IEC 61937-1:2021

Overview

IEC 61937-1:2021 - "Digital audio – Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 – Part 1: General" is an IEC consumer‑focused standard that defines how non‑linear PCM (compressed) audio bitstreams are carried over the IEC 60958 digital audio interface family. This third edition (2021, with corrigendum March 2024 included) replaces the 2007 edition and 2011 amendment, and introduces key technical updates such as activation of the Pe field, enhanced use of channel status bits, and Annex B describing monaural linear PCM transfer alongside non‑linear streams. The professional AES/EBU mode is explicitly out of scope.

Key topics and technical requirements

• Interface mapping to IEC 60958: Specifies how encoded audio frames and control information are mapped onto IEC 60958 frames and subframes for transmission.
• Data‑burst structure: Defines the composition of a data‑burst (burst‑preamble + burst‑payload), including preamble words, burst‑info fields, and payload length coding (length‑code).
• Burst types: Describes audio data‑bursts, pause data‑bursts and null data‑bursts, and procedures for bridging gaps between bursts.
• Channel status usage: Enhances channel status bit definitions to signal presence and properties of non‑linear PCM streams in consumer applications.
• Pe field activation: Introduces or activates the extended data‑type field (Pe) for additional payload/type identification.
• Normative annexes: Annex A (channel status allocation for consumer use) and Annex B (informative guidance on simultaneous monaural linear PCM transfer with non‑linear PCM bitstreams).
• Reference and cross‑requirements: Normative linkage to IEC 60958 series and IEC 61937-2 (burst‑info).

Practical applications and users

Who uses IEC 61937-1:

• Consumer electronics manufacturers (S/PDIF/IEC 60958 interface design)
• Digital audio hardware and firmware engineers implementing compressed‑audio passthrough
• Audio decoder and receiver developers validating burst decoding and channel status handling
• Compliance and test laboratories performing interoperability testing
• Product managers and integrators ensuring consumer devices correctly transport non‑linear PCM streams

Typical applications:

• Transport of compressed (non‑linear PCM) audio frames across consumer digital audio interfaces
• Signalling and synchronization of encoded audio bursts for home AV receivers, soundbars, Blu‑ray players and similar consumer devices
• Ensuring correct burst formatting, pause handling and channel status signalling for downstream decoders

Related standards

• IEC 60958 (all parts) - Digital audio interface (consumer and general format)
• IEC 61937 (all parts) - Digital audio interface for non‑linear PCM bitstreams (Part 2: Burst‑info is directly related)

Keywords: IEC 61937-1, digital audio interface, IEC 60958, non-linear PCM, data-burst, burst-preamble, channel status, consumer audio standards.