Creating a simple video gallery

I am using php and i want to create a video gallery.

THe videos as i know would 开发者_StackOverflow社区be uploaded to an external source...

However i am confused about how to implement this... For example if the user put a video from youtube ,ok i can write code to limit its width/height But if itsnt from utube what can i do ?? I am confused . Any ideas/suggestions?

To get the width and height of the video you can use the console tool ffmpeg.

There are a lot of questions related to this tool here at SO and in the internet.