1、 Reference number ISO/IEC 14496-26:2010/Amd.3:2014(E) ISO/IEC 2014INTERNATIONAL STANDARD ISO/IEC 14496-26 First edition 2010-05-01 AMENDMENT 3 2014-01-15 Information technology Coding of audio-visual objects Part 26: Audio conformance AMENDMENT 3: Conformance for Low Delay AAC v2 profile Technologie
2、s de linformation Codage des objets audiovisuels Partie 26: Conformit audio AMENDEMENT 3: Conformit pour profil Low Delay AAC v2 ISO/IEC 14496-26:2010/Amd. 3:2014(E) COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduc
3、ed or utilized 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. I
4、SO copyright office 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 ii ISO/IEC 2014 All rights reservedISO/IEC 14496-26:2010/Amd.3:2014(E) ISO/IEC 2014 All rights reserved iiiForeword ISO (the Internation
5、al Organization for Standardization) and IEC (the International Electrotechnical Commission) 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
6、 the respective organization to deal with particular fields of technical activity. ISO 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
7、 information technology, ISO and IEC have established a joint technical committee, ISO/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 Inte
8、rnational Standards adopted by the joint technical committee are circulated to national 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 docume
9、nt may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Amendment 3 to ISO/IEC 14496-26:2010 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multime
10、dia and hypermedia information. It adds the conformance testing for the Low Delay AAC v2 profile defined in ISO/IEC 14496-3. ISO/IEC 14496-26:2010/Amd.3:2014(E) ISO/IEC 2014 All rights reserved 1Information technology Coding of audio-visual objects Part 26: Audio conformance AMENDMENT 3: Conformance
11、 for Low Delay AAC v2 profile In 2, Normative references, add: ISO/IEC 23003-1, Information technology MPEG audio technologies Part 1: MPEG Surround ISO/IEC 23003-2, Information technology MPEG audio technologies Part 2: Spatial Audio Object Coding (SAOC) In 6.1, File name conventions, insert the fo
12、llowing rows at the end of Table 2: “ LD MPEG Surround (+ER AAC LD) er_ad_ldmps_ er_ad_ldmps_ LD MPEG Surround (+ER AAC ELD) er_eld_ldmps_ er_eld_ldmps_ “ After 7.25, Low Delay SBR, add: 7.26 Low Delay MPEG Surround 7.26.1 Compressed data 7.26.1.1 Characteristics The Low Delay MPEG Surround tool can
13、 be used in combination with the ER AAC LD AOT and the ER AAC ELD AOT. The compressed data shall be stored as outlined in ISO/IEC 14496-3:2009, 4.5.2.13. The extension_type for Low Delay MPS is EXT_LDSAC_DATA. The transport and signalling of LD MPS in an MPEG-4 Audio/Systems Environment is done in t
14、he same way as for the SAOC object type, as described in 8.2.2 of ISO/IEC 23003-2. LD MPS uses the AOT 44. The ldsac_extension_data() is used to carry a LDSacDataFrame() as described in B.4 of ISO/IEC 23003-2. 7.26.1.2 Test procedure Each compressed data shall meet the syntactic and semantic require
15、ments specified in ISO/IEC 23003- 2:2010, Annex B. If a syntactic element is not listed below, no restrictions apply to that element. ISO/IEC 14496-26:2010/Amd.3:2014(E) 2 ISO/IEC 2014 All rights reserved7.26.1.2.1 Compressed MPEG-4 data payload 7.26.1.2.1.1 LDSpatialSpecificConfig() bsSamplingFrequ
16、encyIndex For further restrictions, see 7.26.1.2.2 bsSamplingFrequency For restrictions, see 7.26.1.2.2 bsFreqRes Shall not be encoded with a value of 0 bsFrameLength For restrictions, see 7.26.1.2.2 bsTreeConfig For restrictions, see 7.26.1.2.2 bsQuantMode Shall not be encoded with a value of 3 bsO
