Hello, I just registered to suggest this feature.
Many people use 16:9 screens, especial Mac users. While VLC does offer crop video function, it very often does not work, not only because videos sometimes have black bars.
In Media Player classic, which is in my opinion the best player available (but unavailable on Mac), it is possible to achieve image zoom very easily or automatically (2-3 clicks) or using keypad 9.
I am writing this both to you and IINA, because yesterday I was so frustrated that I decided to run a virtual machine and play a movie from inside to watch it.
Why only Media Player Classic has this feature implemented in a simple and usable way is beyond me. Please add it.