Bars can be encoded into the video frame or added by the player to preserve its aspect ratio. Media dimensions and a careful crop comparison help distinguish them. The difference matters because a display may treat encoded bars as ordinary picture content rather than unused screen space.
Compare the frame and the image
A 1920 × 1080 stream can contain a much wider film with black pixels above and below it. The encoded frame is still 16:9 even though the active scene is not. A player preserving the frame may add further side space on an ultrawide display, producing a picture surrounded by bars.
Use controls without losing text
A crop can remove encoded padding, but subtitles or credits may occupy that padding. Inspect a caption-heavy scene before leaving a crop active. Do not assume a setting that fills the screen is correct merely because it removes black areas; it can also remove deliberate picture information from the sides.
Allow changing aspect ratios
Some programmes intentionally change image shape between sequences. Automatic cropping may then jump or cut content unexpectedly. An aspect-preserving full-frame presentation is the safest baseline for mixed material. If the bars seem inconsistent in one title, compare several scenes before reporting the variation as a streaming failure.
