Problem/Motivation
AVIF image file format is getting traction in browsers' support.
This issue is proposing to implement support to this image format in Drupal core's GD Toolkit.
Prerequisites:
- libgd should support the AVIF format - DONE, first release supporting is 2.3.2, released on: March 6, 2021
- a PHP version supporting an IMAGETYPE_AVIF constant - upstream PR https://github.com/php/php-src/pull/5127
- a DrupalCI testbot container should be available for testing.
Proposed resolution
Need to decide, once the prerequisites are met, whether to provide conditional support (i.e. the toolkit supports AVIF only when libraries are availble and compiled), or strict support (i.e. libraries are required).
In the #2340699: Let GDToolkit support WEBP image format issue, the second path was taken.