1、 Recommendation ITU-R BS.2051-0(02/2014)Advanced sound system forprogramme productionBS SeriesBroadcasting service (sound)ii Rec. ITU-R BS.2051-0 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by a
2、ll 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 Radiocommunication Conferen
3、ces 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 statements and
4、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 Recommendations (Also available o
5、nline 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 service M Mobile, radiodetermination, amateur and related satellite servic
6、es 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 SNG Satellite news gathering TF Time signals and freq
7、uency 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, 2014 ITU 2014 All rights reserved. No part of this publication may be reproduced, by any means whatso
8、ever, without written permission of ITU. Rec. ITU-R BS.2051-0 1 RECOMMENDATION ITU-R BS.2051-0 Advanced sound system for programme production (Question ITU-R 135/6) (2014) Scope This Recommendation specifies an advanced sound system with and without accompanying picture, beyond systems specified in
9、Recommendation ITU-R BS.775. An advanced sound system uses audio data in combination with an appropriate set of metadata to specify a sound scene to be delivered/broadcasted. The specifications include requirements for signalling the properties of advanced sound content and speaker layout to be used
10、 in content production for advanced sound systems. The advanced sound system can apply to the sound component of television and expanded large screen digital imagery (LSDI) programmes, as well as for sound only programmes. The ITU Radiocommunication Assembly, considering a) that Recommendation ITU-R
11、 BS.775 Multichannel stereophonic sound system with and without accompanying picture, specifies a multichannel stereophonic sound system with three front channels and two rear/side channels together with an optional low frequency effect (LFE) channel, as the highest level in a hierarchy of multichan
12、nel sound systems that range from 1/0 (monophonic) up to 3/2; b) that Recommendation ITU-R BT.1769 Parameter values for an expanded hierarchy of LSDI image formats for production and international programme exchange, specifies an expanded hierarchy of LSDI image formats for production and internatio
13、nal programme exchange; c) that Recommendation ITU-R BT.709 Parameter values for the HDTV standards for production and international programme exchange, specifies HDTV system image parameters; d) that Recommendation ITU-R BT.2020 Parameter values for ultra-high definition television systems for prod
14、uction and international programme exchange, specifies UHDTV image system parameters; e) that the wide field of view image presentation of expanded-LSDI, HDTV, and ultra-high definition television (UHDTV) programmes benefit from spatially enhanced sound beyond the 5.1 channel sound; f) that Recommen
15、dation ITU-R BS.1909 Performance requirements for an advanced multichannel stereophonic sound system for use with or without accompanying picture, specifies the requirements for an advanced sound system with or without accompanying picture; g) that Report ITU-R BS.2159 Multichannel sound technology
16、in home and broadcasting applications, includes the results of subjective evaluation experiments on speaker layout to meet the requirements described in Recommendation ITU-R BS.1909, recommends 1 that static or dynamic metadata/descriptors meeting the requirements described in Annex 1 should be used
17、 to signal the properties of all audio signals used in an advanced sound system in order to fully represent the desired audio content; 2 Rec. ITU-R BS.2051-0 2 that the speaker positions and configurations described in Annex 1 should be considered for production of advanced sound programmes; 3 that
18、the appropriate number of audio elements1and speaker layout configurations in programme production should be a choice by agreement between the producer and the recipient in the programme exchange; 4 that consumer interactions with the received audio should be facilitated in the production and broadc
19、ast sound system and that its characteristics should be a choice by agreement between the producer and the recipient in the programme exchange, and further recommends that further work should be conducted to provide information about the features of any advance sound system according to this Recomme
