VR Video Formats Explained: 180 vs 360, SBS vs Over-Under

If a VR video plays as two flat pictures side by side, or the world curves in the wrong direction, or everything looks doubled and slightly nauseating, the file is almost certainly fine and the player is simply set to the wrong format.

VR video is not one thing. It is a normal video file carrying two extra pieces of information — how the image is projected, and how the two eyes are packed into one frame — and if the player guesses either of them wrongly the result is broken in a specific, recognisable way.

The two settings that matter

Projection describes how a spherical view has been flattened into a rectangular video frame. The common values:

• 180 — a half sphere in front of you. The dominant format for adult VR because the camera rig faces one way and there is nothing behind it worth filming.
• 360 — a full sphere. You can turn around. Less common in this category and generally lower effective resolution for the part you are actually looking at, because the same pixels are spread over twice the area.
• Fisheye or 190/200 — a wider-than-180 capture from a specific lens. Playing this as plain 180 leaves the world subtly stretched at the edges, which is why players offer an explicit fisheye setting.
• Flat or 2D — not VR at all, just a normal video shown on a virtual screen.

Stereo packing describes how the left-eye and right-eye images share one frame:

• SBS (side by side) — left eye in the left half, right eye in the right half. The most common packing for 180 content.
• TB or OU (top-bottom / over-under) — left eye on top, right eye underneath.
• Mono — one image shown to both eyes. No depth, and it is not broken, it is just flat.

How to read a VR filename

Producers encode this in the filename precisely so a player can pick it up. A typical name contains, in some order: a resolution, a projection, a stereo packing, and sometimes a lens designation.

That last row causes more disappointment than any other. In a side-by-side file, the advertised width is shared between two eyes, so each eye receives roughly half of it. A file described by its total frame width will always sound sharper than it looks.

The symptom-to-cause table

Fixing any of these takes one setting change in the player. Nothing needs re-downloading.

Why the file is so large

VR video is enormous compared to flat video and the reason is geometry rather than greed.

A flat video fills a screen. A VR video fills a sphere, of which you see a fraction at any moment, and it has to carry two eyes' worth of that sphere. To make the part you are looking at appear as sharp as an ordinary video, the whole frame has to be several times larger — and then the bitrate has to be high enough to keep it from falling apart in motion.

This is also why a high-resolution VR file can still look soft: resolution sets the ceiling, bitrate decides how much of that ceiling survives compression. A high resolution at a low bitrate looks worse than a moderate resolution at a generous one. The full version of that argument is in why VR porn looks blurry.

Codecs, briefly

Two families matter in practice. H.264 is universally supported and produces larger files for a given quality. H.265 / HEVC produces smaller files at the same quality and is not decoded in hardware by every device — where it is not, playback stutters or fails even though the file is perfectly good.

If a file stutters and a lower-resolution copy of the same thing plays fine, suspect the codec and the decode path before blaming the headset.

The one habit worth having

When a VR file misbehaves, change the player's projection and stereo settings before doing anything else. It is a five-second test that resolves the large majority of problems, and it is faster than re-downloading a file that was never broken.

Once the format is right, the practical questions are storage and playback — covered in how to download VR adult video to Quest storage and choosing a VR video player.

Format conventions vary between producers and player support changes with software updates. Nothing here is a claim about any specific file or application's current behaviour.