Limit Content

Is there a way to limit the size of a video and the amount of text that a user can upload. For example

What if you want to limit the amount of text to say 100 characters for a package and want to make the max upload video size say 5 megabytes.

These figures are just for examples.

Any help is appreciated, because I would want a user uploading maxi files for each listing. Also any suggested plugins will be useful