In the example with the spinning DVD flying by discussed in the previous section,
, you would most likely want to be able to see the start or end frame video through
the DVD’s hole and around its edges. For this to happen, there must be an alpha channel
for DVD Studio Pro to know which parts of the asset movie video should appear and
which should be ignored.
There are two ways to provide this alpha channel: embedded with the asset movie or as
a separate asset matte movie (described in
Asset Matte Movie
Preparing Alpha Transitions
When the alpha channel is embedded with the asset movie, be sure the video
output is premultiplied.