Overview
IEC TS 62312-2:2018 - "Guideline for synchronization of audio and video – Part 2: Methods for synchronization of audio and video systems" provides practical guidance on methods for synchronizing audio and video in digital systems. This second edition (2018) updates and replaces the 2007 edition and introduces fingerprint-based synchronization and related SMPTE synchronization information. The specification defines a system model, the types of synchronization information, controller roles, and practical synchronization methods while explicitly excluding synchronization of the signal source and spatial audio delays.
Key topics
- System model: Defines audio/video devices, controllers, interfaces and the boundaries for synchronization control (what the controller can and cannot adjust).
- Latency and delay: Clear definitions of latency (inevitable processing delay) and delay (intentional or functional delays), and how to represent their sum as latency information.
- Synchronization information types:
- Time-code information (e.g., SMPTE time-code)
- Latency information (device-reported latency/delay totals)
- Fingerprint / synchronization information (new in this edition - fingerprints and SMPTE-based metadata)
- Methods for synchronization:
- Using time-code to align audio/video timing
- Using latency information to compute compensation delays
- Using synchronization information (including fingerprint-based methods) to derive alignment
- Guidance on applying these methods across digital interfaces and controllers
- Controller role: How a controller gathers synchronization metadata and applies compensating delay to devices to achieve audio-video alignment.
- Interface considerations: Examples and references to interface standards where synchronization metadata may be transported.
Applications
IEC TS 62312-2 is directly applicable to:
- Consumer electronics (TVs, AV receivers, media players)
- Broadcast and streaming systems
- Professional AV installations and live-event systems
- Video conferencing and multimedia distribution networks
- System integrators and testing/QA teams resolving audio/video lip-sync issues
Practical benefits include improved lip-sync performance, consistent end-user experience, and standardized ways to exchange synchronization metadata across devices.
Who should use it
- AV system designers and equipment manufacturers
- Broadcast engineers and standards developers
- Integration specialists and QA/test engineers focused on latency and lip-sync
- Software/hardware teams implementing metadata transport or controller logic
Related standards
- IEC 60958-1 / IEC 60958-3 (Digital audio interfaces, consumer applications)
- IEC 61883-6 (AV digital interface - audio/music data transmission)
- SMPTE 12M (Time and control code / time-code specifications)
Keywords: IEC TS 62312-2:2018, audio-video synchronization, latency, time-code, fingerprint, SMPTE, synchronization methods, digital interfaces, lip-sync.