You could add to these tips some ideas like mixing videos and high quality images like in
For your information, there's very little chances that I can optimize this tool in the near future.

Mixing video and realistic pictures is a really good idea, thxs for the tips !

Regarding optimization, what do you need (time of course ) ? Maybe I could help or find some help

As I read in another post, using GPU (or better OPenCL on OSX which managed CPU/GPU dispatching) would be really efficient ( GPU engine are now highly flexible )

regards,

Juju