Say "no" to vertical videos! *)
Convert/rotate videos which are shot the wrong way.
ffmpeg -i in.mp4 -filter_complex '[0:v]scale=ih*16/9:-1,boxblur=luma_radius=min(h\,w)/20:luma_power=1:chroma_radius=min(cw\,ch)/20:chroma_power=1[bg];[bg][0:v]overlay=(W-w)/2:(H-h)/2,crop=h=iw*9/16' out.mp4
*)
#VVS
Vertical Video Syndrome is dangerous.
https://www.youtube.com/watch?v=dechvhb0Meo
https://www.youtube.com/watch?v=f2picMQC-9E