Overview
ISO/IEC 23001-11:2023/Amd 2:2025 (MPEG Part 11 - Energy-efficient media consumption, Amendment 2) extends the existing green metadata framework to cover new display power–reduction metadata and interactive signalling. The amendment specifies metadata types, message syntaxes and semantics used by encoders and decoders to coordinate energy savings in decoding, encoding and presentation (display) subsystems. Key additions include Attenuation Map Information (AMI), display attenuation signalling (DAMPR/DAMPR-Resp) and attenuated-video requests (DPRAV/DPRAV-Resp).
Key technical topics and requirements
- Green metadata categories: complexity metrics (CM), decoding operation reduction requests/responses (DOR-Req / DOR-Resp), and energy-efficient presentation metadata including AMI and RGB-component statistics.
- Interactive signalling for decoder power reduction: new message formats and syntax tables (e.g., Table 11 → Table 14) define fields such as dec_pow_reduction_type (values 0–3) and corresponding request/response fields.
- dec_pow_reduction_type:
- 0 - Decoder operations reduction
- 1 - Coding tool configuration
- 2 - Spatial and temporal scaling
- 3 - Extension of request types (cancellation/other extensions)
- Response semantics: DOR-Resp fields (e.g., dec_ops_reduction_resp, disabled_loop_filters_resp, pic_width_in_luma_samples_resp, frames_per_second_resp) indicate what the encoder accepts or implements and quantify permitted changes (percentage or specific parameter values).
- Display power reduction mechanisms:
- DAMPR-Req / DAMPR-Resp: request and acknowledge transmission of attenuation maps to be applied at the display to reduce emitted light and energy.
- DPRAV-Req / DPRAV-Resp: request and acknowledge generation/transmission of an attenuated video stream (encoder-applied attenuation).
- Syntax and semantics: amendment adds concrete bitfield syntax and semantics for interactive messages to ensure interoperable implementation between transmitters and receivers.
Practical applications
- Reducing energy consumption in:
- Video conferencing endpoints (point-to-point signalling to trade off quality vs. power)
- Streaming and broadcast workflows that adapt streams for low-power devices
- Display adaptation in mobile, battery-powered, and energy-constrained devices
- Use cases include encoder/decoder runtime adaptation, dynamic adjustment of coding tools, spatial/temporal downscaling, and content attenuation to reduce display luminance.
Who should use this standard
- MPEG/codec implementers and encoder/decoder vendors
- Set-top box and media player manufacturers
- Mobile device and display OEMs implementing attenuation maps and display adaptation
- Streaming platforms and conferencing solution developers seeking energy-efficient delivery
- Standards engineers and systems integrators implementing the ISO/IEC 23001 series
Related standards
- Other parts of ISO/IEC 23001 (MPEG systems technologies / green metadata) - see the ISO/IEC 23001 series for broader context and interoperability guidance.
Keywords: ISO/IEC 23001-11, green metadata, MPEG, energy-efficient media consumption, DOR-Req, DOR-Resp, DAMPR, DPRAV, attenuation map, display power reduction.