【英文标准名称】:Informationtechnology-Codingofaudio-visualobjects-Part24:Audioandsystemsinteraction
【原文标准名称】:信息技术.视听对象的编码.第24部分:音频与系统交互作用
【标准号】:ISO/IECTR14496-24-2008
【标准状态】:现行
【国别】:国际
【发布日期】:2008-01
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/IECJTC1
【标准类型】:()
【标准水平】:()
【中文主题词】:声信号;视听的;视听资料;比特率;代码表示;编码(数据转换);配置;数据交换;数据格式;数据处理;译码器;编码器;编码;文档结构;文档;(数据)格式;信息交换;信息技术;多媒体;音乐;信号
【英文主题词】:Acousticsignals;Audiovisual;Audiovisualmaterials;Bitrates;Codedrepresentation;Coding(dataconversion);Configuration;Dataexchange;Dataformats;Dataprocessing;Decoders;Encoders;Encoding;Filestructure;Files;Formats;Informationinterchange;Informationtechnology;Multimedia;Music;Signals
【摘要】:ThispartofISO/IECTR14496describesthedesiredjointbehaviorofMPEG-4Systems(MPEG-4FileFormat)andMPEG-4Audiocodecs.ItisdesiredthatMPEG-4Audioencodersanddecoderspermitfinitelengthsignalstobeencodedtoafile(particularlyMPEG-4files)anddecodedagaintoobtaintheidenticalsignal,subjecttocodecdistortions.Thiswillallowtheuseofaudioinsystemsimplementations(particularlyMPEG-4Systems),perhapswithothermediasuchasvideo,inadeterministicfashion.Mostimportantly,thedecodedsignalwillhavenothing“extra”atthebeginningor“missing”attheend.Thispermits:a)anexact‘roundtrip’fromrawaudiotoencodedfilebacktorawaudio(exceptingencodingartifacts);b)predictablesynchronizationbetweenaudioandothermediasuchasvideo;c)correctbehaviorwhenperformingrandomaccessaswellaswhenstartingatthebeginningofastream;d)identicalbehaviorwheneditsareappliedintherawdomainandtheencodeddomain(again,exceptingencodingartifacts).Itisalsorequiredthattherebepredictableinteroperabilitybetweenencoders(asrepresentedbyfiles)anddecoders.Therearetwokindsofaudio‘offsets’(or‘delay’inthecontextoftransmission):thosethatresultfromtheencodingprocess,andthosethatresultfromthedecodingprocess.Thisdocumentisprimarilyconcernedwiththelatter.Theseissuesareresolvedbythefollowing:?Thehandlingofcompositiontimestampsforaudiocompositionunitsisspecified.Specialcareistakeninthecaseofcompresseddata,likeHE-AACcodedaudio,thatcanbedecodedinabackwardcompatiblefashionaswellasinanenhancedfashion.?ExamplesaregiventhatshowhowfinitelengthsignalscanbeencodedtoanMPEG-4fileanddecodedagaintoobtaintheidenticalsignal,exceptingcodecdistortions.Mostimportantly,thedecodedsignalhasnothing“extra”atthebeginningor“missing”attheend.
【中国标准分类号】:L71
【国际标准分类号】:35_040
【页数】:8P;A4
【正文语种】:英语


【英文标准名称】:Metalliccoatings.Measurementofcoatingthickness.Scanningelectronmicroscopemethod.
【原文标准名称】:金属镀层.镀层厚度的测量.扫描电子显微镜法
【标准号】:NFA91-108-1995
【标准状态】:现行
【国别】:法国
【发布日期】:1995-04-01
【实施或试行日期】:1995-04-05
【发布单位】:法国标准化协会(AFNOR)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:金属覆层;厚度;测量;尺寸测量;覆层厚度;测定;显微分析;试验;试验;;;定义;材料试验;厚度测量;覆层
【英文主题词】:
【摘要】:
【中国标准分类号】:A29
【国际标准分类号】:17_040_20
【页数】:11P;A4
【正文语种】:其他