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- x265-devel@videolan.org– x265discussionsonDoom9forums

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