blind-set-alpha - Multiply the alpha channel of a video
blind-set-alpha [-i] alpha-stream
blind-set-alpha reads a video from stdin and a mask video from
alpha-stream. The video is printed to stdout, with each alpha value
multiplied by the product of the luminosity and the alpha value of the
corresponding pixel and frame in the mask video.
If stdin is longer than alpha-stream, the remainder of
stdin is printed without any changes. If stdin is shorter than
alpha-stream, the remainder of alpha-stream is ignored but may
be partially read.
blind(7), blind-single-colour(1), blind-dissolve(1),
blind-arithm(1), blind-set-luma(1), blind-invert-luma(1),
Mattias Andrée <firstname.lastname@example.org>
- Use the inverse luminosity of the mask video instead of the luminosity. It
is still multiplied by the alpha value.