Output file. Extension should match format.
OptionalformatTarget subtitle format. Default: 'srt'
OptionalstreamWhich subtitle stream to convert. Default: 0
OptionalshiftShift all cue timings by this many seconds. Positive is later.
Mutually exclusive with fixDuration.
OptionalfixRescale cue timings so each cue's duration matches its on-screen duration
(-fix_sub_duration). Often needed after a VFR → CFR conversion, where
subtitle timing drifts out of sync with the video.
OptionalburnBurn the subtitles in as well as converting them. Default: false
OptionalvideoOptionalbinary
Input video or subtitle-bearing file.