The goal is in the first paragraph: "aim was to let consumer gear that can't bitstream TrueHD Atmos render real object-based Atmos with height."

Summary is also clear: ffmpeg doesnt have channel coupling and proprietary cryptographic blocks it.

I was once wondering what would be the problem of doing such a project. Now it's clear to me what problems I would run into and I don't have to burn my tokens.

What answers are actually unclear for you?

Oh the project seems cool, no doubt.

I'm talking more about text like:

  > # Why It Can't Fully Work
  > # Wall 2 — EMDF keyed authentication (the decisive one)
  > coregraft = a real Dolby core + our metadata → Dolby Surround. The metadata is rejected too, and we traced it to the EMDF emdf_protection field, which is a keyed authentication code, not a computable checksum:

  > EMDF container (ETSI TS 102 366 Annex H) — wraps OAMD (id 11) + JOC (id 14) with the emdf_protection field, carried in the E-AC-3 audio-block skip field exactly where real Dolby streams put it (recomputing frmsiz + crc2).