QVideo Widget should show the first frame after set it.

KonradMD

Hi,

I am working with a QVideoWidget and if I start my programm a video is set in the background. But it does not show the first frame. So it looks like nothing is load. But if I move the window, I can see the already drawn first frame. But it looks like it is in the background. I really dont know whats in front. It is the same with an resizing event, I directly loose the preview frame.

It is a mediaWidget in the mainwindow, and a QVideowidget with the mediaWidget as parent. So it seems not logic for me.

I implemented everything normaly.

...
mediaPlayerWidget = new QVideoWidget(_pMainWindow);
mediaPlayerWidget->setParent(_pMainUi->mediawidget);

_moviePlayer = new QMediaPlayer(this);
_moviePlayer->setVideoOutput( mediaPlayerWidget);
_moviePlayer->setMedia(QUrl::fromLocalFile(moviePath));
...
void Video::play(state)
{
if(state()!=QMediaPlayer::PlayingState)
{
_moviePlayer->play();
}
}

SGaist

Hi,

Why are you parenting mediaPlayerWidget like that ? That part looks a bit suspicious.

KonradMD

Hi @SGaist

If I want to use a QVideoWidget I could not put it directly into my Qt Creator. So I put a Widget first and then I created a VideoWidget and set the Widget from the QtCreator as parent.

Is there a better way? Just creating the videoWidget and set it to the Layout manually? I tested your way:

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QWidget>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    videoWidgetTransform     = new QVideoWidget(this);
    videoWidgetTransform->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);


    videoWidgetLayout = new QVBoxLayout(this);
    videoWidgetLayout->addWidget(videoWidgetTransform);
    videoWidgetLayout->setMargin(0);

    _videoPlayer =  new QMediaPlayer(this);
    _videoPlayer->setVideoOutput(videoWidgetTransform);
    _videoPlayer->setMedia(QUrl::fromLocalFile("C:/Users/Public/Videos/Sample Videos/Wildlife.wmv"));
   connect(_videoPlayer,SIGNAL(stateChanged(QMediaPlayer::State)),_videoPlayer,SLOT(play()));
}


MainWindow::~MainWindow()
{
    delete ui;
    delete _videoPlayer;
    delete videoWidgetTransform;
    delete videoWidgetLayout;
}
void MainWindow::resizeEvent(QResizeEvent *event)
{
    Q_UNUSED(event)
    QSize s = this->size();



    if(this->height()*16/9>this->size().width() && this->width()*9/16<this->size().height())
    {
        s.setHeight(s.width()*9/16);
        s.setWidth(this->width());

    }
    else
    {
        s.setWidth(s.height()*16/9);
        s.setHeight(this->height());
    }

    videoWidgetTransform->setGeometry((this->width()-s.width())/2,(this->height()-s.height())/2,s.width(),s.height());
}

I still have the same problem, taht the first frame is not shown

SGaist

Why are you not calling the base implementation of resizeEvent ?

KonradMD

How do you mean @SGaist ?
Is below the part of resize Event you mean?

The widget will be erased and receive a paint event immediately after processing the resize event. No drawing need be (or should be) done inside this handler.

I want to resize the videoWidget by 16:9, thats working properly.

SGaist

Have a call to QMainWindow::resizeEvent at the end of the method.

KonradMD

@SGaist said in QVideo Widget should show the first frame after set it.:

Have a call to QMainWindow::resizeEvent at the end of the method.

I dont have another method than resizeEvent(). callinf resizeEvent in resizeEvent would be a loop.
Where exactly would you implement it?

J.Hilk

@KonradMD hi, what @SGaist meant is to add QMainWindow::resizeEvent(event); which is not the same as resizeEvent(event).

resizeEvent() calls your custom overwritten implementation, QMainWindow::resizeEvent calls the base implementation resizeEvent.

KonradMD

Unfortunaly it does not work, I still see the frame when I am resizing, but not when I finished resizing.

Does it work on your systems? Maybe I just have a bad computer ... :/

void MainWindow::resizeEvent(QResizeEvent *event)
{
    Q_UNUSED(event)
    QSize s = this->size();



    if(this->height()*16/9>this->size().width() && this->width()*9/16<this->size().height())
    {
        s.setHeight(s.width()*9/16);
        s.setWidth(this->width());

    }
    else
    {
        s.setWidth(s.height()*16/9);
        s.setHeight(this->height());
    }

    videoWidgetTransform->setGeometry((this->width()-s.width())/2,(this->height()-s.height())/2,s.width(),s.height());
    QMainWindow::resizeEvent(event);
}