ISO/IEC 23094-1:2020

Overview

ISO/IEC 23094-1:2020 - Essential Video Coding (EVC) specifies a general video coding technology called Essential Video Coding (EVC). The standard defines the bitstream syntax and semantics, and a complete decoding process that ensures interoperable decoders. Conformance is defined by producing identical cropped decoded output pictures for a specified combination of profile, level and toolset. ISO/IEC 23094-1:2020 is intended for a wide range of applications including digital storage media, television broadcasting, and real‑time communications.

Key Topics and Requirements

The standard covers both high-level and detailed technical components necessary for implementing compliant EVC decoders:

• Bitstream and picture formats: raw bitstream layouts, NAL units, RBSPs and byte alignment rules.
• Partitioning and scanning: picture partitioning into slices, tiles and coding tree units (CTUs); scanning orders.
• Syntax and semantics: exhaustive tabular definitions of syntax elements and their meanings.
• Decoding process: step‑by‑step decoding for NAL units, slices, intra/inter/IBC prediction, motion vectors, reference picture management, and residual reconstruction.
• Scaling, transform and quantization: processes for coefficient scaling, inverse transforms and picture construction.
• In-loop filters: deblocking, advanced deblocking and Adaptive Loop Filter (ALF) procedures to improve visual quality.
• DRA process: decoding range/adaptation procedures (document describes DRA derivation and inverse mapping).
• Parsing and entropy coding: parsing rules for Exp‑Golomb codes and the CABAC parsing process including initialization and binarization.
• Conformance and tooling (normative annexes): profiles, levels and toolsets; raw bitstream storage format; hypothetical reference decoder; supplemental enhancement information (SEI) and video usability information (VUI).

Applications

ISO/IEC 23094-1:2020 is designed for practical video applications where interoperable, efficient compression is required:

• Broadcast and OTT streaming - standards‑compliant encoding/decoding for distribution.
• Real‑time communications - low‑latency decoder implementations for conferencing and streaming.
• Consumer and professional storage - coded formats for disks, files and archives.
• Silicon and device vendors - hardware and firmware decoders in SoCs, TVs and set‑top boxes.
• Software codec developers and test labs - implementation, validation and conformance testing.

Who Should Use This Standard

• Codec implementers and decoder vendors
• Video streaming platforms and broadcasters
• Semiconductor/SoC engineers and device manufacturers
• QA, interoperability and conformance testing organizations
• Researchers and developers working on video compression

Related Standards

ISO/IEC 23094-1 is Part 1 of the ISO/IEC 23094 series and complements other international video coding standards and normative documents addressing bitstream storage, SEI and usability metadata.

For implementers and integrators, ISO/IEC 23094-1:2020 provides the definitive specification for EVC decoders and the authoritative basis for conformance and interoperability.