Kev tso tawm ntawm SVT-AV1 2.0 (Scalable Video Technology AV1) lub tsev qiv ntawv tau luam tawm nrog kev siv cov encoder thiab decoder ntawm AV1 video encoding hom, rau acceleration uas txhais tau tias ntawm hardware parallel xam tam sim no nyob rau hauv niaj hnub Intel CPUs siv. Lub phiaj xwm tau tsim los ntawm Intel hauv kev koom tes nrog Netflix nrog lub hom phiaj ntawm kev ua tiav ib theem ntawm kev ua tau zoo tsim nyog rau kev hloov pauv hauv video thiab siv hauv video-on-demand (VOD) cov kev pabcuam. Tam sim no, kev txhim kho tau ua tiav raws li kev txhawb nqa ntawm Open Media Alliance (AOMedia), uas saib xyuas kev txhim kho ntawm AV1 video encoding hom. Yav dhau los, qhov project tau tsim nyob rau hauv lub moj khaum ntawm OpenVisualCloud project, uas kuj tsim cov SVT-HEVC thiab SVT-VP9 encoders. Cov cai tau muab faib raws li BSD daim ntawv tso cai.
SVT-AV1 tuaj yeem muab sau ua ke rau cov kab ke ntawm txhua lub architecture nrog lub compiler txhawb nqa tus qauv C99, tab sis kev ua tau zoo tshaj plaws yog ua tiav ntawm x86_64 systems, uas siv SIMD-based assembler optimizations (AVX2 kev txhawb nqa yog qhov nyiam hauv CPU, tab sis SS2 txaus ua qhov tsawg kawg nkaus). Kev siv lub cim xeeb nyob ntawm tus lej ntawm cov processor cores siv rau kev encoding, uas yog tswj los ntawm kev xaiv "--lp". Vim yog qhov nyuaj ntawm cov algorithms siv hauv AV1, encoding hom ntawv no xav tau ntau cov peev txheej ntau dua li lwm hom ntawv, uas txwv tsis pub siv cov native AV1 encoder rau lub sijhawm tiag tiag transcoding. Piv txwv li, cov native AV1 encoder xav tau 5721, 5869, thiab 658 npaug ntau dua li x264 (main profile), x264 (high profile), thiab libvpx-vp9 encoders.
Ntawm cov kev hloov pauv hauv qhov kev tso tawm tshiab ntawm SVT-AV1:
- Muaj kev hloov pauv mus rau lub kaw lus lej tshiab, uas tus lej thawj zaug hauv qhov version yuav hloov pauv nrog txhua qhov kev hloov pauv hauv API/ABI.
- Cov kev hloov pauv API tau ua los hloov mus rau qhov qhia txog qhov kawg ntawm cov kwj deg (EOS) hauv daim duab kawg es tsis txhob siv daim duab khoob, tshem tawm qhov kev ncua sij hawm los ntawm kev tos ib daim duab ntxiv. Qhov kev hloov pauv API no twb tau pom tseeb hauv FFmpeg codebase.
- Peb-pass variable bitrate (3-pass VBR) tau raug tshem tawm, hloov los ntawm multi-pass VBR mechanism. Multi-pass VBR tau raug txo kom mus rau ob pass kom ntseeg tau tias muaj kev koom ua ke nrog FFmpeg.
- Kev txhim kho tau ntxiv rau lub encoder, ua kom muaj kev ua haujlwm ntawm kev nias rau cov presets M9-M13 ntau dua 1-4%, thiab txo kev siv nco rau preset M5 ntau dua 20-35% hauv hom LP 8 thiab ntau dua 1-5% hauv lwm hom. Kev siv nco rau lwm cov presets tau txo qis 1-5%.
- Cov kev sib pauv zoo/ceev rau cov presets uas teeb tsa qib zoo tau raug kho kom zoo dua. MR preset, uas muab cov qauv zoo, tau raug ua kom nrawm dua 100%.
- Kev ua kom zoo dua ntawm ARM architecture tau ntxiv rau C-only functions.
Tseem ceeb heev yog qhov kev tso tawm ntawm dav1d 1.4.1, ib qhov project uas VideoLAN thiab FFmpeg cov zej zog tab tom tsim ib lub tsev qiv ntawv uas siv lwm txoj hauv kev decoder dawb rau AV1 video encoding hom ntawv. Lub tsev qiv ntawv dav1d txhawb nqa txhua yam ntxwv AV1, suav nrog cov hom subsampling siab heev thiab txhua qhov kev tswj xim tob (8, 10, thiab 12 bits). Ib qho tseem ceeb ntawm dav1d yog nws qhov kev tsom mus rau kev ua tiav qhov kev ua tau zoo tshaj plaws thiab xyuas kom meej tias muaj kev ua haujlwm zoo hauv hom multithreaded. Cov lej project yog sau ua C (C99) nrog cov ntawv sib dhos (NASM / GAS) thiab faib raws li daim ntawv tso cai BSD. Kev txhawb nqa yog muab rau x86, x86_64, ARMv7, thiab ARMv8 architectures, thiab cov operating systems hauv qab no: FreeBSD, Linux, Windows, macOS, Android, thiab iOS.
dav1d 1.4 tseem ceeb rau nws txoj kev txhawb nqa rau Loongarch thiab RISC-V architectures tshiab, nrog rau kev ua kom zoo dua ntxiv raws li AVX-512 cov lus qhia, kev ua kom nrawm ntawm 6tap lim dej ntawm ARM systems, kev ua haujlwm ntau lub threading zoo dua, thiab txo qhov loj ntawm cov ntaub ntawv binary ntawm ARM64, ARM32, thiab RISC-V systems. CVE-2024-1580, qhov tsis muaj zog uas ua rau muaj kev sau tawm ntawm ciam teb vim muaj integer overflow thaum ua cov thav duab loj heev, tau kho lawm.
Tau qhov twg los: opennet.ru
