1、 Report ITU-R BS.2159-2(05/2011)Multichannel sound technology in homeand broadcasting applicationsBS SeriesBroadcasting service (sound)ii Rep. ITU-R BS.2159-2 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency
2、spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunica
3、tion Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent st
4、atements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Reports (Also availa
5、ble online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite s
6、ervices P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This ITU-R Report was approved in English
7、by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2011 ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R BS.2159-2 1 REPORT ITU-R BS.2159-2 Multichann
8、el sound technology in home and broadcasting applications (2009-2010-2011) TABLE OF CONTENTS Page 1 Introduction 2 2 5.1 multichannel sound system . 2 3 Basic requirements of multichannel sound systems beyond the 5.1 sound system 4 3.1 Basic requirements of the sound image 4 3.2 Basic requirement of
9、 sensation of a spatial impression 5 3.3 Basic requirement of listening area 5 3.4 Basic requirement of compatibility with existing sound systems 5 3.5 Basic requirement of live broadcasting 6 4 Multichannel sound systems beyond the 5.1 sound system under development for broadcasting applications .
10、6 4.1 22.2 multichannel sound system . 6 4.2 10.2 surround sound system . 11 4.3 Wave-field-synthesis 15 4.4 Object-based audio formats 19 5 Multichannel sound systems in use for home audio release media 21 5.1 DVD audio 21 5.2 SACD 21 5.3 BD . 22 6 Multichannel sound programme production in studio
11、for home audio 24 6.1 Production of 5.1, 6.1 and 7.1 channels 24 6.2 Production of 22.2 multichannel sound 24 6.3 Production of 10.2 multichannel sound 27 6.4 Object-based post-production system . 28 2 Rep. ITU-R BS.2159-2 Page 7 Quality performance of the multichannel sound systems . 30 8 Relevant
12、documents concerning the multichannel sound systems developed by organizations outside ITU 31 8.1 SMPTE . 31 8.2 MPEG (ISO/IEC JTC 1/SC 29/WG 11) . 35 8.3 EBU 35 8.4 Japan . 37 1 Introduction ITU-R has developed Recommendation ITU-R BS.775 for multichannel stereophonic sound system with and without
13、accompanying picture. Multichannel stereo as well as 2-channel stereo audio services are widely used as part of digital broadcasting services. Recommendation ITU-R BS.775 specifies a hierarchy of compatible multichannel sound systems to enhance the directional stability of the frontal sound image an
14、d the sensation of spatial reality (ambience), and each loudspeaker is set at the same height as a listeners ears. Some television applications with higher resolution imagery and large screen digital imaginary (LSDI) application , both providing wider viewing angle, may need multichannel stereophoni
15、c sound systems that can reproduce the sound sources, which are localized at a higher position over the listener and a lower position below the screen, and vertical movements of the sound sources. Several multichannel stereophonic sound systems are currently applied or studied for higher resolution
16、imagery, and some of them have loudspeakers arranged above and below the viewer. There would be value in continued studies in this area for future broadcasting applications in order to evolve beyond the current 5.1 channel sound system. This Report contains information on the subject of Multichannel
17、 sound technology in home and broadcasting applications, beyond the current 5.1 channel sound system specified in Recommendation ITU-R BS.775. 2 5.1 multichannel sound system The 5.1 channel sound system has been specified in Recommendation ITU-R BS.775. The system is widely used as a part of digita
18、l broadcasting services. It enhances the directional stability of the frontal sound image and the sensation of spatial reality (ambience). The reference loudspeaker arrangement is shown in Fig. 1, in which each loudspeaker is set at the same height as a listeners ears. Rep. ITU-R BS.2159-2 3 FIGURE
19、1 Reference loudspeaker arrangement with loudspeakers L/C/R an LS/RS Report BS.2159-01Screen 1 HDTV - Reference distance = 3 (2H1= 33)Screen 2 H: height of screenB: loudspeaker base width= 2 (2 = 48)H2LoudspeakerCL, RLS, RSHorizontal angle fromcentre (degrees)030100 . 120Height(meters)1.21.2 1.2Incl
20、ination(degrees)000 . 15 dwnB21RLC6021RSLS1001201001204 Rep. ITU-R BS.2159-2 3 Basic requirements of multichannel sound systems beyond the 5.1 sound system The following requirements are related to the multichannel sound system beyond the current 5.1 channel sound system specified in Recommendation
21、ITU-R BS.775. 1. The directional stability of the frontal sound image should be maintained over the entire higher resolution imagery area. Coincidence of position between sound image and video image also should be maintained over the wide imagery area. 2. The sound image should be reproduced in all
22、directions around the listener, including elevation. 3. The sensation of three-dimensional spatial impression that augments a sense of reality should be significantly enhanced. This may be achieved by the use of side and/or back, top and/or bottom loudspeakers. 4. Exceptional sound quality should be
23、 maintained over wider listening area than that provided by current 5.1 channel sound system. 5. Compatibility with the current 5.1 channel sound system specified in Recommendation ITU-R BS.775 should be ensured to an acceptable degree. 6. Live recording, mixing and transmission should be possible.
