Audio/Video Transcoder for Paperclip using FFMPEG/Avconv.

With a few lines of code, your application can produce

- a transcoded 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 ratio

- a screenshot thumbnail with the requested dimensions regardless of the aspect
  ratio.

WWW: https://github.com/ruby-av/paperclip-av-transcoder/