Kutulutsidwa kwa laibulale ya SVT-AV1 2.0 (Scalable Video Technology AV1) kwasindikizidwa ndikukhazikitsa kwa encoder ndi decoder ya AV1 kanema kabisidwe kawonekedwe, kuti ifulumizitse momwe njira zama computing zofananira zomwe zilipo mu Intel CPUs zamakono zimagwiritsidwa ntchito. Pulojekitiyi idapangidwa ndi Intel mothandizana ndi Netflix ndi cholinga chokwaniritsa magwiridwe antchito oyenera pamayendedwe apakanema apakanema ndikugwiritsa ntchito mautumiki a pavidiyo pakufunika (VOD). Pakali pano, chitukuko chikuchitika mothandizidwa ndi Open Media Alliance (AOMedia), yomwe imayang'anira chitukuko cha AV1 kanema kabisidwe kawonekedwe. M'mbuyomu, ntchitoyi idapangidwa mkati mwa projekiti ya OpenVisualCloud, yomwe imapanganso ma encoder a SVT-HEVC ndi SVT-VP9. Khodiyo imagawidwa pansi pa layisensi ya BSD.
SVT-AV1 ikhoza kusonkhanitsidwa pamakina otengera kamangidwe kalikonse komwe kuli kophatikiza komwe kumathandizira mulingo wa C99, koma magwiridwe antchito abwino amapezedwa pamakina a x86_64, omwe kukhathamiritsa kwa msonkhano kutengera malangizo a SIMD kumagwiritsidwa ntchito (ndikofunikira kukhala nawo. Thandizo la AVX2 mu CPU, koma zochepa ndizokwanira ndi SS2). Kugwiritsa ntchito pamtima kumadalira kuchuluka kwa ma processor cores omwe amagwiritsidwa ntchito pakubisa, motsogozedwa ndi "-lp". Chifukwa cha zovuta za ma aligorivimu omwe amagwiritsidwa ntchito mu AV1, kuyika kalembedwe kameneka kumafuna chuma chochulukirapo kuposa mawonekedwe ena, omwe salola kugwiritsa ntchito encoder yokhazikika ya AV1 pakusintha ma transcoding munthawi yeniyeni. Mwachitsanzo, encoder ya masheya kuchokera ku projekiti ya AV1 imafuna kuwerengera nthawi 5721, 5869 ndi 658 kuyerekeza ndi ma encoder a x264 ("main"), x264 ("mkulu") ndi ma encoder a libvpx-vp9.
Zina mwa zosintha pakutulutsidwa kwatsopano kwa SVT-AV1:
- Kusintha kwasinthidwa kukhala manambala amtundu watsopano, malinga ndi momwe manambala oyamba amasinthira pakusintha kulikonse kwa API/ABI.
- Kusintha kwapangidwa ku API yokhudzana ndi kusintha kwa mapeto a mtsinje (EOS - End Of Stream) mu chimango chomaliza m'malo mogwiritsa ntchito chimango chopanda kanthu, chomwe chinathetsa kuchedwa kuyembekezera chimango chowonjezera. Kusintha kwa API kwawonetsedwa kale mu FFmpeg codebase.
- Njira ya bitrate yodutsa katatu (3-pass VBR) yachotsedwa, ndipo tsopano yasinthidwa ndi njira yodutsa VBR yambiri. VBR multi-pass mode yachepetsedwa kukhala magawo awiri kuti atsimikizire kuphatikiza ndi FFmpeg.
- Kukhathamiritsa kwawonjezedwa ku encoder, chifukwa chake kukakamiza kwa ma preset a M9-M13 kwawonjezeka ndi 1-4%, komanso kukumbukira kukumbukira kwa M5 preset kwatsika ndi 20-35% mu LP 8 mode ndi ndi 1-5% m'njira zina. Kugwiritsa ntchito kukumbukira m'makonzedwe ena kunatsika ndi 1-5%.
- Kukhathamiritsa kwa kukhathamiritsa kwaubwino / kuthamanga kwachitika pazokonzekera zomwe zimakhazikitsa mulingo wapamwamba kwambiri. Mawonekedwe amtundu wa MR preset yapititsidwa patsogolo ndi 100%.
- Kukhathamiritsa kwapadera kwa ARM kwawonjezeredwa ku ntchito za C-okha.
Kuphatikiza apo, titha kuzindikira kutulutsidwa kwa pulojekiti ya dav1d 1.4.1, momwe anthu a VideoLAN ndi FFmpeg akupanga laibulale ndikukhazikitsa njira ina yaulere yamtundu wa AV1 encoding format. Laibulale ya dav1d imathandizira mawonekedwe onse a AV1, kuphatikiza mitundu yapamwamba yamasampuli ndi magawo onse owongolera kuya kwamitundu omwe afotokozedwa mwatsatanetsatane (8, 10 ndi 12 bits). Chofunikira chachikulu cha dav1d ndikuyika kwake pakukwaniritsa magwiridwe antchito apamwamba kwambiri ndikuwonetsetsa kuti ntchito zamtundu wapamwamba zimagwira ntchito mumitundu yambiri. Khodi ya pulojekitiyi imalembedwa mu C (C99) ndi zoyika pagulu (NASM/GAS) ndipo imagawidwa pansi pa layisensi ya BSD. Kuthandizira kwa zomangamanga za x86, x86_64, ARMv7 ndi ARMv8, ndi makina ogwiritsira ntchito FreeBSD, Linux, Windows, macOS, Android ndi iOS zakhazikitsidwa.
Mtundu wa dav1d 1.4 ndiwodziwikiratu pothandizira zomanga zatsopano za Loongarch ndi RISC-V, komanso kubweretsa kukhathamiritsa kwina kutengera malangizo a AVX-512, kufulumizitsa ntchito zosefera za 6tap pamakina a ARM, kukulitsa luso la ntchito zamitundu yambiri ndikuchepetsa kukula kwa data ya binary pa ARM64, ARM32 ndi RISC-systems V. Chiwopsezo chosasunthika CVE-2024-1580, chomwe chidapangitsa kuti anthu alembe mopitilira malire chifukwa chakusefukira kwakanthawi pokonza makulidwe akulu kwambiri.
Source: opennet.ru
