International Telecommunication Union
ITU-T
G.719
TELECOMMUNICATION
STANDARDIZATION SECTOR
OF ITU
(06/2008)
SERIES G: TRANSMISSION SYSTEMS AND MEDIA,
DIGITAL SYSTEMS AND NETWORKS
Digital terminal equipments – Coding of analogue signals
Low-complexity, full-band audio coding for
high-quality, conversational applications
Recommendation ITU-T G.719
ITU-T G-SERIES RECOMMENDATIONS
TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS
INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100–G.199
GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-
TRANSMISSION SYSTEMS
G.200–G.299
INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE
SYSTEMS ON METALLIC LINES
G.300–G.399
GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS
ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC
LINES
G.400–G.449
COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450–G.499
TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600–G.699
DIGITAL TERMINAL EQUIPMENTS G.700–G.799
General G.700–G.709
Coding of analogue signals G.710–G.729
Principal characteristics of primary multiplex equipment G.730–G.739
Principal characteristics of second order multiplex equipment G.740–G.749
Principal characteristics of higher order multiplex equipment G.750–G.759
Principal characteristics of transcoder and digital multiplication equipment G.760–G.769
Operations, administration and maintenance features of transmission equipment G.770–G.779
Principal characteristics of multiplexing equipment for the synchronous digital hierarchy G.780–G.789
Other terminal equipment G.790–G.799
DIGITAL NETWORKS G.800–G.899
DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900–G.999
QUALITY OF SERVICE AND PERFORMANCE – GENERIC AND USER-RELATED
ASPECTS
G.1000–G.1999
TRANSMISSION MEDIA CHARACTERISTICS G.6000–G.6999
DATA OVER TRANSPORT – GENERIC ASPECTS G.7000–G.7999
PACKET OVER TRANSPORT ASPECTS G.8000–G.8999
ACCESS NETWORKS G.9000–G.9999
For further details, please refer to the list of ITU-T Recommendations.
Rec. ITU-T G.719 (06/2008) i
Recommendation ITU-T G.719
Low-complexity, full-band audio coding for high-quality,
conversational applications
Summary
Recommendation ITU-T G.719 describes the G.719 coding algorithm for low-complexity full-band
conversational speech and audio, operating from 32 kbit/s up to 128 kbit/s.
The encoder input and decoder output are sampled at 48 kHz. The codec enables full bandwidth,
from 20 Hz to 20 kHz, encoding of speech, music and general audio content. The codec operates on
20-ms frames and has an algorithmic delay of 40 ms.
The coding algorithm is based on transform coding with adaptive time-resolution, adaptive
bit-allocation and low-complexity lattice vector quantization.
This Recommendation contains an electronic attachment containing a set of test signals, which can
be used together with the ANSI-C code in order to verity bit-exactness.
Amendment 1 adds new Annex A that specifies the use of the ISO base media file format as
container for the G.719 bitstream addresses non-conversational use cases of the codec (e.g., call
waiting music playback and recording of teleconferencing sessions, voice mail messages, online
"jam"-sessions).
Amendment 1 also includes Annex B, an alternative implementation of the G.719 using floating-
point arithmetic. Examples of application of the floating point implementations include DSP
platforms optimized for floating point and codec implementations using desktop computers.
Amendment 2 adds new Annex C specifying the G.719 packet format, capability identifier and
capability parameters and related procedures for H.245 based systems.
Source
Recommendation ITU-T G.719 was approved on 13 June 2008 by ITU-T Study Group 16
(2005-2008) under Recommendation ITU-T A.8 procedure.
This edition includes the amendments approved on 13 November 2008 and 16 March 2009 by ITU-T
Study Group 16 (2009-2012) under Recommendation ITU-T A.8 procedure.
Keywords
Adaptive time-frequency transform, fast lattice vector quantization, full-band, low-complexity.
格型矢量量化
改进
ii Rec. ITU-T G.719 (06/2008)
FOREWORD
The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of
telecommunications, information and communication technologies (ICTs). The ITU Telecommunication
Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical,
operating and tariff questions and issuing Recommendations on them with a view to standardizing
telecommunications on a worldwide basis.
The World Telecommunication Standardization Assembly (WTSA), which meets every four years,
establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on
these topics.
The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
In some areas of information technology which fall within ITU-T's purview, the necessary standards are
prepared on a collaborative basis with ISO and IEC.
NOTE
In this Recommendation, the expression "Administration" is used for conciseness to indicate both a
telecommunication administration and a recognized operating agency.
Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain
mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the
Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some
other obligatory language such as "must" and the negative equivalents are used to express requirements. The
use of such words does not suggest that compliance with the Recommendation is required of any party.
INTELLECTUAL PROPERTY RIGHTS
ITU draws attention to the possibility that the practice or implementation of this Recommendation may
involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence,
validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others
outside of the Recommendation development process.
As of the date of approval of this Recommendation, ITU had received notice of intellectual property,
protected by patents, which may be required to implement this Recommendation. However, implementers
are cautioned that this may not represent the latest information and are therefore strongly urged to consult the
TSB patent database at http://www.itu.int/ITU-T/ipr/.
© ITU 2009
All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the
prior written permission of ITU.
Rec. ITU-T G.719 (06/2008) iii
CONTENTS
Page
1 Scope ............................................................................................................................ 1
2 References..................................................................................................................... 1
3 Definitions .................................................................................................................... 2
4 Abbreviations and acronyms ........................................................................................ 2
5 Notations and conventions............................................................................................ 2
6 General description of the codec .................................................................................. 4
6.1 Encoder........................................................................................................... 4
6.2 Decoder........................................................................................................... 5
6.3 Algorithmic delay analysis............................................................................. 6
6.4 Complexity and memory requirements .......................................................... 6
6.5 Description of the codec................................................................................. 7
7 Functional description of the encoder........................................................................... 7
7.1 Transient detection ......................................................................................... 7
7.2 Adaptive time-frequency transform ............................................................... 9
7.3 Grouping of spectral coefficients ................................................................... 14
7.4 Norm estimation and quantization.................................................................. 17
7.5 Bit allocation .................................................................................................. 18
7.6 Fast lattice vector quantization....................................................................... 21
7.7 Noise level adjustment ................................................................................... 26
7.8 Bit stream format............................................................................................ 27
8 Functional description of the decoder........................................................................... 28
8.1 Flags decoding................................................................................................ 28
8.2 Norm decoding ............................................................................................... 28
8.3 Spectral coefficient decoding ......................................................................... 28
8.4 Spectrum filling.............................................................................................. 29
8.5 Inverse transform............................................................................................ 31
8.6 Frame erasure concealment ............................................................................ 34
9 Flexible rate selection................................................................................................... 34
10 Simulation software...................................................................................................... 35
10.1 Use of the simulation software ....................................................................... 35
10.2 Organization of the simulation software ........................................................ 35
Annex A Storage format definitions ....................................................................................... 39
A.1 Scope .............................................................................................................. 39
A.2 Raw storage format for the ITU-T G.719 bitstream....................................... 39
A.3 Sample entry description for ISO base file format......................................... 40
Annex B Floating point implementation................................................................................. 43
B.1 Scope .............................................................................................................. 43
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