Filter blend
  Blend two video frames into each other.
    slice threading supported
    Inputs:
       #0: top (video)
       #1: bottom (video)
    Outputs:
       #0: default (video)
blend AVOptions:
  c0_mode           <int>        ..FV..... set component #0 blend mode (from 0 to 32) (default normal)
     addition        1            ..FV..... 
     addition128     28           ..FV..... 
     grainmerge      28           ..FV..... 
     and             2            ..FV..... 
     average         3            ..FV..... 
     burn            4            ..FV..... 
     darken          5            ..FV..... 
     difference      6            ..FV..... 
     difference128   7            ..FV..... 
     grainextract    7            ..FV..... 
     divide          8            ..FV..... 
     dodge           9            ..FV..... 
     exclusion       10           ..FV..... 
     extremity       32           ..FV..... 
     freeze          31           ..FV..... 
     glow            27           ..FV..... 
     hardlight       11           ..FV..... 
     hardmix         25           ..FV..... 
     heat            30           ..FV..... 
     lighten         12           ..FV..... 
     linearlight     26           ..FV..... 
     multiply        13           ..FV..... 
     multiply128     29           ..FV..... 
     negation        14           ..FV..... 
     normal          0            ..FV..... 
     or              15           ..FV..... 
     overlay         16           ..FV..... 
     phoenix         17           ..FV..... 
     pinlight        18           ..FV..... 
     reflect         19           ..FV..... 
     screen          20           ..FV..... 
     softlight       21           ..FV..... 
     subtract        22           ..FV..... 
     vividlight      23           ..FV..... 
     xor             24           ..FV..... 
  c1_mode           <int>        ..FV..... set component #1 blend mode (from 0 to 32) (default normal)
     addition        1            ..FV..... 
     addition128     28           ..FV..... 
     grainmerge      28           ..FV..... 
     and             2            ..FV..... 
     average         3            ..FV..... 
     burn            4            ..FV..... 
     darken          5            ..FV..... 
     difference      6            ..FV..... 
     difference128   7            ..FV..... 
     grainextract    7            ..FV..... 
     divide          8            ..FV..... 
     dodge           9            ..FV..... 
     exclusion       10           ..FV..... 
     extremity       32           ..FV..... 
     freeze          31           ..FV..... 
     glow            27           ..FV..... 
     hardlight       11           ..FV..... 
     hardmix         25           ..FV..... 
     heat            30           ..FV..... 
     lighten         12           ..FV..... 
     linearlight     26           ..FV..... 
     multiply        13           ..FV..... 
     multiply128     29           ..FV..... 
     negation        14           ..FV..... 
     normal          0            ..FV..... 
     or              15           ..FV..... 
     overlay         16           ..FV..... 
     phoenix         17           ..FV..... 
     pinlight        18           ..FV..... 
     reflect         19           ..FV..... 
     screen          20           ..FV..... 
     softlight       21           ..FV..... 
     subtract        22           ..FV..... 
     vividlight      23           ..FV..... 
     xor             24           ..FV..... 
  c2_mode           <int>        ..FV..... set component #2 blend mode (from 0 to 32) (default normal)
     addition        1            ..FV..... 
     addition128     28           ..FV..... 
     grainmerge      28           ..FV..... 
     and             2            ..FV..... 
     average         3            ..FV..... 
     burn            4            ..FV..... 
     darken          5            ..FV..... 
     difference      6            ..FV..... 
     difference128   7            ..FV..... 
     grainextract    7            ..FV..... 
     divide          8            ..FV..... 
     dodge           9            ..FV..... 
     exclusion       10           ..FV..... 
     extremity       32           ..FV..... 
     freeze          31           ..FV..... 
     glow            27           ..FV..... 
     hardlight       11           ..FV..... 
     hardmix         25           ..FV..... 
     heat            30           ..FV..... 
     lighten         12           ..FV..... 
     linearlight     26           ..FV..... 
     multiply        13           ..FV..... 
     multiply128     29           ..FV..... 
     negation        14           ..FV..... 
     normal          0            ..FV..... 
     or              15           ..FV..... 
     overlay         16           ..FV..... 
     phoenix         17           ..FV..... 
     pinlight        18           ..FV..... 
     reflect         19           ..FV..... 
     screen          20           ..FV..... 
     softlight       21           ..FV..... 
