1、 ETSI TR 126 950 V14.0.0 (2017-04) Universal Mobile Telecommunications System (UMTS); LTE; Study on Surround Sound codec extension for Packet Switched Streaming (PSS) and Multimedia Broadcast/Multicast Service (MBMS) (3GPP TR 26.950 version 14.0.0 Release 14) TECHNICAL REPORT ETSI ETSI TR 126 950 V1
2、4.0.0 (2017-04)13GPP TR 26.950 version 14.0.0 Release 14Reference RTR/TSGS-0426950ve00 Keywords LTE,UMTS ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la
3、 Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present document can be downloaded from: http:/www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or print versions of the present document sh
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9、TSI TR 126 950 V14.0.0 (2017-04)23GPP TR 26.950 version 14.0.0 Release 14Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and
10、 non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (https:/ipr.etsi.org/).
11、 Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the presen
12、t document. Foreword This Technical Report (TR) has been produced by ETSI 3rd Generation Partnership Project (3GPP). The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or GSM identities. These should be interpreted as being references t
13、o the corresponding ETSI deliverables. The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under http:/webapp.etsi.org/key/queryform.asp. Modal verbs terminology In the present document “should“, “should not“, “may“, “need not“, “will“, “will not“, “can“ and “cannot“ are to
14、be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. ETSI ETSI TR 126 950 V14.0.0 (2017-04)33GPP TR 26.950 version 14.0.0 Release 14Content
15、s Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 4g31 Scope 5g32 References 5g33 Definitions and abbreviations . 6g33.1 Definitions 6g33.2 Abbreviations . 6g34 Use cases 6g34.1 Surround sound over headphones . 7g34.2 Surround sound over loudspeakers . 7g34.2.1 De
16、coding and rendering on a UE 8g34.2.2 Decoding and rendering on a non-3GPP device connected to a UE . 8g34.2.3 Decoding on a UE and rendering on a non-3GPP device connected to a UE . 9g34.2.4 PSS/MBMS delivery methods 9g35 Design constraints 9g35.1 Mono/Stereo Backwards compatibility 9g35.2 Number o
17、f audio channels 10g35.2.1 Number of audio input channels . 10g35.2.2 Number of audio output channels . 10g35.3 Sampling frequency 10g35.4 Bit rates 10g35.5 Computational complexity . 10g35.6 Other design constraints . 11g36 Test item selection criteria . 11g37 Performance requirements 12g37.1 Gener
18、al requirements . 12g37.2 Loudspeaker requirements 12g37.3 Binaural test 13g37.4 Backward compatibility test . 13g37.5 Error test . 13g37.6 Listening test on HRTF 13g38 Validation of the user benefits and feasibility through evaluation of at least one example of surround sound . 13g38.1 Listening te
19、st over loudspeakers 13g38.2 Listening test over headphones 15g38.3 Backward compatibility . 17g38.4 Test under errors conditions . 18g38.4.1 Results with interleaver 18g38.4.2 Results without interleaver . 20g38.5 Test on HRTFs . 22g39 Conclusion 23g3Annex A: Test plans and global analysis reports
20、24g3Annex B: Change history 25g3History 26g3ETSI ETSI TR 126 950 V14.0.0 (2017-04)43GPP TR 26.950 version 14.0.0 Release 14Foreword This Technical Report has been produced by the 3rdGeneration Partnership Project (3GPP). The contents of the present document are subject to continuing work within the
21、TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an identifying change of release date and an increase in version number as follows: Version x.y.z where: x the first digit: 1 presented to TSG for info
22、rmation; 2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc. z the third digit is incremented when editorial only changes have been
23、incorporated in the document. ETSI ETSI TR 126 950 V14.0.0 (2017-04)53GPP TR 26.950 version 14.0.0 Release 141 Scope The present document investigates the potential user experience benefits of surround audio in 3GPP services. The investigation will be performed as follows: Identify and document rele
24、vant use cases for surround sound in 3GPP. Define design constraints that would need to be met by a surround audio codec extension method for adoption by 3GPP. Identify suitable testing methodology for surround sound in relevant use cases of the PSS and MBMS services. Define subjective minimum perfo
25、rmance criteria that would need to be met in order to motivate the consideration of a surround audio coding extension for adoption by 3GPP. Validate the user benefits and the feasibility of the deployment of surround sound for the PSS and MBMS services according to the defined minimum performance cr
26、iteria, bit rate and design constraints for all the use cases (such as surround sound speaker set-up and headphone decoding mode) through evaluation of at least one example of surround sound coding methods which may be MPS. 2 References The following documents contain provisions which, through refer
27、ence in this text, constitute provisions of the present document. - References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific. - For a specific reference, subsequent revisions do not apply. - For a non-specific reference, the latest vers
28、ion applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document. 1 3GPP TR 21.905: “Vocabulary for 3GPP Specifications“. 2 3GPP TS 26.346: “Multimedia
29、Broadcast/Multicast Service (MBMS); Protocols and codecs“. 3 3GPP TS 26.234: “Transparent end-to-end Packet-switched Streaming Service (PSS); Protocols and codecs“. 4 ITU-R Recommendation BS.775-2: “Multichannel stereophonic sound system with and without accompanying picture,“ Jul. 2006. 5 ITU- Reco
30、mmendation BS.1534-1: “Method for the subjective assessment of intermediate quality level of coding systems“, Geneva, 2003. 6 ISO/IEC JTC1/SC29/WG11 N2006 “Report on the MPEG-2 AAC Stereo Verification Tests“; Feb 1998, http:/www.chiariglione.org/mpeg/working_documents/mpeg-02/audio/AAC_results.zip.
