ffmpegcommands. However, as usual,
ffmpegoptions quite difficult to get right if you are not a regular user of that tool. So I had to spent some time on that, but at the end I think I've found a simple sequence of commands which I can understand and that do the job.
i.movfile which was recorded by QuickTime player (File -> New Movie Recording) using an external microphone.
i.movfiles, disables the video (
-vn) and copies the audio (
-acodec copy) and produces a new audio file
orig.aacI am doing all of this on a Mac, so my videos are recorded using typical formats and codecs used by Apple.
i.movand copy audio stream from the
mono.aacfile to get the final result.
i.mov) to the first video stream of the output (
-map 0:v:0), and the audio of the second stream to the first audio stream of the resulting file (