Video+Masking+Carousel Performance Help

As you have probably guessed the title says it all.

I have a carousel in as3 using classes which currently loads in images from xml
however for my next project I am going to be loading video into each carousel using a netstream.

I also need to mask each video in the carousel I am worried that this combination is going to kill the CPU and performance in general especially on macs

does anyone have any helpful advise or possible solutions to increasing performance?

I cannot drop any method with the accpetion of a different masking solution.