Set caption alignment

list

top | middle | bottom, left | center | right (bottom,center)

Set caption bounce animation

integer | boolean

true | false | milliseconds

Set caption fade-in animation

integer | boolean

true | false | milliseconds

Set caption text color

color

-

Embed VTT track with burn-in captions

boolean

true | false (true)

Set caption font

font

-

Set caption highlight color

color

-

Set caption horizontal margin

integer

-

Set caption vertical margin

integer

-

Set caption font size

integer | unit_scalar

0.0 - 1.0

Keep spoken caption words highlighted

boolean

true | false (false)

Set caption animation style

string

plain | karaoke | word-pop

Generate AI subtitles from audio

string

true | on | auto | false | off

Set subtitle source language

string

ISO 639-1 or ISO 639-2 code

Add custom subtitle track

url

-

Translate subtitles into other languages

list

ISO 639-1 or ISO 639-2 codes

Set VTT sidecar language

string

ISO 639-1 or ISO 639-2 code