ITU-T G 729 1-2006 G 729-based embedded variable bit-rate coder An 8-32 kbit s scalable wideband coder bitstream interoperable with G 729 (Study Group 16 Incorporated Amendment 1 1.pdf
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1、I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o nITU-T G.729.1TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU(05/2006)SERIES G: TRANSMISSION SYSTEMS AND MEDIA,DIGITAL SYSTEMS AND NETWORKSDigital terminal equipments Coding of analogue signalsby methods other than PCMG.729-based embe
2、dded variable bit-rate coder:An 8-32 kbit/s scalable wideband coderbitstream interoperable with G.729ITU-T Recommendation G.729.1ITU-T G-SERIES RECOMMENDATIONSTRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKSINTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199GENERAL CHARACTERISTIC
3、S COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMSG.200G.299INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONESYSTEMS ON METALLIC LINESG.300G.399GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMSON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLICLINESG.4
4、00G.449COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499TRANSMISSION MEDIA CHARACTERISTICS G.600G.699DIGITAL TERMINAL EQUIPMENTS G.700G.799General G.700G.709Coding of analogue signals by pulse code modulation G.710G.719Coding of analogue signals by methods other than PCM G.720G.729Princip
5、al characteristics of primary multiplex equipment G.730G.739Principal characteristics of second order multiplex equipment G.740G.749Principal characteristics of higher order multiplex equipment G.750G.759Principal characteristics of transcoder and digital multiplication equipment G.760G.769Operation
6、s, administration and maintenance features of transmission equipment G.770G.779Principal characteristics of multiplexing equipment for the synchronous digital hierarchy G.780G.789Other terminal equipment G.790G.799DIGITAL NETWORKS G.800G.899DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999QUALITY
7、OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATEDASPECTSG.1000G.1999TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999PACKET OVER TRANSPORT ASPECTS G.8000G.8999ACCESS NETWORKS G.9000G.9999For further details, please refer to the list of ITU-T Recommenda
8、tions.ITU-T Rec. G.729.1 (05/2006) iITU-T Recommendation G.729.1G.729-based embedded variable bit-rate coder:An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729SummaryThis Recommendation describes an 8-32 kbit/s scalable wideband speech and audio codingalgorithm interoperable w
9、ith G.729, G.729A and G.729B.The output of the G.729EV coder has a bandwidth of 50-4000 Hz at 8 and 12 kbit/s and 50-7000 Hzfrom 14 to 32 kbit/s. At 8 kbit/s, G.729EV is fully interoperable with G.729, Annex A/G.729 andAnnex B/G.729. Hence, an efficient deployment in existing G.729-based VoIP infras
10、tructures isforeseen. The coder operates on 20 ms frames and has an algorithmic delay of 48.9375 ms. Bydefault, the encoder input and decoder output are sampled at 16 kHz.The encoder produces an embedded bitstream structured in 12 layers corresponding to 12 availablebit rates from 8 to 32 kbit/s. Th
11、e bitstream can be truncated at the decoder side or by any componentof the communication system to adjust “on the fly“ the bit rate to the desired value with no need foroutband signalling.The underlying algorithm is based on a three-stage coding structure: embedded Code-Excited LinearPrediction (CEL
12、P) coding of the lower band (50-4000 Hz), parametric coding of the higher band(4000-7000 Hz) by Time-Domain Bandwidth Extension (TDBWE), and enhancement of the fullband (50-7000 Hz) by a predictive transform coding technique referred to as Time-Domain AliasingCancellation (TDAC).Amendment 1 introduc
13、es the new Annex A containing the RTP payload format, capability identifiersand parameters for signalling of G.729.1 capabilities using H.245. Both format and capabilityparameters are fully compatible with the corresponding G.729.1 RTP definitions to allow seamlessinteroperability. Besides the new A
14、nnex, Amendment 1 to G.729.1 incorporates changes needed tocorrect defects in G.729.1 and provides new, more comprehensive test vectors.Amendment 2 introduces the new Annex B, which defines an alternative implementation of theG.729.1 algorithm using floating point arithmetic to be used for implement
15、ation on DSP hardwareoptimized for floating-point operations. The accompanying floating point C-code is fullyinteroperable with the fixed-point C-code.SourceITU-T Recommendation G.729.1 was approved on 29 May 2006 by ITU-T Study Group 16(2005-2008) under the ITU-T Recommendation A.8 procedure.This e
16、dition incorporates the modifications introduced by Amendment 1 approved on13 January 2007 and Amendment 2 approved on 13 February 2007.ii ITU-T Rec. G.729.1 (05/2006)FOREWORDThe International Telecommunication Union (ITU) is the United Nations specialized agency in the field oftelecommunications. T
17、he ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ ofITU. ITU-T is responsible for studying technical, operating and tariff questions and issuingRecommendations on them with a view to standardizing telecommunications on a worldwide basis.The World Telecommunication Standard
18、ization Assembly (WTSA), which meets every four years,establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations onthese topics.The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.In some areas of information techno
19、logy which fall within ITU-Ts purview, the necessary standards areprepared on a collaborative basis with ISO and IEC.NOTEIn this Recommendation, the expression “Administration“ is used for conciseness to indicate both atelecommunication administration and a recognized operating agency.Compliance wit
20、h this Recommendation is voluntary. However, the Recommendation may contain certainmandatory provisions (to ensure e.g., interoperability or applicability) and compliance with theRecommendation is achieved when all of these mandatory provisions are met. The words “shall“ or someother obligatory lang
21、uage such as “must“ and the negative equivalents are used to express requirements. Theuse of such words does not suggest that compliance with the Recommendation is required of any party.INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Rec
22、ommendation mayinvolve 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 othersoutside of the Recommendation development process.As of the date of appro
23、val of this Recommendation, ITU had not received notice of intellectual property,protected by patents, which may be required to implement this Recommendation. However, implementorsare cautioned that this may not represent the latest information and are therefore strongly urged to consult theTSB pate
24、nt database.ITU 2007All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without theprior written permission of ITU.ITU-T Rec. G.729.1 (05/2006) iiiCONTENTSPage1 Scope. 12 References. 13 Abbreviations 24 Notations and conventions 35 General description of the
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