360-degree videos, also known as immersive videos or spherical videos, are video recordings where a view in every direction is recorded at the same time, shot using an omnidirectional camera or a collection of cameras. During playback the viewer has control of the viewing direction like a panorama.
360-degree video is typically recorded using either a special rig of multiple cameras, or using a dedicated camera that contains multiple camera lenses embedded into the device. The resulting footage is then stitched to form a single video. This process is done either by the camera itself, or using specialized video editing software that can analyze common visuals and audio to synchronize and link the different camera feeds together. Generally, the only area that cannot be viewed is the view toward the camera support.
Specialized omnidirectional cameras and rigs have been developed for the purpose of filming 360-degree video, including rigs such as GoPro's Omni and Odyssey, the Nokia OZO, the Facebook Surround 360, the Kodak Pixpro SP360 4K Dual Pack Pro and the Axon's AZilPix Studio.One (all of which consist of multiple cameras installed into a single rig), the Vuze camera, handheld dual-lens cameras such as the Ricoh Theta S and Samsung Gear 360, and the Kogeto Dot 360—a panoramic camera lens accessory developed for the iPhone 4, 4S, and Samsung Galaxy Nexus. In videoconferencing, 360° cameras are used, so that all participants on one location can be recorded with one camera. In Dec 2016, 360/VR specialist Orah. started shipping its 4K Live VR camera called Orah 4i, making it simpler to capture, stitch and broadcast live 360 / VR to platforms such as YouTube, Facebook or Twitter's Periscope.
Due to the newness of the technology, developer communities have begun to be developed around the various cameras, including the RICOH THETA Unofficial Guide, the Samsung Developer Program, LG Friends Developer, and more.
Most 360-degree video is monoscopic (2D), meaning that it is viewed as a one (360x180 equirectangular) image directed to both eyes. Stereoscopic video (3D) is viewed as two distinct (360x180 equirectangular) images directed individually to each eye. 360-degree videos are typically viewed via personal computers, mobile devices such as smartphones, or dedicated head-mounted displays. When viewed on PCs, the mouse is typically used to pan around the video by clicking and dragging. On smartphones, internal sensors such as the gyroscope are used to pan the video based on the orientation of the device. Taking advantage of this behavior, devices such as Google Cardboard viewers and the Samsung Gear VR serve as stereoscope-style headset enclosures that a smartphone can be inserted into, for viewing this content in a virtual reality format. They emulate the operation of a dedicated head-mounted display, but utilizing the display of the phone itself and internal lenses, rather than containing dedicated screens of their own.