ITU-T G 729 1 AMD 6-2010 G 729-based embedded variable bit-rate coder An 8-32 kbit s scalable wideband coder bitstream interoperable with G 729 Amendment 6 New Annex E on superwide.pdf

1、 fb International Telecommunication Union ITU-T G.729.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 6(03/2010) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments Coding of voice and audio signals G.729-based embedded variable bit-rate code

2、r: An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729 Amendment 6: New Annex E on superwideband scalable extension Recommendation ITU-T G.729.1 (2006) Amendment 6 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHON

3、E 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 CARRIER TELEPHONE SYSTEMS ON RADIO-

4、RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 General G.700G.709 Coding of voice and audio signals G.710

5、G.729Principal 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 G.750G.759 Principal characteristics of transcoder and digital multiplication equipment G.76

6、0G.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 terminal equipment G.790G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTE

7、M G.900G.999 MULTIMEDIA 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 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, pleas

8、e refer to the list of ITU-T Recommendations. Rec. ITU-T G.729.1 (2006)/Amd.6 (03/2010) i Recommendation ITU-T G.729.1 G.729-based embedded variable bit-rate coder: An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729 Amendment 6 New Annex E on superwideband scalable extension S

9、ummary Recommendation ITU-T G.729.1 describes an 8-32 kbit/s scalable wideband speech and audio coding algorithm interoperable with ITU-T G.729, ITU-T G.729A and ITU-T G.729B. The output of the ITU-T G.729EV coder has a bandwidth of 50-4000 Hz at 8 and 12 kbit/s and 50-7000 Hz from 14 to 32 kbit/s.

10、At 8 kbit/s, ITU-T G.729EV is fully interoperable with ITU-T G.729, Annex A/G.729 and Annex B/G.729. Hence, an efficient deployment in existing ITU-T G.729-based VoIP infrastructures is foreseen. The coder operates on 20 ms frames and has an algorithmic delay of 48.9375 ms. By default, the encoder i

11、nput and decoder output are sampled at 16 kHz. The encoder produces an embedded bitstream structured in 12 layers corresponding to 12 available bit rates from 8 to 32 kbit/s. The bitstream can be truncated at the decoder side or by any component of the communication system to adjust “on the fly“ the

12、 bit rate to the desired value with no need for outband signalling. The underlying algorithm is based on a three-stage coding structure: embedded Code-Excited Linear Prediction (CELP) coding of the lower band (50-4000 Hz), parametric coding of the higher band (4000-7000 Hz) by Time-Domain Bandwidth

13、Extension (TDBWE), and enhancement of the full band (50-7000 Hz) by a predictive transform coding technique referred to as Time-Domain Aliasing Cancellation (TDAC). Amendment 1 introduces the new Annex A containing the RTP payload format, capability identifiers and parameters for signalling of ITU-T

14、 G.729.1 capabilities using ITU-T H.245. Both format and capability parameters are fully compatible with the corresponding ITU-T G.729.1 RTP definitions to allow seamless interoperability. Besides the new Annex, Amendment 1 to ITU-T G.729.1 incorporates changes needed to correct defects in ITU-T G.7

15、29.1 and provides new, more comprehensive test vectors. Amendment 2 introduces the new Annex B, which defines an alternative implementation of the ITU-T G.729.1 algorithm using floating point arithmetic to be used for implementation on DSP hardware optimized for floating-point operations. The accomp

16、anying floating point C-code is fully interoperable with the fixed-point C-code. Amendment 3 extends the low-delay functionality of main body and Annex B to the first wideband bit rate (14 kbit/s). It also incorporates changes needed to correct defects in the text and C-code of ITU-T G.729.1 main bo

17、dy and Annex B. Amendment 4 introduces a new Annex C specifying a discontinuous transmission (DTX) and comfort noise generation for ITU-T G.729.1. With this annex, the ITU-T G.729.1 encoder is capable of generating a silence insertion description (SID) each time an update of the ambient background n

