iOS sdk - extract part of video clip - which framework?

I have created a very simple iPhone app to play videos.  
Now I need to enhance the app to allow some editing.
In general I am working with very short video clips ( less than 10 seconds).
I need the video clip to playback in a continuous looping mode.
The playback needs to be in a view that is not full screen so there can be edit controls under the video.
The user needs to be able to set edit points (Edit Start, Edit End).  This would be done by using a slider control for each edit point.
The editing resolution needs to be less than 1 second.  
For example - The user may want to extract out a portion of a video starting at 2.15 seconds and ending at 4.83 seconds
Once the user gets the edit points where they want, they would click a button and the video would start looping only the segment that they have isolated.
The user could then make additional adjustments until they get the segment exactly the way they want it.
The final step would be a button that allows the user to save the segment as a new file.

My question is, which framework will I need to work with to get this kind of control?  

I see that the MPMoviePlayerController has initialPlaybackTime and endPlaybackTime.  But those properties only set down to the second.  I need similar properties that can be set to fraction of a second.