WEBP image formats

[mgearh]

Is your enhancement related to a problem? Please describe.

Yes, when distributing posts that are using a WEBP featured image, the image does not transfer.

Describe the solution you'd like

For the plugin to support the WEBP format.

Designs

Describe alternatives you've considered

Additional context

[meksone]

Also SVG format doesn't being transfered.
Thanks

[willemb2]

It's 2024. All browsers support WEBP for some time now and AV1 is around the corner. IMHO it is essential to support those. WEBP already saves 42% in size on average compared to JPEG. Maybe that is why in #1144 the same issue is labelled as bug? 🤓
Why filter on file type at all? If it's in the Media Library WordPress will be able to handle it? But I'm no developer so this might be naive.

[benlk]

Notes from the changeset https://core.trac.wordpress.org/changeset/50810 that implemented WebP support for https://core.trac.wordpress.org/ticket/35725, released in WP 5.8:

• WP supports image/webp if function_exists( 'imagecreatefromwebp' ) or function_exists( 'imagewebp' )
• MIME type is image/webp
• extensions are .webp
• related constants defined by PHP, or by WordPress as a fallback, are IMAGETYPE_WEBP and IMG_WEBP

Notes from current WordPress image support:

• AVIF added WP 6.5.0, 'avif' => 'image/avif'
• HEIC added WP 6.7.0, 'heic' => 'image/heic'

Other notes:

• Distributor's minimum supported WordPress version is "6.4 or later" as of release 2.0.5, so we don't shouldn't have to worry that a sending or receiving version of Distributor is running on version of WordPress that doesn't support webp — We're probably fine to enable WebP by default
• Distributor's minimum supported WordPress version does not rule out versions of WordPress that do not support AVIF/HEIC. Adding support for AVIF and HEIC may require some defensive coding to prevent sending HEIC or AVIF image files to an instance of WordPress/Distributor that doesn't support those files.
• Distributor's filter name prefix is dt_
• Distributor's allowed MIME types are at

  distributor/tests/php/includes/common.php

  Lines 261 to 270 in cf96557

  	function get_allowed_mime_types() {
  	return [
  	'jpg|jpeg|jpe' => 'image/jpeg',
  	'gif' => 'image/gif',
  	'png' => 'image/png',
  	'bmp' => 'image/bmp',
  	'tif|tiff' => 'image/tiff',
  	'ico' => 'image/x-icon',
  	];
  	}

• Distributor also has a dt_allowed_media_extensions filter which has a separate list of IDs
• WordPress' filter for removing MIME types upload_mimes in https://developer.wordpress.org/reference/functions/get_allowed_mime_types/ uses the array format shown in the source of https://developer.wordpress.org/reference/functions/wp_get_mime_types/ of ['a regex' => 'mime/type', ...], which is the same format that 10up's filter uses.

[benlk]

@meksone SVG support and integration with https://github.com/10up/safe-svg seems like it would be a separate issue, since WordPress does not natively support SVG. I've opened a separate issue to track that: #1268