1、 Recommendation ITU-R BS.1738-1 (10/2015) Identification and ordering of 4 and 8 track audio channels carried on international contribution circuits BS Series Broadcasting service (sound) ii Rec. ITU-R BS.1738-1 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable,
2、 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 Radiocommunication Sect
3、or 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 Resolution ITU-
4、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 database ca
5、n 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 service
6、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 Spectru
7、m 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, 2015 ITU 2015 All rights reserved.
8、No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BS.1738-1 1 RECOMMENDATION ITU-R BS.1738-1 Identification and ordering of 4 and 8 track audio channels carried on international contribution circuits (Question ITU-R 37/6) (2007-2015
9、) Scope This Recommendation provides the means to identify the allocation of multiple audio signals on international contribution circuits as well as the preferred ordering of these signals. The ITU Radiocommunication Assembly, considering a) that the exchange of television programmes is very import
10、ant and extensive; b) that there is a requirement to transmit more than one sound signal including stereophony with a television picture; c) that within a television channel as used in present systems several sound channels could be accommodated; d) that Recommendation ITU-R BR.779 Operating practic
11、es for digital television recording; contains allocation of mono, stereo and multichannel audio channels, and the use of audio channels as data recording channels for international exchange of digitally recorded television programmes; e) that Recommendation ITU-R BS.1726 Signal level of digital audi
12、o accompanying television in international programme exchange recommends reference level and permitted maximum level (PML) of digital audio signal for international programme exchange; f) that international identification of media content and of the format used for programme exchange offers both eco
13、nomical and operational advantages; g) that an alignment of operational practices used in connection with the identification of the content and format of sound programmes is highly desirable; h) that a technique is applied where simultaneous availability of a line-up tone on the channels present in
14、stereo and multi-channel modes so that the phase relationship between channels can be checked to mitigate a 180 phase reversal; i) that transmission systems with bit-rate reduced coding for multichannel sound transmission are in use in several countries; j) that production scenarios increasingly inv
15、olve eight audio channels for 5.1 surround sound; k) that coding of multi-track sound into an audio multiplex for audio production in many programme genres is increasing as a requirement for international programme exchange for sound and television broadcasting; l) that specifications for internatio
16、nal exchange of programmes with multiple channel audio is subject to contractual and commercials arrangements among the broadcasters and programme rights holders; m) that many administrations are becoming increasingly involved in the exchange of television programme material, 2 Rec. ITU-R BS.1738-1
17、recommends 1 that, if audio channel identification is required or in use, then the signalling should at least provide minimum information to ensure that downstream of the source any user can unambiguously determine the channel number and thus the content; 2 that the reference signal of each channel
18、in a stereo signal should be a 1 000 Hz alignment tone at the reference level of either 18 dB FS or 20 dB FS in accordance with Recommendation ITU-R BS.1726, interrupted at least once every 30 s by a voice announcement indicating the channel number and optionally the source name; 3 that in stereo an
19、d multi-channel contribution circuits the reference tone should be applied simultaneously to all channels to aid in confirming correct phase relationship between channels at the destination end; 4 that the use of the channels to carry the various audio components of the programme should be mutually
20、agreed in advance among the parties concerned; 5 that in the absence of such advance agreement, the use of channels indicated in Annexes 1, 2 and 3 should be preferred for the production scenarios described in it; 6 that Annexes 1, 2 and 3 should be extended, when required, to reflect other scenario
21、s. Annex 1 Identification and ordering of four track audio channels carried on international contribution circuits This Annex describes preferred identification of audio channels for production scenarios for stereophonic or monophonic sound programs using four audio channels in the absence of advanc
22、ed mutual agreement among the parties concerned. Production scenario 1 This scenario is the one in which the commentator of the destination broadcaster is located at the destination broadcasters facility. In this case the destination broadcaster will often translate the host guide commentary from th
23、e host language and make a new mix of local commentary with international sound. Two instances are considered in Table 1, namely, stereophonic or monophonic sound. TABLE 1 Channel number Stereo audio signal Monophonic audio signal 1 International sound (stereo effects Lt) International sound (mono)
24、2 International sound (stereo effects Rt) International sound (mono) 3 Guide commentary (stereo Lt) Guide commentary (mono) 4 Guide commentary (stereo Rt) Guide commentary (mono) International Sound = Music + Effects + Interview Dialogue Rec. ITU-R BS.1738-1 3 Guide Commentary Stereo, Host Language
25、as Lt/Rt = Music + Effects + Dialogue Interview dialogue is voice signals during interviews between host broadcast commentators and interviewees. Guide commentary is provided by the host broadcaster for the purpose of guidance for those providing commentary at the destination(s). NOTE 1 In situation
26、s where monophonic sound or guide commentary is required it is recommended that both channels carry the same monophonic audio as shown in Table 1 to avoid operation confusion. NOTE 2 In this Recommendation, the terms Lt, and Rt are used only to differentiate these channels of a stereo signal from th
