ISO/IEC 23001-11:2023

Overview - ISO/IEC 23001-11:2023 (green metadata)

ISO/IEC 23001-11:2023, "Information technology - MPEG systems technologies - Part 11: Energy-efficient media consumption (green metadata)," specifies a metadata framework that enables reduced energy use during media consumption. The standard defines formats and semantics for metadata used to reduce decoder power, display power, and to support energy-aware media selection and quality recovery after low‑power encoding. It is the third edition (2023), updating the 2019 edition with new VVC SEI messages and finer interactive signalling for encoder/decoder control.

Key topics and technical requirements

• Green metadata formats: Defines metadata structures for energy-efficient decoding, encoding, presentation, and selection of media.
• Decoder power reduction: Introduces complexity metrics (CM) metadata and decoding operation reduction request (DOR‑Req) metadata. CM helps decoders adapt operating frequency; DOR‑Req allows remote encoders to request lower-complexity encoding.
• Interactive signalling: Syntax and semantics for signalling between decoder and encoder to request or negotiate power-saving decoding operations.
• Display power reduction: Metadata (including RGB-component statistics and quality levels) for display subsystems to dynamically adapt presentation parameters and lower display energy use.
• Energy‑efficient media selection: Metadata that assists clients (e.g., adaptive streaming clients) to choose video representations that optimize the tradeoff between power savings and quality of experience (QoE).
• Quality recovery metrics: Metrics and metadata to support restoration of quality after low‑power encoding; includes syntax for AVC/HEVC and VVC SEI messages.
• Conformance and implementation guidance: Clauses and annexes for conformance, reference software, SEI syntax, implementation guidelines, and objective distortion metrics.

Practical applications and who uses this standard

• Streaming platforms and CDN providers: to offer energy‑aware bitrate/representation selection for mobile or battery‑constrained clients.
• Codec and encoder vendors: to implement DOR‑Req and CM signalling in encoders and bitstreams (AVC, HEVC, VVC).
• Decoder and SoC manufacturers: to adapt decoder frequency/power based on CM metadata for lower power consumption.
• Display and device manufacturers: to use RGB statistics and quality levels for display-adaptive power savings.
• Video conferencing and real‑time communication systems: to enable remote low‑complexity encoding for participant devices with power constraints.
• Standards engineers and researchers: for integration, conformance testing, and developing energy‑efficient media workflows.

Related standards (normative references)

• ISO/IEC 14496-10 (AVC/H.264)
• ISO/IEC 23008-2 (HEVC/H.265)
• ISO/IEC 23009-1 (DASH)
• References to VVC SEI message syntax and MPEG systems technologies in the ISO/IEC 23001 family

This standard is essential for implementing energy-efficient media consumption, enabling interoperable metadata-driven strategies across encoders, decoders, displays, and adaptive streaming clients.