VideoProbeSurface for when your QVideoProbe isn't working.

VideoProbeSurface.h

#ifndef VIDEOPROBESURFACE_H
#define VIDEOPROBESURFACE_H

#include <QAbstractVideoSurface>
#include <QVideoSurfaceFormat>

/* A bit of a hack, but... 
 *
 * Example:
 *
 * QMediaPlayer *player = ...;
 *
 * QVideoWidget *widget = ...;
 *
 * VideoProbeSurface *probe = new VideoProbeSurface(...);
 * probe->setFormatSource(widget->videoSurface());
 * connect(probe, &VideoProbeSurface::videoFrameProbed, ...);
 *
 * player->setVideoOutput({ widget->videoSurface(), probe });
 */

class VideoProbeSurface : public QAbstractVideoSurface {
    Q_OBJECT
public:
    VideoProbeSurface (QObject *parent = nullptr)
        : QAbstractVideoSurface(parent)
        , formatSource_(nullptr)
    {
    }
    void setFormatSource (QAbstractVideoSurface *source) {
        formatSource_ = source;
    }
    QList<QVideoFrame::PixelFormat> supportedPixelFormats (QAbstractVideoBuffer::HandleType type) const override {
        return formatSource_ ? formatSource_->supportedPixelFormats(type)
                             : QList<QVideoFrame::PixelFormat>();
    }
    QVideoSurfaceFormat nearestFormat (const QVideoSurfaceFormat &format) const override {
        return formatSource_ ? formatSource_->nearestFormat(format)
                             : QAbstractVideoSurface::nearestFormat(format);
    }
    bool present (const QVideoFrame &frame) override {
        emit videoFrameProbed(frame);
        return true;
    }
signals:
    void videoFrameProbed (const QVideoFrame &frame);
private:
    QAbstractVideoSurface *formatSource_;
};

#endif // VIDEOPROBESURFACE_H

Related posts:

• https://forum.qt.io/topic/102436/qvideoprobe-not-emitting-videoframeprobed-signal/13
• https://stackoverflow.com/a/68088990/616460 (also contains QImage example)