IEC 61937-6:2006

• Abstract:

  IEC 61937-6:2006 specifies the method for IEC 60958 to convey non-linear PCM bitstreams encoded in accordance with the MPEG-2 AAC (Advanced Audio Coding) and MPEG-4 AAC formats. This second edition of IEC 61937-6 cancels and replaces the first edition published in 2002. It contains the following significant technical changes:; - addition of data-type for MPEG2 AAC low sampling frequency;; - addition of data-type for MPEG-4 AAC.

• Status: Published
• Publication Date: 28-Jan-2014
• ICS: 33.160.60 - Multimedia systems and teleconferencing equipment
• ICS: 35.040.40 - Coding of audio, video, multimedia and hypermedia information
• Technical Committee: TC 100 - Audio, video and multimedia systems and equipment
• Current Stage: PPUB - Publication issued
• Start Date: 25-Jan-2006
• Completion Date: 15-Sep-2006

• Amended By: IEC 61937-6:2006/AMD1:2014 - Amendment 1 - Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4 AAC formats
• Effective Date: 05-Sep-2023
• Revises: IEC 61937-6:2002 - Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC format
• Effective Date: 05-Sep-2023

Overview

IEC 61937-6:2006 defines how to carry non-linear PCM audio bitstreams encoded as MPEG-2 AAC and MPEG-4 AAC over the digital audio interface defined by IEC 60958. This second edition updates the mapping and burst formats to add support for MPEG-2 AAC low sampling frequency data-types and for MPEG-4 AAC. The standard specifies burst-info fields, data-type identifiers, repetition timing, pause bursts, and decoding latency considerations needed to transport AAC streams reliably over S/PDIF-like interfaces.

Key Topics

• Mapping to IEC 60958: Specifies how AAC bitstreams are encapsulated as IEC 61937 data-bursts carried in IEC 60958 frames.
• Data-types and burst-info: Defines data-type identifiers (for example, data-type = 7 for MPEG-2 AAC ADTS; data-type = 19 for MPEG-2 AAC low sampling; data-type = 20 for MPEG-4 AAC) and the burst-info field layouts used to identify payloads.
• Data-burst format: Audio data-bursts include a burst-preamble, burst-payload (one or more complete AAC ADTS frames), and stuffing bits. The document details the content and structure of pause data-bursts and audio data-bursts.
• Timing and repetition: Repetition periods for pause bursts and rules for scheduling data-bursts are defined (e.g., recommended pause repetition periods such as 32 IEC 60958 frames for standard bursts, 64/128 frames for half- and quarter-rate low sampling frequency variants).
• Latency and synchronization: Specifies decoding latency definitions and recommended use of latency values so transmitters can synchronize decoded audio with video.
• Low/high sampling frequency variants: Adds support for half-rate and quarter-rate low sampling frequency mappings and a double-rate high sampling frequency mapping for certain MPEG-4 AAC modes (including SBR/HE-AAC considerations).

Applications

• Implementation of S/PDIF/IEC 60958 interfaces in consumer AV equipment, such as set-top boxes, Blu-ray players, digital TVs and home theater receivers.
• Design of external AAC decoders and audio processors that accept IEC 61937-encapsulated AAC streams.
• Broadcast and professional audio systems that need a standardized method to transport AAC bitstreams over digital audio links.
• Firmware and driver development for multimedia SoCs, digital audio transmitters, and interfacing hardware.

Who should use this standard

• Audio and consumer electronics manufacturers
• System integrators and AV engineers
• Codec and decoder developers
• Standards and compliance testers

Related Standards

• IEC 60958 (Digital audio interface)
• IEC 61937 (all parts) - Part 1: General; Part 2: Burst-info
• ISO/IEC 13818-7 (MPEG-2 AAC)
• ISO/IEC 14496-3 (MPEG-4 AAC)

Keywords: IEC 61937-6, IEC 60958, MPEG-2 AAC, MPEG-4 AAC, digital audio interface, AAC ADTS, non-linear PCM, S/PDIF, burst-info, data-burst, decoding latency.