Content for TR 26.865 Word version: 18.0.0

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7.1 General 7.2 Functional design constraints applicable for IVAS split rendering scenarios

7 Functional Design Constraints p. 27

7.1 General p. 27

Functional design constraints ensure that the required immersive audio formats, operation modes and ranges of a native codec/system and essential properties remain supported in split rendering scenarios. Different functional design constraints may apply for different immersive audio codecs/systems.

7.2 Functional design constraints applicable for IVAS split rendering scenarios p. 27

The following functional design constraints apply for split rendering solutions involving the IVAS codec:

Functional attribute	Constraint
Immersive audio formats of native coding format	All required immersive IVAS encoder input formats according to Pdoc IVAS-4 shall be supported. IVAS stereo input format should be supported for 0-DOF operation.
Bit rates of required immersive audio coding modes of native coding format	All required bit rates of IVAS immersive operation modes according to Pdoc IVAS-4 shall be supported. All IVAS stereo bit rates should be supported for 0-DOF operation.
Head-trackability of immersive audio formats	The head-trackability of the immersive audio formats of the native coding format shall be retained. Preservation of the DOF level is the objective, reduced DOF levels may be provided. NOTE: an audio format supported by the native coding system may be 3-DOF head-trackable, i.e., around 3 axes (yaw, pitch, roll). The Split Rendering system should retain this possibility. Complexity or bit rate reduced variants may though reduce this to lower DOF levels like yaw-only correction (1-DOF).
Packet loss concealment (PLC)	A PLC solution shall be provided.
Non-diegetic audio support	The solution shall support (1DOF - 3DOF) diegetic audio and (0-DOF) one-channel non-diegetic audio and two-channel (stereo or binaural) non-diegetic audio. It shall be possible to overlay post rendered audio obtained from instances operated with diegetic and non-diegetic audio.