27、e front left and front right channels of a surround sound program. In other contexts, the terms Lt, Rt, Lo, and Ro, are used to denote downmixes of a surround sound signal wherein the left surround and right surround channels have been combined with the front left and front right channels. In those
28、contexts, Lt and Rt denote a “matrix encoded surround mix” in which the surround signals have been summed, and the sum added to the front left and front right channels, with 90 and 90 phase shifts respectively. This creates a pair of signals that can be decoded to recreate a surround experience. Lo
29、and Ro (not used in this Recommendation) denote a downmix in which the left surround channel is added to the left front channel, the right surround signal is added to the front right channel, without a phase shift being applied to either. In both cases the centre channel signal is also added to fron
30、t left and front right. In both cases, the signals that are added to front left and front right are, in general, attenuated before they are added. The amount of attenuation for Lt and Rt is 3 dB, but for Lo and Ro may be chosen to suit the nature of the programme material. In this Recommendation, th
31、ere is no implication of the nature of the stereo channels. Production scenario 2 This scenario is the one in which the destination broadcaster has a commentator located at the host broadcasters facility and this commentary is mixed with international sound in the destination facility. TABLE 2 Chann
32、el number Stereophonic audio signal Monophonic audio signal 1 Left channel international sound International sound (Mono) 2 Right channel international sound International sound (Mono) 3 Mono dialogue destination language Commentary or mono dialogue 4 User defined/cue channel/mono dialogue host dial
33、ogue User defined/cue channel/mono dialogue host dialogue International Sound = Music + Effects + Interview Dialogue Production scenario 3 This scenario is the one in which the destination broadcaster has a commentator located at the host broadcasters facility and this commentary is mixed with inter
34、national sound at the host facility. 4 Rec. ITU-R BS.1738-1 TABLE 3 Channel number Stereophonic audio signal Monophonic audio signal 1 Left channel, complete mix Complete monophonic mix 2 Right channel, complete mix Complete monophonic mix 3 Left channel international sound International sound (mono
35、) 4 Right channel international sound International sound (mono) Annex 2 Identification and ordering of eight track audio channels carried on international contribution circuits This Annex describes preferred identification of audio channels for production scenarios for 5.1 surround sound programs u
36、sing eight audio channels in the absence of advanced mutual agreement among the parties concerned. Production scenario 4 This scenario involves the international exchange of programs using 5.1 audio in which the outbound circuits from the broadcaster include a fully integrate stream of programs, com
37、mercials, and promotions. TABLE 4* Channel number 5.1 Surround sound audio signal 1 Left channel, complete mix 2 Right channel, complete mix 3 Centre channel, complete mix 4 Low frequency effects 5 Left surround channel 6 Right surround channel 7 Optional secondary audio program channel 8 Optional v
38、ideo description channel * Tables 4 and 5 conform to SMPTE 320M-1999 (Table 2). Production scenario 5 This scenario involves production using 5.1 audio in which the destination broadcaster has a commentator located at the host broadcasters facility and this commentary is mixed at the host facility.
39、Rec. ITU-R BS.1738-1 5 TABLE 5* Channel number 5.1 Surround sound audio signal 1 Left channel, complete mix 2 Right channel, complete mix 3 Centre channel, complete mix 4 Low frequency effects 5 Left surround channel 6 Right surround channel 7 Optional left channel international sound 8 Optional rig
40、ht channel international sound * Tables 4 and 5 conform to SMPTE 320M-1999 (Table 2). Production scenario 6 This scenario involves a production using both a stereo complete mix on channels 1 and 2, and a 5.1 surround sound complete mix on channels 3 to 8. TABLE 6 Channel number Stereo and 5.1 surrou
41、nd sound audio signals 1 Stereo left channel, complete mix 2 Stereo right channel, complete mix 3 5.1 Left channel, complete mix 4 5.1 Right channel, complete mix 5 5.1 Centre channel, complete mix 6 5.1 Low frequency effects channel, complete mix 7 5.1 Left surround channel, complete mix 8 5.1 Righ
42、t surround channel, complete mix Annex 3 Identification and ordering of audio signal content using digital audio multiplexes This Annex describes the preferred identification and ordering of audio signal content using digital audio multiplexes in the absence of advanced mutual agreement among the pa
43、rties concerned. 6 Rec. ITU-R BS.1738-1 Production scenario 7 This scenario is possible when the Host broadcaster can provide a multichannel mix (typically 5.1) and this is required by the Destination broadcaster. The centre channel of the multichannel mix may be either in the Host or Destination la
44、nguage. If it is in the Host language then the defined primary contents of contribution channels 3 and 4 are necessary to enable the Destination broadcaster to create a new centre channel for its transmission. Depending on the type of Audio Multiplex used, there may be a relative timing issue with r
45、espect to vision which will need to be corrected when the new centre channel is created. TABLE 7 Channel number Data/audio signal content 1 Digital audio multiplex 2 Digital audio multiplex 3 Mono dialogue Destination language or user defined 4 Mono interview dialogue or user defined The internal co
46、ntents of the digital audio multiplex should have its channels ordered as per Tables 4 and 5 above. Production scenario 8 For broadcasters who are concerned about possible stability issues of the compressed audio data of a multiplex on satellite or fibre-optic contribution circuits, this scenario ma
47、y be used. TABLE 8 Channel number Data/audio signal content 1 Left channel, complete mix or international sound 2 Right channel, complete mix or international sound 3 Digital audio multiplex 4 Digital audio multiplex Channels 7 and 8 of the audio multiplex may carry the additional audio information necessary when the host and destination languages are different.
