wp_get_image_editor_output_format()

wp_get_image_editor_output_format( string $filename, string $mime_type ): string[]

function wp_get_image_editor_output_format( $filename, $mime_type ) {
	$output_format = array(
		'image/heic'          => 'image/jpeg',
		'image/heif'          => 'image/jpeg',
		'image/heic-sequence' => 'image/jpeg',
		'image/heif-sequence' => 'image/jpeg',
	);

	/**
	 * Filters the image editor output format mapping.
	 *
	 * Enables filtering the mime type used to save images. By default HEIC/HEIF images
	 * are converted to JPEGs.
	 *
	 * @see WP_Image_Editor::get_output_format()
	 *
	 * @since 5.8.0
	 * @since 6.7.0 The default was changed from an empty array to an array
	 *              containing the HEIC/HEIF images mime types.
	 *
	 * @param string[] $output_format {
	 *     An array of mime type mappings. Maps a source mime type to a new
	 *     destination mime type. By default maps HEIC/HEIF input to JPEG output.
	 *
	 *     @type string ...0 The new mime type.
	 * }
	 * @param string $filename  Path to the image.
	 * @param string $mime_type The source image mime type.
	 */
	return apply_filters( 'image_editor_output_format', $output_format, $filename, $mime_type );
}