     subtract        22           ..FV..... 
     vividlight      23           ..FV..... 
     xor             24           ..FV..... 
  c3_mode           <int>        ..FV..... set component #3 blend mode (from 0 to 32) (default normal)
     addition        1            ..FV..... 
     addition128     28           ..FV..... 
     grainmerge      28           ..FV..... 
     and             2            ..FV..... 
     average         3            ..FV..... 
     burn            4            ..FV..... 
     darken          5            ..FV..... 
     difference      6            ..FV..... 
     difference128   7            ..FV..... 
     grainextract    7            ..FV..... 
     divide          8            ..FV..... 
     dodge           9            ..FV..... 
     exclusion       10           ..FV..... 
     extremity       32           ..FV..... 
     freeze          31           ..FV..... 
     glow            27           ..FV..... 
     hardlight       11           ..FV..... 
     hardmix         25           ..FV..... 
     heat            30           ..FV..... 
     lighten         12           ..FV..... 
     linearlight     26           ..FV..... 
     multiply        13           ..FV..... 
     multiply128     29           ..FV..... 
     negation        14           ..FV..... 
     normal          0            ..FV..... 
     or              15           ..FV..... 
     overlay         16           ..FV..... 
     phoenix         17           ..FV..... 
     pinlight        18           ..FV..... 
     reflect         19           ..FV..... 
     screen          20           ..FV..... 
     softlight       21           ..FV..... 
     subtract        22           ..FV..... 
     vividlight      23           ..FV..... 
     xor             24           ..FV..... 
  all_mode          <int>        ..FV..... set blend mode for all components (from -1 to 32) (default -1)
     addition        1            ..FV..... 
     addition128     28           ..FV..... 
     grainmerge      28           ..FV..... 
     and             2            ..FV..... 
     average         3            ..FV..... 
     burn            4            ..FV..... 
     darken          5            ..FV..... 
     difference      6            ..FV..... 
     difference128   7            ..FV..... 
     grainextract    7            ..FV..... 
     divide          8            ..FV..... 
     dodge           9            ..FV..... 
     exclusion       10           ..FV..... 
     extremity       32           ..FV..... 
     freeze          31           ..FV..... 
     glow            27           ..FV..... 
     hardlight       11           ..FV..... 
     hardmix         25           ..FV..... 
     heat            30           ..FV..... 
     lighten         12           ..FV..... 
     linearlight     26           ..FV..... 
     multiply        13           ..FV..... 
     multiply128     29           ..FV..... 
     negation        14           ..FV..... 
     normal          0            ..FV..... 
     or              15           ..FV..... 
     overlay         16           ..FV..... 
     phoenix         17           ..FV..... 
     pinlight        18           ..FV..... 
     reflect         19           ..FV..... 
     screen          20           ..FV..... 
     softlight       21           ..FV..... 
     subtract        22           ..FV..... 
     vividlight      23           ..FV..... 
     xor             24           ..FV..... 
  c0_expr           <string>     ..FV..... set color component #0 expression
  c1_expr           <string>     ..FV..... set color component #1 expression
  c2_expr           <string>     ..FV..... set color component #2 expression
  c3_expr           <string>     ..FV..... set color component #3 expression
  all_expr          <string>     ..FV..... set expression for all color components
  c0_opacity        <double>     ..FV..... set color component #0 opacity (from 0 to 1) (default 1)
  c1_opacity        <double>     ..FV..... set color component #1 opacity (from 0 to 1) (default 1)
  c2_opacity        <double>     ..FV..... set color component #2 opacity (from 0 to 1) (default 1)
  c3_opacity        <double>     ..FV..... set color component #3 opacity (from 0 to 1) (default 1)
  all_opacity       <double>     ..FV..... set opacity for all color components (from 0 to 1) (default 1)

framesync AVOptions:
  eof_action        <int>        ..FV..... Action to take when encountering EOF from secondary input  (from 0 to 2) (default repeat)
     repeat          0            ..FV..... Repeat the previous frame.
     endall          1            ..FV..... End both streams.
     pass            2            ..FV..... Pass through the main input.
  shortest          <boolean>    ..FV..... force termination when the shortest input terminates (default false)
  repeatlast        <boolean>    ..FV..... extend last frame of secondary streams beyond EOF (default true)

This filter has support for timeline through the 'enable' option.

