Confused working of Qt5.0 Multimedia and video render

amitqt

My target is to render video from custom container format.
The video is in h264 encoded and would decode to yuv 420. I would like to render it to qwidget so that controls can be overlayed.
But browsing Qt5 Multimedia architecture, following points were not clear:

how do I use QVideoWidget "http://qt-project.org/doc/qt-5.0/qtmultimedia/qvideowidget.html",
to render my individual frames?
If I have my source (frame producer) how do I integrate it in the QtMultimedia system as to use is default playback pipeline.
http://qt-project.org/doc/qt-5.0/qtmultimedia/multimediawidgets-videowidget.html says that it is an example using QAbstractVideoSurface, but somehow it is not. There is no mention of this class in any files.
http://qt-project.org/doc/qt-5.0/qtmultimedia/videooverview.html mentions MyVideoProducer class, but it really does not do anything, why is it even there?

regards,

mrdebug

Maybe you have to use advanced multimedia features. In this case I will use the ffmpeg libraries. This isn't easy but you can do everything.

amitqt

I am using ffmpeg for decoding. But want to render to QVideoWidget, how can I use QVideoWidget standalone.

amitqt

One way is, to make a qwidget and override paint event, but I would really like to know implementation details.
Do we send a update event and in the resulting paint event render the frame, what are the performance issues here!
Qt is a great lib but sometimes we get stuck in such petty issues, hope someone has any experience in said above.