1、Information technology MPEG audio technologies Part 3: Unified speech and audio coding AMENDMENT 1: Conformance Technologies de linformation Technologies audio MPEG Partie 3: Discours unifi et codage audio AMENDEMENT 1: Conformit ISO/IEC 2014 INTERNATIONAL STANDARD ISO/IEC 23003-3 First edition 2012
2、-04-01 Reference number ISO/IEC 23003-3:2012/Amd.1:2014(E) AMENDMENT 1 2014-03-15 ISO/IEC 23003-3:2012/Amd.1:2014(E)ii ISO/IEC 2014 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized
3、 otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright o
4、ffice Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO/IEC 23003-3:2012/Amd.1:2014(E) Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commi
5、ssion) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO
6、 and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO
7、/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to nationa
8、l bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for
9、identifying any or all such patent rights. Amendment 1 to ISO/IEC 23003-3:2012 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information. ISO/IEC 2014 All rights reserved iii Information techno
10、logy MPEG audio technologies Part 3: Unified speech and audio coding AMENDMENT 1: Conformance In Clause 2, “Normative References”, add the following entry: ISO/IEC 14496-26:2010, Information technology Coding of audio-visual objects Part 26: Audio conformance In 4.5.4 replace: Four different hierarc
11、hical levels are defined with increasing number of audio channels and increasing complexity. All four levels include Level 2 of the Baseline USAC profile. The definition of the four levels of the Extended HE AAC profile is given in Table 3. All notes in Table 3 and all restrictions listed in the col
12、umns 2, 3, 4, and 5 (“Max. channels/object”, “Max. AAC sampling rate, SBR not present kHz”, “Max. AAC sampling rate, SBR present kHz”, “Max. SBR sampling rate kHz (in/out)”) of Table 3 apply only when decoding HE AAC v2 profile compliant bit streams. Table 3 Levels for the Extended HE AAC profile Le
13、vel (NOTE 1) Max. channels / object Max. AAC sampling rate, SBR not present kHz Max. AAC sampling rate, SBR present kHz Max. SBR sampling rate kHz (in/out) Max. PCU Max. RCU Max. PCU HQ / LP SBR (NOTE 5) Max. RCU HQ / LP SBR (NOTE 5) 1 NA NA NA NA NA NA NA NA 2 2 48 24 24/48 12 11 12 11 3 2 48 24/48
14、 (NOTE 3) 48/48 (NOTE 2) 15 11 15 11 4 5 48 24/48 (NOTE 4) 48/48 (NOTE 2) 25 28 20 23 5 5 96 48 48/96 49 28 39 23 NOTE 1: Level 2, 3, and 4 Extended HE AAC profile decoders implement the baseline version of the parametric stereo tool. A level 5 decoder shall not be limited to the baseline version of
15、 the parametric stereo tool. NOTE 2: For level 3 and level 4 decoders, it is mandatory to operate the SBR tool in downsampled mode if the sampling rate of the AAC core is higher than 24kHz. Hence, if the SBR tool operates on a 48kHz signal, the internal sampling rate of the SBR tool will be 96kHz, h
16、owever, the output signal will be downsampled by the SBR tool to 48kHz. NOTE 3: If Parametric Stereo data are present the maximum AAC sampling rate is 24kHz, if Parametric Stereo data are not present the maximum AAC sampling rate is 48kHz. NOTE 4: For one or two channels the maximum AAC sampling rat
17、e, with SBR present, is 48kHz. For more than two channels the maximum AAC sampling rate, with SBR present, is 24kHz. NOTE 5: The PCU/RCU number are given for a decoder operating the LP SBR tool whenever applicable. with: A number of hierarchical levels are defined with increasing number of audio cha
18、nnels and increasing complexity. All levels include Level 2 of the Baseline USAC profile. The definition of the levels of the Extended HE AAC profile is given in Table 3. All notes in Table 3 and all restrictions listed in the columns 2, 3, 4, and 5 (“Max. channels/object”, “Max. AAC sampling rate,
19、SBR not present kHz”, “Max. AAC ISO/IEC 23003-3:2012/Amd.1:2014(E) ISO/IEC 2014 All rights reserved 1 ISO/IEC 23003-3:2012/Amd.1:2014(E) sampling rate, SBR present kHz”, “Max. SBR sampling rate kHz (in/out)”) of Table 3 apply only when decoding HE AAC v2 profile compliant bit streams. Table 3 Levels
20、 for the Extended HE AAC profile Level (NOTE 1) Max. channels / object Max. AAC sampling rate, SBR not present kHz Max. AAC sampling rate, SBR present kHz Max. SBR sampling rate kHz (in/out) Max. PCU Max. RCU Max. PCU HQ / LP SBR (NOTE 5) Max. RCU HQ / LP SBR (NOTE 5) 1 NA NA NA NA NA NA NA NA 2 2 4
