Overview
ISO 26429-9:2009 - "Digital cinema (D‑cinema) packaging - Part 9: Asset mapping and file segmentation" defines a generic, media‑agnostic method for mapping a D‑Cinema Package (DCP) onto one or more file storage volumes. It specifies the Asset Map and Volume Index XML structures that link DCP asset UUIDs (as listed in the Packing List) to concrete file paths and broken‑up file segments (“chunks”). The standard enables assets larger than a single volume to be segmented across volumes and provides a framework for consistent ingestion, delivery and playback across diverse file storage systems.
Key topics and technical requirements
- Asset Map structure: XML-based mapping that associates Packing List asset identifiers (UUIDs) with storage locations and chunk lists. Elements include Id, AnnotationText, Creator, VolumeCount, IssueDate, Issuer and AssetList.
- Asset and Chunk definitions: An Asset may be divided into multiple chunks. Chunk entries contain path, optional volume index, offset and length so an asset can be reconstructed by concatenating chunk files.
- Volume Index: Identifies each volume in multi‑volume sets; an Asset Map must be present on every volume and shall contain the complete map for all volumes.
- Segmentation rules: Assets may be split to span volumes-allowing efficient use of media and support for volumes with limited capacity.
- Media‑specific DCP Map Profiles: Profiles define constraints such as URL/URI schemes, path formats, XML encoding, chunk size and asset map location for a given media type.
- XML schema and interoperability: The standard references W3C XML and XML Schema and aligns with RFCs for URL/URI and UUID handling to ensure cross‑platform compatibility.
Practical applications
- Authoring and delivery of DCPs that must be mapped onto different storage media (optical, disk, network share).
- Creating ingest and playback tools for cinema servers that need deterministic ways to locate and reassemble assets.
- Enabling multi‑volume distribution for very large assets (e.g., high‑resolution JPEG 2000 track files) by splitting them into chunks.
- Archival workflows where packing lists remain stable while physical storage schemes change.
Who uses this standard
- DCP authoring and mastering houses
- Digital cinema integrators and projection server manufacturers
- Post‑production facilities and content distributors
- Archival and preservation teams managing large cinema assets
- Software developers building DCP ingest, verification and playback tools
Related standards
- ISO 26429 series (D‑Cinema Packaging), including Parts 3, 4, 6, 7, 8 and 10 (equivalent to SMPTE 429‑x documents)
- SMPTE 429‑8 (Packing List)
- W3C XML and XML Schema; RFC 2396/4122 for URI/UUID conventions
Keywords: D‑Cinema, DCP, Asset Map, Volume Index, file segmentation, chunk, packaging, UUID, packing list, file storage, digital cinema packaging.