17、neIcc Not present if bsTreeConfig = 7. No further restrictions apply bsArbitraryDownmix No restrictions apply bsFixedGainsSur Not present if bsTreeConfig = 7. Shall be in the range 04 bsFixedGainsLFE Not present if bsTreeConfig = 7. Shall be in the range 04 bsFixedGainsDMX No restrictions apply bsMa
18、trixMode Not present if bsTreeConfig = 7. No further restrictions apply bsTempShapeConfig Shall not be encoded with a value of 3 bsDecorrConfig Shall not be encoded with a value of 3 bs3DaudioMode Not present if bsTreeConfig = 7. No further restrictions apply bsEnvQuantMode Shall be 0 bs3DaudioHRTFs
19、et Shall be 0 7.26.1.2.1.2 OttConfig() bsOttBands Shall not be encoded with a value larger than numBands given in table Table B.9 of ISO/IEC 23003-2:2010 7.26.1.2.1.3 TttConfig() bsTttDualMode No restrictions apply bsTttModeLow Shall be in the range of 05 bsTttModeHigh Shall be in the range of 05 bs
20、TttBandsLow Shall not be encoded with a value larger than numBands given in table Table B.9 of ISO/IEC 23003-2:2010 7.26.1.2.1.4 ParamHRTFset() bsHRTFfreqRes Shall not be encoded with a value of 0 bsHRTFasymmetric No restrictions apply bsHRTFlevelLeft No restrictions apply bsHRTFlevelRight No restri
21、ctions apply bsHRTFphase No restrictions apply bsHRTFphaseLR No restrictions apply bsHRTFicc No restrictions apply bsHRTFiccLR No restrictions apply ISO/IEC 14496-26:2010/Amd.3:2014(E) ISO/IEC 2014 All rights reserved 37.26.1.2.1.5 SpatialExtensionConfig() bsSacExtType Shall be in the range of 215.
22、Note that in the case of values indicated as “reserved” in Table 54 of ISO/IEC 23003-1:2007, the parsing function SpatialExtensionConfigData(bsSacExtType) shall return the value 0, such that possibly present data is read as bsFillBits (i.e., skipped) and correct parsing of the bitstream can continue
23、 bsSacExtLen No restrictions apply bsSacExtLenAdd No restrictions apply bsSacExtLenAddAdd No restrictions apply bsFillBits No restrictions apply 7.26.1.2.1.6 SpatialExtensionConfigData(0) None 7.26.1.2.1.7 SpatialExtensionConfigData(1) None 7.26.1.2.1.8 TreeConfig() bsOttBoxPresent No restrictions a
24、pply bsOttDefaultCld No restrictions apply bsOttModeLFE No restrictions apply bsOttBands Shall not be encoded with a value larger than numBands given in Table B.9 of ISO/IEC 23003-2:2010 bsOutputChannelPos Shall be in the range 026 For restrictions, see 7.26.1.2.2 7.26.1.2.1.9 LDSacDataFrame() ldsac
25、HeaderFlag No restrictions apply ldsacHeaderLen No restrictions apply ldsacHeaderLenAdd No restrictions apply bsFillBits No restrictions apply ldsacTimeAlignFlag No restrictions apply ldsacTimeAlign Shall be 0 7.26.1.2.1.10 LDSpatialFrame() bsIndependencyFlag No restrictions apply 7.26.1.2.1.11 Fram
26、ingInfo() bsFramingType No restrictions apply bsNumParamSets For restrictions, see 7.26.1.2.2 bsParamSlotps Shall be in the range 0bsFrameLength 7.26.1.2.1.12 OttData() No restrictions apply ISO/IEC 14496-26:2010/Amd.3:2014(E) 4 ISO/IEC 2014 All rights reserved7.26.1.2.1.13 TttData() ICC values of a
27、 certain TTT box shall not be encoded with a value of 0 if (bsTTTModeLow 2 | (bsTTTDualMode=1 estimation of twiddle factors. X=1, 2 (downsampled SBR) _param_X Test various numbers of parameter bands. X=4, 5, 7, 9, 12, 15, 23 _X_ts Test various numbers of time slots. X=8, 15, 16 _Xkhz Tests various s
28、ampling rates. X=16, 22, 24, 32, 44 _tree_X Test various tree configurations. X=5151, 5152, 525 _one_ICC Test one ICC mode. mp4 Au dec R MS c om paris on Downmixw a v e Co m pre s s e dd ata w/ o L DSBR Com pr e ss e d data with L DSBR form mpspayload.dat LD-MPS decoder qmfdata.dat ld-twiddle.dat L D SBR c onf too l T e s t dec od e r outp ut
