fixes #3735

app/models/pixiv_ugoira_frame_data.rb

@@ -1,3 +1,15 @@
 class PixivUgoiraFrameData < ApplicationRecord
   serialize :data
+  before_validation :normalize_data, on: :create
+
+  def normalize_data
+    return if data.nil?
+    
+    if data[0]["delay_msec"]
+      self.data = data.map.with_index do |datum, i|
+        filename = "%06d.jpg" % [i + 1]
+        {"delay" => datum["delay_msec"], "file" => filename}
+      end
+    end
+  end
 end