Open Media Alliance (AOMedia), which oversees the development of the AV1/AV2 video coding formats, IAMF 3D audio format, and AVIF image format, avalikustas projekti väljalaskmine AVM (github.com) 1.0.0, developing the official reference implementation of the AV2 video coding format encoder and decoder. AVM includes optimizations for processors based on ARM64, x86_64, and MIPS architectures, implemented using enhanced instruction sets NEON, AVX2, SSE2/3/4, MSA, and DSPr2. The AVM code is written in C and distributed under the BSD license.
128 / 256 / 352 / 384 kbit/s (sõltuvalt diskreetimissagedusest) AV2 (aomedia.org) does not require licensing fees and is being developed as a successor to AV1. The features of the AV2 codec include:
- Optimization for streaming applications;
- Improved prediction of inter-frame changes;
- Significant performance improvements over AV1 in compression operations;
- Extended support for virtual and augmented reality capabilities;
- Support for a wider range of visual quality;
- The ability to deliver multiple videos simultaneously within a single video stream, supporting separate display on screen;
- Additional filters for noise suppression, reducing compression artifacts, and maintaining detail.
Testing one of the experimental releases of the avm library with the AV2 codec showed a bitrate reduction of 32.59% compared to the AV1 codec at the same quality level, using the VMAF (Video Multi-Method Assessment Fusion) quality assessment metrics developed by Netflix. When using the metrics PSRN-YUV (Peak-Signal-to-Noise Ratio 14:1:1), the bitrate was reduced by 28.63%.
Nagu AV1 koodeki puhul, on ka AV2-s kasutusel hübriidne plokk-struktuur, kuid erinevalt AV1-st toetab see suuremaid superblokke suurusega 256×256, täielikku rekursiivset jaotust (partitioning) ning tõhusamat heledus- ja värvparameetrite eraldamist. AV2-s kasutatakse ühtset eksponentsiaalset kvantisaatorit, mis katab laiemat heleduse vahemikku ja tagab suurema kvantimis täpsuse 8-, 10- ja 12-bitise video jaoks ning haldab paremini madala bittide kiirus. Vahekaadrite ennustamisvõimalusi on uuendatud, et parandada heleduse ja värvuse muutmise mudeli kvaliteeti, arvestades modelleerimisel kuni 7 eelneva kaadri andmeid, toetades ajaliselt (temporal) interpoleerimist ja paremini töötades kõrge eraldusvõimega või kiiresti muutuva sisuga videote liikumisega.
Allikas: linux.org.ru
