1、 International Telecommunication Union ITU-T G.726TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Corrigendum 1(05/2005) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments Coding of analogue signals by methods other than PCM 40, 32, 24, 16 kbit/s Adapt
2、ive Differential Pulse Code Modulation (ADPCM) Corrigendum 1: Correction to Annex A: Extensions of Recommendation G.726 for use with uniform-quantized input and output ITU-T Recommendation G.726 (1990) Corrigendum 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND N
3、ETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRI
4、ER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 General G.700G.709 Coding of analogue signals by
5、 pulse code modulation G.710G.719 Coding of analogue signals by methods other than PCM G.720G.729 Principal characteristics of primary multiplex equipment G.730G.739 Principal characteristics of second order multiplex equipment G.740G.749 Principal characteristics of higher order multiplex equipment
6、 G.750G.759 Principal characteristics of transcoder and digital multiplication equipment G.760G.769 Operations, administration and maintenance features of transmission equipment G.770G.779 Principal characteristics of multiplexing equipment for the synchronous digital hierarchy G.780G.789 Other term
7、inal equipment G.790G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 ETHERNET OVER TR
8、ANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. G.726 (1990)/Cor.1 (05/2005) i ITU-T Recommendation G.726 40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM) Corrigendum 1 Correction to
9、 Annex A: Extensions of Recommendation G.726 for use with uniform-quantized input and output Summary ITU-T Rec. G.726 contains the specification for the adaptive differential PCM voice-coding algorithm at 16, 24, 32, and 40 kbit/s. Its Annex A contains the specification for linear PCM input and outp
10、ut. This corrigendum to ITU-T Rec. G.726 fixes an omission in Decoder Block LIMO of its Annex A, which limits the output linear twos complement sample to a 14-bit value. The pseudo-code, as originally published, misses the case for reconstructed samples SR equal to 57 344. Source Corrigendum 1 to IT
11、U-T Recommendation G.726 (1990) was approved on 14 May 2005 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. G.726 (1990)/Cor.1 (05/2005) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of t
12、elecommunications. 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 Tel
13、ecommunication 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
14、areas of information technology which fall within ITU-Ts 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
15、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 “sh
16、all“ 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 p
17、ractice 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 dev
18、elopment process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are ther
19、efore strongly urged to consult the TSB patent database. ITU 2005 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. G.726 (1990)/Cor.1 (05/2005) 1 ITU-T Recommendation G.726 40, 32, 24, 16 kbit/s Adapt
20、ive Differential Pulse Code Modulation (ADPCM) Corrigendum 1 Correction to Annex A: Extensions of Recommendation G.726 for use with uniform-quantized input and output Description In the LIMO (decoder only) routine in A.3.5/G.726, Output limiting (decoder only), “SR & 16383, SR 57 344“ should be repl
21、aced with “SR & 16 383, SR 57 343“. The code is missing the case for SR = 57 344. Amend Block LIMO as indicated: _ LIMO (decoder only) Input: SR Output: SO Function: Limit output to 14-bit twos complement value | 8191, SR 8191 and SR 57 3434 | 57 344, SR 32 767 and SR 57 344 _ Printed in Switzerland
22、 Geneva, 2005 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and m
23、edia, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installatio
24、n and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone trans
25、mission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
