I use the standard Vimeo shortcode for embedding Vimeo videos (http://en.support.wordpress.com/videos/vimeo/), and really like the responsive markup it produces.
I also have my own video player that I would like to embed in the EXCACT same way, by simple pasting http://www.mydomain/v/12345 in the text editor (12345 is the id of the video). Should parse out the id, insert an iframe with a slightly different url (say http://www.mydomain/v/player?id=12345) etc. Basically the same stuff that happens with the Vimeo shortcode.
Do I have to edit core files, and in that case which and what, or could I add something to my functions.php file?
All help is much appreciated!