Class
QMediaService
QVideoRendererControl
QAbstractVideoSurface

Class Member
void QVideoRendererControl::setSurface ( QAbstractVideoSurface * surface )

Suggestion
QMediaService should provide a valid renderer control, which means the renderer control is working actually.

Reason
Currently, although we can get a renderer control from a media service, but this renderer control doesn't work as expected (as its description in the document.)

Scenario
We want to get each frame of a video file, so use the following code :
QVideoRendererControl *rendererControl = qobject_cast<QVideoRendererControl *>(mediaService->requestControl(QVideoRendererControl_iid));
rendererControl->setSurface(myVideoSurface);
Then bool QAbstractVideoSurface::present ( const QVideoFrame & frame ) will be called, so we can get the video frame.