24、The reasoning for the basic requirements for advanced multichannel sound systems is provided below: 3.1 Basic requirements of the sound image The directional stability of the frontal sound image should be maintained over the entire higher resolution imagery area. Coincidence of position between soun
25、d image and video image also should be maintained over the wide imagery area. The sound image should be reproduced in all directions around the listener, including in the elevation. Reason: The following requirements are defined in Recommendation ITU-R BS.775 for the 5.1 channel sound system: The di
26、rectional stability of the frontal sound image shall be maintained within reasonable limits over a listening area larger than that provided by a conventional two-channel stereophony. The following requirement is also defined: It is not required that the side/rear loudspeakers should be capable of th
27、e prescribed image locations outside the range of the front loudspeakers. For advanced multichannel sound systems beyond the 5.1 channel sound system, the reproduction of the sound images should be improved from the following two aspects: The directional stability of the sound image come from all ho
28、rizontal directions, i.e. the front/back and left/right directions, should be maintained within reasonable limits over the listening area. The sound image included in the elevation directions should also be reproduced. Therefore, the aforementioned basic requirement 2) is defined. Rep. ITU-R BS.2159
29、-2 5 In addition, considering advanced multichannel sound systems applied for television applications, which have high-resolution imagery with a horizontally and vertically wide field of view, the coincidence of the position between sound images and video images is needed over the entire imagery are
30、a. Therefore, the aforementioned basic requirement 1) is defined. 3.2 Basic requirement of sensation of a spatial impression The sensation of three-dimensional spatial impression that augments a sense of reality should be significantly enhanced. This may be achieved by the use of side and/or back, t
31、op and/or bottom loudspeakers. Reason: The following requirement is defined in Recommendation ITU-R BS.775 for the 5.1 channel sound system: The sensation of spatial reality (ambience) shall be significantly enhanced over that provided by a conventional two-channel stereophony. This shall be achieve
32、d by the use of side and/or rear loudspeakers. Because each loudspeaker of the 5.1 channel sound system is set at the same height as the listeners ears, the sensation of spatial reality is fundamentally limited to the horizontal plane. For advanced multichannel sound systems beyond the 5.1 channel s
33、ound system, the sensation of spatial impression should be enhanced around the listener, including in the upward/downward elevation sensation, reverberation and ambience. Therefore, the aforementioned basic requirement 3) is defined. 3.3 Basic requirement of listening area Exceptional sound quality
34、should be maintained over wider listening area than that provided by current 5.1 channel sound system. Reason: The following requirement is defined in Recommendation ITU-R BS.775 for the 5.1 channel sound system: The directional stability of the frontal sound image shall be maintained within reasona
35、ble limits over a listening area larger than that provided by a conventional two-channel stereophony. As frontal two (left and right) loudspeakers are placed for the conventional 2-channel sound system, the listening area of the 5.1 channel sound system should be considered only for the frontal soun
36、d image by comparing it to that of a conventional 2-channel stereophony. To extend the basic requirement of the 5.1 channel sound system, the listening area of advanced multichannel sound systems should be enlarged by comparing them to the 5.1 channel sound system. Therefore, the aforementioned basi
