Detect videos with no sound, handle them like gifv

lib/paperclip/video_transcoder.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Paperclip
+  # This transcoder is only to be used for the MediaAttachment model
+  # to check when uploaded videos are actually gifv's
+  class VideoTranscoder < Paperclip::Processor
+    def make
+      meta = ::Av.cli.identify(@file.path)
+      attachment.instance.type = MediaAttachment.types[:gifv] unless meta[:audio_encode]
+
+      Paperclip::Transcoder.make(file, options, attachment)
+    end
+  end
+end