Overview
ISO/IEC 21000-16:2005 - MPEG-21 Part 16: Binary Format - specifies a binary serialization for XML-based MPEG-21 descriptions to enable efficient interchange, storage and streaming of MPEG-21 metadata. Built as a constrained profile of the Binary MPEG format for XML (BiM, ISO/IEC 23001-1), this standard defines how MPEG-21 descriptions (for example Digital Item Declarations) are binarized, fragmented into access units, decoded and reconstructed into a schema-valid binary current description tree.
Keywords: ISO/IEC 21000-16, MPEG-21 binary, BiM, binary format for XML, MPEG-21 serialization, XML binarization.
Key Topics and Requirements
- BiM-based binarization: Uses ISO/IEC 23001-1 (BiM) methods with MPEG-21-specific constraints (clauses 5–9 of 23001-1 are refined).
- Access Units (AU): Descriptions are partitioned into individually addressable AUs; each AU has composition timing for progressive delivery.
- Schema-driven encoding: BiM relies on schema analysis to map XML elements, types and attributes to compact binary codes; encoder and decoder should share schema information (mechanisms exist to transmit schema when unknown).
- Validation after each AU: The binary current description tree must be XML Schema–valid after decoding every access unit; additional MPEG-21 validity rules (e.g., for DID) apply for progressive transmission.
- Canonical consistency: Decoding must ensure the Schema Centric XML Canonical (SCC14N) representation of the reconstructed description is bit-for-bit identical to the original SCC14N form.
- Deferred nodes & fragments: Support for deferred nodes and fragment references allows selective, on-demand acquisition of parts of the description.
- Limitations preserved: Binarization does not preserve processing instructions, attribute order, comments or non-significant whitespace in the textual XML.
Applications
- Efficient storage and interchange of MPEG-21 metadata (Digital Item Declarations, rights data, adaptation metadata).
- Low-bandwidth or progressive streaming of multimedia metadata where incremental decoding and schema validation are required.
- Embedded or resource-constrained devices (set-top boxes, mobile clients) needing compact MPEG-21 representations.
- Content delivery systems and middleware that need reliable, schema-valid reconstruction of MPEG-21 descriptions.
Who Would Use This Standard
- Multimedia systems architects and implementers of MPEG-21 encoders/decoders.
- Software developers building content delivery platforms, streaming services or metadata repositories.
- Standards and interoperability engineers working on MPEG-21 deployments or cross-standard integration.
- Device manufacturers and service providers targeting efficient metadata transport and storage.
Related Standards
- ISO/IEC 23001-1 (Binary MPEG format for XML - BiM)
- ISO/IEC 21000 (MPEG-21 family: Parts 1–17, including Part 2 Digital Item Declaration)
- XML, XML Schema, XPath, Canonical XML, SCC14N
This standard is essential where compact, schema-valid binary representations of MPEG-21 XML descriptions are required for reliable delivery, storage and progressive consumption.
