ISO/IEC 13818-7-2006 信息技术.运动图像及其伴音信息的通用编码.第7部分:高保真音频编码(AAC)
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【英文标准名称】:Informationtechnology-Genericcodingofmovingpicturesandassociatedaudioinformation-Part7:AdvancedAudioCoding(AAC)
【原文标准名称】:信息技术.运动图像及其伴音信息的通用编码.第7部分:高保真音频编码(AAC)
【标准号】:ISO/IEC13818-7-2006
【标准状态】:现行
【国别】:国际
【发布日期】:2006-01
【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/SC29
【标准类型】:()
【标准水平】:()
【中文主题词】:音频;音频信号;计算机制图;数据转换;定义;编码;图像处理;信息技术;多媒体;脉冲编码调制;视频记录;视频信号
【英文主题词】:Audio;Audiosignals;Computergraphics;Dataconversion;Definitions;Encoding;Imageprocessing;Informationtechnology;Multimedia;PCM;Videorecording;Videosignals
【摘要】:1GeneralThisInternationalStandarddescribestheMPEG-2audionon-backwardscompatiblestandardcalledMPEG-2AdvancedAudioCoding,AAC[1],ahigherqualitymultichannelstandardthanachievablewhilerequiringMPEG-1backwardscompatibility.ThisMPEG-2AACaudiostandardallowsforITU-R“indistinguishable”qualityaccordingto[2]atdataratesof320kbit/sforfivefull-bandwidthchannelaudiosignals.TheAACdecodingprocessmakesuseofanumberofrequiredtoolsandanumberofoptionaltools.Table1liststhetoolsandtheirstatusasrequiredoroptional.Requiredtoolsaremandatoryinanypossibleprofile.Optionaltoolsmaynotberequiredinsomeprofiles.2MPEG-2AACToolsOverviewThebasicstructureoftheMPEG-2AACsystemisshowninFigure1andFigure2.AsisshowninTable1,therearebothrequiredandoptionaltoolsinthedecoder.Thedataflowinthisdiagramisfromlefttoright,toptobottom.Thefunctionsofthedecoderaretofindthedescriptionofthequantizedaudiospectrainthebitstream,decodethequantizedvaluesandotherreconstructioninformation,reconstructthequantizedspectra,processthereconstructedspectrathroughwhatevertoolsareactiveinthebitstreaminordertoarriveattheactualsignalspectraasdescribedbytheinputbitstream,andfinallyconvertthefrequencydomainspectratothetimedomain,withorwithoutanoptionalgaincontroltool.Followingtheinitialreconstructionandscalingofthespectrumreconstruction,therearemanyoptionaltoolsthatmodifyoneormoreofthespectrainordertoprovidemoreefficientcoding.Foreachoftheoptionaltoolsthatoperateinthespectraldomain,theoptionto“passthrough”isretained,andinallcaseswhereaspectraloperationisomitted,thespectraatitsinputarepasseddirectlythroughthetoolwithoutmodification.TheinputtothebitstreamdemultiplexertoolistheMPEG-2AACbitstream.ThedemultiplexerseparatesthepartsoftheMPEG-AACdatastreamintothepartsforeachtool,andprovideseachofthetoolswiththebitstreaminformationrelatedtothattool.
【中国标准分类号】:L81;A15
【国际标准分类号】:35_040
【页数】:194P;A4
【正文语种】:英语
【原文标准名称】:信息技术.运动图像及其伴音信息的通用编码.第7部分:高保真音频编码(AAC)
【标准号】:ISO/IEC13818-7-2006
【标准状态】:现行
【国别】:国际
【发布日期】:2006-01
【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/SC29
【标准类型】:()
【标准水平】:()
【中文主题词】:音频;音频信号;计算机制图;数据转换;定义;编码;图像处理;信息技术;多媒体;脉冲编码调制;视频记录;视频信号
【英文主题词】:Audio;Audiosignals;Computergraphics;Dataconversion;Definitions;Encoding;Imageprocessing;Informationtechnology;Multimedia;PCM;Videorecording;Videosignals
【摘要】:1GeneralThisInternationalStandarddescribestheMPEG-2audionon-backwardscompatiblestandardcalledMPEG-2AdvancedAudioCoding,AAC[1],ahigherqualitymultichannelstandardthanachievablewhilerequiringMPEG-1backwardscompatibility.ThisMPEG-2AACaudiostandardallowsforITU-R“indistinguishable”qualityaccordingto[2]atdataratesof320kbit/sforfivefull-bandwidthchannelaudiosignals.TheAACdecodingprocessmakesuseofanumberofrequiredtoolsandanumberofoptionaltools.Table1liststhetoolsandtheirstatusasrequiredoroptional.Requiredtoolsaremandatoryinanypossibleprofile.Optionaltoolsmaynotberequiredinsomeprofiles.2MPEG-2AACToolsOverviewThebasicstructureoftheMPEG-2AACsystemisshowninFigure1andFigure2.AsisshowninTable1,therearebothrequiredandoptionaltoolsinthedecoder.Thedataflowinthisdiagramisfromlefttoright,toptobottom.Thefunctionsofthedecoderaretofindthedescriptionofthequantizedaudiospectrainthebitstream,decodethequantizedvaluesandotherreconstructioninformation,reconstructthequantizedspectra,processthereconstructedspectrathroughwhatevertoolsareactiveinthebitstreaminordertoarriveattheactualsignalspectraasdescribedbytheinputbitstream,andfinallyconvertthefrequencydomainspectratothetimedomain,withorwithoutanoptionalgaincontroltool.Followingtheinitialreconstructionandscalingofthespectrumreconstruction,therearemanyoptionaltoolsthatmodifyoneormoreofthespectrainordertoprovidemoreefficientcoding.Foreachoftheoptionaltoolsthatoperateinthespectraldomain,theoptionto“passthrough”isretained,andinallcaseswhereaspectraloperationisomitted,thespectraatitsinputarepasseddirectlythroughthetoolwithoutmodification.TheinputtothebitstreamdemultiplexertoolistheMPEG-2AACbitstream.ThedemultiplexerseparatesthepartsoftheMPEG-AACdatastreamintothepartsforeachtool,andprovideseachofthetoolswiththebitstreaminformationrelatedtothattool.
【中国标准分类号】:L81;A15
【国际标准分类号】:35_040
【页数】:194P;A4
【正文语种】:英语
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