ffmpeg -i
ffmpeg -fflags +genpts -i input.avi -c:v copy -c:a copy output.mkv
ffmpeg -i Matilda\ \(1996\)\ \(1080p\ BluRay\ x265\ FreetheFish\).mkv -codec:v libx265 -codec:a ac3 -map 0:v:0 -map 0:a:2 Matilda.mkv
ffmpeg -i Film-avec-language-unkown.avi -map 0 -c copy -metadata:s:a:0 language=fre Film-avec-language-francais.avi