21、8 24 24/48 12 11 12 11 3 2 48 24/48 (NOTE 3) 48/48 (NOTE 2) 15 11 15 11 4 5 48 24/48 (NOTE 4) 48/48 (NOTE 2) 25 28 20 23 5 5 96 48 48/96 49 28 39 23 6 7 48 24/48 (NOTE 4) 48/48 34 37 27 30 7 7 96 48 48/96 67 37 53 30 NOTE 1: Level 2, 3, 4, 6 and 7 Extended HE AAC profile decoders implement the basel
22、ine version of the parametric stereo tool. A level 5 decoder shall not be limited to the baseline version of the parametric stereo tool. NOTE 2: For level 3, 4 and 6 decoders, it is mandatory to operate the SBR tool in downsampled mode if the sampling rate of the AAC core is higher than 24kHz. Hence
23、, if the SBR tool operates on a 48kHz signal, the internal sampling rate of the SBR tool will be 96kHz, however, the output signal will be downsampled by the SBR tool to 48kHz. NOTE 3: If Parametric Stereo data are present the maximum AAC sampling rate is 24kHz, if Parametric Stereo data are not pre
24、sent the maximum AAC sampling rate is 48kHz. NOTE 4: For one or two channels the maximum AAC sampling rate, with SBR present, is 48kHz. For more than two channels the maximum AAC sampling rate, with SBR present, is 24kHz. NOTE 5: The PCU/RCU number are given for a decoder operating the LP SBR tool w
25、henever applicable. NOTE 6: A Level 6 or 7 decoder is not required to decode a Level 5 stream. In 5.3.2 amend Table 36 as follows:2 ISO/IEC 2014 All rights reserved ISO/IEC 23003-3:2012/Amd.1:2014(E) Table 36 Syntax of acelp_coding() Syntax No. of bits Mnemonic acelp_coding(acelp_core_mode) switch (
26、acelp_core_mode) case 0 icb_indexsfr; 20 uimsbfbreak; case 1 icb_indexsfr; 28 uimsbfbreak; case 2 icb_indexsfr; 36 uimsbfbreak; case 3 icb_indexsfr; 44 uimsbfbreak; case 4 icb_indexsfr; 52 uimsbfbreak; case 5 icb_indexsfr; 64 uimsbfbreak; case 6 icb_indexsfr; 12 uimsbfbreak; case 7 icb_indexsfr; 16
27、uimsbfbreak; gainssfr; 7 uimsbf NOTE: coreCoderFrameLength designates the core frame length in samples and is equal to either 1024 or 768. See also 6.1.1.2. In 7.14.5.2.1, replace: Depending on the coding mode, the following codebooks are used: with: Depending on the coding mode, the following codeb
28、ooks are used: 12-bit codebook with 2 pulses i 0 and i 1 . Pulse i 0can be selected from either track 0 or 2, pulse i 1 can be selected from either track 1 or 3 (52+2) ISO/IEC 2014 All rights reserved 3 ISO/IEC 23003-3:2012/Amd.1:2014(E) 16-bit codebook with 3 pulses on three tracks. One pulse on tr
29、ack 0, one pulse on track 2 and one pulse on either track 1 or 3 (selected track signalled by a 1 bit field), which amounts to (53+1) = 16 bits. Add a new Clause 8, “Conformance testing”, as shown below: 8 Conformance testing 8.1 Introduction The present Clause 8 specifies conformance criteria for b
30、oth bitstreams and decoders compliant with the USAC standard as defined in this document. This is done to assist implementers and to ensure interoperability. 8.2 Terms and definitions bitstream encoded audio data conformance data conformance test sequences and conformance tools conformance tool tool
31、 to check certain conformance criteria conformance test sequence generic term for conformance test bitstreams and corresponding reference waveforms conformance test bitstream USAC bitstream used for testing the conformance of a USAC decoder conformance test condition condition which applies to prope
32、rties of a conformance test bitstream in order to test a certain func- tionality of the USAC decoder conformance test case combination of one or more conformance test conditions for which a set of conformance test sequences is provided main audio channel audio channel conveyed by means of a UsacSing
33、leChannelElement or UsacChannelPairElement reference waveform decoded counterpart of a bitstream USAC bitstream data encoded according to the USAC standard UsacCPE UsacChannelPairElement UsacEXT UsacExtElement UsacLFE UsacLfeElement UsacSCE UsacSingleChannelElement4 ISO/IEC 2014 All rights reserved
34、ISO/IEC 23003-3:2012/Amd.1:2014(E) 8.3 USAC conformance testing 8.3.1 Profiles Profiles are defined in 4.5. Some conformance criteria apply to USAC in general, while others are specific to certain profiles and their respective levels. Conformance shall be tested for the level of the profile with whi
35、ch a given bitstream or decoder claims to comply. In addition to the conformance requirements described in this clause, a decoder which claims to comply with the Extended HE AAC Profile shall fulfill conformance for the HE AAC v2 profile according to ISO/IEC 14496-26:2010. 8.3.2 Conformance tools an
