ISO/IEC 14496-12:2022

Overview

ISO/IEC 14496-12:2022 - ISO base media file format - defines a general, extensible media container that specifies the timing, structure, and media information for timed sequences (audio‑visual presentations). Published as the seventh edition in 2022, this part of ISO/IEC 14496 provides the object‑structured file organization used as the foundation for a number of more specific file formats (for example, MP4 and HEIF). The standard separates metadata (structure) from media data, supports fragments for streaming, and defines identifiers and branding for interoperability.

Key topics and technical requirements

• Object‑structured file organization: box (atom)-based hierarchy that encapsulates metadata and media data; clear rules for box order and extensibility.
• File‑type and extended type boxes: mechanisms for brand identification and file compatibility indications.
• Movie/Track/Media boxes: containers such as movie box, track box, media box, and sample table box that describe presentation structure and per‑track information.
• Sample tables and timing: definitions for sample descriptions, time‑to‑sample mappings, sync samples, edit lists and other time structures required to present timed media accurately.
• Track data layout: data reference, sample size, sample‑to‑chunk and chunk offset structures that map logical samples to physical media data.
• Fragmentation and streaming support: movie fragments, fragment headers, random access boxes and related boxes to enable fragmented MP4 for low‑latency delivery and adaptive streaming.
• Identifiers and URIs: uniform resource locators and type indicators used for external data referencing and extensibility.
• Metadata and extensibility: structured approach to add new boxes and fields while preserving backward compatibility.

Applications and who uses it

• Content creators and encoders: produce compliant files that carry synchronized audio/video and metadata.
• Packagers and streaming vendors: implement fragmentation and branding for DASH/HLS packaging and low‑latency streaming.
• Media players and SDKs: parse box structures, sample tables and timing to enable accurate playback, seeking and random access.
• Transcoders, muxers and CDN operators: read/write sample tables and fragments for repackaging and delivery.
• DRM and metadata providers: use box structures and identifiers to embed protection and descriptive metadata.

Related standards

• Part of the ISO/IEC 14496 (MPEG‑4) family; serves as the base for derived formats (commonly used MP4/HEIF file types) and is widely referenced by adaptive streaming and packaging specifications.

Keywords: ISO/IEC 14496-12:2022, ISO base media file format, MP4, media container, fragmented MP4, sample table, movie box, streaming, timed media.