~WebP~ AVIF support

[TomasSestak]

Are you planning on supporting WebP?

[kornelski]

There are no plans. There's not much to optimize in WebP files, and there are no alternative implementations that I know of, so you should just use the latest version of the encoder.

The WebP format itself isn't very interesting: worse color fidelity than JPEG, not much compression improvement over optimized JPEG in realistic quality range, no support for progressive rendering.

[kornelski]

Browsers are working on AVIF which is half the size of WebP, so when this comes out maybe I'll add AVIF.

[mathiasbynens]

Browser are working on AVIF which is half the size of WebP, so when this comes out maybe I'll add AVIF.

This is happening now! What’s your current stance on adding AVIF support?

[kornelski]

I'm developing a bunch of AVIF tools:

https://github.com/kornelski/cavif/
https://lib.rs/avif-parse
https://lib.rs/avif-serialize

[mathiasbynens]

Does it make sense to optimize existing AVIF files (strip unnecessary metadata, if nothing else)?

[kornelski]

Maybe! I may have the first AVIF metadata optimizer already: https://github.com/kornelski/avif-serialize/blob/main/examples/optimize.rs

Buuut it sucks that the AVIF spec requires a lot of unnecessary bloat, and sadly Chrome enforces the spec.

https://crbug.com/1120973

• I'm afraid that AVIF spec changes are nearly impossible, because it's based on HEIF/MIAF/BMFF, which are already ISO standards set in stone, and ISO seems to value compatibility with its own old specs and legacy video editing tools more than web-oriented use-cases.

• Supporting minimal metadata would require Chrome/libavif to willfully break "shall" parts of the specs.

[mathiasbynens]

Maybe! I may have the first AVIF metadata optimizer already: https://github.com/kornelski/avif-serialize/blob/main/examples/optimize.rs

Awesome! Do you think it’d make sense to include this in ImageOptim.app? Even if it only strips a minimum amount of metadata for now, we can always make it more eager in the future depending on how the Chrome metadata situation evolves.

[mathiasbynens]

Apologies for pinging this issue. @kornelski do you have an opinion re: the above?