Gradient Mask
gradient-mask
Uses the gradient as a mask instead of drawing color. The picture stays visible where the stops are opaque and fades into bg where they are transparent.
| Value | Description |
|---|---|
false (default) | Draws the gradient’s colors over the picture. |
true | Fades the picture into bg wherever the stops are transparent. Only the stops’ alpha is used; their RGB values, gradient-alpha, gradient-cs, gradient-hue, and gradient-mode are ignored. |
Video has no alpha channel, so the masked area shows bg rather than turning transparent. bg defaults to black on video. See bg for the defaults on stills.