High Efficiency Video Coding (HEVC) / H.265
Sep 15, 2017
High Efficiency Video Coding (HEVC), tseem hu ua H.265 thiab MPEG-H Tshooj 2, yog tus txheej txheem video compression, ib qho ntawm ntau cov neeg tau hloov los ua siv AVC (H.264 lossis MPEG-4 Tshooj 10). Nyob rau hauv comparison nrog AVC, HEVC muaj txog ob npaug ntawm cov ntaub ntawv nrawm piv ntawm tib theem ntawm kev yees duab zoo, los sis zoo nkauj saib xyuas kev ua zoo ntawm cov nqi tib yam. Nws txhawb kev tsim kho txog 8192 × 4320, suav nrog 8K UHD.
Feem ntau, HEVC yog qhov kev txuas ntxiv ntawm cov ntsiab lus hauv H.264 / MPEG-4 AVC. Ob leeg ua haujlwm los ntawm kev sib piv ntau qhov chaw ntawm cov duab thaij duab los nrhiav cov cheeb tsam uas muaj kev rov qab, ob qho tib si nyob rau hauv ib qho thiab ib qho ntxiv tom ntej. Cov chaw no yuav rov qab hloov nrog ib qho kev qhia luv luv es tsis txhob siv cov pixels thawj. Cov kev hloov ntawm HEVC muaj xws li nthuav cov qauv kev sib txawv thiab qhov sib txawv-coding thaj tsam ntawm 16 × 16 pixel loj txog 64 x 64, txhim kho qhov txawv-qhov loj me me, kev txhim kho "intra" hauv tib duab, vector twv ua ntej thiab cov cheeb tsam khiav ua ke, txhim kho cov lus txiav plaub ntug zoo dua, thiab ib qho ntxiv ntsig tsom xam cov npe hu ua qauv coj los ua kom zoo. Txoj kev siv cov kev txhim kho no yuav tsum muaj peev xwm ua tau ntau tshaj qhov ua kom muaj peev xwm ua rau kev yees duab, tab sis muaj feem cuam tshuam rau qhov nqi ntawm qhov tsim nyog rau decompression.
HEVC tau tsim los ntawm Pab Koom Tes Koom Tes Ua Yeeb Yam (Video Joint) (JCT-VC), kev koom tes ntawm ISO / IEC MPEG thiab ITU-T VCEG. Cov pawg ISO / IEC hais txog nws li MPEG-H Tshooj 2 thiab ITU-T ua H.265. Tus thawj version ntawm HEVC tus qauv tau muab tso rau lub Ib Hlis xyoo 2013 thiab luam tawm thaum Lub Rau Hli 2013. Tus thib ob version, nrog ntau hom kev txuas ntxiv (MV-HEVC), ntau qhov ntxiv (RExt), thiab Extension Scalability (SHVC), tiav thiab pom zoo rau 2014 thiab luam tawm nyob rau thaum ntxov 2015. Extensions rau 3D video (3D-HEVC) tau ua tiav thaum ntxov xyoo 2015, thiab kev txuas ntxiv rau cov ntsiab lus ntawm cov npav ntsuas (SCC) tau ua tiav thaum xyoo 2016 thiab pub nyob rau hauv thaum xyoo 2017, pub cov video uas muaj duab, lossis animation li zoo li (los yog tsis txhob) cov yees duab yees duab.
HEVC muaj cov kev yees los ntawm patents uas yog cov koomhaum uas koom rau hauv JCT-VC. Kev siv lub cuab yeej lossis kev siv software uas siv HEVC kuj yuav tsum tau muaj daim ntawv tso cai los ntawm HEVC tus neeg tuav ntaub ntawv. Lub ISO / IEC thiab ITU yuav tsum muaj cov tuam txhab uas lawv cov koom haum muab lawv cov patents onReasonable thiab cov tsis muaj kev ntxub ntxaug (RAND). Patent licenses tuaj yeem tau ncaj qha los ntawm txhua tus neeg tuav ntaub ntawv, los yog los ntawm patent licensing bodies, xws li MPEG LA, HEVC Advance, thiab Velos Media. Cov nqi them ua ke nrog tam sim no los ntawm tag nrho cov patent licensing body yog siab tshaj rau AVC. Cov ntawv tso cai them nqi yog ib qho tseem ceeb ntawm HEVC qhov kev tu plaub muaj tsawg hauv lub vev xaib thiab yog vim li cas qee cov lag luam loj tshaj plaws (Amazon, AMD, ARM, Cisco, Google, Intel, Microsoft, Mozilla, Netflix, Nvidia, thiab ntau tshaj) tau koom lub Alliance rau Kev Tshaj Tawm, uas yuav tsum ua kom tiav qhov kev pub dawb uas tsis pub muaj lwm txoj kev video coding AV1 los xaus rau xyoo 2017.
Nta
HEVC yog tsim los tsim kom muaj kev ua kom zoo tshaj qhov ua piv txwv nrog H.264 / MPEG-4 AVC HP, xws li kom txo cov kev txwv ntawm ib nrab ntawm cov duab zoo sib xws, ntawm cov nuj nqis ntawm kev ua kom tsis yooj yim. HEVC tau tsim nrog lub hom phiaj ntawm kev tso tawm cov ntsiab lus yeeb yaj kiab kom muaj cov ntaub ntawv sib txuam ntawm 1000: 1. Raws li daim ntawv thov yuav tsum, HEVC encoders yuav pauv tawm computational complexity, compression rate, robustness rau cov teeb meem, thiab encoding ncua sij hawm. Ob ntawm cov yam ntxwv tseem ceeb uas HEVC raug kho dua piv rau H.264 / MPEG-4 AVC yog pab txhawb kev yees duab siab dua thiab kev ua haujlwm zoo dua qub.
HEVC yog tsim los ntawm cov cim ntxiv ntawm HDTV thiab cov ntsiab lus cuam tshuam cov txheej txheem uas muaj cov qauv scanned ncej thiab pom cov kev cai ntawm QVGA (320x240) mus rau 4320p (7680x4320), nrog rau kev ua haujlwm zoo dua ntawd cov suab nrov, xim chaw, thiab dynamic ntau.
