How to use the QMediaPlayer module to connect to a rtsp stream?

Question

I'm creating an RTSP stream using FFmpeg:

ffmpeg -f gdigrab -framerate 30 -probesize 100M -i title="" -c:v libx264 -preset veryfast -maxrate 1000k -bufsize 1000k -pix_fmt yuv420p -g 50 -c:a aac -b:a 128k -f rtsp -rtsp_transport udp rtsp://...129:8554/stream

and trying to connect to it using the Qt module QMediaPlayer.

It stuck for many seconds when it read the line player->setSource(QUrl("rtsp://....129:8554/stream"));

and then debug this message:

qt.multimedia.ffmpeg.mediadataholder: AVStream duration -9223372036854775808 is invalid. Taking it from the metadata

Also, connect(player, &QMediaPlayer::errorOccurred print:

Error: "Invalid argument"

class MediaPlayer : public QObject
{
    Q_OBJECT
public:
    MediaPlayer (QObject* parent = nullptr) : QObject(parent)
    {
        player = new QMediaPlayer;
        player->setSource(QUrl("rtsp://....129:8554/stream"));
        connect(player, &QMediaPlayer::errorOccurred, this, [this](QMediaPlayer::Error error, const QString& errorString)
        {
            qDebug() << "Error:" << errorString;
        });

        videoWidget = new QVideoWidget;
        player->setVideoOutput(videoWidget);

        videoWidget->show();
        player->play();
    }

private:
    QMediaPlayer* player;
    QVideoWidget* videoWidget;
};

Testing the exactly same streamUrl on vlc does work correctly. I'm using Qt 6.6, and Win10. ffmpeg 6.0

How I could debug this?

Answer 1

On the window platform, use the ffmpeg backend, currently Qt does not support playing rtsp video streams.

If you want to support rtsp protocol, you need to compile qt & ffmpeg yourself

--enable-protocol=rtsp

qt 6.5 build config Env.FFMPEG_DIR_MSVC ref https://wiki.qt.io/Qt_6.5_Tools_and_Versions

Answer 2

FFMpeg in Qt does not support RTSP streams directly. If you want, you can use GStreamer. By changing the environment variable to gstreamer. Please see these links:

QtMultimedia

QPut Env