rotating video filmed in portarit .. back to portrait without cropping top and bottom

[mqos]

Hello I'm a newbie .. trying to rotate a video which i filmed in portrait on my camera, i uploaded into my windows 10 it sits in landscape .. so into VLC and bingo rotate it 90 deg to portrait but it crops it top and bottom!! ... can anyone tell me if it can be done without automatic cropping? and if so how!
many thanks and responses are much appreciated.
regards.

[-neco-]

You can try permanetly change the rotation of video with Avidemux and then save it. It's free, open source software. The task is very quick and lossless, without reencoding!
There is maybe some way also with VLC player, but at the moment I don't know.