ASSERT: “m_surface” when playing video

matuQt

Hi,

I am having a problem when trying to display a video in a QGraphicsview on Windows. I am constantly getting an assert in debug

Program: c:\Qt\Qt5.3.2\5.3\msvc2013_64_opengl\bin\Qt5Cored.dll
Module: 5.3.2
File: global\qglobal.cpp
Line: 2127

ASSERT: “m_surface” in file player\mfvideorenderercontrol.cpp, line 2349

Which I can ignore and it will work, however in release mode, it crashes instead.

Is there some call that I should be making prior to ensure that m_surface is never null by the time it hits this line?
more informations:
Os: windows 8.1 64 bit

this is snip of my code
@ QGraphicsScene *scene;
QMediaPlayer mp;
QGraphicsVideoItem v;
scene = new QGraphicsScene;
ui->graphicsView->setScene(scene);
QStringList list;
list <<QString("D:/files/3240/mov/1.mov") << QString("D:/files/3240/videos/newmov/1.mov")<<
QString("D:/files/3240/videos/3.mov")<< QString("D:/files/3240/videos/4.mov")
<<QString("D:/files/3240/videos/5.mov");
mp.setVideoOutput(&v);
mp.setMedia(QUrl::fromLocalFile(list.at(i%5)));
mp.play();
mp.setVolume(0);
scene->addItem(&v);@

SGaist

Hi,

Where's that code called from ?

matuQt

in the Button click event

matuQt

this is my code
@#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
i = 0;
scene = new QGraphicsScene;
ui->graphicsView->setScene(scene);
// setWindowFlags(Qt::FramelessWindowHint);
}

MainWindow::~MainWindow()
{
delete ui;
}

void MainWindow::resizeEvent(QResizeEvent *)
{

}

void MainWindow::mousePressEvent(QMouseEvent *)
{

}

void MainWindow::on_pushButton_clicked()
{
resize(1080,400);
QStringList list;
list <<QString("D:/files/3240/mov/1.mov") << QString("D:/files/3240/videos/newmov/1.mov")<<
QString("D:/files/3240/videos/3.mov")<< QString("D:/files/3240/videos/4.mov")
<<QString("D:/files/3240/videos/5.mov");
mp.setVideoOutput(&v);
mp.setMedia(QUrl::fromLocalFile(list.at(i%5)));
mp.play();
mp.setVolume(0);
scene->addItem(&v);
//v->setSize(QSize(width(),height()));
i++;
}
@

SGaist

What is w ?

matuQt

w? didn't exist any w in this code. but if your mean is v.
v is QGraphicsVideoItem and mp is QMediaPlayer

SGaist

What happens if you start playing only after adding v to the scene ?

matuQt

at this time it show me the mention assert error

SGaist

Since Qt 5.4 has been released, can you check if you still encounter this problem ?

matuQt

yes , i don't have any idea to solve it

SGaist

Yes you will test or yes you still have this problem ?

matuQt

both, i tested Qt5.4 and the error exist in Qt 5.4

SGaist

Where's the assert located this time ?

Did you install the latest driver for your graphic card ?

matuQt

i update my graphic card again and the assert error does exist yet :( . what should i do to solve it?

SGaist

@
mp.setVideoOutput(&v);
scene->addItem(&v);
@

I'd move that in the constructor, there's no need to do that again each time.