36、d test procedure To test USAC compliant audio decoders, ISO/IEC JTC 1/SC 29/WG 11 supplies a number of conformance test sequences. Supplied sequences cover all profiles as defined in 4.5. For a supplied test sequence, testing can be done by comparing the output of a decoder under test with a referen
37、ce waveform also supplied by ISO/IEC JTC 1/SC 29/WG 11. In cases where the decoder under test is followed by additional operations (e.g. quantizing a signal to a 16 bit output signal) the conformance point is prior to such additional operations, i.e. it is permitted to use the actual decoder output
38、(e.g. with more than 16 bit) for conformance testing. Measurements are carried out relative to full scale where the output signals of the decoders are normalized to be in the range between 1.0 and +1.0. In ISO/IEC 14496-26:2010 a set of test methods is defined to test the output of the decoder under
39、 test against the reference output. RMS/LSB Measurement, Segmental SNR and PNS conformance criteria are used for the comparison. A particular test method for a certain test sequence is specified in 8.5. For elements producing output that cannot be tested with the methods described in ISO/IEC 14496-
40、26:2010, specific conformance testing procedures are described in 8.5. 8.3.2.1 Conformance data All test sequences are provided in the shape of a zip archive as an electronic attachment. Furthermore, an MS Excel worksheet (“Usac_Conformance_Tables.xlsx”) is provided as an electronic attachment that
41、lists all test sequences for each module. For all conformance test sequences, the file names are composed of several parts which convey information about: which module of the decoder is tested which channelConfigurationIndex is employed which test conditions apply to the test sequence which coreSbrF
42、rameLengthIndex applies to the test sequence which sampling frequency is signalled in the test sequence The file naming convention given in Table 149 is used. Values in box brackets are optional. ISO/IEC 2014 All rights reserved 5 ISO/IEC 23003-3:2012/Amd.1:2014(E) Table 149 File name conventions Mo
43、dule File Name (compressed) File Name (uncompressed) Frequency domain cod- ing (FD mode), 8.4.4 Fd_c_.mp4 FD_c_.wav Linear predictive domain coding (LPD mode), 8.4.5 Lpd_c_.mp4 Lpd_c_.wav Common core coding tools, 8.4.6 Cct_c_.mp4 Cct_c_.wav Enhanced spectral band replication (eSBR), 8.4.7 eSbr_.mp4
44、 eSbr_.wav MPEG Surround 2-1-2, 8.4.10 Mps_Sc_.mp4 Mps_Sc_.wavchannelConfigurationIndex as described in Table 68.Setup string. May consist of a concatenation of one or more abbrevia- tions as listed in Table 150. If no setup string is specified the basic test conditions applycoreSbrFrameLengthIndex
45、as described in Table 70.usacSamplingFrequencyIndex as described in Table 67. If the escape value is specified the used sampling frequency is appended, e.g. “xx_1f_42000.mp4” for a sampling frequency of 42 kHz.bsFreqRes as described in ISO/IEC 23003-1:2007, Table 39stereoConfigIndex as described in
46、Table 72 Table 150 Test conditions and abbreviations FD core mode Test Condition Abbrev. FD window switching test condition Win Noise filling test condition Nf Tns test condition Tns Varying max_sfb test condition Sfb Handling of extensions condition Ex Arithmetic coder test condition Ac Non-meaning
47、ful FD window switching test condtion Nmf M/S stereo test condition Ms Complex prediction stereo test condition Cp6 ISO/IEC 2014 All rights reserved ISO/IEC 23003-3:2012/Amd.1:2014(E)LPD core mode Test Condition Abbrev. LPC coding test condition Lpc ACELP core mode test condition Ace TCX and noise f
48、illing test condition Tcx LPD mode coverage and FAC test condition Lpd Bass-post filter test condition Bpf AVQ test condition AvqCombined core coding Test Condition Abbrev. FD-LPD transition and FAC test condition Flt FD/TCX noise filling test condition Cnf Bass-post filter test condition Cbf synchr
49、. FD-LPD transition and FAC test condition Flts asynchr. FD-LPD transition and FAC test condition Flta Arithmetic coder test condition CAceSbr Test Condition Abbrev. QMF accuracy test condition Qma Envelope adjuster accuracy and SBR pre- processing test condition Eaa Header and grid control test condition test condition Hgt Inverse filtering test condition Ift Additional sine test (missing harmonics) test condition Ast Sampling rate tes