18、oise parameters is required to maintain the quality of the generated background noise. The SID information includes a core lower band layer, which can be decoded by the decoder of Annex B/G.729, an enhancement lower band layer and a higher band layer. The non-transmission ii Rec. ITU-T G.729.1 (2006

19、)/Amd.6 (03/2010) between SID updates and the small size of the SID provide a significant reduction of bandwidth during inactive segments. Besides this new annex, Amendment 4 incorporates changes needed to correct defects identified in ITU-T G.729.1 C source code (main body and Annex B), provides a

20、revised set of test vectors, and updates the complexity figures table of ITU-T G.729.1 text. Annex D introduced by Amendment 5 provides an alternative implementation using floating point arithmetic of the discontinuous transmission (DTX) and comfort noise generation (CNG) of Annex C which uses fixed

21、-point arithmetic. Besides this new annex, Amendment 5 incorporates changes needed to correct defects identified in the ITU-T G.729.1 C source code for its main body and Annex B, and provides a revised set of test vectors. Corrigendum 1 addressed some problems discovered recently in the ANSI C-codes

22、 of the main body of ITU-T G.729.1 and of its Annexes B, C and D, in the so-called Release 1.5 of the code. Amendment 6 brings in new Annex E a scalable superwideband (SWB, 50-14000 Hz) speech and audio coding algorithm operating from 36 to 64 kbit/s and interoperable with ITU-T G.729 and ITU-T G.72

23、9.1. For consistency, the existing ANSI-C code for the whole of ITU-T G.729.1 is reissued as part of this publication and labelled as Release 1.6, without any additional change. Test vectors that complement this release are also available in the ITU-T test signal database at http:/itu.int/net/ITU-T/

24、sigdb/speaudio/Gseries.htm#ITU-T G.729.1. History Edition Recommendation Approval Study Group 1.0 ITU-T G.729.1 2006-05-29 16 1.1 ITU-T G.729.1 (2006) Amend. 1 2007-01-13 16 1.2 ITU-T G.729.1 (2006) Amend. 2 2007-02-13 16 1.3 ITU-T G.729.1 (2006) Amend. 3 2007-08-29 16 1.4 ITU-T G.729.1 (2006) Amend

25、. 4 2008-06-29 16 1.5 ITU-T G.729.1 (2006) Amend. 5 2008-12-07 16 1.6 ITU-T G.729.1 (2006) Cor.1 2009-08-29 16 1.7 ITU-T G.729.1 (2006) Amend.6 2010-03-29 16 Rec. ITU-T G.729.1 (2006)/Amd.6 (03/2010) iii FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agenc

26、y 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 t

27、o 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 Recommendation

28、s is covered by the procedure laid down in WTSA Resolution 1. In some 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

29、 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

30、 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. INTELLE

31、CTUAL 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, whet

32、her 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 cautio

33、ned 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 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of IT

34、U. iv Rec. ITU-T G.729.1 (2006)/Amd.6 (03/2010) CONTENTS Page Amendment 6 New Annex E on superwideband scalable extension 1 E.1 Scope 1 E.2 Overview 1 E.3 Abbreviations . 1 E.4 Mathematical expressions 2 E.5 General description of the coder . 3 E.6 Functional description of the encoder 4 E.7 Functio

35、nal description of the decoder 37 E.8 Description of the transmitted parameter indices . 66 E.9 Bit-exact description of the SWB extension 68 Bibliography. 69 Electronic attachment: ANSI C source code Rec. ITU-T G.729.1 (2006)/Amd.6 (03/2010) 1 Recommendation ITU-T G.729.1 G.729-based embedded varia

36、ble bit-rate coder: An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729 Amendment 6 New Annex E on superwideband scalable extension (This annex forms an integral part of this Recommendation) E.1 Scope This annex contains the description of a scalable superwideband (SWB, 50-1400

37、0 Hz) speech and audio coding algorithm operating from 36 to 64 kbit/s and interoperable with ITU-T G.729 and ITU-T G.729.1. Annex E is organized as follows. The abbreviations and mathematical expressions used throughout this annex are defined in clauses E.3 and E.4, respectively. Clause E.5 gives a

