You can do this in After Effects using a black mask, alpha inverted track matte, roughen edges, and mask expansion.
Setup your comp in this way:
Layer 1 black solid (roughly 2x the size of your comp)
Layer 2 footage 1
Layer 3 Footage 2
On the black solid draw an ellipse mask, doesn't have to be perfect, you can free hand it, in fact it sells it better if it isn't perfect. Add the effect "Roughen Edges" to the solid layer. Adjust your settings to either get a real soft or extremely detailed edge. After you have that, keyframe your mask expansion until the mask is completely off the screen (this is why you need the larger layer size). Then set your Layer 2's track matte to alpha inverted and there you go. All in after effect ink reveal effect