Audio/Video Transcoder for Paperclip using FFMPEG/Avconv
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Adds more detailed instructions on how to get file meta data
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Paperclip Transcoder

Audio/Video Transcoder for Paperclip using FFMPEG/Avconv.

This is a replacement for ( ).


Build Status Coverage Status Code Climate Dependency Status Gem Version


Add this line to your application's Gemfile:

gem 'paperclip-av-transcoder'

And then execute:

$ bundle

Or install it yourself as:

$ gem install paperclip-av-transcoder


In your model:

# app/models/user.rb
class User < ActiveRecord::Base
  has_attached_file :avatar, :styles => {
    :medium => { :geometry => "640x480", :format => 'flv' },
    :thumb => { :geometry => "100x100#", :format => 'jpg', :time => 10 }
  }, :processors => [:transcoder]

This will produce:

  1. A transcoded :medium FLV file with the requested dimensions if they will match the aspect ratio of the original file, otherwise, width will be maintained and height will be recalculated to keep the original aspect ration.
  2. A screenshot :thumb with the requested dimensions regardless of the aspect ratio.

Meta Data

Then paperclip-av-transcoder can optionally add uploaded file meta data to a database column for <your_attachment>_meta.

Example: Given a model called User with an attachment field named :avatar, create a new migration to add an avatar_meta column to the users table.

def change
  add_column :users, :avatar_meta, :data_type

You can use a data type of :json, :jsonb, :hstore or even just :string. Check what data types your database supports.


The geometry option has the following available modifiers:

  1. '!' - Keep the same aspect of the image/video, but with the passed dimesion.
  2. '#' - Pad the image/video.
  3. '<' - Enlarge the image/video.
  4. '>' - Shrink the image/video.


The convert_options option lets you specify custom command line options to be sent to the ffmpeg command. The options are split into output and input, which define where in the pipeline they will be applied. Read more about which flags go where on the official documentation.

For example, sending in the -an flag would look like this:

has_attached_file :video, styles: {
  mobile: {
    format: "mp4",
    convert_options: {
      output: {
        an: nil # Remove audio track resulting in a silent movie, passing in nil results in `-an`,
        name: "value" # Results in `-name value` in the command line


  1. Fork it ( )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request