[Cin] Test alpha channel and reroute plugin (from Igor Vladimirsky's blog)

[Andrea paz]

I open a new post to better recall the subject; the discussion in the
post "CinGG's Youtube channel" is off topic.
I tried to repeat Igor Valdimirsky's tutorial; maybe I did something
wrong but my result is not good. Already with the default overlay
(Normal) the result is not exactly the same as in the tutorial. For
example, the outline of the letters is all white while in the tutorial
there are plays of light and shadows that make it three-dimensional.
But the worst comes when I set the center track to "Multiply": a
completely wrong color comes out!
See video:

https://streamable.com/a7viox

One difference is that I used a video source (h264, mov) and not a
still image as in the tutorial, but I don't think it makes any
difference.