Overview
ISO/IEC 13818-1:2022/Cor.1:2023 is a Technical Corrigendum to ISO/IEC 13818-1 (also published as ITU‑T H.222.0) that corrects the published Systems syntax by adding the missing field compatibleProfileSetsPresent to the MPEG‑H 3D audio descriptor. This corrigendum restores an omitted 1‑bit syntax element whose value controls conditional parsing of subsequent fields in the descriptor. The correction is editorial but essential for interoperable parsing and implementation of MPEG‑H audio metadata in systems and broadcast streams.
Key topics and technical requirements
- Inserted field:
compatibleProfileSetsPresent (1 bit, bslbf) added to Table 2‑121 (MPEG‑H 3D audio descriptor).
- Conditional syntax: When
compatibleProfileSetsPresent == '0', the syntax requires numCompatibleSets (8 bits, uimsbf) followed by numCompatibleSets entries of CompatibleSetIndication (8 bits each). The published 8th edition’s syntax and semantics depend on this field.
- Descriptor structure: The table shows other fields such as
mpegh3daProfileLevelIndication (8 bits), interactivityEnabled (1 bit), reserved bytes and referenceChannelLayout (6 bits). The corrigendum clarifies parsing order and conditional blocks.
- Standards traceability: Prepared by ITU‑T as H.222.0 Cor.1 and adopted by ISO/IEC JTC 1/SC 29 for the Systems part of the MPEG family.
Applications and who uses it
- Codec implementers: Encoder and decoder developers for MPEG‑H 3D audio must parse
compatibleProfileSetsPresent to correctly handle profile compatibility metadata.
- Broadcast and streaming vendors: Multiplexers, packagers, and broadcast equipment that insert or interpret MPEG‑H audio descriptors need this corrigendum for compliant stream generation and monitoring.
- Middleware and players: Media players, set‑top boxes, and OTT clients that rely on descriptor metadata for profile negotiation, channel mapping or interactivity must implement the corrected syntax.
- Test and compliance labs: Conformance testing and interoperability testing rely on the corrected syntax table to detect and avoid ambiguity in descriptor handling.
Related standards
- ISO/IEC 13818‑1 (Systems) - core standard for generic coding of moving pictures and associated audio.
- ITU‑T H.222.0 - corresponding Recommendation version and source for this corrigendum.
- MPEG‑H audio specifications - for detailed audio coding profiles and semantics referenced by the descriptor.
Keywords: ISO/IEC 13818-1, MPEG-H 3D audio descriptor, compatibleProfileSetsPresent, technical corrigendum, ITU‑T H.222.0, audio metadata, systems standard, codec interoperability, broadcast stream.