37、c requirement 4) is defined. 3.4 Basic requirement of compatibility with existing sound systems Compatibility with the current 5.1 channel sound system specified in Recommendation ITU-R BS.775 should be ensured to an acceptable degree. 6 Rep. ITU-R BS.2159-2 Reason: The following requirement is defi
38、ned in Recommendation ITU-R BS.775 for the 5.1 channel sound system: Downward compatibility with sound systems providing lower number of channels (down to stereophonic and monophonic sound systems) shall be maintained. The aforementioned compatibility means that, for example, the down-mixed stereoph
39、onic or monophonic sound quality from 5.1 channel sound signals should be maintained to an acceptable degree. To extend the basic requirement of the 5.1 channel sound system, the down-mixed 5.1 channel or 2-channel sound quality from advanced multichannel sound signals should be maintained to an acc
40、eptable degree for advanced multichannel sound systems. Additionally, the compatibility should be considered from the view of programme production facilities and exploiting the expertise of sound mixing engineer. Even in future broadcasting services, every programme will not likely be produced by th
41、e advanced multichannel sound format. In other words conventional sound formats, such as mono, 2-channel stereo, or 5.1 channel sound format may be operated even in the future broadcasting depending on the programme genre or other service requirements. Thus, broadcasters would prefer to be able to p
42、roduce various sound programme formats even in a single production studio. As a result, channel compatibility with the 5.1 channel sound system and conventional 2-channel sound system should be considered to an acceptable degree. It also takes advantage of sound mixing engineers know-how, cultivated
43、 by the 5.1 channel sound production. Therefore, the aforementioned basic requirement 5) is defined. 3.5 Basic requirement of live broadcasting Live recording, mixing and transmission should be possible. Reason: The following requirement is defined in Recommendation ITU-R BS.775 for the 5.1 channel
44、sound system: Real-time mixing for live broadcast shall be practicable. The live broadcast is the most essential factor for broadcasting services. Therefore, the aforementioned basic requirement 6) is defined. 4 Multichannel sound systems beyond the 5.1 sound system under development for broadcastin
45、g applications Several multichannel sound systems have been studied to improve the spatial impression of sound. The following systems seem to have the capability for practical use. 4.1 22.2 multichannel sound system The 22.2 multichannel sound system was developed by NHK (Japan Broadcasting Corporat
46、ion). It has nine channels at the top layer, ten channels at the middle layer, three channels at the bottom layer and two low frequency effects (LFE) channels. This system is suited to wide screens such as 100 inch FPD display, because it can localize two-dimensionally a sound image over the entire
47、screen by using three bottom channels, five middle channels and three top channels around the screen. Rep. ITU-R BS.2159-2 7 FIGURE 2 The 22.2 multichannel sound system Report BS.2159-02TpBCSiRTV screenMiddle layer10 channelsBottom layer3 channelsLFE2 channelsTpFLTpFCTpSiLTpCTpSiRTpBRBLBCBRFLFLc FCF
48、RcBtFLBtFCLFE1 LFE2Top layer9 channelsTpFRTpBCSiLTpFLTpFCTpFRTpBL TpBC TpBRTpSiRTop layerSiLBottom layerBL BC BRMiddle layerTpBLFRTpSiLTpCFL FLC FC FRSiRFRCBtFL BtFC BtFRLEF1 LEF2BtFRThis system has common channels at each three layers with other multichannel systems so that its audio can be easily
49、down-mixed to other multichannel sound systems and has compatibility with every multichannel sound system. Audio characteristics and audio channel mapping for UHDTV programme production for the 22.2 multichannel sound format has been standardized by SMPTE (SMPTE 2036-2), as mentioned in 8.1.1. Several sound reproduction systems based on the 22.2 multichannel sound have been developed and exhibited at more than a dozen international expositions and exhibitions, such as World Exposition at Aichi (Japan), NAB Show in Las Vegas
