AudioDub

AviSynth+
Up-to-date documentation: https://avisynthplus.readthedocs.io

AudioDub(video_clip, audio_clip)
AudioDubEx(video_clip, audio_clip)

AudioDub takes the video stream from the first argument and the audio stream from the second argument and combines them into a single clip. If either track isn't available, it tries it the other way around, and if that doesn't work it returns an error. Example:

# Load capture segments from patched AVICAP32 which puts
# video in multiple AVI segments and audio in a WAV file
video = AVISource("capture1.avi") + AVISource("capture2.avi")
audio = WavSource("capture.wav")
# combine them into a single clip
AudioDub(video, audio)

AudioDubEx takes the video stream from the first argument if present, the audio stream from the second argument if present and combines them into a single clip. Thus if you feed it with two video clips, and the second one has no audio, the resulting clip will have the video of the first clip and no audio. If you feed it with two audio clips, the resulting clip will have the audio of the second clip and no video.