Sorry to bump an old thread but it's difficult to narrow down to specifically what I'm looking to do, and this is the closest yet.I can't see the BB code in that screenshot, but I assume it's a plain URL tag with no option.
For a replacement like that you can use this addon:
Here are settings for your replacement:
Quick Find: youtube.com
Regular expression: #\[url\]http:.+youtube\.com.+v=([a-zA-Z0-9_\-]+?).*\[/url\]#siU
Replacement String: [media=youtube]\1[/media]