How to play video using libavcodec frames using QLable Widget

[vijayQt]

Hi All,
I am new to Qt and am implementing video phone in my new company. For displaying video I choosed QLable Widget and I am able to play video frame by frame, But when I trying to
display all frames in one shot It's not displaying (I put nextFrame function in a loop to diplay continue frames). Only I am seeing last frame . Is this correct approach or am I doing anything wrong here.
Please help me to come out of this problem.


Here is my code:

/************************************/
Working code: Frame by Frame display   
/************************************/
 
void MainWindow::image2Pixmap(QImage &img,QPixmap &pixmap)
{
      // Convert the QImage to a QPixmap for display
      pixmap = QPixmap(img.size());
      QPainter painter;
      painter.begin(&pixmap);
      painter.drawImage(0,0,img);
      painter.end();
}
 
 
void MainWindow::displayFrame()
{.
.
.
.....
 
QPixmap p;
   image2Pixmap(img,p);
   // Display the QPixmap
   ui->labelVideoFrame->setPixmap(p);
....
....
}
 
 
void MainWindow::on_pushButtonNextFrame_clicked()
{
   if(!decoder.seekNextFrame())
      {
         QMessageBox::critical(this,"Error","seekNextFrame failed");
   }
 
   decoder.decodeSeekFrame();
 
   displayFrame();
}
 
/*********************************/
Not Working: play all frames in one shot (playing video)
/*********************************/
void MainWindow::on_pushButtonNextFrame_clicked()
{
   while(decoder.seekNextFrame()) {
 
       decoder.decodeSeekFrame();
 
      displayFrame();
    }
}

/************************************/
Working code: Frame by Frame display   
/************************************/
   
void MainWindow::image2Pixmap(QImage &img,QPixmap &pixmap)
{
      // Convert the QImage to a QPixmap for display
      pixmap = QPixmap(img.size());
      QPainter painter;
      painter.begin(&pixmap);
      painter.drawImage(0,0,img);
      painter.end();
}


void MainWindow::displayFrame()
{.
.
.
.....

QPixmap p;
   image2Pixmap(img,p);
   // Display the QPixmap
   ui->labelVideoFrame->setPixmap(p);
....
....
}


void MainWindow::on_pushButtonNextFrame_clicked()
{
   if(!decoder.seekNextFrame())
      {
         QMessageBox::critical(this,"Error","seekNextFrame failed");
   }

   decoder.decodeSeekFrame();

   displayFrame();
}

/*********************************/
Not Working: play all frames in one shot (playing video)
/*********************************/
void MainWindow::on_pushButtonNextFrame_clicked()
{
   while(decoder.seekNextFrame()) {

       decoder.decodeSeekFrame();

      displayFrame();
    }
}

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Thanks in advance