使用 OpenCV 和 Qt 打开视频时出错

Posted 2023-02-14

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【中文标题】使用 OpenCV 和 Qt 打开视频时出错【英文标题】：Error while opening a video with OpenCV and Qt 【发布时间】：2013-12-17 09:05:26 【问题描述】：

当我想要获取视频捕获以在图像中逐帧查看时，我有大约 15 个错误。

首先我从我的链接调用我的视频。

然后从中获取我的框架。

然后转换成图片。

最后在像素图中查看。

我的代码

#include "form1.h"
#include "ui_form1.h"
#include <QtCore>
#include <QtGui>
#include <QGraphicsAnchorLayout>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsWidget>
#include "qimage.h"
#include <QFileDialog>
#include <QPixmap>
#include "qpixmap.h"

Form1::Form1(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Form1)

    ui->setupUi(this);
    video->open("D:/Downloads/DirectX/Zlatan Ibrahimovic ● Taekwondo Goals.mp4");
    timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(updatePicture()));
    timer->start(20);


QString fileName;

QImage Form1::getQImageFromFrame(cv::Mat frame) 
    //converts the color model of the image from RGB to BGR because OpenCV uses BGR
    cv::cvtColor(frame, frame, CV_RGB2BGR);
    return QImage((uchar*) (frame.data), frame.cols, frame.rows, frame.step, QImage::Format_RGB888);


Form1::~Form1()

    delete ui;


void Form1::updatePicture()

    cv::Mat frame1;
    video->operator >>( frame1);
    img = getQImageFromFrame(frame1);
    ui->label->setPixmap(QPixmap::fromImage(img));



void Form1::on_pushButton_clicked()

    //fileName = QFileDialog::getOpenFileName(this,
        //tr("Open Image"), "/elhandasya/Desktop", tr("Image Files (*.png *.jpg *.bmp)"));
    //QPixmap pix(fileName);

这样的错误：

undefined reference to `cv::Mat::Mat()
D:\ubunto\QT5\Tools\QtCreator\bin\Video_Player-build-Desktop_Qt_5_0_1_MinGW_32bit-Debug\debug\form1.o:-1: In function `ZN5Form1D2Ev'

我的库

#-------------------------------------------------
#
# Project created by QtCreator 2013-12-16T09:23:28
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = Video_Player
TEMPLATE = app


SOURCES += main.cpp\
        form1.cpp

HEADERS  += form1.h

FORMS    += form1.ui

INCLUDEPATH += -I"D:/ubunto/OpenCV/opencv/build/include/opencv2/imgproc"
INCLUDEPATH += -I"D:/ubunto/OpenCV/opencv/build/include/"
#INCLUDEPATH += "D:/ubunto/OpenCV/opencv/build/include/"


LIBS += -LD:/ubunto/OpenCV/opencv/build/x86/mingw/bin
 -lopencv_core
 -lopencv_imgproc
 -lopencv_highgui
 -lopencv_legacy
 -lopencv_gpu
 -lopencv_video
 -lopencv_ml
 -lopencv_contrib


#LIBS += D:\ubunto\emgu\emgucv-windows-x86 2.4.0.1717\lib


#-opencv_calib3d240
#-opencv_videostab240
#-opencv_calib3d240
#-opencv_contrib240
#-opencv_core240
#-opencv_features2d240
#-opencv_flann240
#-opencv_gpu240
#-opencv_highgui240
#-opencv_imgproc240
#-opencv_legacy240
#-opencv_ml240
#-opencv_nonfree240
#-opencv_objdetect240
#-opencv_photo240
#-opencv_stitching240
#-opencv_video240

【问题讨论】：

你能用qt-creator编译和链接一个简单的hello world opencv程序吗？你使用 windows 和 minGW 吗？这些库真的在 /bin 文件夹中还是 /lib 文件夹中？不，我不能:(我试图编译一个新项目，但我不能这样做我应该怎么做才能编译它？？？你用的是windows还是linux？您从哪里获得 OpenCV 库（您是自己构建的还是预先构建的）？ D:/ubunto/OpenCV/opencv/build/x86/mingw/bin 中有哪些文件以及 ``D:/ubunto/OpenCV/opencv/build/x86/mingw` 中的所有文件夹是什么？有人可以修正语法吗？它的英文读起来很糟糕，但我目前没有足够的时间。 'D:/ubunto/OpenCV/opencv/build/x86/mingw/bin'.dll中的文件类型和D:/ubunto/OpenCV/opencv/build/x86/mingwmingw文件夹VC9文件夹VC10文件夹中的文件夹 【参考方案1】：

如果您查看cvVideo的源代码（一个展示如何创建 Qt 窗口以显示使用 OpenCV 加载的视频的应用程序），您可以看看如何实现您的目标。

cvVideo.pro：

TEMPLATE = app

QT      += core gui

contains(QT_VERSION, ^5\\.[0-8]\\..*) 
        message("* Using Qt $$QT_VERSION.")
        QT += widgets

        # On my system I have to specify g++ as compiler else it will use clang++ by default
        #QMAKE_CXX=g++
        #QMAKE_CC=gcc


HEADERS += \
    cvWindow.h

SOURCES += \
    main.cpp \
    cvWindow.cpp

## OpenCV settings for Unix/Linux
unix:!mac 
        message("* Using settings for Unix/Linux.")
    INCLUDEPATH += /usr/local/include/opencv

    LIBS += -L/usr/local/lib/ \
        -lopencv_core \
        -lopencv_highgui \
        -lopencv_imgproc


## OpenCV settings for Mac OS X
macx 
        message("* Using settings for Mac OS X.")
    INCLUDEPATH += /usr/local/include/opencv

    LIBS += -L/usr/local/lib/ \
        -lopencv_core \
        -lopencv_highgui \
        -lopencv_imgproc


## OpenCV settings for Windows and OpenCV 2.4.2
win32 
        message("* Using settings for Windows.")
    INCLUDEPATH += "C:\\opencv\\build\\include" \
                   "C:\\opencv\\build\\include\\opencv" \
                   "C:\\opencv\\build\\include\\opencv2"

    LIBS += -L"C:\\opencv\\build\\x86\\vc10\\lib" \
        -lopencv_core242 \
        -lopencv_highgui242 \
        -lopencv_imgproc242


# Runs this app automatically after the building has succeeded
#QMAKE_POST_LINK=./$$TARGET

【讨论】：

我的代码也使用了 QT5 并且打算在 Windows/Linux/Mac OS X 上编译。【参考方案2】：

错误告诉您必须在 makefile 中链接包含 Mat 的特定库：