qt6+opencv获取视频帧

QT版本：QT 6.3

OpenCV版本：opencv 4.6

编译环境：MSVC 2019 64bit

主要功能：通过OpenCV实现提取视频的单个视频帧图像或者全部视频帧图像，还可以获取视频的宽度、高度、帧率、帧数等，可自己添加。

opencv的配置我这里采用的MSVC的编译环境，可以直接导入外部库即可使用，部分步骤如下：

1. 右键项目，添加库，外部库 

2. 选择库文件路径如下，选择包含路径如下

opencv方法实现类

opencv.h

#ifndef OPENCV_H
#define OPENCV_H

#include 
#include 
#include 
#include 
#include 
#include 

using namespace cv;

class opencv : public QObject
{
    Q_OBJECT
public:
    explicit opencv(QObject *parent = nullptr);

    void setVideoCapture(VideoCapture cap);
    VideoCapture getVideoCapture();
    bool openVideo(QString path);
    int getFrameNum();
    int getFrameRate();
    int getFrameWidth();
    int getFrameHeight();
    QImage getOneFrame(int posNum);
    QList getAllFrame();
    QImage MatToQImage(const cv::Mat& mat);

    void test01();

signals:

private:
    VideoCapture m_cap;

};

#endif // OPENCV_H

opencv.cpp

#include "opencv.h"
#include 

opencv::opencv(QObject *parent)
    : QObject{parent}
{
    /* template:
    QImage img;
    QList imgList;
    openVideo("F:/videoTest.mp4");
    test01();
    // 获取指定帧数的单个视频帧
    img = getOneFrame(89);
    img.save("imgimg.png");
    // 获取全部视频帧
    imgList = getAllFrame();
    for(int i = 0; i < getFrameNum(); i++)
    {
        imgList.at(i).save(QString("img%1.png").arg(i));
    }
    */
}
// 设置VideoCapture
void opencv::setVideoCapture(VideoCapture cap)
{
    this->m_cap = cap;
}
// 获取VideoCapture
VideoCapture opencv::getVideoCapture()
{
    return this->m_cap;
}
// 打开视频
bool opencv::openVideo(QString path)
{
    this->m_cap.open(path.toStdString());
    if(!m_cap.isOpened())
    {
        qDebug() << "video open fail";
        return false;
    }
    return true;
}
// 获取总帧数
int opencv::getFrameNum()
{
    return this->m_cap.get(CAP_PROP_FRAME_COUNT);
}
// 获取帧率
int opencv::getFrameRate()
{
    return this->m_cap.get(CAP_PROP_FPS);
}
// 获取宽度
int opencv::getFrameWidth()
{
    return this->m_cap.get(CAP_PROP_FRAME_WIDTH);
}
// 获取高度
int opencv::getFrameHeight()
{
    return this->m_cap.get(CAP_PROP_FRAME_HEIGHT);
}
// 获取指定位置的视频帧
QImage opencv::getOneFrame(int posNum)
{
    QImage img;
    Mat frame;

    if(!this->m_cap.isOpened())
    {
        qDebug() << "video open fail";
        return img;
    }

    if(posNum >= getFrameNum())
    {
        qDebug() << "video frame position num overflow";
        return img;
    }

    this->m_cap.set(CAP_PROP_POS_FRAMES, posNum);
    if(!this->m_cap.grab())
    {
        qDebug() << "grab in opencv failed";
        return img;
    }
    this->m_cap >> frame;
    img = MatToQImage(frame);

    return img;
}
// 获取全部视频帧
QList opencv::getAllFrame()
{
    QList imgList;

    for(int i = 0; i < getFrameNum(); i++)
    {
        imgList.insert(i, getOneFrame(i));
    }

    return imgList;
}
// Mat转图像
QImage opencv::MatToQImage(const cv::Mat& mat)
{
    // 8-bits unsigned, NO. OF CHANNELS = 1
    if (mat.type() == CV_8UC1)
    {
        QImage image(mat.cols, mat.rows, QImage::Format_Indexed8);
        // Set the color table (used to translate colour indexes to qRgb values)
        image.setColorCount(256);
        for (int i = 0; i < 256; i++)
        {
            image.setColor(i, qRgb(i, i, i));
        }
        // Copy input Mat
        uchar *pSrc = mat.data;
        for (int row = 0; row < mat.rows; row++)
        {
            uchar *pDest = image.scanLine(row);
            memcpy(pDest, pSrc, mat.cols);
            pSrc += mat.step;
        }
        return image;
    }
    // 8-bits unsigned, NO. OF CHANNELS = 3
    else if (mat.type() == CV_8UC3)
    {
        // Copy input Mat
        const uchar *pSrc = (const uchar*)mat.data;
        // Create QImage with same dimensions as input Mat
        QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_RGB888);
        return image.rgbSwapped();
    }
    else if (mat.type() == CV_8UC4)
    {
        // Copy input Mat
        const uchar *pSrc = (const uchar*)mat.data;
        // Create QImage with same dimensions as input Mat
        QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_ARGB32);
        return image.copy();
    }
    else
    {
        return QImage();
    }
}

void opencv::test01()
{
    qDebug() << getFrameWidth() << getFrameHeight() << getFrameRate() << getFrameNum();
}

3. 编译后出现缺失文件提示，则将对应文件拷贝至编译文件内即可

项目资源免费下载地址：

qt6+opencv获取视频帧图像源码-QT文档类资源-CSDN下载

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