Interlace
            clips to restore deinterlaced fields to interlaced frames. The result
            clip is half as long as the original.
         
         To interlace clips:
         
         
            - Display
               the Video menu and then enable Interlace. 
            
- From the Field Dominance box, select
               Field 1 or Field 2.
            
- Select the clip that you want to interlace.
            
- Select the destination reel.
               The result clip—half
                  as long as the original clip—appears.