schema_version: 0.1
type: filter
identifier: movit.opacity
title: Opacity (GLSL)
version: 1
copyright: Dan Dennedy
creator: Steinar H. Gunderson
license: GPLv2
language: en
tags:
  - Video
description: Adjust the opacity of an image through the alpha channel.
notes: >
  When used in some transitions this will cause this video to be mixed with
  the other video. If the video this is applied to already has an alpha channel,
  then this preserves that by multiplying the opacity level with the alpha channel.
  This filter is especially handy when used in conjunction with movit.overlay.
  You can also use this to fade a clip from and to black.

parameters:
  - identifier: opacity
    title: Opacity
    type: float
    minimum: 0
    maximum: 1
    default: 1
    mutable: yes

  - identifier: alpha
    title: Alpha
    description: >
      When this is less than zero, the alpha component of the Movit mutliply
      effect follows opacity. Otherwise, you can set this to another value to
      control the alpha component independently. If you set this to 1, then
      the opacity parameter can be used to fade to and from black.
    type: float
    minimum: -1
    maximum: 1
    default: -1
    mutable: yes