presented by, pradeep ramachandran
TRANSCRIPT
MulticoreWare Inc
Presentedby,PradeepRamachandran
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• Open-sourceHEVCencoderavailableunderGPLv2– SupportsfullHEVCspec,highlyparallel,SIMDoptimized– Successortox264– bitbucket.org/multicoreware/x265– x265.org
• x265projectisrunbyMulticoreWare– Developmentiscommerciallyfunded(fulltimedevteam)– DualLicenseModel(GPLv2orCommercialLicense)
• Noprivateforks– commercialcustomersgetsamecodeasopensource
– Allpatches,bugreports,fixesinopen-source
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x264@400kbps
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@400kbps
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Featuresofx265• AllHEVCprofilesandlevels
– Main,Main10,Main12,MainStillPicture
– 4:2:0,4:2:2,4:4:4variants• HDR10,HDR10+,DolbyVisionHDR• AllHEVCcolorspacesandtransfer
functions• AverageBitRate,ConstantBitRate,
ConstantRateFactor(constantquality),ConstantQP,VideoBufferVerification,2pass,Npass,2passwithspatialdistortionoptimization,lossless
• 10performancepresets• Lookaheadwithsceneandflashdetection• 6levelsofratedistortionoptimization• Temporalscalability• Wavefront ParallelProcessing• Frameparallelism• Sliceparallelism• SampleAdaptiveOffset,Deblocking
Psychovisualoptimizations• AdaptiveQuantization
• CUTreeoptimization• Fullyconfigurableencoding- #refframes,
min/maxCUsize,RECT,AMP,GOPstructure,keyframeinterval,motionsearchmethodandrange,subpelrefinement,culossless
• LimitModes,LimitRefs• AnalysisSave,AnalysisLoad2pass• Tunepsnr,ssim,grain,zero-latency,fast-
decode• Pools– assignthreadpools onspecific
cores• RegionofInterestoptimization• VUIandSEImessagesupport• Reconfigurableonthefly• CommaSeparatedValuelogging• FullAPI• x265isthedefaultHEVCencoderin
FFMPEG• Documentationispartofsourcecode• OnlineDocumentation
x265.readthedocs.io5
HEVCAdoption
• DevicesupportforHEVCplaybackisnearlyubiquitous– MostnewTVsare4K/HDRHEVCcapable– MostPCChipsets(Intel/AMD/NVIDIA)– AllconnectedSTB(Roku/Amazon/AppleTV/GoogleCast)– AllflagshipphonessupportHEVC
• SamsungGalaxyS8,Note8,Book12,TabS2;SonyXperiaXZPremium;LGG6;MSSurfacebooks;iPhonessince5swillsupportHEVCwithiOS11update(Tuesday!)
• PlatformsupportforHEVCgainingpopularity– MacOSHighSierra/iOS11usingHEVCforvideo,andimages;in1week!– AndroidsupportforHEVCmandatoryforplayingbackHDRcontent
• BroadcasterstransitioningtoHEVC– ATSC3.0,DVB-T2standardsbasedonHEVC
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x265Improvementsinthepastyear
• Encodingefficiency(quality@bitrate)– Newlambdatablesformain,main10,main12– SSIM-basedRDO– SEAmotionsearch– HDRoptimization– 2-passspatialdistortionoptimization
• Performance– Limit-tu,limit-sao,dynamic-rd
• Otherimprovements– Dynamicallyreconfigurebitrateonthefly(viaAPI)– Differentlevelsofanalysisreuseandrefinements(viaAPI)– SamsungHDR10+(SMPTE2094-40)support– AssemblyoptimizationsforARM,POWERPC
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Contribute!
• Helpdefinethevideoandstillimagecompression– HEVCstartingtoreplaceAVCeverywhere– ReplacingJPEG2000withHEIFastheimagestandard
• Welcomeideas&collaborationtowardsimprovingx265– Contributetotheworld’sleadingHEVCencoderimplementation– Seeushere,orintheIntelbooth(5.B65)
• Activelyparticipateinopen-sourcemulti-mediacommunity– DeveloperMailingList- [email protected]– x265discussionsonDoom9forums
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