Problem with Video Recording in Qt 5.8 on Windows 10

pj0909

Hi all,

I am new to Qt and was trying to explore the video recording through webcam with Qt but I am unable to do so. I am able to access the camera but cannot record the video. Below is my code

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

    camera = new QCamera(this); //  declared in header file as QCamera *camera
    player = new QMediaPlayer(this); // declared in header file as QMediaPlayer *player

    videowidget = new QVideoWidget; // declared in header file as QVideoWidget *videowidget
    player->setVideoOutput(videowidget);

    recorder = new QMediaRecorder(camera,this); // declared in header file as QMediaRecorder *recorder

    QVideoEncoderSettings settings = recorder->videoSettings();
    settings.setCodec("video/mpeg2");
    settings.setResolution(1280,720);
    settings.setQuality(QMultimedia::VeryHighQuality);
    settings.setFrameRate(30.0);
    settings.setEncodingMode(QMultimedia::ConstantQualityEncoding);
    recorder->setVideoSettings(settings);

    camera->setCaptureMode(QCamera::CaptureVideo);
    camera->setViewfinder(ui->viewer);
    camera->start();
}

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

void MainWindow::on_pushButton_clicked()
{
    if(ui->pushButton->text()==tr("Start"))
    {
        QString file = "F:/trial/Qt/VideoRecording";
        QFile file1(file);
        file1.open(QIODevice::WriteOnly);
        recorder->setContainerFormat("mpeg");
        recorder->setOutputLocation(QUrl::fromLocalFile(file));
        recorder->record();
        ui->pushButton->setText(tr("Stop"));
    }
    else
    {
        recorder->stop();
        ui->pushButton->setText(tr("Start"));
    }
}

Can anyone please guide me on my code for video recording?

Thank you for your time and knowledge.

mrjj

Hi
Check path for file.. Does subfolders exits ?
also try to out any errors

qDebug()<<record.state();
qDebug()<<record.status();
qDebug()<<record.error();

( note , syntax for you is recorder-> )

pj0909

@mrjj Yes, the subfolder exists. For the following code:

qDebug()<<recorder.state();
qDebug()<<recorder.status();
qDebug()<<recorder.error();

I get the output as:
QMediaRecorder::StoppedState
QMediaRecorder::UnavailableStatus
QMediaRecorder::NoError

I don't know how to proceed further. Can you please guide me a little bit on this.

mrjj

Hi
Try to hook up the error signal
http://doc.qt.io/qt-5/qmediarecorder.html#error

Also
Im not sure recording is supported in windows
http://doc.qt.io/qt-5/qtmultimedia-windows.html
Limitations:
"Video recording is currently not supported" :(

Alternatively
http://kibsoft.ru/
Have been suggested on SO and here in forum.
I have no experience with it.

ronaldo

Use this:

qDebug() << recorder->isCaptureModeSupported(QCamera::CaptureVideo);

In my case, it returns false. No idea what is needed in terms of hardware and/or software to turn this into true.