I am using the paperclip and paperclip-av-transcoder in my rails app and I have gotten to the point where I can upload videos locally. But when I try it in heroku I get this error. Av::UnableToDetect (Unable to detect any supported library):

I may have to add something to make it work with s3 but I had it working with images earlier so everything should be setup for s3.

This is the code in my model

```
class Classvideo < ActiveRecord::Base
    belongs_to :user
    has_attached_file :video, :styles => { 
        :medium => {:geometry => "640x480", :format => 'flv'},
        :thumb => { :geometry => "100x100#", :format => 'jpg', :time => 10 }
    }, :processors => [:transcoder]

validates_attachment_content_type :video, :content_type => ["video/mp4", "video.mov", "video/mpeg","video/mpeg4", "image/jpg", "image/jpeg"]
end

```