> coded image items compliant to the AVIF Baseline profile may not have a number of pixels greater than 8912896, a width greater than 8192 or a height greater than 4352.

https://aomediacodec.github.io/av1-avif/#profiles

I'm assuming if both the encoder and decoder support more than the baseline profile, then higher resolutions up to 64k x 64k are possible, although I would worry the file would be incompatible with some software.

It's been a few years since I last tried, so hopefully no longer an issue, but trying to encode 8192 × 5464 images from a Canon R5 a few years ago with libavif, and avifEncoderAddImage() would return a generic error.

If I reduced the res a bit, then it worked, so there did seem to be a limit there somewhere. height and width are stored as u32s internally though, so yes, the format itself technically supports it...

I never looked into it more, so might have been a libavif issue, or maybe the way I was using it (maybe it has defaults or profiles?)