How to improve frame rate while using QParallelAnimationGroup and QPropertyAnimation

Hi,

I am using QParallelAnimationGroup and QPropertyAnimation to create an animation with a QGraphicsPixmapItem.

What I am doing is whenever a property changes, the pixmap in QGraphicsPixmapItem is processed/updated.
In some cases the processing of pixels (by an external library) takes long and I end with extremely poor frame rates like 0.3-0.6 FPS.
When there is no processing involved and only transform animations is used, I get around 60-62 FPS.

Is there some way I can improve the frame rate? Maybe caching or something like that? In the graphicsItem I have set setCacheMode(DeviceCoordinateCache).

Thanks,
Karthik