[Feature Request] Keep original filename of input file in output file

[CreativiTimothy]

Is your feature request related to a problem? Please describe.
No.

Describe the solution you'd like
I'm unsure of this has already been suggested--I searched the Issues but couldn't find it. Maybe we can have a filename flag like "?filename?" or "?originalfilename?" or something like that to keep the original input filename. For example,

Input file: helloworld.mp4
Output file: helloworld.gif

The reason is because often I just want a simple conversion from video format to gif format because some platforms don't allow videos.

Describe alternatives you've considered
I don't think using the date flags work for this situation.

Additional context

[Rootkit-]

omg yes.