1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU J.53 (05/2000) SERIES J: TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Digital transmission of sound-programme signals Sampling frequencies to be used for the digital transmission o
2、f stud io-q ua I i ty and h ig h -q ual i ty sound-programme signals ITU-T Recommendation J.53 (Formerly CCITT Recommendation) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesGeneral Recommendations General specifications for analogue s
3、ound-programme transmission Performance characteristics of analogue sound-programme circuits Equipment and lines used for analogue sound-programme circuits Digital encoders for analogue sound-programme signals 1 transmission of sound-pro Circuits for analogue television transmission Analogue televis
4、ion transmission over metallic lines and interconnection with radio-relay links Digital transmission of television signals Ancillary digital services for television transmission Operational requirements and methods for television transmission Interactive systems for digital television distribution T
5、ransport of MPEG-2 signals on packetised networks Measurement of the quality of service Digital television distribution through local subscriber networks ITU-T J-SERIES RECOMMENDATIONS TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS For further details, please refer to the l
6、ist of ITU-TRecommendations. J.1-J.9 J. 10-J.19 J.20-J.29 5.30-J.39 5.40-5.49 J.504.59 J.60-J.69 J.70-J.79 J.80-J.89 J.90-J.99 J. 100-J. 109 J.110-J.129 J. 130-5.139 5.140-J.149 J. 150-J. 159 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Serv
7、icesITU-T Recommendation 5.53 Sampling frequencies to be used for the digital transmission of studio-quality and high-quality sound-programme signals Summary The present Recommendation specifies the sampling frequency and tolerance to be used for the digital transmission of studio-quality and high-q
8、uality sound-programme signals. Source ITU-T Recommendation J.53 was revised by ITU-T Study Group 9 (1997-2000) and approved under the WTSC Resolution 1 procedure on 18 May 2000. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesFOREWORD
9、The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. 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 R
10、ecommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics
11、. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSC Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “A
12、dministration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. 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 P
13、roperty 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 not received notice
14、 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 therefore strongly urged to consult the TSB patent database. o ITU 2001 All rights reserved. No part
15、 of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing fi-om ITU. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesCON
16、TENTS 1 2 3 4 Scope Nonnative references Terms and Definitions Sampling frequencies . Page 1 1 1 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesIntroduction Digital systems for the transmission of high-quality sound-programme signals
17、 are in wide and current use, and it is important to specify for them a single sampling frequency, in order to simplify equipment and facilitate programme exchange. For ease of implementation, the sampling frequency should in any case be an integer multiple of the 8 kHz network clock According to su
18、bjective tests, limiting the audio frequency band to 15 kHz does not cause any appreciable degradation in subjective quality, even in critical listening conditions. Consequently, it is appropriate to specify a sampling frequency of 32 kHz for the transmission of high-quality sound-programme signals.
19、 Such a sampling frequency is close to the theoretical limit compatible with a nominal passband of 15 Wz, it is also already in use in current equipment, and it is compatible with the bit rates corresponding to the various hierarchical levels defined by the Digital systems in the broadcast studio en
20、vironment are covered in ITU-R BS 646, which specifies a sampling fiequency of 48 kHz for the digital coding of sound-programme signals in the studio. Consequently it is appropriate to specify a sampling frequency of 48 kHz for connections that carry studio-quality sound-programme signals. ITU-T. CO
21、PYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T Recommendation 5.53 Sampling frequencies to be used for the digital transmission of studio-quality and high-quality sound-programme signals 1 . Scope The present Recommendation specifi
22、es the sampling frequencies and the tolerance to be used for the digital transmission of studio-quality and of high-quality sound-programme signals. 2 Normative references The following ITU-T Recommendations and other references contain provisions, which, through reference in this text, constitute p
23、rovisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommend
24、ations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - - ITU-T G.703 (1 998), Physical/electrical characteristics of hierarchical digital interfaces. ITU-R BS 646- 1 (1 992), Source encoding for digital sound signals in broadcasting st
25、udios. 3 Terms and Definitions Only conventional, widely employed terms and definitions are used in this Recommendation. 4 Sampling frequencies A g frequency of 48 kHz should be used in coding for the digital transmission systems interconnecting digital broadcast studios according to ITU-R BS 646-1.
26、 A sampling frequency of 32 1Hz should be used in coding for the digital transmission of high quality sound programme signals with a nominal passband of 15 kHz. The associated tolerance should be specified in ITU-T G.703. noted that a tolerance of 50 ppm corresponds to the current network tolerance.
27、 On the a sampling frequency tolerance of 10 ppm is specified by ITU-R BS 646-1 for digital on for the sampling frequency 48 kHz. It is recommended that a tolerance of 10 ppm d be used for 48 kHz as the target tolerance for future digital audio encoders for use in audio ssion networks, while decoder
28、s for use in transmission networks should continue to be able to gramme transmission at quality levels other than “studio quality“ or “high quality“ dio signals with a sampling fkequency tolerance of 50 ppm. er sampling frequencies may be preferred. They should always be multiples of 8 kHz. COPYRIGH
29、T International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesSeries A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series L Series M Series N Series O Series P Series Q Series R Series S Series T Series U Series
30、V Series X Series Y Series Z SERIES OF ITU-T RECOMMENDATIONS Organization of the work of ITU-T Means of expression: definitions, symbols, classification General telecommunication statistics General tariff principles Overall network operation, telephone service, service operation and human factors No
31、n-telephone telecommunication services Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Transmission of television, sound programme and other multimedia signals Protection against interference Construction, installati
32、on and protection of cables and other elements of outside plant TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: international sound programme and television transmission circuits Specifications of measuring e
33、quipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communications Global information infrastructure and Internet protocol aspects Languages and general software aspects for telecommunication systems COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services
