Copy video with select audio track
bartron on 1/1/2021
If you have a video file where the first audio track isn't the primary one, you can use ffmpeg to output a new file with the selected audio track that you want. This example selects the 2nd audio track:
ffmpeg -i input.mkv -map 0:0 -map 0:1 -vcodec copy -acodec copy output.mkv