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.
