IEC TS 62312-2:2007

TECHNICAL IEC
SPECIFICATION TS 62312-2
First edition
2007-06
Guideline for synchronization of audio and video –
Part 2:
Methods for synchronization of audio
and video systems
Reference number
IEC/TS 62312-2:2007(E)
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TECHNICAL IEC
SPECIFICATION TS 62312-2
First edition
2007-06
Guideline for synchronization of audio and video –
Part 2:
Methods for synchronization of audio
and video systems
PRICE CODE
Commission Electrotechnique Internationale P

International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – TS 62312-2 © IEC:2007(E)

CONTENTS
FOREWORD.3

INTRODUCTION.5

1 Scope.6

2 Normative references .6

3 Terms and definitions .6

4 System model.7

4.1 Audio video system .7
4.2 Latency and delay .7
4.3 System model .7
4.4 Audio and video device .8
4.5 Controller .9
4.6 Source device and display device.9
4.7 Controller function of audio and video device .10
5 Methods for synchronization .11
5.1 Information for synchronization.11
5.1.1 Time-code information .11
5.1.2 Latency information .11
5.2 Methods for synchronization.11
5.2.1 General .11
5.2.2 Method with time-code information .13
5.2.3 Method with latency information .14
5.3 Method with IEC 60958-3 .14
5.4 Method with IEC 61883-6 .14
5.5 Method with other interface specifications .15

Bibliography.16

Figure 1 – System model .7
Figure 2 – Audio and video device .8
Figure 3 – Information and control in audio and video device .9
Figure 4 – Source device .10
Figure 5 – Display device.10
Figure 6 – Audio amplifier .10
Figure 7 – Controller function of audio and video device .11
Figure 8 – Additional delay .12
Figure 9 – Multiple reproductions.13

TS 62312-2 © IEC:2007(E) – 3 –

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
GUIDELINE FOR SYNCHRONIZATION OF AUDIO AND VIDEO –

Part 2: Methods for synchronization of audio and video systems

FOREWORD
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all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
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The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical

specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development, or where, for any other reason, there is
the future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 62312-2, which is a technical specification, has been prepared by IEC technical
committee 100: Audio, video and multimedia systems and equipment.

– 4 – TS 62312-2 © IEC:2007(E)

The text of this technical specification is based on the following documents:

Enquiry draft Report on voting

100/1195/DTS 100/1226/RVC
Full information on the voting for the approval of this technical specification can be found in

the report on voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The list of all the parts of IEC 62312, under the general title Guideline for synchronization of
audio and video, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

TS 62312-2 © IEC:2007(E) – 5 –

INTRODUCTION
Audio, video and multimedia systems and equipment have begun to use digital technologies.

Digital systems or equipment may cause delay of audio and video signals because digital

signal processing causes latency and delay. The unevenness of the delay between audio and

video may cause synchronization problems.

For instance, a digital broadcasting system uses signal compression of audio and video. A

receiver has signal decoders, and this may cause unevenness of the delay between audio and

video. Digital video signal processing of display causes a significant delay in the reproduction

time of the video image. Another example is an audio video system consisting of a digital

media player, an audio amplifier and display. A digital media player outputs audio and video
signals separately to the amplifier and display through digital interfaces. This may cause
synchronization problems of audio and video when each processing time of the equipment is
different.
To solve synchronization problems, this technical specification gives guidelines for general
methods for the synchronization of audio and video.

– 6 – TS 62312-2 © IEC:2007(E)

GUIDELINE FOR SYNCHRONIZATION OF AUDIO AND VIDEO –

Part 2: Methods for synchronization of audio and video systems

1 Scope
The IEC 62312 series gives guidelines for methods of synchronization of audio and video.

This part of IEC 62312 describes the system model and general methods for the
synchronization of audio and video. The methods exclude the synchronization of the signal
source and the spatial delay of audio reproduction.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60958-1, Digital audio interface – Part 1: General
IEC 60958-3, Digital audio interface – Part 3: Consumer applications
IEC 61883-6, Consumer audio/video equipment – Digital interface – Part 6: Audio and music
data transmission protocol
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
latency
inevitable delay of signal that is caused by principle or unavoidable signal processing
3.2
delay
general meaning of delay other than latency, including delay that is caused by functional
signal processing and delay that is
...