Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 8: Non-linear PCM bitstreams according to the Windows Media Audio (WMA) Professional format

specifies the method for the digital audio interface specified in IEC 60958 to convey non-linear PCM bitstreams encoded in accordance with the WMA Professional format.

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Status
Published
Publication Date
24-Oct-2006
Current Stage
PPUB - Publication issued
Start Date
25-Oct-2006
Completion Date
25-Oct-2006
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IEC 61937-8:2006 - Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 8: Non-linear PCM bitstreams according to the Windows Media Audio (WMA) Professional format
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INTERNATIONAL IEC
STANDARD 61937-8
First edition
2006-10
Digital Audio –
Interface for non-linear PCM encoded
audio bitstreams applying IEC 60958 –
Part 8:
Non-linear PCM bitstreams according to the
Windows Media Audio (WMA) Professional format
Reference number
IEC 61937-8:2006(E)
---------------------- Page: 1 ----------------------
Publication numbering
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60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.
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---------------------- Page: 2 ----------------------
INTERNATIONAL IEC
STANDARD 61937-8
First edition
2006-10
Digital Audio –
Interface for non-linear PCM encoded
audio bitstreams applying IEC 60958 –
Part 8:
Non-linear PCM bitstreams according to the
Windows Media Audio (WMA) Professional format
© IEC 2006 ⎯ Copyright - all rights reserved

No part of this publication may be reproduced or utilized in any form or by any means, electronic or

mechanical, including photocopying and microfilm, without permission in writing from the publisher.

International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland

Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch

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Commission Electrotechnique Internationale M
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
---------------------- Page: 3 ----------------------
– 2 – 61937-8 © IEC:2006(E)
CONTENTS

FOREWORD...........................................................................................................................3

1 Scope...............................................................................................................................5

2 Normative references .......................................................................................................5

3 Terms, definitions and abbreviations ................................................................................5

3.1 Terms and definitions ..............................................................................................5

3.2 Abbreviations ..........................................................................................................5

3.3 Presentation convention ..........................................................................................5

4 Mapping of the audio bitstream on to IEC 61937 ..............................................................6

4.1 General ...................................................................................................................6

4.2 Windows Media Audio Professional burst-info .........................................................6

5 Format of WMA Professional data-burst ...........................................................................6

5.1 General ...................................................................................................................6

5.2 Pause data-burst.....................................................................................................7

5.3 Audio data-bursts ....................................................................................................7

Bibliography..........................................................................................................................13

Figure 1 – Windows Media Audio Professional type I data-burst .............................................7

Figure 2 – Latency of WMA Professional type I decoding ........................................................8

Figure 3 – Windows Media Audio Professional type II data-burst ............................................8

Figure 4 – Latency of WMA Professional type II decoding.......................................................9

Figure 5 – Windows Media Audio Professional type III data-burst .........................................10

Figure 6 – Latency of WMA Professional type III decoding....................................................10

Figure 7 – Windows Media Audio Professional type IV data-burst .........................................11

Figure 8 – Latency of WMA Professional type IV decoding....................................................11

Table 1 – Fields of burst-info ..................................................................................................6

Table 2 – Repetition period of Pause data-bursts....................................................................7

Table 3 – Data-type-dependent when data-type = 18 and sub-type = 0 ...................................7

Table 4 – Data-type-dependent when data-type = 18 and sub-type = 1 ...................................9

Table 5 – Data-type-dependent when data-type = 18 and sub-type = 2 .................................10

Table 6 – Data-type-dependent when data-type = 18 and sub-type = 3 .................................11

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61937-8 © IEC:2006(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIGITAL AUDIO –
INTERFACE FOR NON-LINEAR PCM ENCODED
AUDIO BITSTREAMS APPLYING IEC 60958
Part-8: Non-linear PCM bitstreams according to
the Windows Media Audio (WMA) Professional format
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

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

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 61937-8 has been prepared by Technical Area 4: Digital system

interfaces, of IEC technical committee 100: Audio, video and multimedia systems and

equipment.
The text of this standard is based on the following documents:
CDV Report on voting
100/1018A/CDV 100/1095/RVC

Full information on the voting for the approval of this standard 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.

---------------------- Page: 5 ----------------------
– 4 – 61937-8 © IEC:2006(E)

The list of all the parts of the IEC 61937 series, under the general title Digital audio –

Interface for non-linear PCM encoded audio bitstreams applying IEC 60958, 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

• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
---------------------- Page: 6 ----------------------
61937-8 © IEC:2006(E) – 5 –
DIGITAL AUDIO –
INTERFACE FOR NON-LINEAR PCM ENCODED
AUDIO BITSTREAMS APPLYING IEC 60958
Part-8: Non-linear PCM bitstreams according to
the Windows Media Audio (WMA) Professional format
1 Scope

This part of IEC 61937 specifies the method for the digital audio interface specified in

IEC 60958 to convey non-linear PCM bitstreams encoded in accordance with the WMA
Professional format.
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 (all parts), Digital audio interface

IEC 61937-1, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 1: General

IEC 61937-2, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 2: Burst-info
3 Terms, definitions and abbreviations

For the purposes of this document, the following terms, definitions, abbreviations and

presentation convention apply.
3.1 Terms and definitions
3.1.1
latency

delay time of an external audio decoder to decode a WMA Professional data burst, defined as

the sum of two values of the receiving delay time and the decoding delay time
3.2 Abbreviations
ATSC Advanced Television Systems Committee
MPEG The Moving Pictures Expert Group, a joint committee of ISO and IEC
ITU-R International Telecommunication Union, Radio communication Bureau
WMA Windows Media Audio
3.3 Presentation convention
F872h
Value ‘F872’ in hexadecimal format
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– 6 – 61937-8 © IEC:2006(E)
4 Mapping of the audio bitstream on to IEC 61937
4.1 General

The coding of the bitstream and data-burst shall be in accordance with IEC 61937-1.

4.2 Windows Media Audio Professional burst-info

The 16-bit burst-info contains information about the data that will be found in the data-burst in

accordance with Table 1.
Table 1 – Fields of burst-info
Reference Repetition period of
Bits of Pc Value Contents point R data-burst in
IEC 60958 frames
0 – 4 Data-type
0-17 According to IEC 61937-2
18 WMA Professional Subtype dependent Subtype dependent
19-31 According to IEC 61937-2
5 – 6 Data subtype
0 WMA Professional – Type I Bit 0 of Pa 2 048
1 WMA Professional – Type II Bit 0 of Pa 2 048
2 WMA Professional – Type III Bit 0 of Pa 1 024
3 WMA Professional – Type IV Bit 0 of Pa 512
7 – 15 According to IEC 61937-2

The reference point for a WMA Professional Type I stream is bit 0 of Pa of the first of a payload pair.

5 Format of WMA Professional data-burst
5.1 General

This clause specifies the audio data-burst for WMA Professional. Specific properties such as

reference points, repetition period, the method of filling stream gaps, and decoding latency

are specified for each data-type.

The decoding latency (or delay), indicated for the data-types, should be used by the

transmitter to schedule d
...

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