How does Apple say 180, 360 and wide-FOV (fisheye) video is signalled in QuickTime/MP4 for APMP, converted from Google Spherical Video tags, streamed with HLS, and played back in visionOS?

Partially verified: the curator re-read S3; S4 was not re-read by the curator and rests on the producer's pinned reading. In Apple's Projected Media Profile the projection kind is the discriminator (rectilinear for 2D/3D/spatial, half-equirectangular for 180, equirectangular for 360, parametric for wide-FOV); HLS publishing declares stereo and projection in REQ-VIDEO-LAYOUT and the init map segment must repeat the format information. Curator qualifications: Partially verified: the curator re-read S3; S4 was not re-read by the curator and rests on the producer's pinned reading. Curator GET 2026-10-23 of the sources not re-read (mechanical source evidence, not semantic verification): S4: HTTP 200, bytes differ from the producer pin. Specs/session text read 2026-10-22; nothing encoded or played. vexu/lens/view-packing box details, Spherical v1/v2 detection and playback modes (session 296) from producer reading. Limitations: Specs/session text read 2026-10-22; nothing encoded or played. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://developer.apple.com/videos/play/wwdc2025/297/",
      "note": "Apple WWDC25 session 297 transcript (live)"
    },
    {
      "url": "https://developer.apple.com/videos/play/wwdc2025/296",
      "note": "cited at https://developer.apple.com/videos/play/wwdc2025/296/; Apple WWDC25 session 297 transcript (live)"
    },
    {
      "url": "https://developer.apple.com/videos/play/wwdc2025/296/",
      "note": "observed URL (dated/alias form of the cited catalogue source; canonical identity retained)"
    }
  ]
}