QT+Opencv实现视频流播放

左手的ㄟ右手 2022-12-10 02:26 356阅读 0赞

# 1.简单流程 #

首先通过opencv打开视频流，获取到数据帧，然后将数据帧转换为QT可识别的图像，显示到QT界面上。

# 2.opencv解码线程源码 #

//DecodeOpencv.h
    
    #pragma once
    
    #include <QThread>
    #include <QObject>
    
    #include "opencv2/core/core.hpp"
    #include "opencv2/highgui/highgui.hpp"
    #include "opencv2/imgproc/imgproc.hpp"
    
    class DecodeOpencv : public QThread
    {
    	Q_OBJECT
    
    Q_SIGNALS:
    	void sigSendFrame(cv::Mat mat);
    
    public:
    	DecodeOpencv(QObject *parent = nullptr);
    	~DecodeOpencv();
    
    public:
    	void setUrl(QString url);
    
    	void setStoped(bool stop);
    
    protected:
    	void run();
    
    private:
    	QString m_rtsp;
    
    	bool m_isStop = false;
    };

//DecodeOpencv.cpp
    
    #include "DecodeOpencv.h"
    #include <QDebug>
    
    DecodeOpencv::DecodeOpencv(QObject *parent)
    	: QThread(parent)
    {
    	qRegisterMetaType<cv::Mat>("cv::Mat");
    }
    
    DecodeOpencv::~DecodeOpencv()
    {
    	m_isStop = true;
    }
    
    void DecodeOpencv::setUrl(QString url)
    {
    	m_rtsp = url;
    }
    
    void DecodeOpencv::setStoped(bool stop)
    {
    	m_isStop = stop;
    }
    
    void DecodeOpencv::run()
    {
    	cv::VideoCapture cap;
    
    	if (m_rtsp.isEmpty())
    	{
    		qDebug() << "未找到视频流地址";
    		return;
    	}
    	bool suc = false;
    	if (m_rtsp.contains("localhost:camera"))
    	{
    		suc = cap.open(0); //打开本地摄像头
    	}
    	else
    	{
    		suc = cap.open(m_rtsp.toStdString()); //打开网络流地址
    	}
    
    	if (!suc)
    	{
    		qDebug() << "播放失败";
    		return;
    	}
    
    	while (true)
    	{
    		if (!m_isStop)
    		{
    			cv::Mat frame;
    			cap >> frame;
    			if (frame.empty())
    			{
    				qDebug() << "播放帧解析失败";
    				continue;
    			}
    			emit sigSendFrame(frame);
    		}
    		else
    		{
    			qDebug() << "停止播放";
    			break;
    		}
    	}
    }

# 3.QT界面 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d6ejk1MzIwMDQ2Mw_size_16_color_FFFFFF_t_70][]

//ShowMatWidget.h
    
    #pragma once
    
    #include <QWidget>
    #include "ui_ShowMatWidget.h"
    #include "DecodeOpencv.h"
    
    class ShowMatWidget : public QWidget
    {
    	Q_OBJECT
    
    public:
    	ShowMatWidget(QWidget *parent = Q_NULLPTR);
    	~ShowMatWidget();
    
    private Q_SLOTS:
    	void slotBtnConnected();
    
    	void slotGetFrame(cv::Mat mat);
    
    	QImage cvMat2QImage(const cv::Mat& mat);
    
    private:
    	Ui::ShowMatWidget ui;
    
    	DecodeOpencv *m_thread = nullptr;
    };

//ShowMatWidget.cpp
    
    #include "ShowMatWidget.h"
    
    #include <QDebug>
    
    ShowMatWidget::ShowMatWidget(QWidget *parent)
    	: QWidget(parent)
    {
    	ui.setupUi(this);
    
    	m_thread = new DecodeOpencv(this);
    
    	connect(m_thread, &DecodeOpencv::sigSendFrame, this, &ShowMatWidget::slotGetFrame);
    
    	connect(ui.pushButton, &QPushButton::clicked, this, &ShowMatWidget::slotBtnConnected);
    }
    
    ShowMatWidget::~ShowMatWidget()
    {
    }
    
    void ShowMatWidget::slotBtnConnected()
    {
    	m_thread->setUrl(ui.lineEdit->text());
    	m_thread->start();
    }
    
    void ShowMatWidget::slotGetFrame(cv::Mat mat)
    {
    	QImage image = cvMat2QImage(mat);
    
    	ui.label->setPixmap(QPixmap::fromImage(image));
    }
    
    QImage ShowMatWidget::cvMat2QImage(const cv::Mat& mat)
    {
    	//8位，通道数为1
    	if (mat.type() == CV_8UC1)
    	{
    		QImage image(mat.cols, mat.rows, QImage::Format_Indexed8);
    		image.setColorCount(256);
    		for (int i = 0; i < 256; i++)
    		{
    			image.setColor(i, qRgb(i, i, i));
    		}
    
    		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位，通道数为3
    	else if (mat.type() == CV_8UC3)
    	{
    		const uchar *pSrc = (const uchar*)mat.data;
    		QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_RGB888);
    		return image.rgbSwapped();
    	}
    	//8位，通道数为4
    	else if (mat.type() == CV_8UC4)
    	{
    		qDebug() << "CV_8UC4";
    
    		const uchar *pSrc = (const uchar*)mat.data;
    		QImage image(pSrc, mat.cols, mat.rows, mat.step, QImage::Format_ARGB32);
    		return image.copy();
    	}
    	//32位，通道数为3
    	else if (mat.type() == CV_32FC3)
    	{
    		cv::Mat temp;
    		mat.convertTo(temp, CV_8UC3);
    
    		const uchar *pSrc = (const uchar*)temp.data;
    		QImage image(pSrc, temp.cols, temp.rows, temp.step, QImage::Format_RGB888);
    		return image.rgbSwapped();
    	}
    	else
    	{
    		qDebug() << "ERROR: Mat could not be converted to QImage.";
    		return QImage();
    	}
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d6ejk1MzIwMDQ2Mw_size_16_color_FFFFFF_t_70]: /images/20221123/a41322eac1144b37ac5fd0457983917e.png