I'm looking for a program that is designed to enable playback of video tracks for specific regions. There are a number of audio transcribing software, but I'm looking for a tool for video.

I'd like to be able to start the program with a video file I specify and ideally a number of regions marked. Then I could loop region 1, or region 2 etc. at will.

Of course, adjustable playback speed would be a big plus.
+- 1/2 step pitch adjust would be nice too.

Open source would be preferred.

Thanks

Perhaps look into software from this company:
http://supermegaultragroovy.com/products/capo/

The Capo app is pretty danged awesome. Chord detection, slow downer, pitch modifier, etc. I've only witnessed the iOS version with my son's guitar teacher.

I see you would like open source. This one is 10$ for iOS. For what it does, it's an absolute steal.

Joe V, this could be your voicing solution as well.