Video shows black screen after uploading with PaperClip AV - ruby-on-rails

Question

I am using PaperClip AV Transcoder, and when I upload a video all I see is a black image. I presume that video is not getting uploaded.
Do I also have to install a video player as well with it, or does that come with the PaperClip AV?
My model that has the video:
class Pin < ActiveRecord::Base
belongs_to :user
has_attached_file :video, :styles => {
:medium => { :geometry => "640x480", :format => 'mp4' },
: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
My show view for the video:
<%= video_tag #pin.video.url %>
<p>
<strong>Description:</strong>
<%= #pin.description %>
</p>
<% if #pin.user == current_user %>
<%= link_to 'Edit', edit_pin_path(#pin) %>
<% end %>
<%= link_to 'Back', pins_path %>
I don't know what other code would help. I'd gladly write any other lines of code that might help.
A picture of what I am talking about:
This is a screenshot of my ffmpeg version from my command line:

Answer 1

As you are using transcoder as your processor. You need to install this paperclip-av-transcoder gem too. (If already not there, add the to your Gemfile and do: bundle install).
Also, you may need to install ffmpeg in your machine to get the processor to work locally.
After these steps, it should work for you.

Answer 2

There are several steps to debug this.
Firstly, you need to check if the video file has been saved.
If the video file exists, it means your problem lies with playback (not processing). Thus you'll need to browse to public/system/.....
If you're on your dev machine, you can do this by simply browsing to /public/system, if you're using Heroku or another web server, you'll have to SSH into the bash and cd to the directory:
Heroku
$ heroku run bash
$ cd public/system
$ ls
SSH
SSH into your system
cd /app_root/public/system
ls
You'll then be able to browse through the folders to get to the appropriate directory containing your videos...
--
If you have the video on your system, it means they've been processed.
If they're not on your system, you need to consult your logs (post them on here), and show us what the error might have been.
To playback your video, you'll be able to use the HTML5 <video> tag (Rails video_tag):
<%= video_tag #attachment.paperclip_object.url %>
This will show the video (if it's been transcoded into MP4 or another compatible file format), allowing the playback to occur.
Cover
Another issue you will have is the cover image.
It seems you've set this up properly; you can use it as follows:
<%= video_tag #attachment.paperclip_object.url, poster: #attachment.paperclip_object.thumb.url %>