Switching the audio between two video files (quickest way for multiple)?

[Serenity23]

Scenario:

File 1a: 360p mp4 w/ AAC audio (full audio).

File 1b: 1080p mp4 w/ AAC audio (audio is muted randomly).

Goal: 1080p w/ AAC audio (full audio)

The video files are identical minus the quality and the audio. I did a test run with MKVToolNix and after the conversion, the audio syncs perfectly.

Is there a way to go about setting it up to do multiple. Maybe like pull video A from Folder A, pull audio from video A in Folder B, put combination in Folder C; and then continue to the next file?

[sneaker]

Yes. You can find a lot of infos about batching mkvmerge if you do a forum search. Without you giving more details (like exact filenames) it is difficult to help you more than that.

[_Al_]

Create those folders, give those videos exactly same name, watch for weird characters , mind you you will run batch script.Download MP4box , that particular EXE from videohelp (32bit or 64bit if having 64bit OS) for installation but do not install it , unzip that downloaded EXE to a folder (I used 7-zip unzip here feature), you need only those files:
js.dll
libeay32.dll
libgpac.dll
mp4box.exe
ssleay32.dll
Correct all paths below , name the text for example transfer.BAT in notepad , put that BAT into folder A and run it,
it takes video from folder A, audio from folder B and muxes it into folder C:

@echo off
setlocal
set "folder_A=G:\folder A"
set "folder_B=G:\folder B"
set "folder_C=G:\folder C"
set "mp4box=C:\tools\MP4box\MP4Box.exe"
set "temp_folder=E:\temp"

for %%a in ("*.mp4") do "%mp4box%" -add "%folder_A%\%%~nxa"#video -add "%folder_B%\%%~nxa"#audio -tmp "%temp_folder%" -new "%folder_C%\%%~nxa"
endlocal

I usually include frame rate in MP4box command line like: -add input.mp4:fps=23.976
not sure if it works correctly without specifying frame rate, it just might

[Serenity23]

Thanks @sneaker and @_AI_

Both solutions worked perfectly fine and I learned about mkvtools, but MP4box was a tad bit more faster and easier for me.