31、7 3GPP TR 26.936: “Performance characterization of 3GPP audio codecs“. ETSI ETSI TR 126 950 V14.0.0 (2017-04)63GPP TR 26.950 version 14.0.0 Release 143 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the terms and definitions given in TR 21.905 1 and the follo
32、wing apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 1. HRTF: A Head-Related Transfer Function (HRTF) represents a pair of filters that are obtained by measurement or modelling. It represents the acoustic transmission from a p
33、oint in space to the entrance of a listeners ear canal. It depends on the relative positions of the source and the listeners head. 3.2 Abbreviations For the purposes of the present document, the abbreviations given in TR 21.905 1 and the following apply. An abbreviation defined in the present docume
34、nt takes precedence over the definition of the same abbreviation, if any, in TR 21.905 1. 5.1ch Loudspeaker set-up with 2 front channels, 2 rear channels, 1 center channel and 1 subwoofer HRTF Head-Related Transfer Function MPS MPEG Surround MUSHRA MUlti Stimulus test with Hidden Reference and Ancho
35、r 4 Use cases The relevant use cases considered in this study are applications in the context of MBMS and/or PSS services. In the home entertainment industry the de facto standard for surround sound content is the 5.1 channel format. The reproduction of such surround signal can be done in various wa
36、ys using a number of channels that is not necessarily equal to the content at the service provider side resulting in different listening modes. The general characteristics of MBMS and PSS services apply and will be considered to derive design constraints and performance requirements for the study it
37、em. We have identified the following use cases for consideration. Table 1: List of use cases considered in the study Use case # Reproduction Description 1 a Headphones Surround decoding with binaural post-processing 1 b Headphones Surround decoding with binaural processing being part of the decoding
38、 process 2.1 a Loudspeakers Surround decoding followed by rendering on the UE 2.1 b Loudspeakers Surround decoding with rendering being part of the decoding process on the UE 2.2 Loudspeakers Surround bit-stream is transported via the UE. Decoding and rendering is performed in a non-3gpp device conn
39、ected to the UE. 2.3 Loudspeakers Surround decoding on the UE. Decoded surround audio data are transported to a non-3gpp device connected to the UE for rendering. NOTE: In the following use cases it is assumed that the surround sound content provided to the server comprises multiple channels, typica
40、lly 6 channels in the 5.1 format. Alternatively, the surround sound content may be presented to the server as a binauralized stereo signal. In this case, the server would encode the surround sound as an artistic downmix (which is also referred to as Binaural ETSI ETSI TR 126 950 V14.0.0 (2017-04)73G
41、PP TR 26.950 version 14.0.0 Release 14Virtual Surround effect). No additional processing would be required when listening over headphones. However, this alternative format would have several implications: o When playing over stereo or multichannel loudspeakers, the decoder would have to remove the b
42、inauralization effect. Some signalling would be needed to indicate that the downmix is binauralized stereo signal. o This alternative format would not offer mono/stereo backward compatibility to existing 3GPP audio codecs, especially when listening over loudspeakers. In the following use cases it is
43、 assumed that the surround bit-stream contains spatial information to control the behaviour of the surround decoder. The surround decoder produces surround sound based on this side information. However, a possible additional function of the surround capable UE is that the surround decoder may be abl
44、e to upmix stereo signals encoded by legacy 3GPP audio codecs, which can then be binauralized for listening over headphones. 4.1 Surround sound over headphones Binaural/Stereo post-processing may or may not be part of the surround sound decoder (see Figures 1 and 2). Figure 1 illustrates a block dia
45、gram where the binaural or stereo post-processing is not part of the surround decoder. A server transmits surround sound bit-streams via PSS or MBMS protocols/services. The UE first decodes the received surround bit-stream to a surround signal. The resulting surround signal is processed by binaural
46、or stereo downmix post-processing to produce a stereo signal. The resulting signal can be represented on headphones. NOTE: The surround bit-stream is decoded inside the UE to a surround signal. This surround signal is input to a binaural or stereo downmix post-processor that produces a representatio
47、n of the surround signal for headphone reproduction. Figure 1: Signal flow for use case 1 a where binaural and stereo downmix post-processing is not part of the surround sound decoder Figure 2 provides a block diagram where binaural post-processing is part of, i.e. integrated into, the surround deco
48、der. The only difference with regard to Figure 1 is that the surround bit-stream is not first decoded to a full surround signal prior to binaural post-processing. Instead the steps of surround decoding and binaural decoding are integrated into a single binaural surround decoder. NOTE: The surround b
49、it-stream is decoded inside the UE directly to produce a representation of the surround signal for headphone reproduction. Figure 2: Signal flow for use case 1 b where binaural processing is part of the surround sound decoder 4.2 Surround sound over loudspeakers In case the surround sound is to be played back over loudspeakers a number of scenarios can be considered. These scenarios are outlined below. ETSI ETSI TR 126 950 V14.0.0 (2017-04)83GPP TR 26.950 version 14.0.0 Release 144.2.1 Decoding and rendering on a UE A loudspeaker scena