20、ndation to fulfil the quality requirements of Recommendation ITU-R BS.1909. Annex 1 (normative) Advanced sound system for programme production 1 Introduction The sound system specified in this Recommendation is defined as an advanced sound system which allows the metadata associated with each audio
21、stream to be static or dynamic for the duration of a programme. This, for example, allows a programme to be represented by elements made by a combination of object signals and channel signals. Channel signals are defined as audio signals that are mixed to a predefined number of channels and accompan
22、ied by metadata being static for the duration of a programme. Each of these channels is associated with a specific speaker position. The production workflows, broadcasting networks and reproduction systems are defined by a set of speaker positions. Examples are systems according to Recommendation IT
23、U-R BS.775. Object signals are audio signals that, when accompanied by dynamic metadata for the duration of a programme, represent audio elements allowing a renderer to play back the audio objects in a way most appropriate to the playback system and listening environment. An object-based approach al
24、so may allow users to fully interact with the audio content. Object-based elements and channel-based elements can be associated with each other or exist independently. To allow any combinations of channel or object-based elements, all signals should be accompanied by necessary metadata/descriptors,
25、including time-independent (static) and/or time-dependent (dynamic) spatial position of the signal. These signals can be reproduced via a configuration of speakers using a variety of rendering and/or mapping techniques. Advanced sound programmes consist of the audio signals and the accompanying meta
26、data. 1An audio element is considered to be a signal with metadata which is either static for the duration of a programme or is dynamic. This enables the delivery of channel-based, object-based and scene-based content. Rec. ITU-R BS.2051-0 3 Section 2 specifies requirements for metadata for sound co
27、ntent of the advanced sound system. Section 3 describes speaker layouts for the systems in production environments. Because a rendering or mapping process is needed for the reproduction of audio signals, the numbers and positions of speakers are required to be well defined. This information enables
28、rendering of the audio signals according to a predefined speaker configuration in a reproduction scenario. 2 Requirements for metadata/descriptors for sound content of advanced sound system content All audio files and streams used in an advanced sound system will require suitable metadata to accompa
29、ny them. Unlike simple fixed channel-based systems where channel ordering is often enough to define the channels, the advanced system will need complete descriptions for all the audio elements used to ensure they are handled correctly. Therefore, a metadata model that has been standardized by a stan
30、dards organization is required to provide consistent definitions for the audio. This model should have the following requirements: Contain all information required to reproduce/render a programme in all reproduction scenarios given by Recommendation ITU-R BS.1909 based on a single representation. Be
31、 able to describe the format of any channel-, object- and scene based audio element. Be flexible enough to describe any combination of elements. The metadata items should be fully described such that they can be used by any renderer. Be specified in an open XML schema to allow the metadata to be rep
32、resented in XML (as its primary method, it could of course be translated to other formats such as JSON). Be able to be added to an existing audio file format. To allow commonly used definitions (in particular existing channel-based configurations) to be open and freely accessible from a reference se
33、t of definitions. 3 Speaker configurations for advanced sound system Channel-based signals (including those in an advanced sound system) require a speaker setup where the number and positions of the speakers are well defined. Object-based signals can be reproduced via speakers configured for channel
34、-based signals or additional speakers for other advanced rendering systems. To ensure the speaker configuration for the advanced multichannel sound system has a consistent definition, a set of parameters have been defined that specify each speaker label, name, its position as described in Table 1: S
