Experimental AV2 Support Added To AVIF Image Encoder

The reference AVIF image encoder for the AV1 Image File Format has added experimental support for AV2, the next-generation codec that remains in development by the Alliance for Open Media.

Going back to 2020 we've heard that AV2 is in research and development for eventually succeeding AV1. There has also been a public repository for what will serve as the reference implementation for their next codec.

The latest now is adding experimental AV2 support to libavif, the reference library built around the AVIF image format.

This merge request that was merged yesterday explains:

Experimental. The AV2 specification is not finalized.
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libavif can only generate AV2 files if it is built with AVIF_CODEC_AVM set to ON. The avifEncoder API can only output AV2 files if codecChoice is explicitly set to AVIF_CODEC_CHOICE_AVM to avoid mistakes.

avifenc can only output AV2 files if --codec=avm is specified to avoid mistakes. aom and avm conflict and cannot be used together in the same libavif binary. Other AV1 codecs can be enabled alongside aom.

libavif will decode any AV1 or AV2 file by default as long as the relevant codecs are enabled. The main behavior change for libavif with only AV1 codecs enabled is that before this change, items or tracks of type av02 were ignored. After this change, conformant AV1-AVIF files with extra av02 items will fail to decode unless avm is enabled.

It looks like work on AV2 is coming along well and nice seeing there will be timely support with updated AVIF image format support too.