << "Built with OpenCV " << CV_VERSION << endl;

    Mat image;
    VideoCapture capture;
    capture.open(0);
    if(capture.isOpened()){
        cout << "Capture is opened" << endl;
        for(;;){
            capture >> image;
            QCoreApplication::processEvents();
            if(image.empty())
                break;
            if(waitKey(10) >= 0)
                break;
            cout << "get a fram pic" << endl;
        }
    }
    else{
        cout << "no camera" << endl;
    }
}

mysteryli

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Re: opencv链接库顺序问题

缺jpeg解码库，试一试加 -ljpeg

好的 我交叉编译下jpeg，不过opencv内部的函数也提示链接错误！

mysteryli

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Re: opencv链接库顺序问题

还缺几个链接库, WebPDecodeBGRInto 等

这些函数都是opencv提示的demo 应该用不到这么多的库啊
我再其他板子上测试过 根本没装这么多库呀
感觉是跟库的引用顺序有关吧

最近编辑记录 mysteryli (2021-04-02 21:37:21)

mysteryli

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注册时间： 2020-03-05

已发帖子： 485

积分： 390

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Re: opencv链接库顺序问题

还缺几个链接库, WebPDecodeBGRInto 等

这些函数都是opencv提示的demo 应该用不到这么多的库啊
我再其他板子上测试过 根本没装这么多库呀
感觉是跟库的引用顺序有关吧

-lwebp

我先把webp和jpeg交叉编译一下吧...
真担心湖面还会不会在缺什么，交叉编译好麻烦的说

mysteryli

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注册时间： 2020-03-05

已发帖子： 485

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Re: opencv链接库顺序问题

-lwebp

我先把webp和jpeg交叉编译一下吧...
真担心湖面还会不会在缺什么，交叉编译好麻烦的说

buildroot解君愁

没啥区别的，编译完电脑上还要有一份，因为电脑上编译也要用，所以和交叉编译差不多
我的问题解决完了 mat image可以用了
不过还不能用capture去打开摄像头，估计是因为没有交叉编译ffmpeg的缘故，毕竟opencv底层摄像头操作也用ffmpeg...