System information
Mode Description Example
Multiply (Mask) Merges the colors of the tracks.
Source Alpha Uses the alpha channel to determine transparency.
The compositing mode is based on the alpha channel  
characteristics of an event or media file. If no alpha 
channel is present,  the Source Alpha mode has no effect.
Add Combines the color values in the composite group.
Subtract Subtracts the overlay color values from the background.
Cut Cuts out the overlay color values from the background.
Screen Multiplies the inverse of  the overlay color values with the 
background color values. This makes  overlay colors weaker and 
less present and results in a lighter video  image. The opposite of 
this mode is Multiply.
Overlay Heightens contrast by using  Multiply mode on darker colors  
and Screen mode on lighter colors.
Hard Light Adds overlay colors as if the overlay were lit by a bright, 
focused spotlight.
Dodge Brightens the background based on the overlay color values.
Burn Darkens the background based on the overlay color values.
Darken Compares the overlay and background pixel by pixel and 
selects the darker color value for each pixel.
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