[Development] [QtMultimedia] The customvideosurface/customvideowidget example is very slow

[Denis Shienkov]

Hi developers,

I use Qt 5.6.0 on Windowd (with DS plugin).

I faced with the problem that the example:

qtmultimedia\examples\multimediawidgets\customvideosurface\customvideowidget\

is very-very-very slow.

For example if I play  any video file, then my CPU loading is 40%, and I 
see that the video
is displayed jerkily, and if I want to drag the window by the mouse, 
then it happens also jerkily.

I suspect that it happens due to there are not used the OpenGL rendering 
(yes?)...
Because if I use the QVideoWidget, I see that my CPU load is 0%, and all 
fine.

Or, maybe the internal QtMultimedia's implementation has a bug when is 
used the custom
QAbstractVideoSurface (instead of QVideoWidget) to show the video content...

So, my question is: is there are any tricks or examples how to implement 
the high-perfomanced
video application with the QAbstractVideoSurface ?

BR,
Denis