File 'FX_ARepl.prm' is a plugin for Adobe Premiere 4.X.
It mixes two video tracks into one. It takes image from first track
(R,G,B components) and alpha component from second track.

This plugin has name "Alpha Replace" in Adobe Premiere effects list.
You can select which component of image from second track will be used
as alpha component of resulting video in 'Custom parameters' dialog of plugin.
It may be one of components R,G,B, alpha component or luminance.

This plugin may be used to combine image(s) and it's mask to one AVI-file:

1) Put image(s) on first video track.
2) Put it's mask to second video track.
3) Put effect "Alpha Replace" on FX-track between video tracks.
4) Select corresponding output options (Forward YUV+Alpha codec).
5) Make resulting AVI.