38、 general outline of the algorithm. The encoder and decoder principles are discussed in clauses E.6 and E.7, respectively. The transmitted parameters are presented in clause E.8. Clause E.9 describes the software that defines this coder in 16-32 bits fixed-point arithmetic. E.2 Overview The output of

39、 the ITU-T G.729.1 SWB coder has a bandwidth of 50-14000 Hz. The coder operates on 20 ms frames and has an algorithmic delay of 55.6875 ms. By default, the encoder input and decoder output are sampled at 32 kHz. The superwideband encoder produces an embedded bitstream structured in five layers corre

40、sponding to five available bit rates from 36 to 64 kbit/s in addition to the twelve layers of ITU-T G.729.1. The bitstream can be truncated at the decoder side or by any component of the communication system to instantaneously adjust the bit rate to the desired value with no need for out-of-band sig

41、nalling. At 32 kbit/s, ITU-T G.729.1 SWB is fully interoperable with ITU-T G.729.1. The underlying algorithm is based on a two-stage coding structure: bandwidth extension coding in the modified discrete cosine transform (MDCT) domain of band 7000-14000 Hz, and enhancement of MDCT coding in the band

42、50-7000 Hz by vector quantization of the MDCT error. Annex E contains an electronic attachment with the ANSI C source code, which is an integral part of this annex, as well as a set of test vectors. The latter can be found online in the ITU-T test signal database at http:/www.itu.int/net/ITU-T/sigdb

43、/speaudio/Gseries.htm#ITU-T G.729.1. E.3 Abbreviations The acronyms used in this annex are summarized in Table E.1. 2 Rec. ITU-T G.729.1 (2006)/Amd.6 (03/2010) Table E.1 Glossary of acronyms Acronym Description ACELP Algebraic CELP CELP Code-Excited Linear Prediction DFT Discrete Fourier Transform F

44、EC Frame Erasure Concealment GLCVQ Gosset Low Complexity Vector Quantization HF High Frequency (7-14 kHz) IDFT Inverse Discrete Fourier Transform IIR Infinite Impulse Response iMDCT Inverse MDCT LF Low Frequency (0-7 kHz) MDCT Modified Discrete Cosine Transform NB Narrowband SVQ Spherical Vector Qua

45、ntization SWB Superwideband TB Transition Band VQ Vector Quantization WB Wideband WMOPS Weighted Million Operations Per Second E.4 Mathematical expressions The following conventions apply to mathematical expressions in this annex: x indicates the largest integer less than or equal to x: 11.1 = , 10.

46、1 = , and 21.1 = ; x indicates the smallest integer greater than or equal to x: 21.1 = , 20.2 = , and 11.1 = ; |x| indicates the absolute value of x: |17| =17, |17| =17; min(x0, x1, xN1) indicates the minimum of x0, x1, xN1, N being the number of components; max(x0, x1, xN1) indicates the maximum of

47、 x0, x1, xN1; =otherwise,1,0 if,1)sgn(xx ATindicates the transpose of matrix A; yx mod indicates the remainder after dividing x by y: ()yxyxyx /mod = ; round(x) is traditional rounding: round(x) = 5.0|)sgn( + xx ; exp(x) is equivalent to exwhere e is the base of the natural algorithm; indicates summ

48、ation; indicates product; Rec. ITU-T G.729.1 (2006)/Amd.6 (03/2010) 3 indicates logical conjunction or AND operation; indicates logical disjunction or OR operation; Re(z) indicates the real part of complex variable z; Im(z) indicates the imaginary part of complex variable z. Unless otherwise specifi

49、ed, log(x) denotes logarithm at base 10, throughout this annex. E.5 General description of the coder The ITU-T G.729.1 superwideband extension comprises 5 layers extending the wideband coding of ITU-T G.729.1 to an embedded superwideband coding, with total bit rates of 36, 40, 48, 56, and 64 kbit/s. The first SWB extension layer comprises a two-mode coding of the high frequencies using Generic mode or Sinusoidal mode coding. In the Generic mode, the coding is