What is the framerate of the macbook pro mid 2012 non retina facetime hd camera?
The hardware is capable of 30fps, I have this model (MacBookPro9,1, i7 2.3 GHz) on my desk in front of me and just shot a movie that lists as 29.81fps at 720p.

However, Apple will, in software, reduce the frame rate if your HDD/SSD/other storage and/or processor and memory are not capable of handling the maximum frame rate at the time of capture. The do this to ensure you can still use the camera even in non-optimal conditions.

How much free space (percentage) do you have on your storage? Are you running any processor intensive applications. How much RAM do you have? These factors can have a serious impact on capture rates.

It is also entirely possible that the frame rate is being affected by other factors if you are using a 3rd party application such as Skype.

Hope this helps?