How to synchronize the movie between PC/Mac and your iPhone.
1) Drag and Drop your movie file(mp4, m4v, move) into iTunes Playlist to copy.
2) Select the movie file on iTunes and show "Music Video info" menu.
3) Select Option and check media kind as "Music Video". If it was not, please change it to "Music Video".
4) Connect your iPhone/iPad to PC/Mac, then select "MUSIC" and click "Include videos".
5) After complete the synchronization, the same Playlist (MOVIE) shows up on your iPhone device.
6) In case you have trouble, please check "OFF" on Setting>Music>Sync Library.