Delay in milliseconds before the background audio starts, relative to the beginning of the video. Default 0.
backgroundAudioVolume
number
Volume multiplier applied to the background audio track. 1.0 is the original level. Default 1.0.
loopAudio
boolean
When true, the background audio is looped to cover the whole video. When false, it plays once. The output keeps the video's length either way, except when the video has no audio track and the background audio is shorter: the output then ends with the background audio. Default false.
originalAudioVolume
number
Volume multiplier applied to the video's original audio track. 1.0 keeps it unchanged, 0 effectively removes it (replace mode). Default 1.0.
