We can't. FFMPEG, FLVTool2, and Mp4Box are all major resource hogs.
You'll also find they don't help you much when the script you're using is actually not allowed:
* File Storage: Accounts are not to be used for file storage, your account will be permenantly suspended if found to be breaking this rule. Downloads are only allowed on your x10Hosting account if they have to do directly with your website. e.g. you developed custom software and are selling it or giving it away. Accounts may not be used for mirrors, game file hosting, or any other type of file hosting not specified here.
Video hosting, like youtube video hosting, is a type of file hosting. It also violates:
Personal accounts are to be used by the primary owner only. Personal account holders are not permitted to resell, store or give away web-hosting services of their website to other parties. Web hosting services are defined as allowing a separate, third party to host content on the owner's web site. Exceptions to this include ad banners, classified ads, and personal ads.
As such, a permanent suspension has been applied.
EDIT: For the curious among us, Clipbucket was installed and visible on his account.