Open a VR video in a normal video player and you will not see a scene – you will see two distorted pictures next to each other or on top of each other. That is how stereo VR is stored. Your VR player needs to know which layout the file uses; set it wrongly and the image looks doubled, squashed or makes you feel slightly sick within seconds.
Side-by-side (SBS)
The left-eye and right-eye images sit next to each other in one wide frame. This is the most common layout for 180° VR and the one most players assume by default. A file name or tag with “SBS”, “LR” or “3D” usually means side-by-side. If the frame is twice as wide as it is tall, it is almost certainly SBS.
Over-under (OU, TB)
The two eye images are stacked, left on top and right below, or the other way round. Some producers prefer it because it keeps more horizontal detail. File names may say “OU”, “TB” or “top-bottom”. A square or tall frame showing two images stacked is over-under.
Fisheye
Some cameras deliver two round images instead of rectangular ones – the raw view of each lens. Good VR players can show this directly if you choose a fisheye or “180 fisheye” mode. On a platform that converts uploads, you usually receive an already corrected file, but a round picture in the preview tells you which mode to try.
Half-SBS and full-SBS
Half-SBS squeezes both eye images into a normal-width frame, so each eye gets half the horizontal resolution. Full-SBS keeps both at full width and needs a wider file. At 8K this difference is the reason one file looks crisp and another soft in the same headset.
The quick fix
If a scene looks wrong, switch the layout in your player before you blame the file: SBS ↔ OU first, then 180 ↔ 360, then flat ↔ fisheye. One of those combinations will snap into a single, deep image. For why nearly all scat VR is 180°, see 360 vs 180 VR; for resolution and frame rate, see 8K and 60 fps.