QOpenGLWidget strage result

gfxx

I update my app, from QT4.8 to QT5.12. GLwidget is obsolete so I use QOpenGLWidget instead and I make a Subclass for drive my widget and webcam.

The problem:

When the GLwidget is active the rendering slows down to 5/10 fps and sometimes it shows instead that a whole image shows 8 identical images (or 6 I don't understand is very fast and like a noise). If, on the other hand, the same stream is on a window opened with opencv and GLwidget is not active (I have a page with GLwidget and a page for debugging) the video runs at 35fps without disturbances.

My cpp file:

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include "glwidg.h"

#include <QThread>
#include <QtCore>
#include <QtConcurrent/QtConcurrent>
#include <QtConcurrent/QtConcurrentRun>
#include <QFuture>
#include <QFutureWatcher>
#include <QtWidgets>
#include <QtWidgets/QAction>
#include <QtWidgets/QWidget>
#include <QtWidgets/QWidgetAction>
#include <QtWidgetsDepends>
#include <QtWidgetsVersion>
#include <QTableWidget>
#include <QTableWidgetItem>
#include <QTableWidgetSelectionRange>
#include <QTableView>

#include <opencv2/opencv.hpp>
#include <opencv2/highgui.hpp>
#include <iostream>
#include <math.h>
#include <stdio.h>
#include <opencv2/opencv.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/core/core.hpp>
#include <sstream>
#include <string.h>
#include <GL/glu.h>
#include <GL/glut.h>
#include <GL/freeglut.h>
#include <GL/glu.h>
#include <QtOpenGL/QGLWidget>
#include <QtOpenGL/QtOpenGL>
#include <QtOpenGL/QGLBuffer>
#include <GLES3/gl3.h>
#include <QOpenGLFunctions>
#include <QtOpenGL/QGLBuffer>
#include <QtOpenGL/QtOpenGL>
#include <QTime>
#include <QTimer>
#include <QDebug>


QImage camera000;
GLuint texture[1];
QImage GL_formatt;
QImage qform;
QImage qform1;
int cambio1 = 0;

cv::Mat imma2;
cv::Mat imma3;


int play = 0;


GLwidg::GLwidg(QWidget *parent) :
    QOpenGLWidget(parent)

{

    this->setAttribute(Qt::WA_DeleteOnClose);

    update();


}

int GLwidg::xAtPress = 0;
int GLwidg::yAtPress = 0;
int GLwidg::xsend = 0;
int GLwidg::ysend = 0;
cv::Point GLwidg::SendMousePoint(0,0);


void GLwidg::mouseMoveEvent(QMouseEvent * event)
{


    xAtPress = event->x();
    yAtPress = event->y();
    xsend = round(xAtPress*1.422222222);
    ysend = round(yAtPress*1.2);
    SendMousePoint = cv::Point(xsend, ysend);
    emit MousePoint(SendMousePoint);

}



void GLwidg::paintGL()
{
    //makeCurrent();
    glClear(GL_COLOR_BUFFER_BIT);



    if (cambio1 == 0)
    {
        qform1.load("/home/mine/images/image480.png");
        qq1frame = qform1.scaled(this->size(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
    }
    else
    {
        qq1frame = qform1.scaled(this->size(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
    }



    qqframe = qq1frame.mirrored(false, true);

    if(!qqframe.isNull()) /* use for render image but when active  */
    {
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        qqframe = qqframe.scaled(QSize(480,360), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);

        // or do 2D texture mapping
        glMatrixMode(GL_MODELVIEW); /**/
        glEnable(GL_DEPTH_TEST);
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        gluOrtho2D(0,qqframe.width(),qqframe.height(),0);
        glMatrixMode(GL_MODELVIEW);
        //glDisable(GL_DEPTH_TEST);
        glLoadIdentity();
        glEnable(GL_TEXTURE_2D);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexImage2D( GL_TEXTURE_2D, 0, 4, qqframe.width(), qqframe.height(), 0, GL_BGRA, GL_UNSIGNED_BYTE, qqframe.bits() );
        glBegin(GL_QUADS);
        glTexCoord2f(0,0); glVertex2f(0,qqframe.height());
        glTexCoord2f(0,1); glVertex2f(0,0);
        glTexCoord2f(1,1); glVertex2f(qqframe.width(),0);
        glTexCoord2f(1,0); glVertex2f(qqframe.width(),qqframe.height());
        glEnd();
        glDisable(GL_TEXTURE_2D);

        glDisable(GL_DEPTH_TEST);


        glFlush();

     }

    if(qqframe.isNull())
    {
        qform1.load("/home/mine/images/image480.png");
        qq1frame = qform1.scaled(this->size(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
    }


    update();

    //qDebug() << "x:   " << qqframe.width() << "y:   " << qqframe.height();

}




void GLwidg::donextcam() /* never use*/
{

    update();

}


void GLwidg::imma_orig_r1(QImage qi1) /* use for update widget with new image captured from other thread and processed from opencv computation */
{
    //qDebug() << "new image to render .....";
    cambio1 = 1;
    qform1 = qi1;
    //glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    //makeCurrent();
    //paintGL();
    update();

}

void GLwidg::stopcam1(bool st1) /* use only for stop webcam */
{
    if (st1)
    {
        cambio1 = 0;
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        //paintGL();
        update();
    }
    else
    {
        cambio1 = 1;
    }
}

I am afraid that my code for rendering on textures is wrong and therefore generates the problem I reported .... Could someone tell me if there is any weirdness?

gfx

gfxx

The problem was not on QOpenGLWidget function .... but on Mat2Qimage function that send image to QOpenGLWidget .... Mat2Qimage fucntion require "cost" mat on input .... my old function:

void thread::Mat2QImage(cv::Mat const& src)
{

    if(!src.empty())
    {
        //cv::Mat test33; <<<<<---------- the error
        cvtColor(src, test33, COLOR_BGR2RGB);
        QImage dest33 = QImage((uchar*)test33.data, test33.cols, test33.rows, test33.step, QImage::Format_RGB888);
        emit _img(dest33);
    }

}

when declare test33 as static cv::Mat all problem disappear .... probabily old opencv3.2, old QT4 can correctly convert image format without problem .... now the street is less large ....

SGaist

Hi,

You are using a constructor that does not copy the data hence you likely have an object lifetime issue.

Ensure you generate a copy of the QImage before emitting it and you should be good to go.

Note that if you do not change the size of the image, you could make dest33 a member variable and then use it as a target for cvtColor.

gfxx

@SGaist sorry for delay. The project was paused until now.
Real thanks you are in right .... thanks again