\back
ffmpeg -i input.mp4 -filter_complex "[0:v]reverse[v];[0:a]areverse[a]" -map "[v]" -map "[a]" -vcodec libx265 -acodec libopus output.mp4
ffmpeg -i input.mp4 -filter_complex "[0:v]reverse[v];[0:a]areverse[a]" -map "[v]" -map "[a]" -vcodec libx265 -acodec libopus output.mp4