. . Set displayed frame to Start-frame
. . Reset Start-Frame
. . Set displayed frame to End-frame
. . Reset End-frame
After the left and right movies have been previously aligned, you may select just a section of the movie for saving rather than all of it.
Move to the required start-frames and click 'Set displayed frame to Start-frame'.
Then, move to the end-frames of the required 'clip' and click 'Set displayed frame to End-frame'.
The window title-bar information will change to reflect the new start, current and end-frame numbers.
'Reset Start-Frame' will return to the original start-frame, applying any previous offset.
'Reset End-Frame' will return to the original end-frame, applying any previous offset.