I have some video files which have stereo audio tracks that were created from a mono source. I think the mono signal got sent to the right channel and not the left because when I created the files in OBS I forgot to select mono audio recording. When I play the videos all the sound is on right side only. Hope that makes sense…
How can I either mix down/combine the stereo tracks intoto a single mono track or replace the empty left channel with the audio content of the right channel? Is there a way to do this without reencoding the whole video file?
I could do it in a video editing gui by copypasting the audio track to the other empty channel but I wonder if there might be a more efficient way of doing it. An ffmpeg command perhaps?
Many thanks
FFmpeg should be able to do that without reencoding the video, possibly also audio. Basically you want to use
-c:v copy -c:a copyand remap the right channel to a single mono channel, and remux all of that in a new output file.https://trac.ffmpeg.org/wiki/AudioChannelManipulation