A brute force method for migrating content out of Wordpress Galleries into a ACF repeat Gallery

ACF -> ACF Flexible Fields

<?php
/** Loads the WordPress Environment and Template */
require('./wp-blog-header.php');


/**
 * Move all ACF media from a post into a ACF flexible content box.
 * NB: Custom WPDB prefix, and names of custom fields
 */
global $wpdb;

	// Get all our post ID's
	$posts = $wpdb->get_results("SELECT `id` FROM `vwbs_posts` WHERE `post_type` = 'projects' OR `post_type` = 'ideas'", OBJECT);

	foreach($posts as $post) {

		if ($post->id != 96) {

			$iterator = 0;
			while (has_sub_field('media', $post->id)) :
				
				update_post_meta($post->id, "media_{$iterator}_module",'a:1:{i:0;s:5:"image";}');
				update_post_meta($post->id, "media_{$iterator}_module_0_image", get_sub_field('image', $post->id));
				update_post_meta($post->id, "media_{$iterator}_module_0_image_caption","");
				update_post_meta($post->id, "media_{$iterator}_module_0_type_colour",'black');
				update_post_meta($post->id, "media", $iterator);

				$iterator++;
			endwhile;

			echo "<hr/>";
		}
	}


die();

gistfile1.php

/** Loads the WordPress Environment and Template */
require('./wp-blog-header.php');


/**
 * Move all image attachments from a post into a ACF custom gallery.
 * NB: Custom WPDB prefix, and names of custom fields
 */
global $wpdb;

	// Get all our post ID's
	$posts = $wpdb->get_results("SELECT `id` FROM `vwbs_posts` WHERE `post_type` = 'projects' OR `post_type` = 'ideas'", OBJECT);

	foreach($posts as $post) {
		// Get all images from this post
		$images = $wpdb->get_results("SELECT `ID`,`post_excerpt` FROM `vwbs_posts` WHERE `post_parent` = $post->id", OBJECT);

		$thumbnail_id = get_post_thumbnail_id($post->id);

		$iterator = 0;
		foreach($images as $image) {

			if ($thumbnail_id != $image->ID) {
				update_post_meta($post->id, "media_{$iterator}_image", $image->ID);
				update_post_meta($post->id, "media_{$iterator}_caption",$image->post_excerpt);
				$iterator++;
			}
		}
		update_post_meta($post->id, "media", $iterator);
	}