Apple’s Mysterious Fisheye Projection (opens in new tab)

If you’ve read my first post about Spatial Video, the second about Encoding Spatial Video, or if you’ve used my command-line tool, you may recall a mention of Apple’s mysterious “fisheye” projection format. Mysterious because they’ve documented a CMProjectionType.fisheye enumeration with no elaboration, they stream their immersive Apple TV+ videos in this format, yet they’ve provided no method to produce or playback third-party content using this projection type.