ffmpeg how to blend two videos together

Written by John Riselvato - original link

Blending has an interesting effect when two inputs are used. The blend filter has the potential to create outstanding artistic results, so let’s try it out. 

Tip: In order to blend two files, they must contain the same resolution.

{width=“336” height=“187”}
blending two videos

In this example, using the difference filter applied to both video inputs gives an interesting inverted look as seen above: 

$ ffmpeg -i input1.mp4 -i input2.mp4 -filter_complex "blend=difference" output.mp4

The available blending modes are listed below:

addition
grainmerge
and
average
burn
darken
difference
grainextract
divide
dodge
freeze
exclusion
extremity
glow
hardlight
hardmix
heat
lighten
linearlight
multiply
multiply128
negation
normal
or
overlay
phoenix
pinlight
reflect
screen
softlight
subtract
vividlight
xor

{width=“336” height=“185”}
blending with a color

A lot of these filters work better when color is applied instead of another video. For example, blending a solid color video (red.mp4) with a lighten blending, as seen above:

  $ ffmpeg -i input1.mp4 -i red.mp4 -filter_complex "blend=lighten" output.mp4

Using colors or gradients and multiple blends, custom Instagram-like filters can easily be created.