Black bars at the top and bottom widen the frame horizontally and give a cinematic feel.
When to use it
16:9 cinematic ads, or when you want to look like a movie scene inside 9:16.
In AI video, like this
Generate in the original aspect ratio and make the bars in editing with drawbox or crop+pad. Don't put important subjects in the area the bars will cover, and in 9:16 use the bar space for captions and a logo.
One-click prompt
Add cinematic 2.39:1 black bars to a 1920x1080 clip (138 pixels top and bottom): ffmpeg -i in.mp4 -vf "drawbox=y=0:w=iw:h=138:color=black:t=fill,drawbox=y=ih-138:w=iw:h=138:color=black:t=fill" -c:a copy out.mp4. Keep important subjects out of the bar area.
You're doing cinematic black bars WRONG — Explainer: See the difference between laying black bars over the picture and actually cropping to the ratio.Aspect Ratios in Film: How to Choose The Most Cinematic Aspect Ratio #aspectratio — Explainer: Compare the feel of film aspect ratios and the bars at the top and bottom.Create Cinematic Black Bars in Premiere Pro — Explainer: See how to add cinematic black bars in under 20 seconds.