For certain videos, you may need to loop or stretch a video to match the timing of your script. To loop or stretch your video:
Navigate to the scene and select the video on the canvas.
Select one of the options from the Video panel on the right hand side of the canvas:
Play Once
Stretch
Loop/Cut
The video will now be updated within your scene.
Learn more about these option on the Media Reference Documentation.
Want to trim your video? See the How do I trim a video? article.