The VideoLAN Forums

Posted: **10 Mar 2020 21:06**

And calling libvlc_video_set_scale just interrupts the program without any messages. In version 3 everything works correctly. Help, please, what am I doing wrong?

Code: Select all

int main(int argc, char *argv[])
{
	libvlc_instance_t* inst = libvlc_new(0, NULL);
	libvlc_media_t* m = libvlc_media_new_path(inst, "1.mp4");
	libvlc_media_player_t* mp = libvlc_media_player_new_from_media(m);
	libvlc_media_release(m);
	libvlc_media_player_set_hwnd(mp, GetDesktopWindow()); // Desktop for example
	// libvlc_media_player_set_hwnd(mp, reinterpret_cast<unsigned __int64*>(ui.videoWidget->winId())); // Tried Qt widget
	libvlc_media_player_play(mp);
	Sleep(1000);
	libvlc_video_set_scale(mp, 2.0); // crash
	Sleep(10000);
	return 0;
}

OS: Windows 10
Compiler: MSVC 2017
vout: direct3d11

Posted: **10 Mar 2020 21:33**

Hard to say without stack backtrace

Posted: **11 Mar 2020 19:28**

Full code:

Code: Select all

#include <QApplication>
#include <vlc/vlc.h>
#include <QWidget>

class MyWidget : public QWidget
{
    libvlc_instance_t* inst;
    libvlc_media_player_t* mp;
public:
    MyWidget() : QWidget()
    {
        inst = libvlc_new (0, NULL);
        libvlc_media_t* m = libvlc_media_new_path (inst, "q.mp4");
        mp = libvlc_media_player_new_from_media(m);
        libvlc_media_release (m);

        void* drawable = reinterpret_cast<unsigned __int64*>(this->winId());
        libvlc_media_player_set_hwnd (mp, drawable);
        libvlc_media_player_play (mp);
    }
protected:
    void mouseDoubleClickEvent(QMouseEvent *) override
    {
        libvlc_video_set_scale(mp, 2.0); // <=========================== CRASH!!!
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWidget* widget = new MyWidget();
    widget->show();
    a.exec();
    return 0;
}

Call stack (gdb bt full) large enough:
https://gist.github.com/FilippVolodin/31890ba8eea29f5cedf6197cea32326c

Posted: **12 Mar 2020 12:17**

Seems like a regression in the VLC Windows windowing code.

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