  In video production, inserting B-roll is a widely used technique to enrich
the story and make a video more engaging. However, determining the right
content and positions of B-roll and actually inserting it within the main
footage can be challenging, and novice producers often struggle to get both
timing and content right. We present B-Script, a system that supports B-roll
video editing via interactive transcripts. B-Script has a built-in
recommendation system trained on expert-annotated data, recommending users
B-roll position and content. To evaluate the system, we conducted a
within-subject user study with 110 participants, and compared three interface
variations: a timeline-based editor, a transcript-based editor, and a
transcript-based editor with recommendations. Users found it easier and were
faster to insert B-roll using the transcript-based interface, and they created
more engaging videos when recommendations were provided.
