Resize video

[Dominique-Sauquet]

Hi everyone,
I would like to resize a video (mp4 file) before uploading it on the server.
By resize, I mean reduce its width and height while keeping the same ratio, as it works for an image.
I tried to use the following options for my dropzone:
resizeWidth: 400,
resizeHeight: 400
but it does not seem to work. I need to do that on the web.
Does dropzone implement this feature?
And if not, has anyone a suggestion of how to do it?
Many many thanks
Dominique