DelayAudio
From Avisynth wiki
AviSynth+
Up-to-date documentation: https://avisynthplus.readthedocs.io
DelayAudio(clip, float seconds)
DelayAudio delays the audio track by seconds seconds. seconds can be negative and/or have a fractional part.
Example:
# plays audio half a second earlier DelayAudio(-0.5)
PS: if audio loaded from separate file (for example WavSource), it's better do negative delay after AudioDub this clip, or else it may cause problems.
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