ISO IEC 23094-2-2021 PDF

Full title and description

ISO/IEC 23094-2:2021 — Information technology — General video coding — Part 2: Low complexity enhancement video coding. This part specifies the LCEVC (Low Complexity Enhancement Video Coding) bitstream and tools intended to be used as an enhancement layer in conjunction with existing base codecs to improve compression efficiency and/or reduce encoding/decoding complexity.

Abstract

ISO/IEC 23094-2:2021 defines the syntax, semantics and decoding processes for a low-complexity enhancement layer (LCEVC) that works with a variety of underlying video codecs. The specification focuses on lightweight enhancement tools, encoder-driven upsampling and residual coding to provide improved visual quality or bitrate reduction while keeping implementation complexity low.

General information

• Status: Published.
• Publication date: November 2021 (2021-11).
• Publisher: ISO/IEC (prepared under ISO/IEC JTC 1/SC 29 — Coding of audio, picture, multimedia and hypermedia information).
• ICS / categories: 35.040.40 (Coding of audio, video, multimedia and hypermedia information).
• Edition / version: Edition 1 (2021).
• Number of pages: 119 pages (ISO catalogue listing).

Scope

This standard specifies a low-complexity enhancement video coding bitstream and associated decoding process intended to be used as an enhancement layer on top of a variety of base codecs. It covers enhancement-layer tools, bitstream structure and decoding behavior so that an LCEVC-compliant decoder can reconstruct enhanced output when used together with a specified base-layer decoder or rendition. The design goal is to enable improved compression efficiency and/or reduced computational complexity by coding residuals and enhancement data in a compact, interoperable form.

Key topics and requirements

• Definition of the LCEVC enhancement-layer bitstream syntax and semantics, including headers, payloads and signaling.
• Enhancement tools for encoder-driven upsampling and residual coding designed to be low complexity.
• Interoperation model with existing base codecs (how enhancement layer augments a base rendition).
• Conformance points and reference software are specified in companion parts of the series (see Related standards).
• Levels/profiles and amendment history (additional levels introduced via amendments).

Typical use and users

Intended users include codec implementers, encoder and decoder vendors, streaming and broadcast service providers, chipset and device manufacturers, and testing laboratories. Typical uses are augmenting existing codecs in live streaming, OTT delivery, broadcasting and low-power decoding scenarios where improved quality or lower bitrates are desired without replacing the base codec in the ecosystem.

Related standards

ISO/IEC 23094 is a multipart family (MPEG‑5). Related parts include ISO/IEC 23094-1:2020 (Essential Video Coding — EVC), ISO/IEC 23094-3:2022 (Conformance and reference software for LCEVC) and ISO/IEC 23094-4:2022 (Conformance and reference software for Essential Video Coding), along with amendments published in 2023–2024 updating conformance data and adding supplementary information. These companion parts define reference data, conformance tests and related metadata for the series.

Keywords

LCEVC, Low Complexity Enhancement Video Coding, MPEG‑5, enhancement layer, residual coding, upsampling, video coding, ISO/IEC 23094-2:2021, conformance.

FAQ

Q: What is this standard?

A: ISO/IEC 23094-2:2021 is the international standard that specifies Low Complexity Enhancement Video Coding (LCEVC) — the enhancement-layer bitstream and decoding behavior intended to work together with a variety of base video codecs.

Q: What does it cover?

A: It covers the enhancement-layer syntax, semantics, tools (encoder-driven upsampling, residual coding), and decoder requirements for LCEVC so that enhancement data can be interoperably applied on top of existing base-layer video renditions to improve quality or reduce bitrate.

Q: Who typically uses it?

A: Codec developers, system integrators, streaming and broadcast vendors, hardware and SoC designers, and conformance/test labs use this standard to implement, validate and deploy LCEVC-based enhancement solutions. Service providers use it to add enhancement layers to existing delivery pipelines without replacing deployed base codecs.

Q: Is it current or superseded?

A: The standard was published in November 2021 (Edition 1) and is published/active; the series has seen subsequent companion amendments and conformance-part updates published in 2022–2024. Users should check the ISO catalogue or national standards body for the latest amendments or corrigenda before procurement or implementation.

Q: Is it part of a series?

A: Yes — ISO/IEC 23094 is a multipart series (MPEG‑5). Part 1 specifies Essential Video Coding (EVC), Part 2 is LCEVC, Part 3 and Part 4 cover conformance and reference software for the respective technologies; amendments providing additional levels and conformance updates were published in 2023–2024.

Q: What are the key keywords?

A: LCEVC, enhancement layer, low complexity, residuals, upsampling, MPEG‑5, ISO/IEC 23094-2, conformance.