35、P Label: an abbreviation of the channel name. Azimuth: the azimuth angle expressed in degrees, positive values rotate to the left when facing the front. Elevation: the elevation angle expressed in degrees, positive values go up from the horizontal plane. 4 Rec. ITU-R BS.2051-0 TABLE 1 List of possib
36、le speaker positions for advanced sound system, identification of the speaker layouts in form of “Upper speakers + Middle speakers + Bottom speakers” SP Label Azimuth Elevation A B C D EF G H 0+2+0 0+5+0 2+5+0 4+5+0 4+5+1 3+7+0 4+9+0 9+10+3 M+000 0 0 X X X X X X X M-022 22.5 0 M+022 +22.5 0 M-SC Lef
37、t edge of display 0 X M+SC Right edge of display 0 X M-030 30 0 X X X X X X X X M+030 +30 0 X X X X X X X X M-045 45 0 M+045 +45 0 M-060 60 0 X M+060 +60 0 X M-090 90 0 X X X M+090 +90 0 X X X M-110 110 0 X X X X M+110 +110 0 X X X X M-135 135 0 X X X M+135 +135 0 X X X M+180 +180 0 X U+000 0 +30 X
38、U-022 22.5 +30 U+022 +22.5 +30 U-030 30 +30 X X X U+030 +30 +30 X X X U-045 45 +30 X X X U+045 +45 +30 X X X U-060 60 +30 U+060 +60 +30 U-090 90 +30 X U+090 +90 +30 X U-110 110 +30 X X X U+110 +110 +30 X X X U-135 135 +30 X U+135 +135 +30 X U+180 +180 +30 X X T+000 +90 X B+000 0 30 X X B-022 22.5 30
39、 B+022 +22.5 30 B-030 30 30 B+030 +30 30 Rec. ITU-R BS.2051-0 5 TABLE 1 (end) SP Label Azimuth Elevation A B C D EF G H 0+2+0 0+5+0 2+5+0 4+5+0 4+5+1 3+7+0 4+9+0 9+10+3 B-045 45 30 X B+045 +45 30 X B-060 60 30 B+060 +60 30 B-090 90 30 B+090 +90 30 B-110 110 30 B+110 110 30 B-135 135 30 B+135 135 30
40、B+180 +180 30 LFE1 45 30 X X X X X X X LFE2 +45 30 X X NOTE The loudspeakers are assumed to be on a sphere. When this is not the case they should preferably be time aligned (at the point of the listener) with an accuracy of 100 s, including the acoustic pathway. It is useful to identify, by means of
41、 metadata, whether the production environment was time aligned. The speaker layouts shown in Table 1 are illustrated in Table 2. 6 Rec. ITU-R BS.2051-0 TABLE 2 Speaker layouts for advanced sound system Lower layer Includes LFE speakers Middle layer Same level as the listener Upper layer Includes ove
42、rhead speaker (T+000) Rec. ITU-R BS.2051-0 7 3.1 Speaker positions in production environments As various conditions may need to be considered for the practical design of speaker set-ups in production studios such as room size, accompanying picture or other constraints, speaker positions may have som
43、e azimuth angle and elevation angle variations. To ensure proper adaptation and rendering of channel-based elements, the speaker positions used in the particular production environment should be stored as part of the metadata according to 2. When the content is transferred to a different reproductio
44、n system/location, it should be ensured that the programme is adapted if necessary so that all quality requirements of the advanced sound system are met. The quality requirements are specified in Recommendation ITU-R BS. 1909. However, speakers should be placed within the sectors from azimuth min/el
45、evation min to azimuth max/elevation max as given in Tables 3 to 6 to lessen the sound quality variations by speaker positions differences. TABLE 3 Speaker configuration for Sound system H (9+10+3) SP Label Channel Azimuth Elevation Label Name Min Max Min Max M+060 FL Front left +45 +60 0 +5 M-060 F
46、R Front right 45 60 0 +5 M+000 FC Front centre 0 0 +5 LFE1 LFE1 Low frequency effects-1 +30 +90 15 30 M+135 BL Back left +110 +135 0 +15 M-135 BR Back right 110 135 0 +15 M+030 FLc Front left centre +22.5 +30 0 +5 M-030 FRc Front right centre 22.5 30 0 +5 M+180 BC Back centre +180 0 +15 LFE2 LFE2 Lo
47、w frequency effects-2 30 90 15 30 M+090 SiL Side left +90 0 +15 M-090 SiR Side right 90 0 +15 U+045 TpFL Top front left +45 +60 +30 +45 U-045 TpFR Top front right 45 60 +30 +45 U+000 TpFC Top front centre 0 +30 +45 T+000 TpC Top centre +90 U+135 TpBL Top back left +110 +135 +30 +45 U-135 TpBR Top ba
48、ck right 110 135 +30 +45 U+090 TpSiL Top side left +90 +30 +45 U-090 TpSiR Top side right 90 +30 +45 U+180 TpBC Top back centre +180 +30 +45 B+000 BtFC Bottom front centre 0 15 30 B+045 BtFL Bottom front left +45 +60 15 30 B-045 BtFR Bottom front right 45 60 15 30 8 Rec. ITU-R BS.2051-0 TABLE 4 Spea
49、ker configuration for Sound system G (4+9+0) Channel Loudspeaker location, Polar Loudspeaker location, Cartesian Azimuth Elevation X (left/ right) Y (rear/ front) Z (bottom/ top) Label Name Min Max Min Max M+000 C Centre 0 0 0 +1 0 M+SC Lsc Left screen Left screen edge 0 1* +1 0 M-SC Rsc Right screen Right screen edge 0 +1* +1 0 M+030 L
