ISO/IEC 23002-7:2022

Overview

ISO/IEC 23002-7:2022 - "Information technology - MPEG video technologies - Part 7: Versatile supplemental enhancement information messages for coded video bitstreams" specifies the syntax and semantics of Video Usability Information (VUI) parameters and Supplemental Enhancement Information (SEI) messages. Drafted to be H.266 / ISO/IEC 23090-3‑friendly, the standard is written generically so the same VUI/SEI definitions can be applied to other coded video bitstreams. The document explains how VUI parameters and SEI messages are conveyed in bitstreams or by system-level signaling and clarifies that use of these elements is optional - decoders may ignore or partially use them unless a referencing specification mandates their interpretation.

Key Topics and Requirements

• VUI parameters: formalized parameter sets that describe display, timing, sampling and other usability metadata for decoders and playout systems.
• SEI message taxonomy: a comprehensive catalog of SEI message types with precise syntax and semantics for each message.
• Representative SEI messages included (names only, as specified):
  • Film grain characteristics, frame packing arrangement, decoded picture hash
  • Mastering display colour volume, content light level information
  • Omnidirectional video messages (equirectangular, generalized cubemap, region-wise packing, viewport)
  • Multiview and depth representation information, alpha channel information
  • Frame-field info, sample aspect ratio, annotated regions, colour transform information
  • Parameter sets inclusion indication, dependent random access point (DRAP) messages
• Conventions and parsing: formal notation, operator conventions, and parsing process descriptions (including Exp‑Golomb code handling) to ensure interoperable implementations.
• Optional interpretation: the standard specifies semantics but does not impose a decoder implementation requirement unless referenced by another specification.

Practical Applications & Who Uses It

• Video codec developers implementing MPEG/H.266 and other video coding specifications to embed interoperable metadata.
• Encoder and packager vendors who insert SEI messages and VUI metadata into coded video bitstreams for streaming, broadcasting, or file delivery.
• Player and decoder implementers that optionally read SEI/VUI to improve display rendering, colour management, HDR tone mapping, film-grain synthesis, viewport handling for 360°/omnidirectional video, and content verification (e.g., decoded picture hash).
• System designers and standards bodies referencing VUI/SEI semantics for interoperable workflows across production, delivery, and playback.

Related Standards

• Rec. ITU‑T H.266 / ISO/IEC 23090‑3 (Versatile Video Coding) - primary pairing for usage.
• Other MPEG and container specifications that reference SEI/VUI for signaling (encapsulation and systems-level integration).

Keywords: ISO/IEC 23002-7:2022, MPEG video, SEI messages, VUI parameters, coded video bitstreams, H.266, video metadata, mastering display colour, omnidirectional video.