Overview
IEC TR 62291:2009 - Multimedia data storage: Application program interface for UDF based file systems defines an API for reading and writing files that conform to the Universal Disk Format (UDF) specification (UDF 2.01) and its security extension. Published by IEC as a Technical Report, this second edition updates references to ISO/IEC 9945-2:2003 (POSIX system interfaces) and aligns the API with UDF 2.01 for interoperable multimedia and optical-storage file handling.
Key topics and technical requirements
- API scope: Specifies application program interfaces to access UDF-based file systems - covering file operations compatible with POSIX interfaces and UDF-specific extensions.
- POSIX conformity: Maps common POSIX functions (e.g., opendir(), readdir(), open(), read(), write(), chmod(), chown(), lseek()) to UDF file operations (see Table 1 in the report).
- UDF-specific operations: Defines structures and functions in header files (e.g., udf.h) for UDF file entries and metadata (file entry structures, extended attributes, timestamps, permissions).
- Security extension (Secure UDF): Includes support for access logging, licensing and environment identifiers. Describes access log descriptor structures, log operations (get a log), and license management operations (get/add/delete/set licenses).
- Error/notation: Uses POSIX-style error numbers per ISO/IEC 9945-2 conventions.
- Normative references: Relies on UDF Specification Revision 2.01, Secure UDF (OSTA), and ISO/IEC 9945-2:2003.
Practical applications
- Implementing file system drivers or middleware that read/write UDF-formatted optical media (DVD, recordable/rewritable discs).
- Building multimedia storage solutions needing interchangeable media compatibility and consistent file semantics across platforms.
- Integrating security features for content protection: access logging, license handling, and usage-environment enforcement.
- Developing authoring tools, playback devices and archival systems that must honor UDF metadata and security extensions.
Who should use this standard
- File system and device driver developers
- Multimedia hardware and optical drive manufacturers
- Software integrators for video, broadcast and content protection systems
- Archival and digital preservation engineers requiring platform-independent media interchange
Related standards
- Universal Disk Format (UDF) Specification, Revision 2.01 (OSTA)
- ISO/IEC 9945-2:2003 (POSIX - Part 2: System Interfaces)
- Secure UDF (OSTA) / JIS/TR X 0040 (Security Extension to UDF)
Practical takeaway: IEC TR 62291:2009 provides the API and structural definitions needed to implement interoperable, secure UDF file-system access consistent with POSIX interfaces and UDF 2.01 - essential for reliable multimedia data exchange on optical and interchangeable media.