1、 Recommendation ITU-R BS.1909(01/2012)Performance requirements for an advanced multichannel stereophonic sound systemfor use with or without accompanying pictureBS SeriesBroadcasting service (sound)ii Rec. ITU-R BS.1909 Foreword The role of the Radiocommunication Sector is to ensure the rational, eq
2、uitable, efficient and economical use of the radio-frequency 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 Radiocommunicat
3、ion Sector are performed by World and Regional Radiocommunication 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 Resolut
4、ion ITU-R 1. Forms to be used for the submission of patent statements 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 dat
5、abase can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/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
6、service M Mobile, radiodetermination, amateur and related satellite services 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
7、 Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2012 ITU 2012 All rights re
8、served. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BS.1909 1 RECOMMENDATION ITU-R BS.1909 Performance requirements for an advanced multichannel stereophonic sound system for use with or without accompanying picture (Questions
9、 ITU-R 15/6 and ITU-R 135/6) (2012) Scope This Recommendation specifies the requirements for an advanced multichannel sound system with or without accompanying picture. Such a system, or a system derived from it, may find application as the sound components of expanded-LSDI and UHDTV programmes. The
10、 ITU Radiocommunication Assembly, considering a) that Recommendation ITU-R BS.1734 Basic performance requirements for the sound components of large-screen digital imagery applications for presentation in a theatrical environment, specifies the requirements relevant to the presentation of the sound c
11、omponents of the large screen digital imagery (LSDI) applications intended for presentation in a theatrical environment, which are mostly based on Recommendation ITU-R BS.775 that specifies the 5.1 channel sound system; b) that Recommendation ITU-R BS.1688 Baseband sound system and audio source-codi
12、ng at delivery interfaces of large screen digital imagery applications, recommends that, for such LSDI applications, the reference digital baseband sound system at the interfaces should be based on the hierarchical reference sound system specified in Recommendation ITU-R BS.775 Multichannel stereoph
13、onic sound system with and without accompanying picture, namely a hierarchy ranging from monophonic, 2-channel stereophonic and up to 5.1 channels of sound; c) that Recommendation ITU-R BT.1769 Parameter values for an expanded hierarchy of LSDI image formats for production and international programm
14、e exchange, specifies an expanded hierarchy of LSDI image formats for production and international programme exchange, in which the two image formats of 3 840 2 160 and 7 680 4 320 are specified; d) that ITU-R has been studying UHDTV, which is a television application that is intended to provide vie
15、wers with an enhanced visual experience primarily by offering a wide field of view that covers virtually all of the human visual field with appropriate screen sizes relevant to usage at home and in public places; e) that Recommendation ITU-R BS.646 Source encoding for digital sound signals in broadc
16、asting studios, specifies the sampling frequency and sample resolution for the digital encoding of sound; f) that Recommendation ITU-R BT.1359 Relative timing of sound and vision for broadcasting, recommends the timing tolerance between sound and vision signals in broadcasting systems; g) that the w
17、ide field of view video of expanded-LSDI and UHDTV programmes requires spatially enhanced sound beyond the 5.1 channel sound; h) that the advancements in video formats should be met with a sufficiently advanced sound formats for broadcasting sound system, for use both with and without accompanying p
18、icture, 2 Rec. ITU-R BS.1909 recommends 1 that an advanced multichannel sound system for use with or without accompanying picture should meet the performance requirements contained in Annex 1; 2 that such an advanced multichannel sound system, or a system derived from it with an appropriate number o
19、f channels, should be considered for use as the sound component of expanded LSDI and UHDTV programmes; 3 that the appropriate number of channels in programme production should be a choice at the discretion of the programme producer; 4 that the appropriate sound presentation arrangements in the home,
20、 such as the number of loudspeakers and the set-up position, should be a choice at the discretion of each member of the public. Annex 1 Performance requirements 1 Sound quality requirements 1.1 The sound image should be reproduced in all directions around the listener, including the elevation direct
21、ion, within reasonable limits of stability. 1.2 The sensation of a three-dimensional spatial impression that augments a sense of reality, which is related to ambience and envelopment, should be significantly enhanced over established sound formats in Recommendation ITU-R BS.775. 1.3 For applications
22、 with accompanying picture, the directional stability of the frontal sound image should be maintained over the entire area of high-resolution large-screen digital imagery. The coincidence of position between sound images and video images should also be maintained over a wide image and listening area
23、. 1.4 Excellent sound quality should be maintained over a wide viewing/listening area. See Appendix 1. 1.5 For the coding parameters of sound signals, see Recommendation ITU-R BS.646. 1.6 For the relative timing of sound and vision, see Recommendation ITU-R BT.1359. Implementers should note that in
24、large venues where sound and vision timing varies relative to seating location, other adjustments may need to be taken into account. NOTE 1 The sound quality is related to timbre, transparency, sound image, and spatial impression. The attributes of sound image and spatial impression include directio
25、nal stability of the frontal sound image, the sensation of a three-dimensional spatial impression, and the prescribed three-dimensional image locations around the listener, including depth perception. The sound quality has to be defined dependent on the target environments of Appendix 2. 2 Functiona
26、l requirements 2.1 Backward compatibility with the 5.1 channel sound system and conventional two-channel sound system should be ensured to an acceptable degree. Rec. ITU-R BS.1909 3 2.2 Appropriate rendering of the sound format should be ensured for loudspeaker configurations suitable for the range
27、of typical listening environments, to provide an optimum sound field and maintain excellent sound quality at least within a limited area, or alternatively for headphone reproduction. See Appendix 2. 3 Operational requirement 3.1 Live recording, mixing and transmission should be possible, if required
28、. Appendix 1 Example of an expanded-LSDI system that gives viewers/listeners audiovisual experiences with a high sensation of reality Figure 1 shows the horizontal viewing angle of an expanded-LSDI system that gives visual experiences with a high sensation of reality (see Recommendation ITU-R BT.176
29、9). FIGURE 1 Horizontal viewing angle of an expanded-LSDI system BS.1909-01NearviewersDistant viewers120604 Rec. ITU-R BS.1909 Figure 2 shows an assumed seating area that gives audiovisual experiences with a high sensation of reality in a theatrical environment. FIGURE 2 Assumed seating area that gi
30、ves audiovisual experiences with a high sensation of reality BS.1909-02120Line of 12060Line of 60Distantviewer/listenerNearviewer/listenerAppendix 2 Typical viewing/listening environments and assumed sound reproduction configurations The following are typical viewing/listening environments and assum
31、ed sound reproduction configurations for an advanced multichannel stereophonic sound system with and without accompanying picture. 1. Public environments: A loudspeaker reproduction system is likely to be used in conjunction with a large screen display, but may also be used without accompanying pict
32、ure. The sound system will be required to produce acceptable quality and directional stability over an extended listening area: theatre/outdoor presentation environments; large theatre/outdoor presentation environments. 2. Home environments: A loudspeaker reproduction system will be used in conjunct
33、ion with a high-resolution display or without accompanying picture. The sound presentation arrangements in a home, such as the number of loudspeakers and the set-up position, are considerably varied. A headphone reproduction system may also be used for individual listening: large-to-average size roo
34、m environment including home theatre environment; small size room environment; Rec. ITU-R BS.1909 5 personal environment. 3. Mobile environments: A sound reproduction system will be used in conjunction with a small high-resolution display or without accompanying picture. The sound presentation arrangements in a mobile environment are likely to vary considerably. In some cases, a headphone reproduction system may be used: personal environment; in-car environment.
