IEC 61937-9:2017

IEC 61937-9 ®
Edition 2.0 2017-08
INTERNATIONAL
STANDARD
Digital audio – Interface for non-linear PCM encoded audio bitstreams applying
IEC 60958 –
Part 9: Non-linear PCM bitstreams according to the MAT format
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IEC 61937-9 ®
Edition 2.0 2017-08
INTERNATIONAL
STANDARD
Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 –
Part 9: Non-linear PCM bitstreams according to the MAT format

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.160.30; 35.040 ISBN 978-2-8322-4702-0

– 2 – IEC 61937-9:2017 © IEC 2017
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviated terms . 5
3.4 Abbreviated terms . 6
4 Mapping of the audio bitstream on to IEC 61937-1 . 6
4.1 General . 6
4.2 MAT burst-info . 6
5 Format of MAT data-bursts . 6
5.1 General . 6
5.2 Pause data-burst . 7
5.3 Audio data-bursts . 7
5.3.1 The MAT data . 7
5.3.2 Latency of the MAT decoder . 10
Bibliography . 11

Figure 1 – MAT data-burst . 7
Figure 2 – Latency of MAT decoding . 10

Table 1 – Shorthand notation for fractional frame rates . 6
Table 2 – Fields of burst-info . 6
Table 3 – Repetition period of the pause data-bursts . 7
Table 4 – Data-type-dependent information for MAT . 7
Table 5 – Sampling frequency of MAT-encoded audio and IEC 60958 frame rate . 8
Table 6 – MAT audio frame rate and corresponding data-burst repetition period for
video-frame-aligned MAT bitstreams . 8
Table 7 – MAT data-burst sequence and repetition period variance to ensure MAT
audio frame alignment at 59,94 and 119,88 fps . 8
Table 8 – MAT data-burst: meaning of Pc bits 8 to 11 when bit 12 of Pc = 1 . 9
Table 9 – Maximum burst-length values per MAT data-burst repetition period . 9

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIGITAL AUDIO –
INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO
BITSTREAMS APPLYING IEC 60958 –

Part 9: Non-linear PCM bitstreams according to the MAT format

FOREWORD
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International Standard IEC 61937-9 has been prepared by technical area 4: Digital system
interfaces and protocols, of IEC technical committee 100: Audio, video and multimedia
systems and equipment.
This second edition cancels and replaces the first edition published in 2007. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of new frame rates.

– 4 – IEC 61937-9:2017 © IEC 2017
The text of this International Standard is based on the following documents:
CDV Report on voting
100/2721/CDV 100/2933/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61973 series, published 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 document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

DIGITAL AUDIO –
INTERFACE FOR NON-LINEAR PCM ENCODED AUDIO
BITSTREAMS APPLYING IEC 60958 –

Part 9: Non-linear PCM bitstreams according to the MAT format

1 Scope
This part of IEC 61937 describes the method to convey non-linear PCM bitstreams encoded
according to the MAT format.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 61937-1:2007, Digital audio interface for non-linear PCM encoded audio bit streams
applying IEC 60958 – Part 1: General
IEC 61937-1:2007/AMD1:2011, Digital audio interface for non-linear PCM encoded audio bit
streams applying IEC 60958 – Part 1: General
IEC 61937-2, Digital audio interface for non-linear PCM encoded audio bit streams applying
IEC 60958 – Part 2: Burst-info
3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
audio frame rate
number of MAT audio frames per second
3.2
fractional frame rates
fractional audio frame rates supported by MAT
Note 1 to entry: These frame rates are written in shorthand notation, as specified in Table 1.

– 6 – IEC 61937-9:2017 © IEC 2017
Table 1 – Shorthand notation for
fractional frame rates
Fractional MAT audio frame rate Shorthand version
(fps)
1 000 47,952
48 × �
1 001
1 000 59,94
60 × �
1 001
1 000 119,88
120 × �
1 001
3.3
latency
delay time of an external audio decoder to decode a MAT data-burst, defined as the sum of
two values: the receiving delay time and the decoding delay time
3.4 Abbreviated terms
MAT Metadata-enhanced Audio Transmission
fps frames per second
4 Mapping of the audio bitstream on to IEC 61937-1
4.1 General
The coding of the bitstream and data-burst is in accordance with IEC 61937-1,
IEC 61937-1:2007/AMD1:2011 and IEC 61937-2, including field names such as "Pc", "Pa" and
"R".
4.2 MAT burst-info
The 16-bit burst-info contains information about the data that will be found in the data-burst
(see Table 2).
Table 2 – Fields of burst-info
Repetition period of
Bits of Data-type Data-type Reference
C
...