Images not strictly compliant (not following recommendations)

[StigNygaard]

Not sure how serious this is. Actually probably not very serious. But images I save with plugin ain't following "recommendations" according to Firefox, when I set "AVIF compliance strictness" to "Strict" in Firefox's "Advanced settings" (about:config).

I use these settings when saving images:

Firefox's level of tolerance can be set in about:config via flag image.avif.compliance_strictness:

0: Accept images with specification violations in both recommendations ("should" language) and requirements ("shall" language), provided they can be safely or unambiguously interpreted.
1 (default): Reject violations of requirements, but allow violations of recommendations.
2: Strict. Reject any violations in requirements or recommendations.

https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Experimental_features#avif_compliance_strictness

In Firefox 97 the default "AVIF compliance strictness" is 1. And with this setting it shows the image. However if I change the flag to 2 (Strict), Firefox wont show my images.

Luckily it doesn't look like Mozilla has plans to change the default to 2, but wonder what kind of recommendation is violated and if we have to do that? https://bugzilla.mozilla.org/show_bug.cgi?id=1443863#c80

[0xC0000054]

But images I save with plugin ain't following "recommendations" according to Firefox,

Firefox uses its own AVIF parser (https://github.com/mozilla/mp4parse-rust), so it may be an issue with their implementation.
I ran a few images through the GPAC ComplianceWarden AVIF Validator, and it shows no issues.

This plugin uses libheif for the AVIF container reading/writing, any compliance issues should be reported to that repository.

...but wonder what kind of recommendation is violated...

I do not know.
I would expect Firefox to display the error details in its web developer console, but I have not investigated that.