GoKawiilConvert a Dolby Atmos Master (DAMF) — as decoded from a Dolby TrueHD + Atmos stream by truehdd — into E-AC-3 (Dolby Digital Plus) with Joint Object Coding (JOC), i.e. "DD+ Atmos". The aim was to let consumer gear that can't bitstream TrueHD Atmos (e.g. an LG TV → Denon AVR over eARC) render real object-based Atmos with height.
Status: research-complete, hardware-blocked Every stage below is provably correct by every software oracle available (ffmpeg 7, VoidXH/Cavern): the output is detected as E-AC-3 (Dolby Digital Plus + Dolby Atmos) , decodes with the right object count and valid 3D object positions (including height), and is CRC-clean. But it does not engage Atmos on Dolby-certified hardware — playback falls back to Dolby Surround. The cause is two independent, proprietary walls (see Why it can't fully work). This repository is the honest, documented artifact of that investigation, with a clean seam for the one missing cryptographic piece.
This is for personal / interoperability research use only. See Licensing & provenance.
What it does (pipeline)
A near-complete reimplementation of the relevant parts of a DD+ Atmos encoder, in Rust:
DAMF reader — parses the Dolby Atmos Master ( .atmos / .audio / .metadata ).
— parses the Dolby Atmos Master ( / / ). 5.1 downmix renderer — VBAP-pans the Atmos objects to a 5.1 bed (L R C LFE Ls Rs).
— VBAP-pans the Atmos objects to a 5.1 bed (L R C LFE Ls Rs). OAMD encoder (ETSI TS 103 420) — per-frame Object Audio Metadata: object positions (with elevation), bed/LFE, program assignment. Round-trips through our decoder and Cavern.
(ETSI TS 103 420) — per-frame Object Audio Metadata: object positions (with elevation), bed/LFE, program assignment. Round-trips through our decoder and Cavern. JOC encoder — Joint Object Coding matrices over the 5-channel core × parameter bands, with Dolby's quant/Huffman config. Bit-exact round-trip.
— Joint Object Coding matrices over the 5-channel core × parameter bands, with Dolby's quant/Huffman config. Bit-exact round-trip. 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 ).
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