How to replace the audio in a video file using an audio file using ffmpeg?
I imagine the command looks like:
ffmpeg -i v.mp4 -i a.wav -MAGIC video-new.mp4
This is very similar to How to replace an audio stream in a video file with multiple audio streams? but that question handles multiple audio tracks, which complicates it very much, making it unclear which part of the solution is enough for a simple audio swap.